[PATCH v3 00/29] TDX MMU part 2

[PATCH v3 00/29] TDX MMU part 2

[Paolo Bonzini]

Compared to v2 this one has no large changes other than the updated
SEAMCALL API.  The small ones include:
- updated SEAMCALL API
- various bugfixes from Yan
- EPT A/D bits are now required
- Disable PML for TD guests

and various conflicts with earlier parts.

Isaku Yamahata (17):
  x86/virt/tdx: Add SEAMCALL wrapper tdh_mem_sept_add() to add SEPT
    pages
  x86/virt/tdx: Add SEAMCALL wrappers to add TD private pages
  x86/virt/tdx: Add SEAMCALL wrappers to manage TDX TLB tracking
  x86/virt/tdx: Add SEAMCALL wrappers to remove a TD private page
  x86/virt/tdx: Add SEAMCALL wrappers for TD measurement of initial
    contents
  KVM: x86/tdp_mmu: Add a helper function to walk down the TDP MMU
  KVM: TDX: Add accessors VMX VMCS helpers
  KVM: TDX: Set gfn_direct_bits to shared bit
  KVM: TDX: Require TDP MMU, mmio caching and EPT A/D bits for TDX
  KVM: x86/mmu: Add setter for shadow_mmio_value
  KVM: TDX: Set per-VM shadow_mmio_value to 0
  KVM: TDX: Handle TLB tracking for TDX
  KVM: TDX: Implement hooks to propagate changes of TDP MMU mirror page
    table
  KVM: TDX: Implement hook to get max mapping level of private pages
  KVM: TDX: Add an ioctl to create initial guest memory
  KVM: TDX: Finalize VM initialization
  KVM: TDX: Handle vCPU dissociation

Paolo Bonzini (1):
  KVM: TDX: Skip updating CPU dirty logging request for TDs

Rick Edgecombe (3):
  KVM: x86/mmu: Implement memslot deletion for TDX
  KVM: VMX: Teach EPT violation helper about private mem
  KVM: x86/mmu: Export kvm_tdp_map_page()

Sean Christopherson (2):
  KVM: VMX: Split out guts of EPT violation to common/exposed function
  KVM: TDX: Add load_mmu_pgd method for TDX

Yan Zhao (6):
  KVM: x86/mmu: Do not enable page track for TD guest
  KVM: x86/mmu: Bail out kvm_tdp_map_page() when VM dead
  KVM: Add parameter "kvm" to kvm_cpu_dirty_log_size() and its callers
  KVM: x86/mmu: Add parameter "kvm" to
    kvm_mmu_page_ad_need_write_protect()
  KVM: x86: Make cpu_dirty_log_size a per-VM value
  KVM: TDX: Handle SEPT zap error due to page add error in premap

 arch/x86/include/asm/kvm_host.h |  12 +-
 arch/x86/include/asm/tdx.h      |  15 +-
 arch/x86/include/asm/vmx.h      |   1 +
 arch/x86/include/uapi/asm/kvm.h |  10 +
 arch/x86/kvm/mmu.h              |   4 +
 arch/x86/kvm/mmu/mmu.c          |  17 +-
 arch/x86/kvm/mmu/mmu_internal.h |   5 +-
 arch/x86/kvm/mmu/page_track.c   |   3 +
 arch/x86/kvm/mmu/spte.c         |  10 +-
 arch/x86/kvm/mmu/tdp_mmu.c      |  49 ++-
 arch/x86/kvm/vmx/common.h       |  43 ++
 arch/x86/kvm/vmx/main.c         | 119 ++++-
 arch/x86/kvm/vmx/tdx.c          | 745 +++++++++++++++++++++++++++++++-
 arch/x86/kvm/vmx/tdx.h          |  93 ++++
 arch/x86/kvm/vmx/tdx_arch.h     |  23 +
 arch/x86/kvm/vmx/vmx.c          |  31 +-
 arch/x86/kvm/vmx/x86_ops.h      |  51 +++
 arch/x86/kvm/x86.c              |   6 +-
 arch/x86/virt/vmx/tdx/tdx.c     | 139 ++++++
 arch/x86/virt/vmx/tdx/tdx.h     |   8 +
 include/linux/kvm_dirty_ring.h  |  11 +-
 virt/kvm/dirty_ring.c           |  11 +-
 virt/kvm/kvm_main.c             |   5 +-
 23 files changed, 1326 insertions(+), 85 deletions(-)
 create mode 100644 arch/x86/kvm/vmx/common.h

-- 
2.43.5

[PATCH 01/29] x86/virt/tdx: Add SEAMCALL wrapper tdh_mem_sept_add() to add SEPT pages

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

TDX architecture introduces the concept of private GPA vs shared GPA,
depending on the GPA.SHARED bit. The TDX module maintains a Secure EPT
(S-EPT or SEPT) tree per TD for private GPA to HPA translation. Wrap the
TDH.MEM.SEPT.ADD SEAMCALL with tdh_mem_sept_add() to provide pages to the
TDX module for building a TD's SEPT tree. (Refer to these pages as SEPT
pages).

Callers need to allocate and provide a normal page to tdh_mem_sept_add(),
which then passes the page to the TDX module via the SEAMCALL
TDH.MEM.SEPT.ADD. The TDX module then installs the page into SEPT tree and
encrypts this SEPT page with the TD's guest keyID. The kernel cannot use
the SEPT page until after reclaiming it via TDH.MEM.SEPT.REMOVE or
TDH.PHYMEM.PAGE.RECLAIM.

Before passing the page to the TDX module, tdh_mem_sept_add() performs a
CLFLUSH on the page mapped with keyID 0 to ensure that any dirty cache
lines don't write back later and clobber TD memory or control structures.
Don't worry about the other MK-TME keyIDs because the kernel doesn't use
them. The TDX docs specify that this flush is not needed unless the TDX
module exposes the CLFLUSH_BEFORE_ALLOC feature bit. Do the CLFLUSH
unconditionally for two reasons: make the solution simpler by having a
single path that can handle both !CLFLUSH_BEFORE_ALLOC and
CLFLUSH_BEFORE_ALLOC cases. Avoid wading into any correctness uncertainty
by going with a conservative solution to start.

Callers should specify "GPA" and "level" for the TDX module to install the
SEPT page at the specified position in the SEPT. Do not include the root
page level in "level" since TDH.MEM.SEPT.ADD can only add non-root pages to
the SEPT. Ensure "level" is between 1 and 3 for a 4-level SEPT or between 1
and 4 for a 5-level SEPT.

Call tdh_mem_sept_add() during the TD's build time or during the TD's
runtime. Check for errors from the function return value and retrieve
extended error info from the function output parameters.

The TDX module has many internal locks. To avoid staying in SEAM mode for
too long, SEAMCALLs returns a BUSY error code to the kernel instead of
spinning on the locks. Depending on the specific SEAMCALL, the caller
may need to handle this error in specific ways (e.g., retry). Therefore,
return the SEAMCALL error code directly to the caller. Don't attempt to
handle it in the core kernel.

TDH.MEM.SEPT.ADD effectively manages two internal resources of the TDX
module: it installs page table pages in the SEPT tree and also updates the
TDX module's page metadata (PAMT). Don't add a wrapper for the matching
SEAMCALL for removing a SEPT page (TDH.MEM.SEPT.REMOVE) because KVM, as the
only in-kernel user, will only tear down the SEPT tree when the TD is being
torn down. When this happens it can just do other operations that reclaim
the SEPT pages for the host kernels to use, update the PAMT and let the
SEPT get trashed.

[Kai: Switched from generic seamcall export]
[Yan: Re-wrote the changelog]
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Message-ID: <20241112073624.22114-1-yan.y.zhao@intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/include/asm/tdx.h  |  7 ++++++-
 arch/x86/virt/vmx/tdx/tdx.c | 19 +++++++++++++++++++
 arch/x86/virt/vmx/tdx/tdx.h |  1 +
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
index 7dd71ca3eb57..5c9bdf68002c 100644
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -147,7 +147,6 @@ struct tdx_vp {
 	struct page **tdcx_pages;
 };
 
-
 static inline u64 mk_keyed_paddr(u16 hkid, struct page *page)
 {
 	u64 ret;
@@ -157,10 +156,16 @@ static inline u64 mk_keyed_paddr(u16 hkid, struct page *page)
 	ret |= (u64)hkid << boot_cpu_data.x86_phys_bits;
 
 	return ret;
+}
 
+static inline int pg_level_to_tdx_sept_level(enum pg_level level)
+{
+        WARN_ON_ONCE(level == PG_LEVEL_NONE);
+        return level - 1;
 }
 
 u64 tdh_mng_addcx(struct tdx_td *td, struct page *tdcs_page);
+u64 tdh_mem_sept_add(struct tdx_td *td, u64 gpa, int level, struct page *page, u64 *ext_err1, u64 *ext_err2);
 u64 tdh_vp_addcx(struct tdx_vp *vp, struct page *tdcx_page);
 u64 tdh_mng_key_config(struct tdx_td *td);
 u64 tdh_mng_create(struct tdx_td *td, u16 hkid);
diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index 3a272e9ff2ca..506a75fbac0b 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -1529,6 +1529,25 @@ u64 tdh_mng_addcx(struct tdx_td *td, struct page *tdcs_page)
 }
 EXPORT_SYMBOL_GPL(tdh_mng_addcx);
 
+u64 tdh_mem_sept_add(struct tdx_td *td, u64 gpa, int level, struct page *page, u64 *ext_err1, u64 *ext_err2)
+{
+	struct tdx_module_args args = {
+		.rcx = gpa | level,
+		.rdx = tdx_tdr_pa(td),
+		.r8 = page_to_phys(page),
+	};
+	u64 ret;
+
+	tdx_clflush_page(page);
+	ret = seamcall_ret(TDH_MEM_SEPT_ADD, &args);
+
+	*ext_err1 = args.rcx;
+	*ext_err2 = args.rdx;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(tdh_mem_sept_add);
+
 u64 tdh_vp_addcx(struct tdx_vp *vp, struct page *tdcx_page)
 {
 	struct tdx_module_args args = {
diff --git a/arch/x86/virt/vmx/tdx/tdx.h b/arch/x86/virt/vmx/tdx/tdx.h
index da384387d4eb..f3e37df4c63a 100644
--- a/arch/x86/virt/vmx/tdx/tdx.h
+++ b/arch/x86/virt/vmx/tdx/tdx.h
@@ -15,6 +15,7 @@
  * TDX module SEAMCALL leaf functions
  */
 #define TDH_MNG_ADDCX			1
+#define TDH_MEM_SEPT_ADD		3
 #define TDH_VP_ADDCX			4
 #define TDH_MNG_KEY_CONFIG		8
 #define TDH_MNG_CREATE			9
-- 
2.43.5

[PATCH 02/29] x86/virt/tdx: Add SEAMCALL wrappers to add TD private pages

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

TDX architecture introduces the concept of private GPA vs shared GPA,
depending on the GPA.SHARED bit. The TDX module maintains a Secure EPT
(S-EPT or SEPT) tree per TD to translate TD's private memory accessed
using a private GPA. Wrap the SEAMCALL TDH.MEM.PAGE.ADD with
tdh_mem_page_add() and TDH.MEM.PAGE.AUG with tdh_mem_page_aug() to add TD
private pages and map them to the TD's private GPAs in the SEPT.

Callers of tdh_mem_page_add() and tdh_mem_page_aug() allocate and provide
normal pages to the wrappers, who further pass those pages to the TDX
module. Before passing the pages to the TDX module, tdh_mem_page_add() and
tdh_mem_page_aug() perform a CLFLUSH on the page mapped with keyID 0 to
ensure that any dirty cache lines don't write back later and clobber TD
memory or control structures. Don't worry about the other MK-TME keyIDs
because the kernel doesn't use them. The TDX docs specify that this flush
is not needed unless the TDX module exposes the CLFLUSH_BEFORE_ALLOC
feature bit. Do the CLFLUSH unconditionally for two reasons: make the
solution simpler by having a single path that can handle both
!CLFLUSH_BEFORE_ALLOC and CLFLUSH_BEFORE_ALLOC cases. Avoid wading into any
correctness uncertainty by going with a conservative solution to start.

Call tdh_mem_page_add() to add a private page to a TD during the TD's build
time (i.e., before TDH.MR.FINALIZE). Specify which GPA the 4K private page
will map to. No need to specify level info since TDH.MEM.PAGE.ADD only adds
pages at 4K level. To provide initial contents to TD, provide an additional
source page residing in memory managed by the host kernel itself (encrypted
with a shared keyID). The TDX module will copy the initial contents from
the source page in shared memory into the private page after mapping the
page in the SEPT to the specified private GPA. The TDX module allows the
source page to be the same page as the private page to be added. In that
case, the TDX module converts and encrypts the source page as a TD private
page.

Call tdh_mem_page_aug() to add a private page to a TD during the TD's
runtime (i.e., after TDH.MR.FINALIZE). TDH.MEM.PAGE.AUG supports adding
huge pages. Specify which GPA the private page will map to, along with
level info embedded in the lower bits of the GPA. The TDX module will
recognize the added page as the TD's private page after the TD's acceptance
with TDCALL TDG.MEM.PAGE.ACCEPT.

tdh_mem_page_add() and tdh_mem_page_aug() may fail. Callers can check
function return value and retrieve extended error info from the function
output parameters.

The TDX module has many internal locks. To avoid staying in SEAM mode for
too long, SEAMCALLs returns a BUSY error code to the kernel instead of
spinning on the locks. Depending on the specific SEAMCALL, the caller
may need to handle this error in specific ways (e.g., retry). Therefore,
return the SEAMCALL error code directly to the caller. Don't attempt to
handle it in the core kernel.

[Kai: Switched from generic seamcall export]
[Yan: Re-wrote the changelog]
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Message-ID: <20241112073636.22129-1-yan.y.zhao@intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/include/asm/tdx.h  |  2 ++
 arch/x86/virt/vmx/tdx/tdx.c | 39 +++++++++++++++++++++++++++++++++++++
 arch/x86/virt/vmx/tdx/tdx.h |  2 ++
 3 files changed, 43 insertions(+)

diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
index 5c9bdf68002c..9f978db2560f 100644
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -165,8 +165,10 @@ static inline int pg_level_to_tdx_sept_level(enum pg_level level)
 }
 
 u64 tdh_mng_addcx(struct tdx_td *td, struct page *tdcs_page);
+u64 tdh_mem_page_add(struct tdx_td *td, u64 gpa, struct page *page, struct page *source, u64 *ext_err1, u64 *ext_err2);
 u64 tdh_mem_sept_add(struct tdx_td *td, u64 gpa, int level, struct page *page, u64 *ext_err1, u64 *ext_err2);
 u64 tdh_vp_addcx(struct tdx_vp *vp, struct page *tdcx_page);
+u64 tdh_mem_page_aug(struct tdx_td *td, u64 gpa, int level, struct page *page, u64 *ext_err1, u64 *ext_err2);
 u64 tdh_mng_key_config(struct tdx_td *td);
 u64 tdh_mng_create(struct tdx_td *td, u16 hkid);
 u64 tdh_vp_create(struct tdx_td *td, struct tdx_vp *vp);
diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index 506a75fbac0b..4ae10246260e 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -1529,6 +1529,26 @@ u64 tdh_mng_addcx(struct tdx_td *td, struct page *tdcs_page)
 }
 EXPORT_SYMBOL_GPL(tdh_mng_addcx);
 
+u64 tdh_mem_page_add(struct tdx_td *td, u64 gpa, struct page *page, struct page *source, u64 *ext_err1, u64 *ext_err2)
+{
+	struct tdx_module_args args = {
+		.rcx = gpa,
+		.rdx = tdx_tdr_pa(td),
+		.r8 = page_to_phys(page),
+		.r9 = page_to_phys(source),
+	};
+	u64 ret;
+
+	tdx_clflush_page(page);
+	ret = seamcall_ret(TDH_MEM_PAGE_ADD, &args);
+
+	*ext_err1 = args.rcx;
+	*ext_err2 = args.rdx;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(tdh_mem_page_add);
+
 u64 tdh_mem_sept_add(struct tdx_td *td, u64 gpa, int level, struct page *page, u64 *ext_err1, u64 *ext_err2)
 {
 	struct tdx_module_args args = {
@@ -1560,6 +1580,25 @@ u64 tdh_vp_addcx(struct tdx_vp *vp, struct page *tdcx_page)
 }
 EXPORT_SYMBOL_GPL(tdh_vp_addcx);
 
+u64 tdh_mem_page_aug(struct tdx_td *td, u64 gpa, int level, struct page *page, u64 *ext_err1, u64 *ext_err2)
+{
+	struct tdx_module_args args = {
+		.rcx = gpa | level,
+		.rdx = tdx_tdr_pa(td),
+		.r8 = page_to_phys(page),
+	};
+	u64 ret;
+
+	tdx_clflush_page(page);
+	ret = seamcall_ret(TDH_MEM_PAGE_AUG, &args);
+
+	*ext_err1 = args.rcx;
+	*ext_err2 = args.rdx;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(tdh_mem_page_aug);
+
 u64 tdh_mng_key_config(struct tdx_td *td)
 {
 	struct tdx_module_args args = {
diff --git a/arch/x86/virt/vmx/tdx/tdx.h b/arch/x86/virt/vmx/tdx/tdx.h
index f3e37df4c63a..5879bdb0045f 100644
--- a/arch/x86/virt/vmx/tdx/tdx.h
+++ b/arch/x86/virt/vmx/tdx/tdx.h
@@ -15,8 +15,10 @@
  * TDX module SEAMCALL leaf functions
  */
 #define TDH_MNG_ADDCX			1
+#define TDH_MEM_PAGE_ADD		2
 #define TDH_MEM_SEPT_ADD		3
 #define TDH_VP_ADDCX			4
+#define TDH_MEM_PAGE_AUG		6
 #define TDH_MNG_KEY_CONFIG		8
 #define TDH_MNG_CREATE			9
 #define TDH_MNG_RD			11
-- 
2.43.5

[PATCH 03/29] x86/virt/tdx: Add SEAMCALL wrappers to manage TDX TLB tracking

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

TDX module defines a TLB tracking protocol to make sure that no logical
processor holds any stale Secure EPT (S-EPT or SEPT) TLB translations for a
given TD private GPA range. After a successful TDH.MEM.RANGE.BLOCK,
TDH.MEM.TRACK, and kicking off all vCPUs, TDX module ensures that the
subsequent TDH.VP.ENTER on each vCPU will flush all stale TLB entries for
the specified GPA ranges in TDH.MEM.RANGE.BLOCK. Wrap the
TDH.MEM.RANGE.BLOCK with tdh_mem_range_block() and TDH.MEM.TRACK with
tdh_mem_track() to enable the kernel to assist the TDX module in TLB
tracking management.

The caller of tdh_mem_range_block() needs to specify "GPA" and "level" to
request the TDX module to block the subsequent creation of TLB translation
for a GPA range. This GPA range can correspond to a SEPT page or a TD
private page at any level.

Contentions and errors are possible with the SEAMCALL TDH.MEM.RANGE.BLOCK.
Therefore, the caller of tdh_mem_range_block() needs to check the function
return value and retrieve extended error info from the function output
params.

Upon TDH.MEM.RANGE.BLOCK success, no new TLB entries will be created for
the specified private GPA range, though the existing TLB translations may
still persist.  TDH.MEM.TRACK will then advance the TD's epoch counter to
ensure TDX module will flush TLBs in all vCPUs once the vCPUs re-enter
the TD. TDH.MEM.TRACK will fail to advance TD's epoch counter if there
are vCPUs still running in non-root mode at the previous TD epoch counter.
So to ensure private GPA translations are flushed, callers must first call
tdh_mem_range_block(), then tdh_mem_track(), and lastly send IPIs to kick
all the vCPUs and force them to re-enter, thus triggering the TLB flush.

Don't export a single operation and instead export functions that just
expose the block and track operations; this is for a couple reasons:

1. The vCPU kick should use KVM's functionality for doing this, which can better
target sending IPIs to only the minimum required pCPUs.

2. tdh_mem_track() doesn't need to be executed if a vCPU has not entered a TD,
which is information only KVM knows.

3. Leaving the operations separate will allow for batching many
tdh_mem_range_block() calls before a tdh_mem_track(). While this batching will
not be done initially by KVM, it demonstrates that keeping mem block and track
as separate operations is a generally good design.

Contentions are also possible in TDH.MEM.TRACK. For example, TDH.MEM.TRACK
may contend with TDH.VP.ENTER when advancing the TD epoch counter.
tdh_mem_track() does not provide the retries for the caller. Callers can
choose to avoid contentions or retry on their own.

[Kai: Switched from generic seamcall export]
[Yan: Re-wrote the changelog]
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Message-ID: <20241112073648.22143-1-yan.y.zhao@intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/include/asm/tdx.h  |  2 ++
 arch/x86/virt/vmx/tdx/tdx.c | 27 +++++++++++++++++++++++++++
 arch/x86/virt/vmx/tdx/tdx.h |  2 ++
 3 files changed, 31 insertions(+)

diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
index 9f978db2560f..cc050cc1367a 100644
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -169,6 +169,7 @@ u64 tdh_mem_page_add(struct tdx_td *td, u64 gpa, struct page *page, struct page
 u64 tdh_mem_sept_add(struct tdx_td *td, u64 gpa, int level, struct page *page, u64 *ext_err1, u64 *ext_err2);
 u64 tdh_vp_addcx(struct tdx_vp *vp, struct page *tdcx_page);
 u64 tdh_mem_page_aug(struct tdx_td *td, u64 gpa, int level, struct page *page, u64 *ext_err1, u64 *ext_err2);
+u64 tdh_mem_range_block(struct tdx_td *td, u64 gpa, int level, u64 *ext_err1, u64 *ext_err2);
 u64 tdh_mng_key_config(struct tdx_td *td);
 u64 tdh_mng_create(struct tdx_td *td, u16 hkid);
 u64 tdh_vp_create(struct tdx_td *td, struct tdx_vp *vp);
@@ -181,6 +182,7 @@ u64 tdh_vp_init(struct tdx_vp *vp, u64 initial_rcx, u32 x2apicid);
 u64 tdh_vp_rd(struct tdx_vp *vp, u64 field, u64 *data);
 u64 tdh_vp_wr(struct tdx_vp *vp, u64 field, u64 data, u64 mask);
 u64 tdh_phymem_page_reclaim(struct page *page, u64 *tdx_pt, u64 *tdx_owner, u64 *tdx_size);
+u64 tdh_mem_track(struct tdx_td *tdr);
 u64 tdh_phymem_cache_wb(bool resume);
 u64 tdh_phymem_page_wbinvd_tdr(struct tdx_td *td);
 #else
diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index 4ae10246260e..f920754bb35e 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -1599,6 +1599,23 @@ u64 tdh_mem_page_aug(struct tdx_td *td, u64 gpa, int level, struct page *page, u
 }
 EXPORT_SYMBOL_GPL(tdh_mem_page_aug);
 
+u64 tdh_mem_range_block(struct tdx_td *td, u64 gpa, int level, u64 *ext_err1, u64 *ext_err2)
+{
+	struct tdx_module_args args = {
+		.rcx = gpa | level,
+		.rdx = tdx_tdr_pa(td),
+	};
+	u64 ret;
+
+	ret = seamcall_ret(TDH_MEM_RANGE_BLOCK, &args);
+
+	*ext_err1 = args.rcx;
+	*ext_err2 = args.rdx;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(tdh_mem_range_block);
+
 u64 tdh_mng_key_config(struct tdx_td *td)
 {
 	struct tdx_module_args args = {
@@ -1761,6 +1778,16 @@ u64 tdh_phymem_page_reclaim(struct page *page, u64 *tdx_pt, u64 *tdx_owner, u64
 }
 EXPORT_SYMBOL_GPL(tdh_phymem_page_reclaim);
 
+u64 tdh_mem_track(struct tdx_td *td)
+{
+	struct tdx_module_args args = {
+		.rcx = tdx_tdr_pa(td),
+	};
+
+	return seamcall(TDH_MEM_TRACK, &args);
+}
+EXPORT_SYMBOL_GPL(tdh_mem_track);
+
 u64 tdh_phymem_cache_wb(bool resume)
 {
 	struct tdx_module_args args = {
diff --git a/arch/x86/virt/vmx/tdx/tdx.h b/arch/x86/virt/vmx/tdx/tdx.h
index 5879bdb0045f..104c97abf264 100644
--- a/arch/x86/virt/vmx/tdx/tdx.h
+++ b/arch/x86/virt/vmx/tdx/tdx.h
@@ -19,6 +19,7 @@
 #define TDH_MEM_SEPT_ADD		3
 #define TDH_VP_ADDCX			4
 #define TDH_MEM_PAGE_AUG		6
+#define TDH_MEM_RANGE_BLOCK		7
 #define TDH_MNG_KEY_CONFIG		8
 #define TDH_MNG_CREATE			9
 #define TDH_MNG_RD			11
@@ -36,6 +37,7 @@
 #define TDH_SYS_RD			34
 #define TDH_SYS_LP_INIT			35
 #define TDH_SYS_TDMR_INIT		36
+#define TDH_MEM_TRACK			38
 #define TDH_PHYMEM_CACHE_WB		40
 #define TDH_PHYMEM_PAGE_WBINVD		41
 #define TDH_VP_WR			43
-- 
2.43.5

[PATCH 04/29] x86/virt/tdx: Add SEAMCALL wrappers to remove a TD private page

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

TDX architecture introduces the concept of private GPA vs shared GPA,
depending on the GPA.SHARED bit. The TDX module maintains a single Secure
EPT (S-EPT or SEPT) tree per TD to translate TD's private memory accessed
using a private GPA. Wrap the SEAMCALL TDH.MEM.PAGE.REMOVE with
tdh_mem_page_remove() and TDH_PHYMEM_PAGE_WBINVD with
tdh_phymem_page_wbinvd_hkid() to unmap a TD private page from the SEPT,
remove the TD private page from the TDX module and flush cache lines to
memory after removal of the private page.

Callers should specify "GPA" and "level" when calling tdh_mem_page_remove()
to indicate to the TDX module which TD private page to unmap and remove.

TDH.MEM.PAGE.REMOVE may fail, and the caller of tdh_mem_page_remove() can
check the function return value and retrieve extended error information
from the function output parameters. Follow the TLB tracking protocol
before calling tdh_mem_page_remove() to remove a TD private page to avoid
SEAMCALL failure.

After removing a TD's private page, the TDX module does not write back and
invalidate cache lines associated with the page and the page's keyID (i.e.,
the TD's guest keyID). Therefore, provide tdh_phymem_page_wbinvd_hkid() to
allow the caller to pass in the TD's guest keyID and invoke
TDH_PHYMEM_PAGE_WBINVD to perform this action.

Before reusing the page, the host kernel needs to map the page with keyID 0
and invoke movdir64b() to convert the TD private page to a normal shared
page.

TDH.MEM.PAGE.REMOVE and TDH_PHYMEM_PAGE_WBINVD may meet contentions inside
the TDX module for TDX's internal resources. To avoid staying in SEAM mode
for too long, TDX module will return a BUSY error code to the kernel
instead of spinning on the locks. The caller may need to handle this error
in specific ways (e.g., retry). The wrappers return the SEAMCALL error code
directly to the caller. Don't attempt to handle it in the core kernel.

[Kai: Switched from generic seamcall export]
[Yan: Re-wrote the changelog]
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Message-ID: <20241112073658.22157-1-yan.y.zhao@intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/include/asm/tdx.h  |  2 ++
 arch/x86/virt/vmx/tdx/tdx.c | 27 +++++++++++++++++++++++++++
 arch/x86/virt/vmx/tdx/tdx.h |  1 +
 3 files changed, 30 insertions(+)

diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
index cc050cc1367a..28d25d1bfa96 100644
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -183,8 +183,10 @@ u64 tdh_vp_rd(struct tdx_vp *vp, u64 field, u64 *data);
 u64 tdh_vp_wr(struct tdx_vp *vp, u64 field, u64 data, u64 mask);
 u64 tdh_phymem_page_reclaim(struct page *page, u64 *tdx_pt, u64 *tdx_owner, u64 *tdx_size);
 u64 tdh_mem_track(struct tdx_td *tdr);
+u64 tdh_mem_page_remove(struct tdx_td *td, u64 gpa, u64 level, u64 *ext_err1, u64 *ext_err2);
 u64 tdh_phymem_cache_wb(bool resume);
 u64 tdh_phymem_page_wbinvd_tdr(struct tdx_td *td);
+u64 tdh_phymem_page_wbinvd_hkid(u64 hkid, struct page *page);
 #else
 static inline void tdx_init(void) { }
 static inline int tdx_cpu_enable(void) { return -ENODEV; }
diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index f920754bb35e..ffa0f6b8254d 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -1788,6 +1788,23 @@ u64 tdh_mem_track(struct tdx_td *td)
 }
 EXPORT_SYMBOL_GPL(tdh_mem_track);
 
+u64 tdh_mem_page_remove(struct tdx_td *td, u64 gpa, u64 level, u64 *ext_err1, u64 *ext_err2)
+{
+	struct tdx_module_args args = {
+		.rcx = gpa | level,
+		.rdx = tdx_tdr_pa(td),
+	};
+	u64 ret;
+
+	ret = seamcall_ret(TDH_MEM_PAGE_REMOVE, &args);
+
+	*ext_err1 = args.rcx;
+	*ext_err2 = args.rdx;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(tdh_mem_page_remove);
+
 u64 tdh_phymem_cache_wb(bool resume)
 {
 	struct tdx_module_args args = {
@@ -1807,3 +1824,13 @@ u64 tdh_phymem_page_wbinvd_tdr(struct tdx_td *td)
 	return seamcall(TDH_PHYMEM_PAGE_WBINVD, &args);
 }
 EXPORT_SYMBOL_GPL(tdh_phymem_page_wbinvd_tdr);
+
+u64 tdh_phymem_page_wbinvd_hkid(u64 hkid, struct page *page)
+{
+	struct tdx_module_args args = {};
+
+	args.rcx = mk_keyed_paddr(hkid, page);
+
+	return seamcall(TDH_PHYMEM_PAGE_WBINVD, &args);
+}
+EXPORT_SYMBOL_GPL(tdh_phymem_page_wbinvd_hkid);
diff --git a/arch/x86/virt/vmx/tdx/tdx.h b/arch/x86/virt/vmx/tdx/tdx.h
index 104c97abf264..c9bea023f2b4 100644
--- a/arch/x86/virt/vmx/tdx/tdx.h
+++ b/arch/x86/virt/vmx/tdx/tdx.h
@@ -32,6 +32,7 @@
 #define TDH_PHYMEM_PAGE_RDMD		24
 #define TDH_VP_RD			26
 #define TDH_PHYMEM_PAGE_RECLAIM		28
+#define TDH_MEM_PAGE_REMOVE		29
 #define TDH_SYS_KEY_CONFIG		31
 #define TDH_SYS_INIT			33
 #define TDH_SYS_RD			34
-- 
2.43.5

[PATCH 05/29] x86/virt/tdx: Add SEAMCALL wrappers for TD measurement of initial contents

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

The TDX module measures the TD during the build process and saves the
measurement in TDCS.MRTD to facilitate TD attestation of the initial
contents of the TD. Wrap the SEAMCALL TDH.MR.EXTEND with tdh_mr_extend()
and TDH.MR.FINALIZE with tdh_mr_finalize() to enable the host kernel to
assist the TDX module in performing the measurement.

The measurement in TDCS.MRTD is a SHA-384 digest of the build process.
SEAMCALLs TDH.MNG.INIT and TDH.MEM.PAGE.ADD initialize and contribute to
the MRTD digest calculation.

The caller of tdh_mr_extend() should break the TD private page into chunks
of size TDX_EXTENDMR_CHUNKSIZE and invoke tdh_mr_extend() to add the page
content into the digest calculation. Failures are possible with
TDH.MR.EXTEND (e.g., due to SEPT walking). The caller of tdh_mr_extend()
can check the function return value and retrieve extended error information
from the function output parameters.

Calling tdh_mr_finalize() completes the measurement. The TDX module then
turns the TD into the runnable state. Further TDH.MEM.PAGE.ADD and
TDH.MR.EXTEND calls will fail.

TDH.MR.FINALIZE may fail due to errors such as the TD having no vCPUs or
contentions. Check function return value when calling tdh_mr_finalize() to
determine the exact reason for failure. Take proper locks on the caller's
side to avoid contention failures, or handle the BUSY error in specific
ways (e.g., retry). Return the SEAMCALL error code directly to the caller.
Do not attempt to handle it in the core kernel.

[Kai: Switched from generic seamcall export]
[Yan: Re-wrote the changelog]
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Message-ID: <20241112073709.22171-1-yan.y.zhao@intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/include/asm/tdx.h  |  2 ++
 arch/x86/virt/vmx/tdx/tdx.c | 27 +++++++++++++++++++++++++++
 arch/x86/virt/vmx/tdx/tdx.h |  2 ++
 3 files changed, 31 insertions(+)

diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
index 28d25d1bfa96..c0841fc87fa8 100644
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -174,6 +174,8 @@ u64 tdh_mng_key_config(struct tdx_td *td);
 u64 tdh_mng_create(struct tdx_td *td, u16 hkid);
 u64 tdh_vp_create(struct tdx_td *td, struct tdx_vp *vp);
 u64 tdh_mng_rd(struct tdx_td *td, u64 field, u64 *data);
+u64 tdh_mr_extend(struct tdx_td *td, u64 gpa, u64 *ext_err1, u64 *ext_err2);
+u64 tdh_mr_finalize(struct tdx_td *td);
 u64 tdh_vp_flush(struct tdx_vp *vp);
 u64 tdh_mng_vpflushdone(struct tdx_td *td);
 u64 tdh_mng_key_freeid(struct tdx_td *td);
diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index ffa0f6b8254d..8eaaf31a4187 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -1667,6 +1667,33 @@ u64 tdh_mng_rd(struct tdx_td *td, u64 field, u64 *data)
 }
 EXPORT_SYMBOL_GPL(tdh_mng_rd);
 
+u64 tdh_mr_extend(struct tdx_td *td, u64 gpa, u64 *ext_err1, u64 *ext_err2)
+{
+	struct tdx_module_args args = {
+		.rcx = gpa,
+		.rdx = tdx_tdr_pa(td),
+	};
+	u64 ret;
+
+	ret = seamcall_ret(TDH_MR_EXTEND, &args);
+
+	*ext_err1 = args.rcx;
+	*ext_err2 = args.rdx;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(tdh_mr_extend);
+
+u64 tdh_mr_finalize(struct tdx_td *td)
+{
+	struct tdx_module_args args = {
+		.rcx = tdx_tdr_pa(td),
+	};
+
+	return seamcall(TDH_MR_FINALIZE, &args);
+}
+EXPORT_SYMBOL_GPL(tdh_mr_finalize);
+
 u64 tdh_vp_flush(struct tdx_vp *vp)
 {
 	struct tdx_module_args args = {
diff --git a/arch/x86/virt/vmx/tdx/tdx.h b/arch/x86/virt/vmx/tdx/tdx.h
index c9bea023f2b4..ed7152f81a6d 100644
--- a/arch/x86/virt/vmx/tdx/tdx.h
+++ b/arch/x86/virt/vmx/tdx/tdx.h
@@ -23,6 +23,8 @@
 #define TDH_MNG_KEY_CONFIG		8
 #define TDH_MNG_CREATE			9
 #define TDH_MNG_RD			11
+#define TDH_MR_EXTEND			16
+#define TDH_MR_FINALIZE			17
 #define TDH_VP_FLUSH			18
 #define TDH_MNG_VPFLUSHDONE		19
 #define TDH_VP_CREATE			10
-- 
2.43.5

[PATCH 06/29] KVM: x86/mmu: Implement memslot deletion for TDX

[Paolo Bonzini]

From: Rick Edgecombe <rick.p.edgecombe@intel.com>

Update attr_filter field to zap both private and shared mappings for TDX
when memslot is deleted.

Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Co-developed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Message-ID: <20241112073426.21997-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/mmu/mmu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index c1c54a7a7735..9d5d50e2464f 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -7072,6 +7072,7 @@ static void kvm_mmu_zap_memslot(struct kvm *kvm,
 		.start = slot->base_gfn,
 		.end = slot->base_gfn + slot->npages,
 		.may_block = true,
+		.attr_filter = KVM_FILTER_PRIVATE | KVM_FILTER_SHARED,
 	};
 	bool flush;
 
-- 
2.43.5

[PATCH 07/29] KVM: x86/tdp_mmu: Add a helper function to walk down the TDP MMU

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

Export a function to walk down the TDP without modifying it and simply
check if a GPA is mapped.

Future changes will support pre-populating TDX private memory. In order to
implement this KVM will need to check if a given GFN is already
pre-populated in the mirrored EPT. [1]

There is already a TDP MMU walker, kvm_tdp_mmu_get_walk() for use within
the KVM MMU that almost does what is required. However, to make sense of
the results, MMU internal PTE helpers are needed. Refactor the code to
provide a helper that can be used outside of the KVM MMU code.

Refactoring the KVM page fault handler to support this lookup usage was
also considered, but it was an awkward fit.

kvm_tdp_mmu_gpa_is_mapped() is based on a diff by Paolo Bonzini.

Link: https://lore.kernel.org/kvm/ZfBkle1eZFfjPI8l@google.com/ [1]
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241112073457.22011-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/mmu.h         |  3 +++
 arch/x86/kvm/mmu/mmu.c     |  3 +--
 arch/x86/kvm/mmu/tdp_mmu.c | 37 ++++++++++++++++++++++++++++++++-----
 3 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 050a0e229a4d..8d0fca4b4a50 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -253,6 +253,9 @@ extern bool tdp_mmu_enabled;
 #define tdp_mmu_enabled false
 #endif
 
+bool kvm_tdp_mmu_gpa_is_mapped(struct kvm_vcpu *vcpu, u64 gpa);
+int kvm_tdp_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code, u8 *level);
+
 static inline bool kvm_memslots_have_rmaps(struct kvm *kvm)
 {
 	return !tdp_mmu_enabled || kvm_shadow_root_allocated(kvm);
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 9d5d50e2464f..800684c3b2c9 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4685,8 +4685,7 @@ int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 	return direct_page_fault(vcpu, fault);
 }
 
-static int kvm_tdp_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code,
-			    u8 *level)
+int kvm_tdp_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code, u8 *level)
 {
 	int r;
 
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 046b6ba31197..22675a5746d0 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1894,16 +1894,13 @@ bool kvm_tdp_mmu_write_protect_gfn(struct kvm *kvm,
  *
  * Must be called between kvm_tdp_mmu_walk_lockless_{begin,end}.
  */
-int kvm_tdp_mmu_get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes,
-			 int *root_level)
+static int __kvm_tdp_mmu_get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes,
+				  struct kvm_mmu_page *root)
 {
-	struct kvm_mmu_page *root = root_to_sp(vcpu->arch.mmu->root.hpa);
 	struct tdp_iter iter;
 	gfn_t gfn = addr >> PAGE_SHIFT;
 	int leaf = -1;
 
-	*root_level = vcpu->arch.mmu->root_role.level;
-
 	tdp_mmu_for_each_pte(iter, vcpu->kvm, root, gfn, gfn + 1) {
 		leaf = iter.level;
 		sptes[leaf] = iter.old_spte;
@@ -1912,6 +1909,36 @@ int kvm_tdp_mmu_get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes,
 	return leaf;
 }
 
+int kvm_tdp_mmu_get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes,
+			 int *root_level)
+{
+	struct kvm_mmu_page *root = root_to_sp(vcpu->arch.mmu->root.hpa);
+	*root_level = vcpu->arch.mmu->root_role.level;
+
+	return __kvm_tdp_mmu_get_walk(vcpu, addr, sptes, root);
+}
+
+bool kvm_tdp_mmu_gpa_is_mapped(struct kvm_vcpu *vcpu, u64 gpa)
+{
+	struct kvm *kvm = vcpu->kvm;
+	bool is_direct = kvm_is_addr_direct(kvm, gpa);
+	hpa_t root = is_direct ? vcpu->arch.mmu->root.hpa :
+				 vcpu->arch.mmu->mirror_root_hpa;
+	u64 sptes[PT64_ROOT_MAX_LEVEL + 1], spte;
+	int leaf;
+
+	lockdep_assert_held(&kvm->mmu_lock);
+	rcu_read_lock();
+	leaf = __kvm_tdp_mmu_get_walk(vcpu, gpa, sptes, root_to_sp(root));
+	rcu_read_unlock();
+	if (leaf < 0)
+		return false;
+
+	spte = sptes[leaf];
+	return is_shadow_present_pte(spte) && is_last_spte(spte, leaf);
+}
+EXPORT_SYMBOL_GPL(kvm_tdp_mmu_gpa_is_mapped);
+
 /*
  * Returns the last level spte pointer of the shadow page walk for the given
  * gpa, and sets *spte to the spte value. This spte may be non-preset. If no
-- 
2.43.5

[PATCH 08/29] KVM: x86/mmu: Do not enable page track for TD guest

[Paolo Bonzini]

From: Yan Zhao <yan.y.zhao@intel.com>

Fail kvm_page_track_write_tracking_enabled() if VM type is TDX to make the
external page track user fail in kvm_page_track_register_notifier() since
TDX does not support write protection and hence page track.

No need to fail KVM internal users of page track (i.e. for shadow page),
because TDX is always with EPT enabled and currently TDX module does not
emulate and send VMLAUNCH/VMRESUME VMExits to VMM.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Cc: Yuan Yao <yuan.yao@linux.intel.com>
Message-ID: <20241112073515.22028-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/mmu/page_track.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c
index 561c331fd6ec..1b17b12393a8 100644
--- a/arch/x86/kvm/mmu/page_track.c
+++ b/arch/x86/kvm/mmu/page_track.c
@@ -172,6 +172,9 @@ static int kvm_enable_external_write_tracking(struct kvm *kvm)
 	struct kvm_memory_slot *slot;
 	int r = 0, i, bkt;
 
+	if (kvm->arch.vm_type == KVM_X86_TDX_VM)
+		return -EOPNOTSUPP;
+
 	mutex_lock(&kvm->slots_arch_lock);
 
 	/*
-- 
2.43.5

[PATCH 09/29] KVM: VMX: Split out guts of EPT violation to common/exposed function

[Paolo Bonzini]

From: Sean Christopherson <sean.j.christopherson@intel.com>

The difference of TDX EPT violation is how to retrieve information, GPA,
and exit qualification.  To share the code to handle EPT violation, split
out the guts of EPT violation handler so that VMX/TDX exit handler can call
it after retrieving GPA and exit qualification.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Message-ID: <20241112073528.22042-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/common.h | 34 ++++++++++++++++++++++++++++++++++
 arch/x86/kvm/vmx/vmx.c    | 25 +++----------------------
 2 files changed, 37 insertions(+), 22 deletions(-)
 create mode 100644 arch/x86/kvm/vmx/common.h

diff --git a/arch/x86/kvm/vmx/common.h b/arch/x86/kvm/vmx/common.h
new file mode 100644
index 000000000000..78ae39b6cdcd
--- /dev/null
+++ b/arch/x86/kvm/vmx/common.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __KVM_X86_VMX_COMMON_H
+#define __KVM_X86_VMX_COMMON_H
+
+#include <linux/kvm_host.h>
+
+#include "mmu.h"
+
+static inline int __vmx_handle_ept_violation(struct kvm_vcpu *vcpu, gpa_t gpa,
+					     unsigned long exit_qualification)
+{
+	u64 error_code;
+
+	/* Is it a read fault? */
+	error_code = (exit_qualification & EPT_VIOLATION_ACC_READ)
+		     ? PFERR_USER_MASK : 0;
+	/* Is it a write fault? */
+	error_code |= (exit_qualification & EPT_VIOLATION_ACC_WRITE)
+		      ? PFERR_WRITE_MASK : 0;
+	/* Is it a fetch fault? */
+	error_code |= (exit_qualification & EPT_VIOLATION_ACC_INSTR)
+		      ? PFERR_FETCH_MASK : 0;
+	/* ept page table entry is present? */
+	error_code |= (exit_qualification & EPT_VIOLATION_RWX_MASK)
+		      ? PFERR_PRESENT_MASK : 0;
+
+	if (error_code & EPT_VIOLATION_GVA_IS_VALID)
+		error_code |= (exit_qualification & EPT_VIOLATION_GVA_TRANSLATED) ?
+			      PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;
+
+	return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);
+}
+
+#endif /* __KVM_X86_VMX_COMMON_H */
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 5a80000d0fdd..18150a38fe09 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -53,6 +53,7 @@
 #include <trace/events/ipi.h>
 
 #include "capabilities.h"
+#include "common.h"
 #include "cpuid.h"
 #include "hyperv.h"
 #include "kvm_onhyperv.h"
@@ -5791,11 +5792,8 @@ static int handle_task_switch(struct kvm_vcpu *vcpu)
 
 static int handle_ept_violation(struct kvm_vcpu *vcpu)
 {
-	unsigned long exit_qualification;
+	unsigned long exit_qualification = vmx_get_exit_qual(vcpu);
 	gpa_t gpa;
-	u64 error_code;
-
-	exit_qualification = vmx_get_exit_qual(vcpu);
 
 	/*
 	 * EPT violation happened while executing iret from NMI,
@@ -5811,23 +5809,6 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
 	gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS);
 	trace_kvm_page_fault(vcpu, gpa, exit_qualification);
 
-	/* Is it a read fault? */
-	error_code = (exit_qualification & EPT_VIOLATION_ACC_READ)
-		     ? PFERR_USER_MASK : 0;
-	/* Is it a write fault? */
-	error_code |= (exit_qualification & EPT_VIOLATION_ACC_WRITE)
-		      ? PFERR_WRITE_MASK : 0;
-	/* Is it a fetch fault? */
-	error_code |= (exit_qualification & EPT_VIOLATION_ACC_INSTR)
-		      ? PFERR_FETCH_MASK : 0;
-	/* ept page table entry is present? */
-	error_code |= (exit_qualification & EPT_VIOLATION_RWX_MASK)
-		      ? PFERR_PRESENT_MASK : 0;
-
-	if (error_code & EPT_VIOLATION_GVA_IS_VALID)
-		error_code |= (exit_qualification & EPT_VIOLATION_GVA_TRANSLATED) ?
-			      PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;
-
 	/*
 	 * Check that the GPA doesn't exceed physical memory limits, as that is
 	 * a guest page fault.  We have to emulate the instruction here, because
@@ -5839,7 +5820,7 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
 	if (unlikely(allow_smaller_maxphyaddr && !kvm_vcpu_is_legal_gpa(vcpu, gpa)))
 		return kvm_emulate_instruction(vcpu, 0);
 
-	return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);
+	return __vmx_handle_ept_violation(vcpu, gpa, exit_qualification);
 }
 
 static int handle_ept_misconfig(struct kvm_vcpu *vcpu)
-- 
2.43.5

[PATCH 10/29] KVM: VMX: Teach EPT violation helper about private mem

[Paolo Bonzini]

From: Rick Edgecombe <rick.p.edgecombe@intel.com>

Teach EPT violation helper to check shared mask of a GPA to find out
whether the GPA is for private memory.

When EPT violation is triggered after TD accessing a private GPA, KVM will
exit to user space if the corresponding GFN's attribute is not private.
User space will then update GFN's attribute during its memory conversion
process. After that, TD will re-access the private GPA and trigger EPT
violation again. Only with GFN's attribute matches to private, KVM will
fault in private page, map it in mirrored TDP root, and propagate changes
to private EPT to resolve the EPT violation.

Relying on GFN's attribute tracking xarray to determine if a GFN is
private, as for KVM_X86_SW_PROTECTED_VM, may lead to endless EPT
violations.

Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Co-developed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Message-ID: <20241112073539.22056-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/common.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/x86/kvm/vmx/common.h b/arch/x86/kvm/vmx/common.h
index 78ae39b6cdcd..7a592467a044 100644
--- a/arch/x86/kvm/vmx/common.h
+++ b/arch/x86/kvm/vmx/common.h
@@ -6,6 +6,12 @@
 
 #include "mmu.h"
 
+static inline bool vt_is_tdx_private_gpa(struct kvm *kvm, gpa_t gpa)
+{
+	/* For TDX the direct mask is the shared mask. */
+	return !kvm_is_addr_direct(kvm, gpa);
+}
+
 static inline int __vmx_handle_ept_violation(struct kvm_vcpu *vcpu, gpa_t gpa,
 					     unsigned long exit_qualification)
 {
@@ -28,6 +34,9 @@ static inline int __vmx_handle_ept_violation(struct kvm_vcpu *vcpu, gpa_t gpa,
 		error_code |= (exit_qualification & EPT_VIOLATION_GVA_TRANSLATED) ?
 			      PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;
 
+	if (vt_is_tdx_private_gpa(vcpu->kvm, gpa))
+		error_code |= PFERR_PRIVATE_ACCESS;
+
 	return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);
 }
 
-- 
2.43.5

[PATCH 11/29] KVM: TDX: Add accessors VMX VMCS helpers

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

TDX defines SEAMCALL APIs to access TDX control structures corresponding to
the VMX VMCS.  Introduce helper accessors to hide its SEAMCALL ABI details.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Co-developed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Message-ID: <20241112073551.22070-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/tdx.c | 13 +++++++
 arch/x86/kvm/vmx/tdx.h | 88 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 101 insertions(+)

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index d85f74c0a965..3fb5410cecb1 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -36,6 +36,19 @@ static enum cpuhp_state tdx_cpuhp_state;
 
 static const struct tdx_sys_info *tdx_sysinfo;
 
+void tdh_vp_rd_failed(struct vcpu_tdx *tdx, char *uclass, u32 field, u64 err)
+{
+	KVM_BUG_ON(1, tdx->vcpu.kvm);
+	pr_err("TDH_VP_RD[%s.0x%x] failed 0x%llx\n", uclass, field, err);
+}
+
+void tdh_vp_wr_failed(struct vcpu_tdx *tdx, char *uclass, char *op, u32 field,
+		      u64 val, u64 err)
+{
+	KVM_BUG_ON(1, tdx->vcpu.kvm);
+	pr_err("TDH_VP_WR[%s.0x%x]%s0x%llx failed: 0x%llx\n", uclass, field, op, val, err);
+}
+
 #define KVM_SUPPORTED_TD_ATTRS (TDX_TD_ATTR_SEPT_VE_DISABLE)
 
 static __always_inline struct kvm_tdx *to_kvm_tdx(struct kvm *kvm)
diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h
index 5fea072b4f56..77d693dfcb08 100644
--- a/arch/x86/kvm/vmx/tdx.h
+++ b/arch/x86/kvm/vmx/tdx.h
@@ -47,6 +47,10 @@ struct vcpu_tdx {
 	enum vcpu_tdx_state state;
 };
 
+void tdh_vp_rd_failed(struct vcpu_tdx *tdx, char *uclass, u32 field, u64 err);
+void tdh_vp_wr_failed(struct vcpu_tdx *tdx, char *uclass, char *op, u32 field,
+		      u64 val, u64 err);
+
 static inline bool is_td(struct kvm *kvm)
 {
 	return kvm->arch.vm_type == KVM_X86_TDX_VM;
@@ -68,6 +72,90 @@ static __always_inline u64 td_tdcs_exec_read64(struct kvm_tdx *kvm_tdx, u32 fiel
 	}
 	return data;
 }
+
+static __always_inline void tdvps_vmcs_check(u32 field, u8 bits)
+{
+#define VMCS_ENC_ACCESS_TYPE_MASK	0x1UL
+#define VMCS_ENC_ACCESS_TYPE_FULL	0x0UL
+#define VMCS_ENC_ACCESS_TYPE_HIGH	0x1UL
+#define VMCS_ENC_ACCESS_TYPE(field)	((field) & VMCS_ENC_ACCESS_TYPE_MASK)
+
+	/* TDX is 64bit only.  HIGH field isn't supported. */
+	BUILD_BUG_ON_MSG(__builtin_constant_p(field) &&
+			 VMCS_ENC_ACCESS_TYPE(field) == VMCS_ENC_ACCESS_TYPE_HIGH,
+			 "Read/Write to TD VMCS *_HIGH fields not supported");
+
+	BUILD_BUG_ON(bits != 16 && bits != 32 && bits != 64);
+
+#define VMCS_ENC_WIDTH_MASK	GENMASK(14, 13)
+#define VMCS_ENC_WIDTH_16BIT	(0UL << 13)
+#define VMCS_ENC_WIDTH_64BIT	(1UL << 13)
+#define VMCS_ENC_WIDTH_32BIT	(2UL << 13)
+#define VMCS_ENC_WIDTH_NATURAL	(3UL << 13)
+#define VMCS_ENC_WIDTH(field)	((field) & VMCS_ENC_WIDTH_MASK)
+
+	/* TDX is 64bit only.  i.e. natural width = 64bit. */
+	BUILD_BUG_ON_MSG(bits != 64 && __builtin_constant_p(field) &&
+			 (VMCS_ENC_WIDTH(field) == VMCS_ENC_WIDTH_64BIT ||
+			  VMCS_ENC_WIDTH(field) == VMCS_ENC_WIDTH_NATURAL),
+			 "Invalid TD VMCS access for 64-bit field");
+	BUILD_BUG_ON_MSG(bits != 32 && __builtin_constant_p(field) &&
+			 VMCS_ENC_WIDTH(field) == VMCS_ENC_WIDTH_32BIT,
+			 "Invalid TD VMCS access for 32-bit field");
+	BUILD_BUG_ON_MSG(bits != 16 && __builtin_constant_p(field) &&
+			 VMCS_ENC_WIDTH(field) == VMCS_ENC_WIDTH_16BIT,
+			 "Invalid TD VMCS access for 16-bit field");
+}
+
+#define TDX_BUILD_TDVPS_ACCESSORS(bits, uclass, lclass)				\
+static __always_inline u##bits td_##lclass##_read##bits(struct vcpu_tdx *tdx,	\
+							u32 field)		\
+{										\
+	u64 err, data;								\
+										\
+	tdvps_##lclass##_check(field, bits);					\
+	err = tdh_vp_rd(&tdx->vp, TDVPS_##uclass(field), &data);		\
+	if (unlikely(err)) {							\
+		tdh_vp_rd_failed(tdx, #uclass, field, err);			\
+		return 0;							\
+	}									\
+	return (u##bits)data;							\
+}										\
+static __always_inline void td_##lclass##_write##bits(struct vcpu_tdx *tdx,	\
+						      u32 field, u##bits val)	\
+{										\
+	u64 err;								\
+										\
+	tdvps_##lclass##_check(field, bits);					\
+	err = tdh_vp_wr(&tdx->vp, TDVPS_##uclass(field), val,			\
+		      GENMASK_ULL(bits - 1, 0));				\
+	if (unlikely(err))							\
+		tdh_vp_wr_failed(tdx, #uclass, " = ", field, (u64)val, err);	\
+}										\
+static __always_inline void td_##lclass##_setbit##bits(struct vcpu_tdx *tdx,	\
+						       u32 field, u64 bit)	\
+{										\
+	u64 err;								\
+										\
+	tdvps_##lclass##_check(field, bits);					\
+	err = tdh_vp_wr(&tdx->vp, TDVPS_##uclass(field), bit, bit);		\
+	if (unlikely(err))							\
+		tdh_vp_wr_failed(tdx, #uclass, " |= ", field, bit, err);	\
+}										\
+static __always_inline void td_##lclass##_clearbit##bits(struct vcpu_tdx *tdx,	\
+							 u32 field, u64 bit)	\
+{										\
+	u64 err;								\
+										\
+	tdvps_##lclass##_check(field, bits);					\
+	err = tdh_vp_wr(&tdx->vp, TDVPS_##uclass(field), 0, bit);		\
+	if (unlikely(err))							\
+		tdh_vp_wr_failed(tdx, #uclass, " &= ~", field, bit, err);\
+}
+
+TDX_BUILD_TDVPS_ACCESSORS(16, VMCS, vmcs);
+TDX_BUILD_TDVPS_ACCESSORS(32, VMCS, vmcs);
+TDX_BUILD_TDVPS_ACCESSORS(64, VMCS, vmcs);
 #else
 static inline int tdx_bringup(void) { return 0; }
 static inline void tdx_cleanup(void) {}
-- 
2.43.5

[PATCH 12/29] KVM: TDX: Add load_mmu_pgd method for TDX

[Paolo Bonzini]

From: Sean Christopherson <sean.j.christopherson@intel.com>

TDX uses two EPT pointers, one for the private half of the GPA space and
one for the shared half. The private half uses the normal EPT_POINTER vmcs
field, which is managed in a special way by the TDX module. For TDX, KVM is
not allowed to operate on it directly. The shared half uses a new
SHARED_EPT_POINTER field and will be managed by the conventional MMU
management operations that operate directly on the EPT root. This means for
TDX the .load_mmu_pgd() operation will need to know to use the
SHARED_EPT_POINTER field instead of the normal one. Add a new wrapper in
x86 ops for load_mmu_pgd() that either directs the write to the existing
vmx implementation or a TDX one.

tdx_load_mmu_pgd() is so much simpler than vmx_load_mmu_pgd() since for the
TDX mode of operation, EPT will always be used and KVM does not need to be
involved in virtualization of CR3 behavior. So tdx_load_mmu_pgd() can
simply write to SHARED_EPT_POINTER.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Co-developed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241112073601.22084-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/include/asm/vmx.h |  1 +
 arch/x86/kvm/vmx/main.c    | 13 ++++++++++++-
 arch/x86/kvm/vmx/tdx.c     | 15 +++++++++++++++
 arch/x86/kvm/vmx/x86_ops.h |  4 ++++
 4 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index f7fd4369b821..9298fb9d4bb3 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -256,6 +256,7 @@ enum vmcs_field {
 	TSC_MULTIPLIER_HIGH             = 0x00002033,
 	TERTIARY_VM_EXEC_CONTROL	= 0x00002034,
 	TERTIARY_VM_EXEC_CONTROL_HIGH	= 0x00002035,
+	SHARED_EPT_POINTER		= 0x0000203C,
 	PID_POINTER_TABLE		= 0x00002042,
 	PID_POINTER_TABLE_HIGH		= 0x00002043,
 	GUEST_PHYSICAL_ADDRESS          = 0x00002400,
diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index e7d402b3a90d..8ed08c53c02f 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -98,6 +98,17 @@ static void vt_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
 	vmx_vcpu_reset(vcpu, init_event);
 }
 
+static void vt_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa,
+			    int pgd_level)
+{
+	if (is_td_vcpu(vcpu)) {
+		tdx_load_mmu_pgd(vcpu, root_hpa, pgd_level);
+		return;
+	}
+
+	vmx_load_mmu_pgd(vcpu, root_hpa, pgd_level);
+}
+
 static int vt_mem_enc_ioctl(struct kvm *kvm, void __user *argp)
 {
 	if (!is_td(kvm))
@@ -231,7 +242,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
 	.write_tsc_offset = vmx_write_tsc_offset,
 	.write_tsc_multiplier = vmx_write_tsc_multiplier,
 
-	.load_mmu_pgd = vmx_load_mmu_pgd,
+	.load_mmu_pgd = vt_load_mmu_pgd,
 
 	.check_intercept = vmx_check_intercept,
 	.handle_exit_irqoff = vmx_handle_exit_irqoff,
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 3fb5410cecb1..ec86c97ada80 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -32,6 +32,9 @@
 bool enable_tdx __ro_after_init;
 module_param_named(tdx, enable_tdx, bool, 0444);
 
+#define TDX_SHARED_BIT_PWL_5 gpa_to_gfn(BIT_ULL(51))
+#define TDX_SHARED_BIT_PWL_4 gpa_to_gfn(BIT_ULL(47))
+
 static enum cpuhp_state tdx_cpuhp_state;
 
 static const struct tdx_sys_info *tdx_sysinfo;
@@ -490,6 +493,18 @@ void tdx_vcpu_free(struct kvm_vcpu *vcpu)
 	tdx->state = VCPU_TD_STATE_UNINITIALIZED;
 }
 
+
+void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int pgd_level)
+{
+	u64 shared_bit = (pgd_level == 5) ? TDX_SHARED_BIT_PWL_5 :
+			  TDX_SHARED_BIT_PWL_4;
+
+	if (KVM_BUG_ON(shared_bit != kvm_gfn_direct_bits(vcpu->kvm), vcpu->kvm))
+		return;
+
+	td_vmcs_write64(to_tdx(vcpu), SHARED_EPT_POINTER, root_hpa);
+}
+
 static int tdx_get_capabilities(struct kvm_tdx_cmd *cmd)
 {
 	const struct tdx_sys_info_td_conf *td_conf = &tdx_sysinfo->td_conf;
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index b6365939cf9f..ad1c2f3e546e 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -131,6 +131,8 @@ int tdx_vcpu_create(struct kvm_vcpu *vcpu);
 void tdx_vcpu_free(struct kvm_vcpu *vcpu);
 
 int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp);
+
+void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int root_level);
 #else
 static inline int tdx_vm_init(struct kvm *kvm) { return -EOPNOTSUPP; }
 static inline void tdx_mmu_release_hkid(struct kvm *kvm) {}
@@ -141,6 +143,8 @@ static inline int tdx_vcpu_create(struct kvm_vcpu *vcpu) { return -EOPNOTSUPP; }
 static inline void tdx_vcpu_free(struct kvm_vcpu *vcpu) {}
 
 static inline int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp) { return -EOPNOTSUPP; }
+
+static inline void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int root_level) {}
 #endif
 
 #endif /* __KVM_X86_VMX_X86_OPS_H */
-- 
2.43.5

[PATCH 13/29] KVM: TDX: Set gfn_direct_bits to shared bit

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

Make the direct root handle memslot GFNs at an alias with the TDX shared
bit set.

For TDX shared memory, the memslot GFNs need to be mapped at an alias with
the shared bit set. These shared mappings will be mapped on the KVM MMU's
"direct" root. The direct root has it's mappings shifted by applying
"gfn_direct_bits" as a mask. The concept of "GPAW" (guest physical address
width) determines the location of the shared bit. So set gfn_direct_bits
based on this, to map shared memory at the proper GPA.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Co-developed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241112073613.22100-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/tdx.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index ec86c97ada80..09c4d314e6f5 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1045,6 +1045,11 @@ static int tdx_td_init(struct kvm *kvm, struct kvm_tdx_cmd *cmd)
 	kvm_tdx->attributes = td_params->attributes;
 	kvm_tdx->xfam = td_params->xfam;
 
+	if (td_params->config_flags & TDX_CONFIG_FLAGS_MAX_GPAW)
+		kvm->arch.gfn_direct_bits = TDX_SHARED_BIT_PWL_5;
+	else
+		kvm->arch.gfn_direct_bits = TDX_SHARED_BIT_PWL_4;
+
 	kvm_tdx->state = TD_STATE_INITIALIZED;
 out:
 	/* kfree() accepts NULL. */
-- 
2.43.5

[PATCH 14/29] KVM: TDX: Require TDP MMU, mmio caching and EPT A/D bits for TDX

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

Disable TDX support when TDP MMU or mmio caching or EPT A/D bits aren't
supported.

As TDP MMU is becoming main stream than the legacy MMU, the legacy MMU
support for TDX isn't implemented.

TDX requires KVM mmio caching. Without mmio caching, KVM will go to MMIO
emulation without installing SPTEs for MMIOs. However, TDX guest is
protected and KVM would meet errors when trying to emulate MMIOs for TDX
guest during instruction decoding. So, TDX guest relies on SPTEs being
installed for MMIOs, which are with no RWX bits and with VE suppress bit
unset, to inject VE to TDX guest. The TDX guest would then issue TDVMCALL
in the VE handler to perform instruction decoding and have host do MMIO
emulation.

TDX also relies on EPT A/D bits as EPT A/D bits have been supported in all
CPUs since Haswell. Relying on it can avoid RWX bits being masked out in
the mirror page table for prefaulted entries.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Co-developed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
---
Requested by Sean at [1].
[1] https://lore.kernel.org/kvm/Zva4aORxE9ljlMNe@google.com/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/mmu/mmu.c  |  1 +
 arch/x86/kvm/vmx/main.c |  1 +
 arch/x86/kvm/vmx/tdx.c  | 10 ++++++++++
 3 files changed, 12 insertions(+)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 800684c3b2c9..48a7e6f32f7f 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -110,6 +110,7 @@ static bool __ro_after_init tdp_mmu_allowed;
 #ifdef CONFIG_X86_64
 bool __read_mostly tdp_mmu_enabled = true;
 module_param_named(tdp_mmu, tdp_mmu_enabled, bool, 0444);
+EXPORT_SYMBOL_GPL(tdp_mmu_enabled);
 #endif
 
 static int max_huge_page_level __read_mostly;
diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 8ed08c53c02f..a4cb3d6b2986 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -3,6 +3,7 @@
 
 #include "x86_ops.h"
 #include "vmx.h"
+#include "mmu.h"
 #include "nested.h"
 #include "pmu.h"
 #include "posted_intr.h"
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 09c4d314e6f5..a44a50db9199 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1528,6 +1528,16 @@ int __init tdx_bringup(void)
 	if (!enable_tdx)
 		return 0;
 
+	if (!enable_ept) {
+		pr_err("EPT is required for TDX\n");
+		goto success_disable_tdx;
+	}
+
+	if (!tdp_mmu_enabled || !enable_mmio_caching || !enable_ept_ad_bits) {
+		pr_err("TDP MMU and MMIO caching and EPT A/D bit is required for TDX\n");
+		goto success_disable_tdx;
+	}
+
 	if (!cpu_feature_enabled(X86_FEATURE_MOVDIR64B)) {
 		pr_err("tdx: MOVDIR64B is required for TDX\n");
 		goto success_disable_tdx;
-- 
2.43.5

[PATCH 15/29] KVM: x86/mmu: Add setter for shadow_mmio_value

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

Future changes will want to set shadow_mmio_value from TDX code. Add a
helper to setter with a name that makes more sense from that context.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
[split into new patch]
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241112073730.22200-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/mmu.h      | 1 +
 arch/x86/kvm/mmu/spte.c | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 8d0fca4b4a50..47e64a3c4ce3 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -79,6 +79,7 @@ static inline gfn_t kvm_mmu_max_gfn(void)
 u8 kvm_mmu_get_max_tdp_level(void);
 
 void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 mmio_mask, u64 access_mask);
+void kvm_mmu_set_mmio_spte_value(struct kvm *kvm, u64 mmio_value);
 void kvm_mmu_set_me_spte_mask(u64 me_value, u64 me_mask);
 void kvm_mmu_set_ept_masks(bool has_ad_bits, bool has_exec_only);
 
diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c
index 22551e2f1d00..c42ac5d1f027 100644
--- a/arch/x86/kvm/mmu/spte.c
+++ b/arch/x86/kvm/mmu/spte.c
@@ -433,6 +433,12 @@ void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 mmio_mask, u64 access_mask)
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_mask);
 
+void kvm_mmu_set_mmio_spte_value(struct kvm *kvm, u64 mmio_value)
+{
+	kvm->arch.shadow_mmio_value = mmio_value;
+}
+EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_value);
+
 void kvm_mmu_set_me_spte_mask(u64 me_value, u64 me_mask)
 {
 	/* shadow_me_value must be a subset of shadow_me_mask */
-- 
2.43.5

[PATCH 16/29] KVM: TDX: Set per-VM shadow_mmio_value to 0

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

Set per-VM shadow_mmio_value to 0 for TDX.

With enable_mmio_caching on, KVM installs MMIO SPTEs for TDs. To correctly
configure MMIO SPTEs, TDX requires the per-VM shadow_mmio_value to be set
to 0. This is necessary to override the default value of the suppress VE
bit in the SPTE, which is 1, and to ensure value 0 in RWX bits.

For MMIO SPTE, the spte value changes as follows:
1. initial value (suppress VE bit is set)
2. Guest issues MMIO and triggers EPT violation
3. KVM updates SPTE value to MMIO value (suppress VE bit is cleared)
4. Guest MMIO resumes.  It triggers VE exception in guest TD
5. Guest VE handler issues TDG.VP.VMCALL<MMIO>
6. KVM handles MMIO
7. Guest VE handler resumes its execution after MMIO instruction

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Co-developed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241112073743.22214-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/mmu/spte.c |  2 --
 arch/x86/kvm/vmx/tdx.c  | 14 ++++++++++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c
index c42ac5d1f027..e819d16655b6 100644
--- a/arch/x86/kvm/mmu/spte.c
+++ b/arch/x86/kvm/mmu/spte.c
@@ -96,8 +96,6 @@ u64 make_mmio_spte(struct kvm_vcpu *vcpu, u64 gfn, unsigned int access)
 	u64 spte = generation_mmio_spte_mask(gen);
 	u64 gpa = gfn << PAGE_SHIFT;
 
-	WARN_ON_ONCE(!vcpu->kvm->arch.shadow_mmio_value);
-
 	access &= shadow_mmio_access_mask;
 	spte |= vcpu->kvm->arch.shadow_mmio_value | access;
 	spte |= gpa | shadow_nonpresent_or_rsvd_mask;
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index a44a50db9199..f42772a5492b 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -8,6 +8,7 @@
 #include "x86_ops.h"
 #include "lapic.h"
 #include "tdx.h"
+#include "mmu/spte.h"
 
 #pragma GCC poison to_vmx
 
@@ -410,6 +411,19 @@ int tdx_vm_init(struct kvm *kvm)
 	kvm->arch.has_protected_state = true;
 	kvm->arch.has_private_mem = true;
 
+	/*
+	 * Because guest TD is protected, VMM can't parse the instruction in TD.
+	 * Instead, guest uses MMIO hypercall.  For unmodified device driver,
+	 * #VE needs to be injected for MMIO and #VE handler in TD converts MMIO
+	 * instruction into MMIO hypercall.
+	 *
+	 * SPTE value for MMIO needs to be setup so that #VE is injected into
+	 * TD instead of triggering EPT MISCONFIG.
+	 * - RWX=0 so that EPT violation is triggered.
+	 * - suppress #VE bit is cleared to inject #VE.
+	 */
+	kvm_mmu_set_mmio_spte_value(kvm, 0);
+
 	/*
 	 * TDX has its own limit of maximum vCPUs it can support for all
 	 * TDX guests in addition to KVM_MAX_VCPUS.  TDX module reports
-- 
2.43.5

[PATCH 17/29] KVM: TDX: Handle TLB tracking for TDX

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

Handle TLB tracking for TDX by introducing function tdx_track() for private
memory TLB tracking and implementing flush_tlb* hooks to flush TLBs for
shared memory.

Introduce function tdx_track() to do TLB tracking on private memory, which
basically does two things: calling TDH.MEM.TRACK to increase TD epoch and
kicking off all vCPUs. The private EPT will then be flushed when each vCPU
re-enters the TD. This function is unused temporarily in this patch and
will be called on a page-by-page basis on removal of private guest page in
a later patch.

In earlier revisions, tdx_track() relied on an atomic counter to coordinate
the synchronization between the actions of kicking off vCPUs, incrementing
the TD epoch, and the vCPUs waiting for the incremented TD epoch after
being kicked off.

However, the core MMU only actually needs to call tdx_track() while
aleady under a write mmu_lock. So this sychnonization can be made to be
unneeded. vCPUs are kicked off only after the successful execution of
TDH.MEM.TRACK, eliminating the need for vCPUs to wait for TDH.MEM.TRACK
completion after being kicked off. tdx_track() is therefore able to send
requests KVM_REQ_OUTSIDE_GUEST_MODE rather than KVM_REQ_TLB_FLUSH.

Hooks for flush_remote_tlb and flush_remote_tlbs_range are not necessary
for TDX, as tdx_track() will handle TLB tracking of private memory on
page-by-page basis when private guest pages are removed. There is no need
to invoke tdx_track() again in kvm_flush_remote_tlbs() even after changes
to the mirrored page table.

For hooks flush_tlb_current and flush_tlb_all, which are invoked during
kvm_mmu_load() and vcpu load for normal VMs, let VMM to flush all EPTs in
the two hooks for simplicity, since TDX does not depend on the two
hooks to notify TDX module to flush private EPT in those cases.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Co-developed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Message-ID: <20241112073753.22228-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/main.c    | 44 +++++++++++++++++++--
 arch/x86/kvm/vmx/tdx.c     | 81 ++++++++++++++++++++++++++++++++++++++
 arch/x86/kvm/vmx/x86_ops.h |  4 ++
 3 files changed, 125 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index a4cb3d6b2986..0ea4bec0626e 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -99,6 +99,42 @@ static void vt_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
 	vmx_vcpu_reset(vcpu, init_event);
 }
 
+static void vt_flush_tlb_all(struct kvm_vcpu *vcpu)
+{
+	if (is_td_vcpu(vcpu)) {
+		tdx_flush_tlb_all(vcpu);
+		return;
+	}
+
+	vmx_flush_tlb_all(vcpu);
+}
+
+static void vt_flush_tlb_current(struct kvm_vcpu *vcpu)
+{
+	if (is_td_vcpu(vcpu)) {
+		tdx_flush_tlb_current(vcpu);
+		return;
+	}
+
+	vmx_flush_tlb_current(vcpu);
+}
+
+static void vt_flush_tlb_gva(struct kvm_vcpu *vcpu, gva_t addr)
+{
+	if (is_td_vcpu(vcpu))
+		return;
+
+	vmx_flush_tlb_gva(vcpu, addr);
+}
+
+static void vt_flush_tlb_guest(struct kvm_vcpu *vcpu)
+{
+	if (is_td_vcpu(vcpu))
+		return;
+
+	vmx_flush_tlb_guest(vcpu);
+}
+
 static void vt_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa,
 			    int pgd_level)
 {
@@ -190,10 +226,10 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
 	.set_rflags = vmx_set_rflags,
 	.get_if_flag = vmx_get_if_flag,
 
-	.flush_tlb_all = vmx_flush_tlb_all,
-	.flush_tlb_current = vmx_flush_tlb_current,
-	.flush_tlb_gva = vmx_flush_tlb_gva,
-	.flush_tlb_guest = vmx_flush_tlb_guest,
+	.flush_tlb_all = vt_flush_tlb_all,
+	.flush_tlb_current = vt_flush_tlb_current,
+	.flush_tlb_gva = vt_flush_tlb_gva,
+	.flush_tlb_guest = vt_flush_tlb_guest,
 
 	.vcpu_pre_run = vmx_vcpu_pre_run,
 	.vcpu_run = vmx_vcpu_run,
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index f42772a5492b..b80fc035e471 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -8,6 +8,7 @@
 #include "x86_ops.h"
 #include "lapic.h"
 #include "tdx.h"
+#include "vmx.h"
 #include "mmu/spte.h"
 
 #pragma GCC poison to_vmx
@@ -519,6 +520,51 @@ void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int pgd_level)
 	td_vmcs_write64(to_tdx(vcpu), SHARED_EPT_POINTER, root_hpa);
 }
 
+/*
+ * Ensure shared and private EPTs to be flushed on all vCPUs.
+ * tdh_mem_track() is the only caller that increases TD epoch. An increase in
+ * the TD epoch (e.g., to value "N + 1") is successful only if no vCPUs are
+ * running in guest mode with the value "N - 1".
+ *
+ * A successful execution of tdh_mem_track() ensures that vCPUs can only run in
+ * guest mode with TD epoch value "N" if no TD exit occurs after the TD epoch
+ * being increased to "N + 1".
+ *
+ * Kicking off all vCPUs after that further results in no vCPUs can run in guest
+ * mode with TD epoch value "N", which unblocks the next tdh_mem_track() (e.g.
+ * to increase TD epoch to "N + 2").
+ *
+ * TDX module will flush EPT on the next TD enter and make vCPUs to run in
+ * guest mode with TD epoch value "N + 1".
+ *
+ * kvm_make_all_cpus_request() guarantees all vCPUs are out of guest mode by
+ * waiting empty IPI handler ack_kick().
+ *
+ * No action is required to the vCPUs being kicked off since the kicking off
+ * occurs certainly after TD epoch increment and before the next
+ * tdh_mem_track().
+ */
+static void __always_unused tdx_track(struct kvm *kvm)
+{
+	struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+	u64 err;
+
+	/* If TD isn't finalized, it's before any vcpu running. */
+	if (unlikely(kvm_tdx->state != TD_STATE_RUNNABLE))
+		return;
+
+	lockdep_assert_held_write(&kvm->mmu_lock);
+
+	do {
+		err = tdh_mem_track(&kvm_tdx->td);
+	} while (unlikely((err & TDX_SEAMCALL_STATUS_MASK) == TDX_OPERAND_BUSY));
+
+	if (KVM_BUG_ON(err, kvm))
+		pr_tdx_error(TDH_MEM_TRACK, err);
+
+	kvm_make_all_cpus_request(kvm, KVM_REQ_OUTSIDE_GUEST_MODE);
+}
+
 static int tdx_get_capabilities(struct kvm_tdx_cmd *cmd)
 {
 	const struct tdx_sys_info_td_conf *td_conf = &tdx_sysinfo->td_conf;
@@ -1073,6 +1119,41 @@ static int tdx_td_init(struct kvm *kvm, struct kvm_tdx_cmd *cmd)
 	return ret;
 }
 
+void tdx_flush_tlb_current(struct kvm_vcpu *vcpu)
+{
+	/*
+	 * flush_tlb_current() is invoked when the first time for the vcpu to
+	 * run or when root of shared EPT is invalidated.
+	 * KVM only needs to flush shared EPT because the TDX module handles TLB
+	 * invalidation for private EPT in tdh_vp_enter();
+	 *
+	 * A single context invalidation for shared EPT can be performed here.
+	 * However, this single context invalidation requires the private EPTP
+	 * rather than the shared EPTP to flush shared EPT, as shared EPT uses
+	 * private EPTP as its ASID for TLB invalidation.
+	 *
+	 * To avoid reading back private EPTP, perform a global invalidation for
+	 * shared EPT instead to keep this function simple.
+	 */
+	ept_sync_global();
+}
+
+void tdx_flush_tlb_all(struct kvm_vcpu *vcpu)
+{
+	/*
+	 * TDX has called tdx_track() in tdx_sept_remove_private_spte() to
+	 * ensure that private EPT will be flushed on the next TD enter. No need
+	 * to call tdx_track() here again even when this callback is a result of
+	 * zapping private EPT.
+	 *
+	 * Due to the lack of the context to determine which EPT has been
+	 * affected by zapping, invoke invept() directly here for both shared
+	 * EPT and private EPT for simplicity, though it's not necessary for
+	 * private EPT.
+	 */
+	ept_sync_global();
+}
+
 int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)
 {
 	struct kvm_tdx_cmd tdx_cmd;
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index ad1c2f3e546e..584db5fa8dab 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -132,6 +132,8 @@ void tdx_vcpu_free(struct kvm_vcpu *vcpu);
 
 int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp);
 
+void tdx_flush_tlb_current(struct kvm_vcpu *vcpu);
+void tdx_flush_tlb_all(struct kvm_vcpu *vcpu);
 void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int root_level);
 #else
 static inline int tdx_vm_init(struct kvm *kvm) { return -EOPNOTSUPP; }
@@ -144,6 +146,8 @@ static inline void tdx_vcpu_free(struct kvm_vcpu *vcpu) {}
 
 static inline int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp) { return -EOPNOTSUPP; }
 
+static inline void tdx_flush_tlb_current(struct kvm_vcpu *vcpu) {}
+static inline void tdx_flush_tlb_all(struct kvm_vcpu *vcpu) {}
 static inline void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int root_level) {}
 #endif
 
-- 
2.43.5

[PATCH 18/29] KVM: TDX: Implement hooks to propagate changes of TDP MMU mirror page table

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

Implement hooks in TDX to propagate changes of mirror page table to private
EPT, including changes for page table page adding/removing, guest page
adding/removing.

TDX invokes corresponding SEAMCALLs in the hooks.

- Hook link_external_spt
  propagates adding page table page into private EPT.

- Hook set_external_spte
  tdx_sept_set_private_spte() in this patch only handles adding of guest
  private page when TD is finalized.
  Later patches will handle the case of adding guest private pages before
  TD finalization.

- Hook free_external_spt
  It is invoked when page table page is removed in mirror page table, which
  currently must occur at TD tear down phase, after hkid is freed.

- Hook remove_external_spte
  It is invoked when guest private page is removed in mirror page table,
  which can occur when TD is active, e.g. during shared <-> private
  conversion and slot move/deletion.
  This hook is ensured to be triggered before hkid is freed, because
  gmem fd is released along with all private leaf mappings zapped before
  freeing hkid at VM destroy.

  TDX invokes below SEAMCALLs sequentially:
  1) TDH.MEM.RANGE.BLOCK (remove RWX bits from a private EPT entry),
  2) TDH.MEM.TRACK (increases TD epoch)
  3) TDH.MEM.PAGE.REMOVE (remove the private EPT entry and untrack the
     guest page).

  TDH.MEM.PAGE.REMOVE can't succeed without TDH.MEM.RANGE.BLOCK and
  TDH.MEM.TRACK being called successfully.
  SEAMCALL TDH.MEM.TRACK is called in function tdx_track() to enforce that
  TLB tracking will be performed by TDX module for private EPT.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Co-developed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
---
 - Remove TDX_ERROR_SEPT_BUSY and Add tdx_operand_busy() helper (Binbin)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/main.c     |  14 ++-
 arch/x86/kvm/vmx/tdx.c      | 213 +++++++++++++++++++++++++++++++++++-
 arch/x86/kvm/vmx/tdx_arch.h |  23 ++++
 arch/x86/kvm/vmx/x86_ops.h  |  37 +++++++
 4 files changed, 284 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 0ea4bec0626e..0c94810b1f48 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -36,9 +36,21 @@ static __init int vt_hardware_setup(void)
 	 * is KVM may allocate couple of more bytes than needed for
 	 * each VM.
 	 */
-	if (enable_tdx)
+	if (enable_tdx) {
 		vt_x86_ops.vm_size = max_t(unsigned int, vt_x86_ops.vm_size,
 				sizeof(struct kvm_tdx));
+		/*
+		 * Note, TDX may fail to initialize in a later time in
+		 * vt_init(), in which case it is not necessary to setup
+		 * those callbacks.  But making them valid here even
+		 * when TDX fails to init later is fine because those
+		 * callbacks won't be called if the VM isn't TDX guest.
+		 */
+		vt_x86_ops.link_external_spt = tdx_sept_link_private_spt;
+		vt_x86_ops.set_external_spte = tdx_sept_set_private_spte;
+		vt_x86_ops.free_external_spt = tdx_sept_free_private_spt;
+		vt_x86_ops.remove_external_spte = tdx_sept_remove_private_spte;
+	}
 
 	return 0;
 }
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index b80fc035e471..5f38c325dfa6 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -154,6 +154,12 @@ static DEFINE_MUTEX(tdx_lock);
 
 static atomic_t nr_configured_hkid;
 
+static bool tdx_operand_busy(u64 err)
+{
+	return (err & TDX_SEAMCALL_STATUS_MASK) == TDX_OPERAND_BUSY;
+}
+
+
 static inline void tdx_hkid_free(struct kvm_tdx *kvm_tdx)
 {
 	tdx_guest_keyid_free(kvm_tdx->hkid);
@@ -520,6 +526,160 @@ void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int pgd_level)
 	td_vmcs_write64(to_tdx(vcpu), SHARED_EPT_POINTER, root_hpa);
 }
 
+static void tdx_unpin(struct kvm *kvm, struct page *page)
+{
+	put_page(page);
+}
+
+static int tdx_mem_page_aug(struct kvm *kvm, gfn_t gfn,
+			    enum pg_level level, struct page *page)
+{
+	int tdx_level = pg_level_to_tdx_sept_level(level);
+	struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+	gpa_t gpa = gfn_to_gpa(gfn);
+	u64 entry, level_state;
+	u64 err;
+
+	err = tdh_mem_page_aug(&kvm_tdx->td, gpa, tdx_level, page, &entry, &level_state);
+	if (unlikely(tdx_operand_busy(err))) {
+		tdx_unpin(kvm, page);
+		return -EBUSY;
+	}
+
+	if (KVM_BUG_ON(err, kvm)) {
+		pr_tdx_error_2(TDH_MEM_PAGE_AUG, err, entry, level_state);
+		tdx_unpin(kvm, page);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
+			      enum pg_level level, kvm_pfn_t pfn)
+{
+	struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+	struct page *page = pfn_to_page(pfn);
+
+	/* TODO: handle large pages. */
+	if (KVM_BUG_ON(level != PG_LEVEL_4K, kvm))
+		return -EINVAL;
+
+	/*
+	 * Because guest_memfd doesn't support page migration with
+	 * a_ops->migrate_folio (yet), no callback is triggered for KVM on page
+	 * migration.  Until guest_memfd supports page migration, prevent page
+	 * migration.
+	 * TODO: Once guest_memfd introduces callback on page migration,
+	 * implement it and remove get_page/put_page().
+	 */
+	get_page(page);
+
+	if (likely(kvm_tdx->state == TD_STATE_RUNNABLE))
+		return tdx_mem_page_aug(kvm, gfn, level, page);
+
+	/*
+	 * TODO: KVM_TDX_INIT_MEM_REGION support to populate before finalize
+	 * comes here for the initial memory.
+	 */
+	return -EOPNOTSUPP;
+}
+
+static int tdx_sept_drop_private_spte(struct kvm *kvm, gfn_t gfn,
+				      enum pg_level level, struct page *page)
+{
+	int tdx_level = pg_level_to_tdx_sept_level(level);
+	struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+	gpa_t gpa = gfn_to_gpa(gfn);
+	u64 err, entry, level_state;
+
+	/* TODO: handle large pages. */
+	if (KVM_BUG_ON(level != PG_LEVEL_4K, kvm))
+		return -EINVAL;
+
+	if (KVM_BUG_ON(!is_hkid_assigned(kvm_tdx), kvm))
+		return -EINVAL;
+
+	do {
+		/*
+		 * When zapping private page, write lock is held. So no race
+		 * condition with other vcpu sept operation.  Race only with
+		 * TDH.VP.ENTER.
+		 */
+		err = tdh_mem_page_remove(&kvm_tdx->td, gpa, tdx_level, &entry,
+					  &level_state);
+	} while (unlikely(tdx_operand_busy(err)));
+
+	if (unlikely(kvm_tdx->state != TD_STATE_RUNNABLE &&
+		     err == (TDX_EPT_WALK_FAILED | TDX_OPERAND_ID_RCX))) {
+		/*
+		 * This page was mapped with KVM_MAP_MEMORY, but
+		 * KVM_TDX_INIT_MEM_REGION is not issued yet.
+		 */
+		if (!is_last_spte(entry, level) || !(entry & VMX_EPT_RWX_MASK)) {
+			tdx_unpin(kvm, page);
+			return 0;
+		}
+	}
+
+	if (KVM_BUG_ON(err, kvm)) {
+		pr_tdx_error_2(TDH_MEM_PAGE_REMOVE, err, entry, level_state);
+		return -EIO;
+	}
+
+	err = tdh_phymem_page_wbinvd_hkid((u16)kvm_tdx->hkid, page);
+
+	if (KVM_BUG_ON(err, kvm)) {
+		pr_tdx_error(TDH_PHYMEM_PAGE_WBINVD, err);
+		return -EIO;
+	}
+	tdx_clear_page(page);
+	tdx_unpin(kvm, page);
+	return 0;
+}
+
+int tdx_sept_link_private_spt(struct kvm *kvm, gfn_t gfn,
+			      enum pg_level level, void *private_spt)
+{
+	int tdx_level = pg_level_to_tdx_sept_level(level);
+	gpa_t gpa = gfn_to_gpa(gfn);
+	struct page *page = virt_to_page(private_spt);
+	u64 err, entry, level_state;
+
+	err = tdh_mem_sept_add(&to_kvm_tdx(kvm)->td, gpa, tdx_level, page, &entry,
+			       &level_state);
+	if (unlikely(tdx_operand_busy(err)))
+		return -EBUSY;
+
+	if (KVM_BUG_ON(err, kvm)) {
+		pr_tdx_error_2(TDH_MEM_SEPT_ADD, err, entry, level_state);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int tdx_sept_zap_private_spte(struct kvm *kvm, gfn_t gfn,
+				     enum pg_level level)
+{
+	int tdx_level = pg_level_to_tdx_sept_level(level);
+	struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+	gpa_t gpa = gfn_to_gpa(gfn) & KVM_HPAGE_MASK(level);
+	u64 err, entry, level_state;
+
+	/* For now large page isn't supported yet. */
+	WARN_ON_ONCE(level != PG_LEVEL_4K);
+
+	err = tdh_mem_range_block(&kvm_tdx->td, gpa, tdx_level, &entry, &level_state);
+	if (unlikely(tdx_operand_busy(err)))
+		return -EBUSY;
+	if (KVM_BUG_ON(err, kvm)) {
+		pr_tdx_error_2(TDH_MEM_RANGE_BLOCK, err, entry, level_state);
+		return -EIO;
+	}
+	return 0;
+}
+
 /*
  * Ensure shared and private EPTs to be flushed on all vCPUs.
  * tdh_mem_track() is the only caller that increases TD epoch. An increase in
@@ -544,7 +704,7 @@ void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int pgd_level)
  * occurs certainly after TD epoch increment and before the next
  * tdh_mem_track().
  */
-static void __always_unused tdx_track(struct kvm *kvm)
+static void tdx_track(struct kvm *kvm)
 {
 	struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
 	u64 err;
@@ -557,7 +717,7 @@ static void __always_unused tdx_track(struct kvm *kvm)
 
 	do {
 		err = tdh_mem_track(&kvm_tdx->td);
-	} while (unlikely((err & TDX_SEAMCALL_STATUS_MASK) == TDX_OPERAND_BUSY));
+	} while (unlikely(tdx_operand_busy(err)));
 
 	if (KVM_BUG_ON(err, kvm))
 		pr_tdx_error(TDH_MEM_TRACK, err);
@@ -565,6 +725,55 @@ static void __always_unused tdx_track(struct kvm *kvm)
 	kvm_make_all_cpus_request(kvm, KVM_REQ_OUTSIDE_GUEST_MODE);
 }
 
+int tdx_sept_free_private_spt(struct kvm *kvm, gfn_t gfn,
+			      enum pg_level level, void *private_spt)
+{
+	struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+
+	/*
+	 * free_external_spt() is only called after hkid is freed when TD is
+	 * tearing down.
+	 * KVM doesn't (yet) zap page table pages in mirror page table while
+	 * TD is active, though guest pages mapped in mirror page table could be
+	 * zapped during TD is active, e.g. for shared <-> private conversion
+	 * and slot move/deletion.
+	 */
+	if (KVM_BUG_ON(is_hkid_assigned(kvm_tdx), kvm))
+		return -EINVAL;
+
+	/*
+	 * The HKID assigned to this TD was already freed and cache was
+	 * already flushed. We don't have to flush again.
+	 */
+	return tdx_reclaim_page(virt_to_page(private_spt));
+}
+
+int tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn,
+				 enum pg_level level, kvm_pfn_t pfn)
+{
+	int ret;
+
+	/*
+	 * HKID is released after all private pages have been removed, and set
+	 * before any might be populated. Warn if zapping is attempted when
+	 * there can't be anything populated in the private EPT.
+	 */
+	if (KVM_BUG_ON(!is_hkid_assigned(to_kvm_tdx(kvm)), kvm))
+		return -EINVAL;
+
+	ret = tdx_sept_zap_private_spte(kvm, gfn, level);
+	if (ret)
+		return ret;
+
+	/*
+	 * TDX requires TLB tracking before dropping private page.  Do
+	 * it here, although it is also done later.
+	 */
+	tdx_track(kvm);
+
+	return tdx_sept_drop_private_spte(kvm, gfn, level, pfn_to_page(pfn));
+}
+
 static int tdx_get_capabilities(struct kvm_tdx_cmd *cmd)
 {
 	const struct tdx_sys_info_td_conf *td_conf = &tdx_sysinfo->td_conf;
diff --git a/arch/x86/kvm/vmx/tdx_arch.h b/arch/x86/kvm/vmx/tdx_arch.h
index b6fe458a4224..a8071409498f 100644
--- a/arch/x86/kvm/vmx/tdx_arch.h
+++ b/arch/x86/kvm/vmx/tdx_arch.h
@@ -120,6 +120,29 @@ struct td_params {
 #define TDX_MIN_TSC_FREQUENCY_KHZ		(100 * 1000)
 #define TDX_MAX_TSC_FREQUENCY_KHZ		(10 * 1000 * 1000)
 
+/* Additional Secure EPT entry information */
+#define TDX_SEPT_LEVEL_MASK		GENMASK_ULL(2, 0)
+#define TDX_SEPT_STATE_MASK		GENMASK_ULL(15, 8)
+#define TDX_SEPT_STATE_SHIFT		8
+
+enum tdx_sept_entry_state {
+	TDX_SEPT_FREE = 0,
+	TDX_SEPT_BLOCKED = 1,
+	TDX_SEPT_PENDING = 2,
+	TDX_SEPT_PENDING_BLOCKED = 3,
+	TDX_SEPT_PRESENT = 4,
+};
+
+static inline u8 tdx_get_sept_level(u64 sept_entry_info)
+{
+	return sept_entry_info & TDX_SEPT_LEVEL_MASK;
+}
+
+static inline u8 tdx_get_sept_state(u64 sept_entry_info)
+{
+	return (sept_entry_info & TDX_SEPT_STATE_MASK) >> TDX_SEPT_STATE_SHIFT;
+}
+
 #define MD_FIELD_ID_FEATURES0_TOPOLOGY_ENUM	BIT_ULL(20)
 
 /*
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index 584db5fa8dab..6344548d6a7a 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -132,6 +132,15 @@ void tdx_vcpu_free(struct kvm_vcpu *vcpu);
 
 int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp);
 
+int tdx_sept_link_private_spt(struct kvm *kvm, gfn_t gfn,
+			      enum pg_level level, void *private_spt);
+int tdx_sept_free_private_spt(struct kvm *kvm, gfn_t gfn,
+			      enum pg_level level, void *private_spt);
+int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
+			      enum pg_level level, kvm_pfn_t pfn);
+int tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn,
+				 enum pg_level level, kvm_pfn_t pfn);
+
 void tdx_flush_tlb_current(struct kvm_vcpu *vcpu);
 void tdx_flush_tlb_all(struct kvm_vcpu *vcpu);
 void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int root_level);
@@ -146,6 +155,34 @@ static inline void tdx_vcpu_free(struct kvm_vcpu *vcpu) {}
 
 static inline int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp) { return -EOPNOTSUPP; }
 
+static inline int tdx_sept_link_private_spt(struct kvm *kvm, gfn_t gfn,
+					    enum pg_level level,
+					    void *private_spt)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int tdx_sept_free_private_spt(struct kvm *kvm, gfn_t gfn,
+					    enum pg_level level,
+					    void *private_spt)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
+					    enum pg_level level,
+					    kvm_pfn_t pfn)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn,
+					       enum pg_level level,
+					       kvm_pfn_t pfn)
+{
+	return -EOPNOTSUPP;
+}
+
 static inline void tdx_flush_tlb_current(struct kvm_vcpu *vcpu) {}
 static inline void tdx_flush_tlb_all(struct kvm_vcpu *vcpu) {}
 static inline void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int root_level) {}
-- 
2.43.5

[PATCH 19/29] KVM: TDX: Implement hook to get max mapping level of private pages

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

Implement hook private_max_mapping_level for TDX to let TDP MMU core get
max mapping level of private pages.

The value is hard coded to 4K for no huge page support for now.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Co-developed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241112073816.22256-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/main.c    | 10 ++++++++++
 arch/x86/kvm/vmx/tdx.c     |  5 +++++
 arch/x86/kvm/vmx/x86_ops.h |  2 ++
 3 files changed, 17 insertions(+)

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 0c94810b1f48..828168e67d4e 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -174,6 +174,14 @@ static int vt_vcpu_mem_enc_ioctl(struct kvm_vcpu *vcpu, void __user *argp)
 	return tdx_vcpu_ioctl(vcpu, argp);
 }
 
+static int vt_gmem_private_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn)
+{
+	if (is_td(kvm))
+		return tdx_gmem_private_max_mapping_level(kvm, pfn);
+
+	return 0;
+}
+
 #define VMX_REQUIRED_APICV_INHIBITS				\
 	(BIT(APICV_INHIBIT_REASON_DISABLED) |			\
 	 BIT(APICV_INHIBIT_REASON_ABSENT) |			\
@@ -331,6 +339,8 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
 
 	.mem_enc_ioctl = vt_mem_enc_ioctl,
 	.vcpu_mem_enc_ioctl = vt_vcpu_mem_enc_ioctl,
+
+	.private_max_mapping_level = vt_gmem_private_max_mapping_level
 };
 
 struct kvm_x86_init_ops vt_init_ops __initdata = {
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 5f38c325dfa6..989db4887963 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1630,6 +1630,11 @@ int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp)
 	return ret;
 }
 
+int tdx_gmem_private_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn)
+{
+	return PG_LEVEL_4K;
+}
+
 static int tdx_online_cpu(unsigned int cpu)
 {
 	unsigned long flags;
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index 6344548d6a7a..bc3cf1c1da37 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -144,6 +144,7 @@ int tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn,
 void tdx_flush_tlb_current(struct kvm_vcpu *vcpu);
 void tdx_flush_tlb_all(struct kvm_vcpu *vcpu);
 void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int root_level);
+int tdx_gmem_private_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn);
 #else
 static inline int tdx_vm_init(struct kvm *kvm) { return -EOPNOTSUPP; }
 static inline void tdx_mmu_release_hkid(struct kvm *kvm) {}
@@ -186,6 +187,7 @@ static inline int tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn,
 static inline void tdx_flush_tlb_current(struct kvm_vcpu *vcpu) {}
 static inline void tdx_flush_tlb_all(struct kvm_vcpu *vcpu) {}
 static inline void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int root_level) {}
+static inline int tdx_gmem_private_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn) { return 0; }
 #endif
 
 #endif /* __KVM_X86_VMX_X86_OPS_H */
-- 
2.43.5

[PATCH 20/29] KVM: x86/mmu: Bail out kvm_tdp_map_page() when VM dead

[Paolo Bonzini]

From: Yan Zhao <yan.y.zhao@intel.com>

Bail out of the loop in kvm_tdp_map_page() when a VM is dead. Otherwise,
kvm_tdp_map_page() may get stuck in the kernel loop when there's only one
vCPU in the VM (or if the other vCPUs are not executing ioctls), even if
fatal errors have occurred.

kvm_tdp_map_page() is called by the ioctl KVM_PRE_FAULT_MEMORY or the TDX
ioctl KVM_TDX_INIT_MEM_REGION. It loops in the kernel whenever RET_PF_RETRY
is returned. In the TDP MMU, kvm_tdp_mmu_map() always returns RET_PF_RETRY,
regardless of the specific error code from tdp_mmu_set_spte_atomic(),
tdp_mmu_link_sp(), or tdp_mmu_split_huge_page(). While this is acceptable
in general cases where the only possible error code from these functions is
-EBUSY, TDX introduces an additional error code, -EIO, due to SEAMCALL
errors.

Since this -EIO error is also a fatal error, check for VM dead in the
kvm_tdp_map_page() to avoid unnecessary retries until a signal is pending.

The error -EIO is uncommon and has not been observed in real workloads.
Currently, it is only hypothetically triggered by bypassing the real
SEAMCALL and faking an error in the SEAMCALL wrapper.

Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Message-ID: <20250220102728.24546-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/mmu/mmu.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 48a7e6f32f7f..f4e18b33a21a 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4700,6 +4700,10 @@ int kvm_tdp_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code, u8 *level
 	do {
 		if (signal_pending(current))
 			return -EINTR;
+
+		if (kvm_check_request(KVM_REQ_VM_DEAD, vcpu))
+			return -EIO;
+
 		cond_resched();
 		r = kvm_mmu_do_page_fault(vcpu, gpa, error_code, true, NULL, level);
 	} while (r == RET_PF_RETRY);
-- 
2.43.5

[PATCH 21/29] KVM: x86/mmu: Export kvm_tdp_map_page()

[Paolo Bonzini]

From: Rick Edgecombe <rick.p.edgecombe@intel.com>

In future changes coco specific code will need to call kvm_tdp_map_page()
from within their respective gmem_post_populate() callbacks. Export it
so this can be done from vendor specific code. Since kvm_mmu_reload()
will be needed for this operation, export its callee kvm_mmu_load() as
well.

Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Message-ID: <20241112073827.22270-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/mmu/mmu.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index f4e18b33a21a..443c4836bc62 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4728,6 +4728,7 @@ int kvm_tdp_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code, u8 *level
 		return -EIO;
 	}
 }
+EXPORT_SYMBOL_GPL(kvm_tdp_map_page);
 
 long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu,
 				    struct kvm_pre_fault_memory *range)
@@ -5751,6 +5752,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
 out:
 	return r;
 }
+EXPORT_SYMBOL_GPL(kvm_mmu_load);
 
 void kvm_mmu_unload(struct kvm_vcpu *vcpu)
 {
-- 
2.43.5

[PATCH 22/29] KVM: TDX: Add an ioctl to create initial guest memory

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

Add a new ioctl for the user space VMM to initialize guest memory with the
specified memory contents.

Because TDX protects the guest's memory, the creation of the initial guest
memory requires a dedicated TDX module API, TDH.MEM.PAGE.ADD(), instead of
directly copying the memory contents into the guest's memory in the case of
the default VM type.

Define a new subcommand, KVM_TDX_INIT_MEM_REGION, of vCPU-scoped
KVM_MEMORY_ENCRYPT_OP.  Check if the GFN is already pre-allocated, assign
the guest page in Secure-EPT, copy the initial memory contents into the
guest memory, and encrypt the guest memory.  Optionally, extend the memory
measurement of the TDX guest.

The ioctl uses the vCPU file descriptor because of the TDX module's
requirement that the memory is added to the S-EPT (via TDH.MEM.SEPT.ADD)
prior to initialization (TDH.MEM.PAGE.ADD).  Accessing the MMU in turn
requires a vCPU file descriptor, just like for KVM_PRE_FAULT_MEMORY.  In
fact, the post-populate callback is able to reuse the same logic used by
KVM_PRE_FAULT_MEMORY, so that userspace can do everything with a single
ioctl.

Note that this is the only way to invoke TDH.MEM.SEPT.ADD before the TD
in finalized, as userspace cannot use KVM_PRE_FAULT_MEMORY at that
point.  This ensures that there cannot be pages in the S-EPT awaiting
TDH.MEM.PAGE.ADD, which would be treated incorrectly as spurious by
tdp_mmu_map_handle_target_level() (KVM would see the SPTE as PRESENT,
but the corresponding S-EPT entry will be !PRESENT).

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Co-developed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
---
 - KVM_BUG_ON() for kvm_tdx->nr_premapped (Paolo)
 - Use tdx_operand_busy()
 - Merge first patch in SEPT SEAMCALL retry series in to this base
   (Paolo)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/include/uapi/asm/kvm.h |   9 ++
 arch/x86/kvm/vmx/tdx.c          | 144 ++++++++++++++++++++++++++++++++
 virt/kvm/kvm_main.c             |   1 +
 3 files changed, 154 insertions(+)

diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index cd55484e3f0c..ee1b517351a3 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -932,6 +932,7 @@ enum kvm_tdx_cmd_id {
 	KVM_TDX_CAPABILITIES = 0,
 	KVM_TDX_INIT_VM,
 	KVM_TDX_INIT_VCPU,
+	KVM_TDX_INIT_MEM_REGION,
 	KVM_TDX_GET_CPUID,
 
 	KVM_TDX_CMD_NR_MAX,
@@ -987,4 +988,12 @@ struct kvm_tdx_init_vm {
 	struct kvm_cpuid2 cpuid;
 };
 
+#define KVM_TDX_MEASURE_MEMORY_REGION   _BITULL(0)
+
+struct kvm_tdx_init_mem_region {
+	__u64 source_addr;
+	__u64 gpa;
+	__u64 nr_pages;
+};
+
 #endif /* _ASM_X86_KVM_H */
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 989db4887963..12f3433d062d 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
+#include <linux/cleanup.h>
 #include <linux/cpu.h>
 #include <asm/cpufeature.h>
 #include <linux/misc_cgroup.h>
@@ -10,6 +11,7 @@
 #include "tdx.h"
 #include "vmx.h"
 #include "mmu/spte.h"
+#include "common.h"
 
 #pragma GCC poison to_vmx
 
@@ -1600,6 +1602,145 @@ static int tdx_vcpu_init(struct kvm_vcpu *vcpu, struct kvm_tdx_cmd *cmd)
 	return 0;
 }
 
+struct tdx_gmem_post_populate_arg {
+	struct kvm_vcpu *vcpu;
+	__u32 flags;
+};
+
+static int tdx_gmem_post_populate(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn,
+				  void __user *src, int order, void *_arg)
+{
+	u64 error_code = PFERR_GUEST_FINAL_MASK | PFERR_PRIVATE_ACCESS;
+	struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+	struct tdx_gmem_post_populate_arg *arg = _arg;
+	struct kvm_vcpu *vcpu = arg->vcpu;
+	gpa_t gpa = gfn_to_gpa(gfn);
+	u8 level = PG_LEVEL_4K;
+	struct page *src_page;
+	int ret, i;
+	u64 err, entry, level_state;
+
+	/*
+	 * Get the source page if it has been faulted in. Return failure if the
+	 * source page has been swapped out or unmapped in primary memory.
+	 */
+	ret = get_user_pages_fast((unsigned long)src, 1, 0, &src_page);
+	if (ret < 0)
+		return ret;
+	if (ret != 1)
+		return -ENOMEM;
+
+	ret = kvm_tdp_map_page(vcpu, gpa, error_code, &level);
+	if (ret < 0)
+		goto out;
+
+	/*
+	 * The private mem cannot be zapped after kvm_tdp_map_page()
+	 * because all paths are covered by slots_lock and the
+	 * filemap invalidate lock.  Check that they are indeed enough.
+	 */
+	if (IS_ENABLED(CONFIG_KVM_PROVE_MMU)) {
+		scoped_guard(read_lock, &kvm->mmu_lock) {
+			if (KVM_BUG_ON(!kvm_tdp_mmu_gpa_is_mapped(vcpu, gpa), kvm)) {
+				ret = -EIO;
+				goto out;
+			}
+		}
+	}
+
+	ret = 0;
+	err = tdh_mem_page_add(&kvm_tdx->td, gpa, pfn_to_page(pfn), src_page,
+			       &entry, &level_state);
+	if (err) {
+		ret = unlikely(tdx_operand_busy(err)) ? -EBUSY : -EIO;
+		goto out;
+	}
+
+	if (arg->flags & KVM_TDX_MEASURE_MEMORY_REGION) {
+		for (i = 0; i < PAGE_SIZE; i += TDX_EXTENDMR_CHUNKSIZE) {
+			err = tdh_mr_extend(&kvm_tdx->td, gpa + i, &entry,
+					    &level_state);
+			if (err) {
+				ret = -EIO;
+				break;
+			}
+		}
+	}
+
+out:
+	put_page(src_page);
+	return ret;
+}
+
+static int tdx_vcpu_init_mem_region(struct kvm_vcpu *vcpu, struct kvm_tdx_cmd *cmd)
+{
+	struct vcpu_tdx *tdx = to_tdx(vcpu);
+	struct kvm *kvm = vcpu->kvm;
+	struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+	struct kvm_tdx_init_mem_region region;
+	struct tdx_gmem_post_populate_arg arg;
+	long gmem_ret;
+	int ret;
+
+	if (tdx->state != VCPU_TD_STATE_INITIALIZED)
+		return -EINVAL;
+
+	guard(mutex)(&kvm->slots_lock);
+
+	/* Once TD is finalized, the initial guest memory is fixed. */
+	if (kvm_tdx->state == TD_STATE_RUNNABLE)
+		return -EINVAL;
+
+	if (cmd->flags & ~KVM_TDX_MEASURE_MEMORY_REGION)
+		return -EINVAL;
+
+	if (copy_from_user(&region, u64_to_user_ptr(cmd->data), sizeof(region)))
+		return -EFAULT;
+
+	if (!PAGE_ALIGNED(region.source_addr) || !PAGE_ALIGNED(region.gpa) ||
+	    !region.nr_pages ||
+	    region.gpa + (region.nr_pages << PAGE_SHIFT) <= region.gpa ||
+	    !vt_is_tdx_private_gpa(kvm, region.gpa) ||
+	    !vt_is_tdx_private_gpa(kvm, region.gpa + (region.nr_pages << PAGE_SHIFT) - 1))
+		return -EINVAL;
+
+	kvm_mmu_reload(vcpu);
+	ret = 0;
+	while (region.nr_pages) {
+		if (signal_pending(current)) {
+			ret = -EINTR;
+			break;
+		}
+
+		arg = (struct tdx_gmem_post_populate_arg) {
+			.vcpu = vcpu,
+			.flags = cmd->flags,
+		};
+		gmem_ret = kvm_gmem_populate(kvm, gpa_to_gfn(region.gpa),
+					     u64_to_user_ptr(region.source_addr),
+					     1, tdx_gmem_post_populate, &arg);
+		if (gmem_ret < 0) {
+			ret = gmem_ret;
+			break;
+		}
+
+		if (gmem_ret != 1) {
+			ret = -EIO;
+			break;
+		}
+
+		region.source_addr += PAGE_SIZE;
+		region.gpa += PAGE_SIZE;
+		region.nr_pages--;
+
+		cond_resched();
+	}
+
+	if (copy_to_user(u64_to_user_ptr(cmd->data), &region, sizeof(region)))
+		ret = -EFAULT;
+	return ret;
+}
+
 int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp)
 {
 	struct kvm_tdx *kvm_tdx = to_kvm_tdx(vcpu->kvm);
@@ -1619,6 +1760,9 @@ int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp)
 	case KVM_TDX_INIT_VCPU:
 		ret = tdx_vcpu_init(vcpu, &cmd);
 		break;
+	case KVM_TDX_INIT_MEM_REGION:
+		ret = tdx_vcpu_init_mem_region(vcpu, &cmd);
+		break;
 	case KVM_TDX_GET_CPUID:
 		ret = tdx_vcpu_get_cpuid(vcpu, &cmd);
 		break;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 622b5a99078a..c88acfa154e6 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2581,6 +2581,7 @@ struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn
 
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_memslot);
 
 bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
 {
-- 
2.43.5

[PATCH 23/29] KVM: TDX: Finalize VM initialization

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

Add a new VM-scoped KVM_MEMORY_ENCRYPT_OP IOCTL subcommand,
KVM_TDX_FINALIZE_VM, to perform TD Measurement Finalization.

Documentation for the API is added in another patch:
"Documentation/virt/kvm: Document on Trust Domain Extensions(TDX)"

For the purpose of attestation, a measurement must be made of the TDX VM
initial state. This is referred to as TD Measurement Finalization, and
uses SEAMCALL TDH.MR.FINALIZE, after which:
1. The VMM adding TD private pages with arbitrary content is no longer
   allowed
2. The TDX VM is runnable

Co-developed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Message-ID: <20240904030751.117579-21-rick.p.edgecombe@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/include/uapi/asm/kvm.h |  1 +
 arch/x86/kvm/vmx/tdx.c          | 78 +++++++++++++++++++++++++++++----
 arch/x86/kvm/vmx/tdx.h          |  3 ++
 3 files changed, 74 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index ee1b517351a3..89cc7a18ef45 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -933,6 +933,7 @@ enum kvm_tdx_cmd_id {
 	KVM_TDX_INIT_VM,
 	KVM_TDX_INIT_VCPU,
 	KVM_TDX_INIT_MEM_REGION,
+	KVM_TDX_FINALIZE_VM,
 	KVM_TDX_GET_CPUID,
 
 	KVM_TDX_CMD_NR_MAX,
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 12f3433d062d..246f924ae6f6 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -557,6 +557,29 @@ static int tdx_mem_page_aug(struct kvm *kvm, gfn_t gfn,
 	return 0;
 }
 
+/*
+ * KVM_TDX_INIT_MEM_REGION calls kvm_gmem_populate() to map guest pages; the
+ * callback tdx_gmem_post_populate() then maps pages into private memory.
+ * through the a seamcall TDH.MEM.PAGE.ADD().  The SEAMCALL also requires the
+ * private EPT structures for the page to have been built before, which is
+ * done via kvm_tdp_map_page(). nr_premapped counts the number of pages that
+ * were added to the EPT structures but not added with TDH.MEM.PAGE.ADD().
+ * The counter has to be zero on KVM_TDX_FINALIZE_VM, to ensure that there
+ * are no half-initialized shared EPT pages.
+ */
+static int tdx_mem_page_record_premap_cnt(struct kvm *kvm, gfn_t gfn,
+					  enum pg_level level, kvm_pfn_t pfn)
+{
+	struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+
+	if (KVM_BUG_ON(kvm->arch.pre_fault_allowed, kvm))
+		return -EINVAL;
+
+	/* nr_premapped will be decreased when tdh_mem_page_add() is called. */
+	atomic64_inc(&kvm_tdx->nr_premapped);
+	return 0;
+}
+
 int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
 			      enum pg_level level, kvm_pfn_t pfn)
 {
@@ -577,14 +600,15 @@ int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
 	 */
 	get_page(page);
 
+	/*
+	 * Read 'pre_fault_allowed' before 'kvm_tdx->state'; see matching
+	 * barrier in tdx_td_finalize().
+	 */
+	smp_rmb();
 	if (likely(kvm_tdx->state == TD_STATE_RUNNABLE))
 		return tdx_mem_page_aug(kvm, gfn, level, page);
 
-	/*
-	 * TODO: KVM_TDX_INIT_MEM_REGION support to populate before finalize
-	 * comes here for the initial memory.
-	 */
-	return -EOPNOTSUPP;
+	return tdx_mem_page_record_premap_cnt(kvm, gfn, level, pfn);
 }
 
 static int tdx_sept_drop_private_spte(struct kvm *kvm, gfn_t gfn,
@@ -615,10 +639,12 @@ static int tdx_sept_drop_private_spte(struct kvm *kvm, gfn_t gfn,
 	if (unlikely(kvm_tdx->state != TD_STATE_RUNNABLE &&
 		     err == (TDX_EPT_WALK_FAILED | TDX_OPERAND_ID_RCX))) {
 		/*
-		 * This page was mapped with KVM_MAP_MEMORY, but
-		 * KVM_TDX_INIT_MEM_REGION is not issued yet.
+		 * Page is mapped by KVM_TDX_INIT_MEM_REGION, but hasn't called
+		 * tdh_mem_page_add().
 		 */
-		if (!is_last_spte(entry, level) || !(entry & VMX_EPT_RWX_MASK)) {
+		if ((!is_last_spte(entry, level) || !(entry & VMX_EPT_RWX_MASK)) &&
+		    !KVM_BUG_ON(!atomic64_read(&kvm_tdx->nr_premapped), kvm)) {
+			atomic64_dec(&kvm_tdx->nr_premapped);
 			tdx_unpin(kvm, page);
 			return 0;
 		}
@@ -1365,6 +1391,36 @@ void tdx_flush_tlb_all(struct kvm_vcpu *vcpu)
 	ept_sync_global();
 }
 
+static int tdx_td_finalize(struct kvm *kvm, struct kvm_tdx_cmd *cmd)
+{
+	struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+
+	guard(mutex)(&kvm->slots_lock);
+
+	if (!is_hkid_assigned(kvm_tdx) || kvm_tdx->state == TD_STATE_RUNNABLE)
+		return -EINVAL;
+	/*
+	 * Pages are pending for KVM_TDX_INIT_MEM_REGION to issue
+	 * TDH.MEM.PAGE.ADD().
+	 */
+	if (atomic64_read(&kvm_tdx->nr_premapped))
+		return -EINVAL;
+
+	cmd->hw_error = tdh_mr_finalize(&kvm_tdx->td);
+	if (tdx_operand_busy(cmd->hw_error))
+		return -EBUSY;
+	if (KVM_BUG_ON(cmd->hw_error, kvm)) {
+		pr_tdx_error(TDH_MR_FINALIZE, cmd->hw_error);
+		return -EIO;
+	}
+
+	kvm_tdx->state = TD_STATE_RUNNABLE;
+	/* TD_STATE_RUNNABLE must be set before 'pre_fault_allowed' */
+	smp_wmb();
+	kvm->arch.pre_fault_allowed = true;
+	return 0;
+}
+
 int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)
 {
 	struct kvm_tdx_cmd tdx_cmd;
@@ -1389,6 +1445,9 @@ int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)
 	case KVM_TDX_INIT_VM:
 		r = tdx_td_init(kvm, &tdx_cmd);
 		break;
+	case KVM_TDX_FINALIZE_VM:
+		r = tdx_td_finalize(kvm, &tdx_cmd);
+		break;
 	default:
 		r = -EINVAL;
 		goto out;
@@ -1656,6 +1715,9 @@ static int tdx_gmem_post_populate(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn,
 		goto out;
 	}
 
+	if (!KVM_BUG_ON(!atomic64_read(&kvm_tdx->nr_premapped), kvm))
+		atomic64_dec(&kvm_tdx->nr_premapped);
+
 	if (arg->flags & KVM_TDX_MEASURE_MEMORY_REGION) {
 		for (i = 0; i < PAGE_SIZE; i += TDX_EXTENDMR_CHUNKSIZE) {
 			err = tdh_mr_extend(&kvm_tdx->td, gpa + i, &entry,
diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h
index 77d693dfcb08..b71f8e9643e4 100644
--- a/arch/x86/kvm/vmx/tdx.h
+++ b/arch/x86/kvm/vmx/tdx.h
@@ -31,6 +31,9 @@ struct kvm_tdx {
 	u64 tsc_offset;
 
 	struct tdx_td td;
+
+	/* For KVM_TDX_INIT_MEM_REGION. */
+	atomic64_t nr_premapped;
 };
 
 /* TDX module vCPU states */
-- 
2.43.5

[PATCH 24/29] KVM: TDX: Handle vCPU dissociation

[Paolo Bonzini]

From: Isaku Yamahata <isaku.yamahata@intel.com>

Handle vCPUs dissociations by invoking SEAMCALL TDH.VP.FLUSH which flushes
the address translation caches and cached TD VMCS of a TD vCPU in its
associated pCPU.

In TDX, a vCPUs can only be associated with one pCPU at a time, which is
done by invoking SEAMCALL TDH.VP.ENTER. For a successful association, the
vCPU must be dissociated from its previous associated pCPU.

To facilitate vCPU dissociation, introduce a per-pCPU list
associated_tdvcpus. Add a vCPU into this list when it's loaded into a new
pCPU (i.e. when a vCPU is loaded for the first time or migrated to a new
pCPU).

vCPU dissociations can happen under below conditions:
- On the op hardware_disable is called.
  This op is called when virtualization is disabled on a given pCPU, e.g.
  when hot-unplug a pCPU or machine shutdown/suspend.
  In this case, dissociate all vCPUs from the pCPU by iterating its
  per-pCPU list associated_tdvcpus.

- On vCPU migration to a new pCPU.
  Before adding a vCPU into associated_tdvcpus list of the new pCPU,
  dissociation from its old pCPU is required, which is performed by issuing
  an IPI and executing SEAMCALL TDH.VP.FLUSH on the old pCPU.
  On a successful dissociation, the vCPU will be removed from the
  associated_tdvcpus list of its previously associated pCPU.

- On tdx_mmu_release_hkid() is called.
  TDX mandates that all vCPUs must be disassociated prior to the release of
  an hkid. Therefore, dissociation of all vCPUs is a must before executing
  the SEAMCALL TDH.MNG.VPFLUSHDONE and subsequently freeing the hkid.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Co-developed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Message-ID: <20241112073858.22312-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/main.c    |  22 ++++-
 arch/x86/kvm/vmx/tdx.c     | 159 +++++++++++++++++++++++++++++++++++--
 arch/x86/kvm/vmx/tdx.h     |   2 +
 arch/x86/kvm/vmx/x86_ops.h |   4 +
 4 files changed, 177 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 828168e67d4e..abb0fc723a0b 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -10,6 +10,14 @@
 #include "tdx.h"
 #include "tdx_arch.h"
 
+static void vt_disable_virtualization_cpu(void)
+{
+	/* Note, TDX *and* VMX need to be disabled if TDX is enabled. */
+	if (enable_tdx)
+		tdx_disable_virtualization_cpu();
+	vmx_disable_virtualization_cpu();
+}
+
 static __init int vt_hardware_setup(void)
 {
 	int ret;
@@ -111,6 +119,16 @@ static void vt_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
 	vmx_vcpu_reset(vcpu, init_event);
 }
 
+static void vt_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
+{
+	if (is_td_vcpu(vcpu)) {
+		tdx_vcpu_load(vcpu, cpu);
+		return;
+	}
+
+	vmx_vcpu_load(vcpu, cpu);
+}
+
 static void vt_flush_tlb_all(struct kvm_vcpu *vcpu)
 {
 	if (is_td_vcpu(vcpu)) {
@@ -199,7 +217,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
 	.hardware_unsetup = vmx_hardware_unsetup,
 
 	.enable_virtualization_cpu = vmx_enable_virtualization_cpu,
-	.disable_virtualization_cpu = vmx_disable_virtualization_cpu,
+	.disable_virtualization_cpu = vt_disable_virtualization_cpu,
 	.emergency_disable_virtualization_cpu = vmx_emergency_disable_virtualization_cpu,
 
 	.has_emulated_msr = vmx_has_emulated_msr,
@@ -216,7 +234,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
 	.vcpu_reset = vt_vcpu_reset,
 
 	.prepare_switch_to_guest = vmx_prepare_switch_to_guest,
-	.vcpu_load = vmx_vcpu_load,
+	.vcpu_load = vt_vcpu_load,
 	.vcpu_put = vmx_vcpu_put,
 
 	.update_exception_bitmap = vmx_update_exception_bitmap,
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 246f924ae6f6..a6696448cb53 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -162,6 +162,21 @@ static bool tdx_operand_busy(u64 err)
 }
 
 
+/*
+ * A per-CPU list of TD vCPUs associated with a given CPU.
+ * Protected by interrupt mask. Only manipulated by the CPU owning this per-CPU
+ * list.
+ * - When a vCPU is loaded onto a CPU, it is removed from the per-CPU list of
+ *   the old CPU during the IPI callback running on the old CPU, and then added
+ *   to the per-CPU list of the new CPU.
+ * - When a TD is tearing down, all vCPUs are disassociated from their current
+ *   running CPUs and removed from the per-CPU list during the IPI callback
+ *   running on those CPUs.
+ * - When a CPU is brought down, traverse the per-CPU list to disassociate all
+ *   associated TD vCPUs and remove them from the per-CPU list.
+ */
+static DEFINE_PER_CPU(struct list_head, associated_tdvcpus);
+
 static inline void tdx_hkid_free(struct kvm_tdx *kvm_tdx)
 {
 	tdx_guest_keyid_free(kvm_tdx->hkid);
@@ -177,6 +192,22 @@ static inline bool is_hkid_assigned(struct kvm_tdx *kvm_tdx)
 	return kvm_tdx->hkid > 0;
 }
 
+static inline void tdx_disassociate_vp(struct kvm_vcpu *vcpu)
+{
+	lockdep_assert_irqs_disabled();
+
+	list_del(&to_tdx(vcpu)->cpu_list);
+
+	/*
+	 * Ensure tdx->cpu_list is updated before setting vcpu->cpu to -1,
+	 * otherwise, a different CPU can see vcpu->cpu = -1 and add the vCPU
+	 * to its list before it's deleted from this CPU's list.
+	 */
+	smp_wmb();
+
+	vcpu->cpu = -1;
+}
+
 static void tdx_clear_page(struct page *page)
 {
 	const void *zero_page = (const void *) page_to_virt(ZERO_PAGE(0));
@@ -243,6 +274,83 @@ static void tdx_reclaim_control_page(struct page *ctrl_page)
 	__free_page(ctrl_page);
 }
 
+struct tdx_flush_vp_arg {
+	struct kvm_vcpu *vcpu;
+	u64 err;
+};
+
+static void tdx_flush_vp(void *_arg)
+{
+	struct tdx_flush_vp_arg *arg = _arg;
+	struct kvm_vcpu *vcpu = arg->vcpu;
+	u64 err;
+
+	arg->err = 0;
+	lockdep_assert_irqs_disabled();
+
+	/* Task migration can race with CPU offlining. */
+	if (unlikely(vcpu->cpu != raw_smp_processor_id()))
+		return;
+
+	/*
+	 * No need to do TDH_VP_FLUSH if the vCPU hasn't been initialized.  The
+	 * list tracking still needs to be updated so that it's correct if/when
+	 * the vCPU does get initialized.
+	 */
+	if (to_tdx(vcpu)->state != VCPU_TD_STATE_UNINITIALIZED) {
+		/*
+		 * No need to retry.  TDX Resources needed for TDH.VP.FLUSH are:
+		 * TDVPR as exclusive, TDR as shared, and TDCS as shared.  This
+		 * vp flush function is called when destructing vCPU/TD or vCPU
+		 * migration.  No other thread uses TDVPR in those cases.
+		 */
+		err = tdh_vp_flush(&to_tdx(vcpu)->vp);
+		if (unlikely(err && err != TDX_VCPU_NOT_ASSOCIATED)) {
+			/*
+			 * This function is called in IPI context. Do not use
+			 * printk to avoid console semaphore.
+			 * The caller prints out the error message, instead.
+			 */
+			if (err)
+				arg->err = err;
+		}
+	}
+
+	tdx_disassociate_vp(vcpu);
+}
+
+static void tdx_flush_vp_on_cpu(struct kvm_vcpu *vcpu)
+{
+	struct tdx_flush_vp_arg arg = {
+		.vcpu = vcpu,
+	};
+	int cpu = vcpu->cpu;
+
+	if (unlikely(cpu == -1))
+		return;
+
+	smp_call_function_single(cpu, tdx_flush_vp, &arg, 1);
+	if (KVM_BUG_ON(arg.err, vcpu->kvm))
+		pr_tdx_error(TDH_VP_FLUSH, arg.err);
+}
+
+void tdx_disable_virtualization_cpu(void)
+{
+	int cpu = raw_smp_processor_id();
+	struct list_head *tdvcpus = &per_cpu(associated_tdvcpus, cpu);
+	struct tdx_flush_vp_arg arg;
+	struct vcpu_tdx *tdx, *tmp;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	/* Safe variant needed as tdx_disassociate_vp() deletes the entry. */
+	list_for_each_entry_safe(tdx, tmp, tdvcpus, cpu_list) {
+		arg.vcpu = &tdx->vcpu;
+		tdx_flush_vp(&arg);
+	}
+	local_irq_restore(flags);
+}
+
 #define TDX_SEAMCALL_RETRIES 10000
 
 static void smp_func_do_phymem_cache_wb(void *unused)
@@ -281,22 +389,21 @@ void tdx_mmu_release_hkid(struct kvm *kvm)
 	bool packages_allocated, targets_allocated;
 	struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
 	cpumask_var_t packages, targets;
-	u64 err;
+	struct kvm_vcpu *vcpu;
+	unsigned long j;
 	int i;
+	u64 err;
 
 	if (!is_hkid_assigned(kvm_tdx))
 		return;
 
-	/* KeyID has been allocated but guest is not yet configured */
-	if (!kvm_tdx->td.tdr_page) {
-		tdx_hkid_free(kvm_tdx);
-		return;
-	}
-
 	packages_allocated = zalloc_cpumask_var(&packages, GFP_KERNEL);
 	targets_allocated = zalloc_cpumask_var(&targets, GFP_KERNEL);
 	cpus_read_lock();
 
+	kvm_for_each_vcpu(j, vcpu, kvm)
+		tdx_flush_vp_on_cpu(vcpu);
+
 	/*
 	 * TDH.PHYMEM.CACHE.WB tries to acquire the TDX module global lock
 	 * and can fail with TDX_OPERAND_BUSY when it fails to get the lock.
@@ -310,6 +417,16 @@ void tdx_mmu_release_hkid(struct kvm *kvm)
 	 * After the above flushing vps, there should be no more vCPU
 	 * associations, as all vCPU fds have been released at this stage.
 	 */
+	err = tdh_mng_vpflushdone(&kvm_tdx->td);
+	if (err == TDX_FLUSHVP_NOT_DONE)
+		goto out;
+	if (KVM_BUG_ON(err, kvm)) {
+		pr_tdx_error(TDH_MNG_VPFLUSHDONE, err);
+		pr_err("tdh_mng_vpflushdone() failed. HKID %d is leaked.\n",
+		       kvm_tdx->hkid);
+		goto out;
+	}
+
 	for_each_online_cpu(i) {
 		if (packages_allocated &&
 		    cpumask_test_and_set_cpu(topology_physical_package_id(i),
@@ -335,6 +452,7 @@ void tdx_mmu_release_hkid(struct kvm *kvm)
 		tdx_hkid_free(kvm_tdx);
 	}
 
+out:
 	mutex_unlock(&tdx_lock);
 	cpus_read_unlock();
 	free_cpumask_var(targets);
@@ -483,6 +601,27 @@ int tdx_vcpu_create(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
+void tdx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
+{
+	struct vcpu_tdx *tdx = to_tdx(vcpu);
+
+	if (vcpu->cpu == cpu || !is_hkid_assigned(to_kvm_tdx(vcpu->kvm)))
+		return;
+
+	tdx_flush_vp_on_cpu(vcpu);
+
+	KVM_BUG_ON(cpu != raw_smp_processor_id(), vcpu->kvm);
+	local_irq_disable();
+	/*
+	 * Pairs with the smp_wmb() in tdx_disassociate_vp() to ensure
+	 * vcpu->cpu is read before tdx->cpu_list.
+	 */
+	smp_rmb();
+
+	list_add(&tdx->cpu_list, &per_cpu(associated_tdvcpus, cpu));
+	local_irq_enable();
+}
+
 void tdx_vcpu_free(struct kvm_vcpu *vcpu)
 {
 	struct kvm_tdx *kvm_tdx = to_kvm_tdx(vcpu->kvm);
@@ -2038,7 +2177,11 @@ void tdx_cleanup(void)
 
 int __init tdx_bringup(void)
 {
-	int r;
+	int r, i;
+
+	/* tdx_disable_virtualization_cpu() uses associated_tdvcpus. */
+	for_each_possible_cpu(i)
+		INIT_LIST_HEAD(&per_cpu(associated_tdvcpus, i));
 
 	if (!enable_tdx)
 		return 0;
diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h
index b71f8e9643e4..8ed96f980d9a 100644
--- a/arch/x86/kvm/vmx/tdx.h
+++ b/arch/x86/kvm/vmx/tdx.h
@@ -47,6 +47,8 @@ struct vcpu_tdx {
 
 	struct tdx_vp vp;
 
+	struct list_head cpu_list;
+
 	enum vcpu_tdx_state state;
 };
 
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index bc3cf1c1da37..6ab10d3cdb6f 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -122,6 +122,7 @@ void vmx_cancel_hv_timer(struct kvm_vcpu *vcpu);
 void vmx_setup_mce(struct kvm_vcpu *vcpu);
 
 #ifdef CONFIG_INTEL_TDX_HOST
+void tdx_disable_virtualization_cpu(void);
 int tdx_vm_init(struct kvm *kvm);
 void tdx_mmu_release_hkid(struct kvm *kvm);
 void tdx_vm_destroy(struct kvm *kvm);
@@ -129,6 +130,7 @@ int tdx_vm_ioctl(struct kvm *kvm, void __user *argp);
 
 int tdx_vcpu_create(struct kvm_vcpu *vcpu);
 void tdx_vcpu_free(struct kvm_vcpu *vcpu);
+void tdx_vcpu_load(struct kvm_vcpu *vcpu, int cpu);
 
 int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp);
 
@@ -146,6 +148,7 @@ void tdx_flush_tlb_all(struct kvm_vcpu *vcpu);
 void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int root_level);
 int tdx_gmem_private_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn);
 #else
+static inline void tdx_disable_virtualization_cpu(void) {}
 static inline int tdx_vm_init(struct kvm *kvm) { return -EOPNOTSUPP; }
 static inline void tdx_mmu_release_hkid(struct kvm *kvm) {}
 static inline void tdx_vm_destroy(struct kvm *kvm) {}
@@ -153,6 +156,7 @@ static inline int tdx_vm_ioctl(struct kvm *kvm, void __user *argp) { return -EOP
 
 static inline int tdx_vcpu_create(struct kvm_vcpu *vcpu) { return -EOPNOTSUPP; }
 static inline void tdx_vcpu_free(struct kvm_vcpu *vcpu) {}
+static inline void tdx_vcpu_load(struct kvm_vcpu *vcpu, int cpu) {}
 
 static inline int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp) { return -EOPNOTSUPP; }
 
-- 
2.43.5

[PATCH 25/29] KVM: Add parameter "kvm" to kvm_cpu_dirty_log_size() and its callers

[Paolo Bonzini]

From: Yan Zhao <yan.y.zhao@intel.com>

Add a parameter "kvm" to kvm_cpu_dirty_log_size() and down to its callers:
kvm_dirty_ring_get_rsvd_entries(), kvm_dirty_ring_alloc().

This is a preparation to make cpu_dirty_log_size a per-VM value rather than
a system-wide value.

No function changes expected.

Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/mmu/mmu.c         |  2 +-
 include/linux/kvm_dirty_ring.h | 11 ++++++-----
 virt/kvm/dirty_ring.c          | 11 ++++++-----
 virt/kvm/kvm_main.c            |  4 ++--
 4 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 443c4836bc62..3caeaebda637 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1311,7 +1311,7 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
 		kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
 }
 
-int kvm_cpu_dirty_log_size(void)
+int kvm_cpu_dirty_log_size(struct kvm *kvm)
 {
 	return kvm_x86_ops.cpu_dirty_log_size;
 }
diff --git a/include/linux/kvm_dirty_ring.h b/include/linux/kvm_dirty_ring.h
index 4862c98d80d3..da4d9b5f58f1 100644
--- a/include/linux/kvm_dirty_ring.h
+++ b/include/linux/kvm_dirty_ring.h
@@ -32,7 +32,7 @@ struct kvm_dirty_ring {
  * If CONFIG_HAVE_HVM_DIRTY_RING not defined, kvm_dirty_ring.o should
  * not be included as well, so define these nop functions for the arch.
  */
-static inline u32 kvm_dirty_ring_get_rsvd_entries(void)
+static inline u32 kvm_dirty_ring_get_rsvd_entries(struct kvm *kvm)
 {
 	return 0;
 }
@@ -42,7 +42,7 @@ static inline bool kvm_use_dirty_bitmap(struct kvm *kvm)
 	return true;
 }
 
-static inline int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring,
+static inline int kvm_dirty_ring_alloc(struct kvm *kvm, struct kvm_dirty_ring *ring,
 				       int index, u32 size)
 {
 	return 0;
@@ -71,11 +71,12 @@ static inline void kvm_dirty_ring_free(struct kvm_dirty_ring *ring)
 
 #else /* CONFIG_HAVE_KVM_DIRTY_RING */
 
-int kvm_cpu_dirty_log_size(void);
+int kvm_cpu_dirty_log_size(struct kvm *kvm);
 bool kvm_use_dirty_bitmap(struct kvm *kvm);
 bool kvm_arch_allow_write_without_running_vcpu(struct kvm *kvm);
-u32 kvm_dirty_ring_get_rsvd_entries(void);
-int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size);
+u32 kvm_dirty_ring_get_rsvd_entries(struct kvm *kvm);
+int kvm_dirty_ring_alloc(struct kvm *kvm, struct kvm_dirty_ring *ring,
+			 int index, u32 size);
 
 /*
  * called with kvm->slots_lock held, returns the number of
diff --git a/virt/kvm/dirty_ring.c b/virt/kvm/dirty_ring.c
index 7bc74969a819..d14ffc7513ee 100644
--- a/virt/kvm/dirty_ring.c
+++ b/virt/kvm/dirty_ring.c
@@ -11,14 +11,14 @@
 #include <trace/events/kvm.h>
 #include "kvm_mm.h"
 
-int __weak kvm_cpu_dirty_log_size(void)
+int __weak kvm_cpu_dirty_log_size(struct kvm *kvm)
 {
 	return 0;
 }
 
-u32 kvm_dirty_ring_get_rsvd_entries(void)
+u32 kvm_dirty_ring_get_rsvd_entries(struct kvm *kvm)
 {
-	return KVM_DIRTY_RING_RSVD_ENTRIES + kvm_cpu_dirty_log_size();
+	return KVM_DIRTY_RING_RSVD_ENTRIES + kvm_cpu_dirty_log_size(kvm);
 }
 
 bool kvm_use_dirty_bitmap(struct kvm *kvm)
@@ -74,14 +74,15 @@ static void kvm_reset_dirty_gfn(struct kvm *kvm, u32 slot, u64 offset, u64 mask)
 	KVM_MMU_UNLOCK(kvm);
 }
 
-int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size)
+int kvm_dirty_ring_alloc(struct kvm *kvm, struct kvm_dirty_ring *ring,
+			 int index, u32 size)
 {
 	ring->dirty_gfns = vzalloc(size);
 	if (!ring->dirty_gfns)
 		return -ENOMEM;
 
 	ring->size = size / sizeof(struct kvm_dirty_gfn);
-	ring->soft_limit = ring->size - kvm_dirty_ring_get_rsvd_entries();
+	ring->soft_limit = ring->size - kvm_dirty_ring_get_rsvd_entries(kvm);
 	ring->dirty_index = 0;
 	ring->reset_index = 0;
 	ring->index = index;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index c88acfa154e6..3187b2ae0e5b 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -4109,7 +4109,7 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, unsigned long id)
 		goto vcpu_free_run_page;
 
 	if (kvm->dirty_ring_size) {
-		r = kvm_dirty_ring_alloc(&vcpu->dirty_ring,
+		r = kvm_dirty_ring_alloc(kvm, &vcpu->dirty_ring,
 					 id, kvm->dirty_ring_size);
 		if (r)
 			goto arch_vcpu_destroy;
@@ -4848,7 +4848,7 @@ static int kvm_vm_ioctl_enable_dirty_log_ring(struct kvm *kvm, u32 size)
 		return -EINVAL;
 
 	/* Should be bigger to keep the reserved entries, or a page */
-	if (size < kvm_dirty_ring_get_rsvd_entries() *
+	if (size < kvm_dirty_ring_get_rsvd_entries(kvm) *
 	    sizeof(struct kvm_dirty_gfn) || size < PAGE_SIZE)
 		return -EINVAL;
 
-- 
2.43.5

[PATCH 26/29] KVM: x86/mmu: Add parameter "kvm" to kvm_mmu_page_ad_need_write_protect()

[Paolo Bonzini]

From: Yan Zhao <yan.y.zhao@intel.com>

Add a parameter "kvm" to kvm_mmu_page_ad_need_write_protect() and its
caller tdp_mmu_need_write_protect().

This is a preparation to make cpu_dirty_log_size a per-VM value rather than
a system-wide value.

No function changes expected.

Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/mmu/mmu_internal.h |  3 ++-
 arch/x86/kvm/mmu/spte.c         |  2 +-
 arch/x86/kvm/mmu/tdp_mmu.c      | 12 ++++++------
 3 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index 75f00598289d..86d6d4f82cf4 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -187,7 +187,8 @@ static inline gfn_t kvm_gfn_root_bits(const struct kvm *kvm, const struct kvm_mm
 	return kvm_gfn_direct_bits(kvm);
 }
 
-static inline bool kvm_mmu_page_ad_need_write_protect(struct kvm_mmu_page *sp)
+static inline bool kvm_mmu_page_ad_need_write_protect(struct kvm *kvm,
+						      struct kvm_mmu_page *sp)
 {
 	/*
 	 * When using the EPT page-modification log, the GPAs in the CPU dirty
diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c
index e819d16655b6..a609d5b58b69 100644
--- a/arch/x86/kvm/mmu/spte.c
+++ b/arch/x86/kvm/mmu/spte.c
@@ -168,7 +168,7 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 
 	if (sp->role.ad_disabled)
 		spte |= SPTE_TDP_AD_DISABLED;
-	else if (kvm_mmu_page_ad_need_write_protect(sp))
+	else if (kvm_mmu_page_ad_need_write_protect(vcpu->kvm, sp))
 		spte |= SPTE_TDP_AD_WRPROT_ONLY;
 
 	spte |= shadow_present_mask;
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 22675a5746d0..fd0a7792386b 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1613,21 +1613,21 @@ void kvm_tdp_mmu_try_split_huge_pages(struct kvm *kvm,
 	}
 }
 
-static bool tdp_mmu_need_write_protect(struct kvm_mmu_page *sp)
+static bool tdp_mmu_need_write_protect(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
 	/*
 	 * All TDP MMU shadow pages share the same role as their root, aside
 	 * from level, so it is valid to key off any shadow page to determine if
 	 * write protection is needed for an entire tree.
 	 */
-	return kvm_mmu_page_ad_need_write_protect(sp) || !kvm_ad_enabled;
+	return kvm_mmu_page_ad_need_write_protect(kvm, sp) || !kvm_ad_enabled;
 }
 
 static void clear_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
 				  gfn_t start, gfn_t end)
 {
-	const u64 dbit = tdp_mmu_need_write_protect(root) ? PT_WRITABLE_MASK :
-							    shadow_dirty_mask;
+	const u64 dbit = tdp_mmu_need_write_protect(kvm, root) ?
+			 PT_WRITABLE_MASK : shadow_dirty_mask;
 	struct tdp_iter iter;
 
 	rcu_read_lock();
@@ -1672,8 +1672,8 @@ void kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm,
 static void clear_dirty_pt_masked(struct kvm *kvm, struct kvm_mmu_page *root,
 				  gfn_t gfn, unsigned long mask, bool wrprot)
 {
-	const u64 dbit = (wrprot || tdp_mmu_need_write_protect(root)) ? PT_WRITABLE_MASK :
-									shadow_dirty_mask;
+	const u64 dbit = (wrprot || tdp_mmu_need_write_protect(kvm, root)) ?
+			  PT_WRITABLE_MASK : shadow_dirty_mask;
 	struct tdp_iter iter;
 
 	lockdep_assert_held_write(&kvm->mmu_lock);
-- 
2.43.5

[PATCH 27/29] KVM: x86: Make cpu_dirty_log_size a per-VM value

[Paolo Bonzini]

From: Yan Zhao <yan.y.zhao@intel.com>

Make cpu_dirty_log_size (CPU's dirty log buffer size) a per-VM value and
set the per-VM cpu_dirty_log_size only for normal VMs when PML is enabled.
Do not set it for TDs.

Until now, cpu_dirty_log_size was a system-wide value that is used for
all VMs and is set to the PML buffer size when PML was enabled in VMX.
However, PML is not currently supported for TDs, though PML remains
available for normal VMs as long as the feature is supported by hardware
and enabled in VMX.

Making cpu_dirty_log_size a per-VM value allows it to be ther PML buffer
size for normal VMs and 0 for TDs. This allows functions like
kvm_arch_sync_dirty_log() and kvm_mmu_update_cpu_dirty_logging() to
determine if PML is supported, in order to kick off vCPUs or request them
to update CPU dirty logging status (turn on/off PML in VMCS).

This fixes an issue first reported in [1], where QEMU attaches an
emulated VGA device to a TD; note that KVM_MEM_LOG_DIRTY_PAGES
still works if the corresponding has no flag KVM_MEM_GUEST_MEMFD.
KVM then invokes kvm_mmu_update_cpu_dirty_logging() and from there
vmx_update_cpu_dirty_logging(), which incorrectly accesses a kvm_vmx
struct for a TDX VM.

Reported-by: ANAND NARSHINHA PATIL <Anand.N.Patil@ibm.com>
Reported-by: Pedro Principeza <pedro.principeza@canonical.com>
Reported-by: Farrah Chen <farrah.chen@intel.com>
Closes: https://github.com/canonical/tdx/issues/202
Link: https://github.com/canonical/tdx/issues/202 [1]
Suggested-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/include/asm/kvm_host.h | 12 +++++++-----
 arch/x86/kvm/mmu/mmu.c          |  4 ++--
 arch/x86/kvm/mmu/mmu_internal.h |  2 +-
 arch/x86/kvm/vmx/main.c         |  1 -
 arch/x86/kvm/vmx/vmx.c          |  6 +++---
 arch/x86/kvm/x86.c              |  6 +++---
 6 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 04f6cc48167a..c89130fda012 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1560,6 +1560,13 @@ struct kvm_arch {
 	struct kvm_mmu_memory_cache split_desc_cache;
 
 	gfn_t gfn_direct_bits;
+
+	/*
+	 * Size of the CPU's dirty log buffer, i.e. VMX's PML buffer. A Zero
+	 * value indicates CPU dirty logging is unsupported or disabled in
+	 * current VM.
+	 */
+	int cpu_dirty_log_size;
 };
 
 struct kvm_vm_stat {
@@ -1813,11 +1820,6 @@ struct kvm_x86_ops {
 			       struct x86_exception *exception);
 	void (*handle_exit_irqoff)(struct kvm_vcpu *vcpu);
 
-	/*
-	 * Size of the CPU's dirty log buffer, i.e. VMX's PML buffer.  A zero
-	 * value indicates CPU dirty logging is unsupported or disabled.
-	 */
-	int cpu_dirty_log_size;
 	void (*update_cpu_dirty_logging)(struct kvm_vcpu *vcpu);
 
 	const struct kvm_x86_nested_ops *nested_ops;
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 3caeaebda637..e6eb3a262f8d 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1305,7 +1305,7 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
 	 * enabled but it chooses between clearing the Dirty bit and Writeable
 	 * bit based on the context.
 	 */
-	if (kvm_x86_ops.cpu_dirty_log_size)
+	if (kvm->arch.cpu_dirty_log_size)
 		kvm_mmu_clear_dirty_pt_masked(kvm, slot, gfn_offset, mask);
 	else
 		kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
@@ -1313,7 +1313,7 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
 
 int kvm_cpu_dirty_log_size(struct kvm *kvm)
 {
-	return kvm_x86_ops.cpu_dirty_log_size;
+	return kvm->arch.cpu_dirty_log_size;
 }
 
 bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index 86d6d4f82cf4..db8f33e4de62 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -198,7 +198,7 @@ static inline bool kvm_mmu_page_ad_need_write_protect(struct kvm *kvm,
 	 * being enabled is mandatory as the bits used to denote WP-only SPTEs
 	 * are reserved for PAE paging (32-bit KVM).
 	 */
-	return kvm_x86_ops.cpu_dirty_log_size && sp->role.guest_mode;
+	return kvm->arch.cpu_dirty_log_size && sp->role.guest_mode;
 }
 
 static inline gfn_t gfn_round_for_level(gfn_t gfn, int level)
diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index abb0fc723a0b..ba3a23747bb1 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -322,7 +322,6 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
 	.check_intercept = vmx_check_intercept,
 	.handle_exit_irqoff = vmx_handle_exit_irqoff,
 
-	.cpu_dirty_log_size = PML_LOG_NR_ENTRIES,
 	.update_cpu_dirty_logging = vmx_update_cpu_dirty_logging,
 
 	.nested_ops = &vmx_nested_ops,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 18150a38fe09..b71125a1b5cf 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7653,6 +7653,9 @@ int vmx_vm_init(struct kvm *kvm)
 			break;
 		}
 	}
+
+	if (enable_pml)
+		kvm->arch.cpu_dirty_log_size = PML_LOG_NR_ENTRIES;
 	return 0;
 }
 
@@ -8506,9 +8509,6 @@ __init int vmx_hardware_setup(void)
 	if (!enable_ept || !enable_ept_ad_bits || !cpu_has_vmx_pml())
 		enable_pml = 0;
 
-	if (!enable_pml)
-		vt_x86_ops.cpu_dirty_log_size = 0;
-
 	if (!cpu_has_vmx_preemption_timer())
 		enable_preemption_timer = false;
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e981e24820a0..edf47b8cb949 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6468,7 +6468,7 @@ void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
 	struct kvm_vcpu *vcpu;
 	unsigned long i;
 
-	if (!kvm_x86_ops.cpu_dirty_log_size)
+	if (!kvm->arch.cpu_dirty_log_size)
 		return;
 
 	kvm_for_each_vcpu(i, vcpu, kvm)
@@ -13055,7 +13055,7 @@ static void kvm_mmu_update_cpu_dirty_logging(struct kvm *kvm, bool enable)
 {
 	int nr_slots;
 
-	if (!kvm_x86_ops.cpu_dirty_log_size)
+	if (!kvm->arch.cpu_dirty_log_size)
 		return;
 
 	nr_slots = atomic_read(&kvm->nr_memslots_dirty_logging);
@@ -13127,7 +13127,7 @@ static void kvm_mmu_slot_apply_flags(struct kvm *kvm,
 		if (READ_ONCE(eager_page_split))
 			kvm_mmu_slot_try_split_huge_pages(kvm, new, PG_LEVEL_4K);
 
-		if (kvm_x86_ops.cpu_dirty_log_size) {
+		if (kvm->arch.cpu_dirty_log_size) {
 			kvm_mmu_slot_leaf_clear_dirty(kvm, new);
 			kvm_mmu_slot_remove_write_access(kvm, new, PG_LEVEL_2M);
 		} else {
-- 
2.43.5

[PATCH 28/29] KVM: TDX: Skip updating CPU dirty logging request for TDs

[Paolo Bonzini]

Wrap vmx_update_cpu_dirty_logging so as to ignore requests to update
CPU dirty logging for TDs, as basic TDX does not support the PML feature.
Invoking vmx_update_cpu_dirty_logging() for TDs would cause an incorrect
access to a kvm_vmx struct for a TDX VM, so block that before it happens.

Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/main.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index ba3a23747bb1..ec8223ee9d28 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -129,6 +129,18 @@ static void vt_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	vmx_vcpu_load(vcpu, cpu);
 }
 
+static void vt_update_cpu_dirty_logging(struct kvm_vcpu *vcpu)
+{
+	/*
+	 * Basic TDX does not support feature PML. KVM does not enable PML in
+	 * TD's VMCS, nor does it allocate or flush PML buffer for TDX.
+	 */
+	if (WARN_ON_ONCE(is_td_vcpu(vcpu)))
+		return;
+
+	vmx_update_cpu_dirty_logging(vcpu);
+}
+
 static void vt_flush_tlb_all(struct kvm_vcpu *vcpu)
 {
 	if (is_td_vcpu(vcpu)) {
@@ -322,7 +334,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
 	.check_intercept = vmx_check_intercept,
 	.handle_exit_irqoff = vmx_handle_exit_irqoff,
 
-	.update_cpu_dirty_logging = vmx_update_cpu_dirty_logging,
+	.update_cpu_dirty_logging = vt_update_cpu_dirty_logging,
 
 	.nested_ops = &vmx_nested_ops,
 
-- 
2.43.5

[PATCH 29/29] KVM: TDX: Handle SEPT zap error due to page add error in premap

[Paolo Bonzini]

From: Yan Zhao <yan.y.zhao@intel.com>

Move the handling of SEPT zap errors caused by unsuccessful execution of
tdh_mem_page_add() in KVM_TDX_INIT_MEM_REGION from
tdx_sept_drop_private_spte() to tdx_sept_zap_private_spte(). Introduce a
new helper function tdx_is_sept_zap_err_due_to_premap() to detect this
specific error.

During the IOCTL KVM_TDX_INIT_MEM_REGION, KVM premaps leaf SPTEs in the
mirror page table before the corresponding entry in the private page table
is successfully installed by tdh_mem_page_add(). If an error occurs during
the invocation of tdh_mem_page_add(), a mismatch between the mirror and
private page tables results in SEAMCALLs for SEPT zap returning the error
code TDX_EPT_ENTRY_STATE_INCORRECT.

The error TDX_EPT_WALK_FAILED is not possible because, during
KVM_TDX_INIT_MEM_REGION, KVM only premaps leaf SPTEs after successfully
mapping non-leaf SPTEs. Unlike leaf SPTEs, there is no mismatch in non-leaf
PTEs between the mirror and private page tables. Therefore, during zap,
SEAMCALLs should find an empty leaf entry in the private EPT, leading to
the error TDX_EPT_ENTRY_STATE_INCORRECT instead of TDX_EPT_WALK_FAILED.

Since tdh_mem_range_block() is always invoked before tdh_mem_page_remove(),
move the handling of SEPT zap errors from tdx_sept_drop_private_spte() to
tdx_sept_zap_private_spte(). In tdx_sept_zap_private_spte(), return 0 for
errors due to premap to skip executing other SEAMCALLs for zap, which are
unnecessary. Return 1 to indicate no other errors, allowing the execution
of other zap SEAMCALLs to continue.

The failure of tdh_mem_page_add() is uncommon and has not been observed in
real workloads. Currently, this failure is only hypothetically triggered by
skipping the real SEAMCALL and faking the add error in the SEAMCALL
wrapper. Additionally, without this fix, there will be no host crashes or
other severe issues.

Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Message-ID: <20250217085642.19696-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/tdx.c | 66 ++++++++++++++++++++++++++++++------------
 1 file changed, 47 insertions(+), 19 deletions(-)

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index a6696448cb53..f2cbd8c440e9 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -775,20 +775,6 @@ static int tdx_sept_drop_private_spte(struct kvm *kvm, gfn_t gfn,
 					  &level_state);
 	} while (unlikely(tdx_operand_busy(err)));
 
-	if (unlikely(kvm_tdx->state != TD_STATE_RUNNABLE &&
-		     err == (TDX_EPT_WALK_FAILED | TDX_OPERAND_ID_RCX))) {
-		/*
-		 * Page is mapped by KVM_TDX_INIT_MEM_REGION, but hasn't called
-		 * tdh_mem_page_add().
-		 */
-		if ((!is_last_spte(entry, level) || !(entry & VMX_EPT_RWX_MASK)) &&
-		    !KVM_BUG_ON(!atomic64_read(&kvm_tdx->nr_premapped), kvm)) {
-			atomic64_dec(&kvm_tdx->nr_premapped);
-			tdx_unpin(kvm, page);
-			return 0;
-		}
-	}
-
 	if (KVM_BUG_ON(err, kvm)) {
 		pr_tdx_error_2(TDH_MEM_PAGE_REMOVE, err, entry, level_state);
 		return -EIO;
@@ -826,8 +812,41 @@ int tdx_sept_link_private_spt(struct kvm *kvm, gfn_t gfn,
 	return 0;
 }
 
+/*
+ * Check if the error returned from a SEPT zap SEAMCALL is due to that a page is
+ * mapped by KVM_TDX_INIT_MEM_REGION without tdh_mem_page_add() being called
+ * successfully.
+ *
+ * Since tdh_mem_sept_add() must have been invoked successfully before a
+ * non-leaf entry present in the mirrored page table, the SEPT ZAP related
+ * SEAMCALLs should not encounter err TDX_EPT_WALK_FAILED. They should instead
+ * find TDX_EPT_ENTRY_STATE_INCORRECT due to an empty leaf entry found in the
+ * SEPT.
+ *
+ * Further check if the returned entry from SEPT walking is with RWX permissions
+ * to filter out anything unexpected.
+ *
+ * Note: @level is pg_level, not the tdx_level. The tdx_level extracted from
+ * level_state returned from a SEAMCALL error is the same as that passed into
+ * the SEAMCALL.
+ */
+static int tdx_is_sept_zap_err_due_to_premap(struct kvm_tdx *kvm_tdx, u64 err,
+					     u64 entry, int level)
+{
+	if (!err || kvm_tdx->state == TD_STATE_RUNNABLE)
+		return false;
+
+	if (err != (TDX_EPT_ENTRY_STATE_INCORRECT | TDX_OPERAND_ID_RCX))
+		return false;
+
+	if ((is_last_spte(entry, level) && (entry & VMX_EPT_RWX_MASK)))
+		return false;
+
+	return true;
+}
+
 static int tdx_sept_zap_private_spte(struct kvm *kvm, gfn_t gfn,
-				     enum pg_level level)
+				     enum pg_level level, struct page *page)
 {
 	int tdx_level = pg_level_to_tdx_sept_level(level);
 	struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
@@ -840,11 +859,19 @@ static int tdx_sept_zap_private_spte(struct kvm *kvm, gfn_t gfn,
 	err = tdh_mem_range_block(&kvm_tdx->td, gpa, tdx_level, &entry, &level_state);
 	if (unlikely(tdx_operand_busy(err)))
 		return -EBUSY;
+
+	if (tdx_is_sept_zap_err_due_to_premap(kvm_tdx, err, entry, level) &&
+	    !KVM_BUG_ON(!atomic64_read(&kvm_tdx->nr_premapped), kvm)) {
+		atomic64_dec(&kvm_tdx->nr_premapped);
+		tdx_unpin(kvm, page);
+		return 0;
+	}
+
 	if (KVM_BUG_ON(err, kvm)) {
 		pr_tdx_error_2(TDH_MEM_RANGE_BLOCK, err, entry, level_state);
 		return -EIO;
 	}
-	return 0;
+	return 1;
 }
 
 /*
@@ -918,6 +945,7 @@ int tdx_sept_free_private_spt(struct kvm *kvm, gfn_t gfn,
 int tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn,
 				 enum pg_level level, kvm_pfn_t pfn)
 {
+	struct page *page = pfn_to_page(pfn);
 	int ret;
 
 	/*
@@ -928,8 +956,8 @@ int tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn,
 	if (KVM_BUG_ON(!is_hkid_assigned(to_kvm_tdx(kvm)), kvm))
 		return -EINVAL;
 
-	ret = tdx_sept_zap_private_spte(kvm, gfn, level);
-	if (ret)
+	ret = tdx_sept_zap_private_spte(kvm, gfn, level, page);
+	if (ret <= 0)
 		return ret;
 
 	/*
@@ -938,7 +966,7 @@ int tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn,
 	 */
 	tdx_track(kvm);
 
-	return tdx_sept_drop_private_spte(kvm, gfn, level, pfn_to_page(pfn));
+	return tdx_sept_drop_private_spte(kvm, gfn, level, page);
 }
 
 static int tdx_get_capabilities(struct kvm_tdx_cmd *cmd)
-- 
2.43.5

Re: [PATCH 22/29] KVM: TDX: Add an ioctl to create initial guest memory

[Yan Zhao]

Just two nits below. Feel free to ignore them.
The rest of this series looks good to me.

On Wed, Feb 26, 2025 at 02:55:22PM -0500, Paolo Bonzini wrote:
> From: Isaku Yamahata <isaku.yamahata@intel.com>
...
> diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
> index 989db4887963..12f3433d062d 100644
> --- a/arch/x86/kvm/vmx/tdx.c
> +++ b/arch/x86/kvm/vmx/tdx.c
> @@ -1,4 +1,5 @@
>  // SPDX-License-Identifier: GPL-2.0
> +#include <linux/cleanup.h>
This include is not necessary.

>  #include <linux/cpu.h>
>  #include <asm/cpufeature.h>
>  #include <linux/misc_cgroup.h>
> @@ -10,6 +11,7 @@
>  #include "tdx.h"
>  #include "vmx.h"
>  #include "mmu/spte.h"
> +#include "common.h"
>  
>  #pragma GCC poison to_vmx
>  
...
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 622b5a99078a..c88acfa154e6 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -2581,6 +2581,7 @@ struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn
>  
>  	return NULL;
>  }
> +EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_memslot);
This EXPORT is not necessary. Though looks kvm_vcpu_gfn_to_memslot() is
the only one not exported among the gfn_to_* functions, e.g. gfn_to_memslot(),
gfn_to_hva_memslot(), kvm_vcpu_gfn_to_hva()...

>  bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
>  {
> -- 
> 2.43.5
> 
> 

Re: [PATCH 22/29] KVM: TDX: Add an ioctl to create initial guest memory

[Paolo Bonzini]

On 2/28/25 05:18, Yan Zhao wrote:
>> diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
>> index 989db4887963..12f3433d062d 100644
>> --- a/arch/x86/kvm/vmx/tdx.c
>> +++ b/arch/x86/kvm/vmx/tdx.c
>> @@ -1,4 +1,5 @@
>>   // SPDX-License-Identifier: GPL-2.0
>> +#include <linux/cleanup.h>
>
> This include is not necessary.

I think it was added because this patch introduces the first use of 
guard().  While it may be included via other files, it's a bit more tidy 
to leave it in.

>> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
>> index 622b5a99078a..c88acfa154e6 100644
>> --- a/virt/kvm/kvm_main.c
>> +++ b/virt/kvm/kvm_main.c
>> @@ -2581,6 +2581,7 @@ struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn
>>   
>>   	return NULL;
>>   }
>> +EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_memslot);
>
> This EXPORT is not necessary. Though looks kvm_vcpu_gfn_to_memslot() is
> the only one not exported among the gfn_to_* functions, e.g. gfn_to_memslot(),
> gfn_to_hva_memslot(), kvm_vcpu_gfn_to_hva()...

Removed, thanks Yan.

Paolo