KVM: VMX: Use kvm_read_cr4() to get cr4 value

calmisi · sean-jc · commit 334006b78ca8 · 2023-05-26T13:41:43.000-07:00
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@intel.com> Link: https://lore.kernel.org/r/20230410125017.1305238-2-xiaoyao.li@intel.com Signed-off-by: Sean Christopherson <seanjc@google.com>
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
@@ -3387,7 +3387,7 @@ 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

Original file line number	Diff line number	Diff line change
`@@ -3387,7 +3387,7 @@ static bool vmx_is_valid_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)`
`3387`	`3387`
`3388`	`3388`	`void vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)`
`3389`	`3389`	`{`
`3390`		`- unsigned long old_cr4 = vcpu->arch.cr4;`
	`3390`	`+ unsigned long old_cr4 = kvm_read_cr4(vcpu);`
`3391`	`3391`	`struct vcpu_vmx *vmx = to_vmx(vcpu);`
`3392`	`3392`	`/*`
`3393`	`3393`	`* Pass through host's Machine Check Enable value to hw_cr4, which`