[PATCH 1/5] KVM: VMX: Open code writing vCPU's PAT in VMX's MSR handler

From: Sean Christopherson
Date: Wed May 03 2023 - 14:29:07 EST


From: Wenyao Hai <haiwenyao@xxxxxxxxxxxxx>

Open code setting "vcpu->arch.pat" in vmx_set_msr() instead of bouncing
through kvm_set_msr_common() to get to the same code in kvm_mtrr_set_msr().

Note, MSR_IA32_CR_PAT is 0x277, and is very subtly handled by

case 0x200 ... MSR_IA32_MC0_CTL2 - 1:

in kvm_set_msr_common().

Signed-off-by: Wenyao Hai <haiwenyao@xxxxxxxxxxxxx>
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 44fb619803b8..53e249109483 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2294,12 +2294,10 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
get_vmcs12(vcpu)->vm_exit_controls & VM_EXIT_SAVE_IA32_PAT)
get_vmcs12(vcpu)->guest_ia32_pat = data;

- if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
+ if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT)
vmcs_write64(GUEST_IA32_PAT, data);
- vcpu->arch.pat = data;
- break;
- }
- ret = kvm_set_msr_common(vcpu, msr_info);
+
+ vcpu->arch.pat = data;
break;
case MSR_IA32_MCG_EXT_CTL:
if ((!msr_info->host_initiated &&
--
2.40.1.495.gc816e09b53d-goog