Ignore the guest's CR3 when looking for a cached root for a direct MMU,
the guest's CR3 has no impact on the direct MMU's shadow pages (the
role check ensures compatibility with CR0.WP, etc...).
Zero out root_cr3 when allocating the direct roots to make it clear that
it's ignored.
Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
arch/x86/kvm/mmu/mmu.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index c4e0b97f82ac..9d617b9dc78f 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3730,7 +3730,9 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
vcpu->arch.mmu->root_hpa = __pa(vcpu->arch.mmu->pae_root);
} else
BUG();
- vcpu->arch.mmu->root_cr3 = vcpu->arch.mmu->get_cr3(vcpu);
+
+ /* root_cr3 is ignored for direct MMUs. */
+ vcpu->arch.mmu->root_cr3 = 0;
return 0;
}
@@ -4272,8 +4274,8 @@ static bool cached_root_available(struct kvm_vcpu *vcpu, gpa_t new_cr3,
for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) {
swap(root, mmu->prev_roots[i]);
- if (new_cr3 == root.cr3 && VALID_PAGE(root.hpa) &&
- page_header(root.hpa) != NULL &&
+ if ((new_role.direct || new_cr3 == root.cr3) &&
+ VALID_PAGE(root.hpa) && page_header(root.hpa) &&
new_role.word == page_header(root.hpa)->role.word)
break;
}
--
2.24.1
