From: Sean Christopherson <seanjc@google.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
"Hyunwoo Kim" <imv4bel@gmail.com>,
"Tom Lendacky" <thomas.lendacky@amd.com>,
"Michael Roth" <michael.roth@amd.com>,
"Jörg Rödel" <joro@8bytes.org>, "Fuad Tabba" <tabba@google.com>,
"Ackerley Tng" <ackerleytng@google.com>
Subject: [PATCH v2 4/9] KVM: Rework .gmem_invalidate() into .gmem_free_folio()
Date: Fri, 26 Jun 2026 16:14:11 -0700 [thread overview]
Message-ID: <20260626231416.3943216-5-seanjc@google.com> (raw)
In-Reply-To: <20260626231416.3943216-1-seanjc@google.com>
Rename .gmem_invalidate() to .gmem_free_folio() as the hook is called when
a folio is freed, which is far too late and lack sufficient information for
KVM to actually invalidate its usage of the memory. Drop guest_memfd's
trampoline and just wire up .free_folio() directly to the arch callback so
that the chain of events is clear and obvious.
Opportunistically guard kvm_x86_ops.gmem_free_folio with an ifdef to
ensure the callback will actually be called, e.g. so that non-SEV code
doesn't try to wire up a callback without enabling
CONFIG_HAVE_KVM_ARCH_GMEM_INVALIDATE.
No functional change intended.
Cc: stable@vger.kernel.org # 6.12.x
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/include/asm/kvm-x86-ops.h | 4 +++-
arch/x86/include/asm/kvm_host.h | 4 +++-
arch/x86/kvm/svm/sev.c | 4 +++-
arch/x86/kvm/svm/svm.c | 4 +++-
arch/x86/kvm/svm/svm.h | 3 +--
arch/x86/kvm/x86.c | 4 ++--
include/linux/kvm_host.h | 2 +-
virt/kvm/guest_memfd.c | 13 +------------
8 files changed, 17 insertions(+), 21 deletions(-)
diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index 83dc5086138b..e36eba952705 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -147,7 +147,9 @@ KVM_X86_OP_OPTIONAL(get_untagged_addr)
KVM_X86_OP_OPTIONAL(alloc_apic_backing_page)
KVM_X86_OP_OPTIONAL_RET0(gmem_prepare)
KVM_X86_OP_OPTIONAL_RET0(gmem_max_mapping_level)
-KVM_X86_OP_OPTIONAL(gmem_invalidate)
+#ifdef CONFIG_HAVE_KVM_ARCH_GMEM_INVALIDATE
+KVM_X86_OP_OPTIONAL(gmem_free_folio)
+#endif
#endif
#undef KVM_X86_OP
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index b517257a6315..dd542c7a7376 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1901,7 +1901,9 @@ struct kvm_x86_ops {
gva_t (*get_untagged_addr)(struct kvm_vcpu *vcpu, gva_t gva, unsigned int flags);
void *(*alloc_apic_backing_page)(struct kvm_vcpu *vcpu);
int (*gmem_prepare)(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, int max_order);
- void (*gmem_invalidate)(kvm_pfn_t start, kvm_pfn_t end);
+#ifdef CONFIG_HAVE_KVM_ARCH_GMEM_INVALIDATE
+ void (*gmem_free_folio)(struct folio *folio);
+#endif
int (*gmem_max_mapping_level)(struct kvm *kvm, kvm_pfn_t pfn, bool is_private);
};
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 30792adcfc8e..3d90aa723dc2 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -5136,8 +5136,10 @@ int sev_gmem_prepare(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, int max_order)
return 0;
}
-void sev_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end)
+void sev_gmem_free_folio(struct folio *folio)
{
+ kvm_pfn_t start = page_to_pfn(folio_page(folio, 0));
+ kvm_pfn_t end = start + (1ul << folio_order(folio));
kvm_pfn_t pfn;
if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP))
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index ef69a51ab27f..6f1823e820a4 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -5460,9 +5460,11 @@ struct kvm_x86_ops svm_x86_ops __initdata = {
.vcpu_get_apicv_inhibit_reasons = avic_vcpu_get_apicv_inhibit_reasons,
.alloc_apic_backing_page = svm_alloc_apic_backing_page,
+#ifdef CONFIG_KVM_AMD_SEV
.gmem_prepare = sev_gmem_prepare,
- .gmem_invalidate = sev_gmem_invalidate,
+ .gmem_free_folio = sev_gmem_free_folio,
.gmem_max_mapping_level = sev_gmem_max_mapping_level,
+#endif
};
/*
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index d077783c287e..2f8215810a08 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -1009,7 +1009,7 @@ int sev_dev_get_attr(u32 group, u64 attr, u64 *val);
extern unsigned int max_sev_asid;
void sev_handle_rmp_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code);
int sev_gmem_prepare(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, int max_order);
-void sev_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end);
+void sev_gmem_free_folio(struct folio *folio);
int sev_gmem_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn, bool is_private);
struct vmcb_save_area *sev_decrypt_vmsa(struct kvm_vcpu *vcpu);
void sev_free_decrypted_vmsa(struct kvm_vcpu *vcpu, struct vmcb_save_area *vmsa);
@@ -1039,7 +1039,6 @@ static inline int sev_gmem_prepare(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, in
{
return 0;
}
-static inline void sev_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end) {}
static inline int sev_gmem_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn, bool is_private)
{
return 0;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0626e835e9eb..adc1e1b244c7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10592,9 +10592,9 @@ int kvm_arch_gmem_prepare(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, int max_ord
#endif
#ifdef CONFIG_HAVE_KVM_ARCH_GMEM_INVALIDATE
-void kvm_arch_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end)
+void kvm_arch_gmem_free_folio(struct folio *folio)
{
- kvm_x86_call(gmem_invalidate)(start, end);
+ kvm_x86_call(gmem_free_folio)(folio);
}
#endif
#endif
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ab8cfaec82d3..e5b47a5e4cea 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -2607,7 +2607,7 @@ long kvm_gmem_populate(struct kvm *kvm, gfn_t start_gfn, void __user *src,
#endif
#ifdef CONFIG_HAVE_KVM_ARCH_GMEM_INVALIDATE
-void kvm_arch_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end);
+void kvm_arch_gmem_free_folio(struct folio *folio);
#endif
#ifdef CONFIG_KVM_GENERIC_PRE_FAULT_MEMORY
diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
index 86690683b2fe..1618acc3ca64 100644
--- a/virt/kvm/guest_memfd.c
+++ b/virt/kvm/guest_memfd.c
@@ -523,23 +523,12 @@ static int kvm_gmem_error_folio(struct address_space *mapping, struct folio *fol
return MF_DELAYED;
}
-#ifdef CONFIG_HAVE_KVM_ARCH_GMEM_INVALIDATE
-static void kvm_gmem_free_folio(struct folio *folio)
-{
- struct page *page = folio_page(folio, 0);
- kvm_pfn_t pfn = page_to_pfn(page);
- int order = folio_order(folio);
-
- kvm_arch_gmem_invalidate(pfn, pfn + (1ul << order));
-}
-#endif
-
static const struct address_space_operations kvm_gmem_aops = {
.dirty_folio = noop_dirty_folio,
.migrate_folio = kvm_gmem_migrate_folio,
.error_remove_folio = kvm_gmem_error_folio,
#ifdef CONFIG_HAVE_KVM_ARCH_GMEM_INVALIDATE
- .free_folio = kvm_gmem_free_folio,
+ .free_folio = kvm_arch_gmem_free_folio,
#endif
};
--
2.55.0.rc0.799.gd6f94ed593-goog
next prev parent reply other threads:[~2026-06-26 23:14 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-26 23:14 [PATCH v2 0/9] KVM: SEV: Fix RMP #PF due freeing in-use VMSA Sean Christopherson
2026-06-26 23:14 ` [PATCH v2 1/9] KVM: SEV: Track the GPA of the guest-controlled VMSA used for SNP guests Sean Christopherson
2026-06-26 23:14 ` [PATCH v2 2/9] KVM: SEV: Extract loading of guest-provided VMSA to a separate helper Sean Christopherson
2026-06-26 23:14 ` [PATCH v2 3/9] KVM: SEV: Mark vCPU RUNNABLE after AP_CREATE, even if VMSA is unusable Sean Christopherson
2026-06-26 23:14 ` Sean Christopherson [this message]
2026-06-29 21:50 ` [PATCH v2 4/9] KVM: Rework .gmem_invalidate() into .gmem_free_folio() Ackerley Tng
2026-06-29 22:02 ` Sean Christopherson
2026-06-30 0:09 ` Ackerley Tng
2026-06-30 0:18 ` Sean Christopherson
2026-06-26 23:14 ` [PATCH v2 5/9] KVM: x86/mmu: Fold kvm_mmu_zap_memslot() into kvm_arch_flush_shadow_memslot() Sean Christopherson
2026-06-26 23:14 ` [PATCH v2 6/9] KVM: x86/mmu: Split kvm_mmu_zap_all_fast() into "front" and "back" halves Sean Christopherson
2026-06-26 23:14 ` [PATCH v2 7/9] KVM: SEV: Forcefully invalidate SNP VMSA if its backing gmem page is zapped Sean Christopherson
2026-06-29 21:59 ` Ackerley Tng
2026-06-29 23:49 ` Sean Christopherson
2026-06-26 23:14 ` [PATCH v2 8/9] KVM: x86: Guard .gmem_prepare() declarations with HAVE_KVM_GMEM_PREPARE=y Sean Christopherson
2026-06-26 23:14 ` [PATCH v2 9/9] KVM: SEV: Mark vCPU has having guest-provided VMSA even if its invalid Sean Christopherson
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