summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorSean Christopherson <seanjc@google.com>2023-03-22 04:14:36 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2023-04-06 20:37:36 +0300
commit9a4c4850137e929d49958fb62d4275bd2f5b8c7a (patch)
treed28123ae21a73c8e91e1ad2c15d772ed45c0d331
parent52887af5650e35ea78b37602722313ff7b3c0c30 (diff)
downloadlinux-9a4c4850137e929d49958fb62d4275bd2f5b8c7a.tar.xz
KVM: VMX: Passthrough MSR_IA32_PRED_CMD based purely on host+guest CPUID
Passthrough MSR_IA32_PRED_CMD based purely on whether or not the MSR is supported and enabled, i.e. don't wait until the first write. There's no benefit to deferred passthrough, and the extra logic only adds complexity. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Message-Id: <20230322011440.2195485-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/kvm/vmx/vmx.c16
1 files changed, 3 insertions, 13 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index f777509ecf17..5c01c76c0d45 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2298,19 +2298,6 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
break;
wrmsrl(MSR_IA32_PRED_CMD, PRED_CMD_IBPB);
-
- /*
- * For non-nested:
- * When it's written (to non-zero) for the first time, pass
- * it through.
- *
- * For nested:
- * The handling of the MSR bitmap for L2 guests is done in
- * nested_vmx_prepare_msr_bitmap. We should not touch the
- * vmcs02.msr_bitmap here since it gets completely overwritten
- * in the merging.
- */
- vmx_disable_intercept_for_msr(vcpu, MSR_IA32_PRED_CMD, MSR_TYPE_W);
break;
case MSR_IA32_CR_PAT:
if (!kvm_pat_valid(data))
@@ -7743,6 +7730,9 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
vmx_set_intercept_for_msr(vcpu, MSR_IA32_XFD_ERR, MSR_TYPE_R,
!guest_cpuid_has(vcpu, X86_FEATURE_XFD));
+ if (boot_cpu_has(X86_FEATURE_IBPB))
+ vmx_set_intercept_for_msr(vcpu, MSR_IA32_PRED_CMD, MSR_TYPE_W,
+ !guest_has_pred_cmd_msr(vcpu));
set_cr4_guest_host_mask(vmx);