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().
This aligns VMX with SVM, avoids hiding a very simple operation behind a
relatively complicated function call (finding the PAT MSR case in
kvm_set_msr_common() is non-trivial), and most importantly, makes it clear
that not unwinding the VMCS updates if kvm_set_msr_common() isn't a bug
(because kvm_set_msr_common() can never fail for PAT).
Opportunistically set vcpu->arch.pat before updating the VMCS info so that
a future patch can move the common bits (back) into kvm_set_msr_common()
without a functional change.
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().
Cc: Kai Huang <kai.huang@xxxxxxxxx>
Signed-off-by: Wenyao Hai <haiwenyao@xxxxxxxxxxxxx>
[sean: massage changelog, hoist setting vcpu->arch.pat up]
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..33b8625d3541 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2290,16 +2290,14 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
if (!kvm_pat_valid(data))
return 1;
+ vcpu->arch.pat = data;
+
if (is_guest_mode(vcpu) &&
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);
break;
case MSR_IA32_MCG_EXT_CTL:
if ((!msr_info->host_initiated &&
--
2.40.1.606.ga4b1b128d6-goog
