[PATCH 11/15] KVM: VMX: Update vmcs.GUEST_CR3 only when the guest CR3 is dirty

From: Lai Jiangshan
Date: Mon Nov 08 2021 - 07:45:41 EST


From: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>

When vcpu->arch.cr3 is changed, it is marked dirty, so vmcs.GUEST_CR3
can be updated only when kvm_register_is_dirty(vcpu, VCPU_EXREG_CR3).

Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d94e51e9c08f..38b65b97fb7b 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3126,9 +3126,9 @@ static void vmx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa,

if (!enable_unrestricted_guest && !is_paging(vcpu))
guest_cr3 = to_kvm_vmx(kvm)->ept_identity_map_addr;
- else if (test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail))
+ else if (kvm_register_is_dirty(vcpu, VCPU_EXREG_CR3))
guest_cr3 = vcpu->arch.cr3;
- else /* vmcs01.GUEST_CR3 is already up-to-date. */
+ else /* vmcs.GUEST_CR3 is already up-to-date. */
update_guest_cr3 = false;
vmx_ept_load_pdptrs(vcpu);
} else {
--
2.19.1.6.gb485710b