diff options
| author | Wenyao Hai <[email protected]> | 2023-05-11 16:33:44 -0700 |
|---|---|---|
| committer | Sean Christopherson <[email protected]> | 2023-06-01 13:41:05 -0700 |
| commit | a33ba1bf0dc6082227d1ddf964632e07b53b8971 (patch) | |
| tree | 155076c8a16f7b0e1d4d1ce05fc867e10cc9f8b4 | |
| parent | b9846a698c9aff4eb2214a06ac83638ad098f33f (diff) | |
KVM: VMX: Open code writing vCPU's PAT in VMX's MSR handler
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 <[email protected]>
Signed-off-by: Wenyao Hai <[email protected]>
[sean: massage changelog, hoist setting vcpu->arch.pat up]
Reviewed-by: Kai Huang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 8 |
1 files 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 && |