linux-kernel - [PATCH 1/2] KVM: VMX: Use kvm_read

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Date:   Mon, 10 Apr 2023 08:50:16 -0400
From:   Xiaoyao Li <xiaoyao.li@...el.com>
To:     Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        xiaoyao.li@...el.com
Subject: [PATCH 1/2] KVM: VMX: Use kvm_read_cr4() to get cr4 value

Directly use vcpu->arch.cr4 is not recommended since it gets stale value
if the cr4 is not available.

Use kvm_read_cr4() instead to ensure correct value.

Signed-off-by: Xiaoyao Li <xiaoyao.li@...el.com>
---
 arch/x86/kvm/vmx/vmx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d7bf14abdba1..befa2486836b 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3431,7 +3431,7 @@ static bool vmx_is_valid_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
 
 void vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
 {
-	unsigned long old_cr4 = vcpu->arch.cr4;
+	unsigned long old_cr4 = kvm_read_cr4(vcpu);
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	/*
 	 * Pass through host's Machine Check Enable value to hw_cr4, which
-- 
2.34.1