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

From: Lai Jiangshan <jiangshanlai@gmail.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	Paolo Bonzini <pbonzini@redhat.com>
Cc: Lai Jiangshan <laijs@linux.alibaba.com>,
	Sean Christopherson <seanjc@google.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>
Subject: [PATCH 11/15] KVM: VMX: Update vmcs.GUEST_CR3 only when the guest CR3 is dirty
Date: Mon,  8 Nov 2021 20:44:03 +0800	[thread overview]
Message-ID: <20211108124407.12187-12-jiangshanlai@gmail.com> (raw)
In-Reply-To: <20211108124407.12187-1-jiangshanlai@gmail.com>

From: Lai Jiangshan <laijs@linux.alibaba.com>

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@linux.alibaba.com>
---
 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

