[PATCH 12/18] KVM: MMU: Implement nested gva_to_gpa functions

[Joerg Roedel <joerg.roedel@amd.com>]

This patch adds the functions to do a nested l2_gva to
l1_gpa page table walk.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
 arch/x86/include/asm/kvm_host.h |    3 +++
 arch/x86/kvm/mmu.c              |    8 ++++++++
 arch/x86/kvm/paging_tmpl.h      |   31 +++++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+), 0 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 76c8b5f..20dd1ce 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -295,6 +295,9 @@ struct kvm_vcpu_arch {
 	bool tpr_access_reporting;
 
 	struct kvm_mmu mmu;
+
+	struct kvm_mmu nested_mmu;
+
 	/* only needed in kvm_pv_mmu_op() path, but it's hot so
 	 * put it here to avoid allocation */
 	struct kvm_pv_mmu_op_buffer mmu_op_buffer;
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index ec3830c..c831955 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2162,6 +2162,14 @@ static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr,
 	return vaddr;
 }
 
+static gpa_t nonpaging_gva_to_gpa_nested(struct kvm_vcpu *vcpu, gva_t vaddr,
+					 u32 access, u32 *error)
+{
+	if (error)
+		*error = 0;
+	return vcpu->arch.nested_mmu.translate_gpa(vcpu, vaddr, error);
+}
+
 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
 				u32 error_code)
 {
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index a72d5ea..c0158d8 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -282,6 +282,16 @@ static int FNAME(walk_addr)(struct guest_walker *walker,
 				        write_fault, user_fault, fetch_fault);
 }
 
+static int FNAME(walk_addr_nested)(struct guest_walker *walker,
+				   struct kvm_vcpu *vcpu, gva_t addr,
+				   int write_fault, int user_fault,
+				   int fetch_fault)
+{
+	return FNAME(walk_addr_generic)(walker, vcpu, &vcpu->arch.nested_mmu,
+					addr, write_fault, user_fault,
+					fetch_fault);
+}
+
 static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
 			      u64 *spte, const void *pte)
 {
@@ -541,6 +551,27 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr, u32 access,
 	return gpa;
 }
 
+static gpa_t FNAME(gva_to_gpa_nested)(struct kvm_vcpu *vcpu, gva_t vaddr,
+				      u32 access, u32 *error)
+{
+	struct guest_walker walker;
+	gpa_t gpa = UNMAPPED_GVA;
+	int r;
+
+	r = FNAME(walk_addr_nested)(&walker, vcpu, vaddr,
+				    !!(access & PFERR_WRITE_MASK),
+				    !!(access & PFERR_USER_MASK),
+				    !!(access & PFERR_FETCH_MASK));
+
+	if (r) {
+		gpa = gfn_to_gpa(walker.gfn);
+		gpa |= vaddr & ~PAGE_MASK;
+	} else if (error)
+		*error = walker.error_code;
+
+	return gpa;
+}
+
 static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu,
 				 struct kvm_mmu_page *sp)
 {
-- 
1.7.0