From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Introduce a "is_mirror" member to the kvm_mmu_page_role union to identify
SPTEs associated with the mirrored EPT.
The TDX module maintains the private half of the EPT mapped in the TD in
its protected memory. KVM keeps a copy of the private GPAs in a mirrored
EPT tree within host memory. This "is_mirror" attribute enables vCPUs to
find and get the root page of mirrored EPT from the MMU root list for a
guest TD. This also allows KVM MMU code to detect changes in mirrored EPT
according to the "is_mirror" mmu page role and propagate the changes to
the private EPT managed by TDX module.
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
Message-ID: <20240718211230.1492011-6-rick.p.edgecombe@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 3 ++-
arch/x86/kvm/mmu/mmu_internal.h | 5 +++++
arch/x86/kvm/mmu/spte.h | 5 +++++
3 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 5f020b097922..cae88f023caf 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -349,7 +349,8 @@ union kvm_mmu_page_role {
unsigned ad_disabled:1;
unsigned guest_mode:1;
unsigned passthrough:1;
- unsigned :5;
+ unsigned is_mirror:1;
+ unsigned :4;
/*
* This is left at the top of the word so that
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index d9425064ecc5..ff00341f26a2 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -157,6 +157,11 @@ static inline int kvm_mmu_page_as_id(struct kvm_mmu_page *sp)
return kvm_mmu_role_as_id(sp->role);
}
+static inline bool is_mirror_sp(const struct kvm_mmu_page *sp)
+{
+ return sp->role.is_mirror;
+}
+
static inline void kvm_mmu_alloc_external_spt(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
{
/*
diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h
index f332b33bc817..49070122f60b 100644
--- a/arch/x86/kvm/mmu/spte.h
+++ b/arch/x86/kvm/mmu/spte.h
@@ -276,6 +276,11 @@ static inline struct kvm_mmu_page *root_to_sp(hpa_t root)
return spte_to_child_sp(root);
}
+static inline bool is_mirror_sptep(u64 *sptep)
+{
+ return is_mirror_sp(sptep_to_sp(sptep));
+}
+
static inline bool is_mmio_spte(struct kvm *kvm, u64 spte)
{
return (spte & shadow_mmio_mask) == kvm->arch.shadow_mmio_value &&
--
2.43.5
