diff options
| author |   Sean Christopherson <seanjc@google.com> | 2022-06-14 21:58:30 +0000 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2022-06-20 06:21:20 -0400 |
| commit | 308a4fffeb361af90f17837c1bcace3139d1f677 (patch) | |
| tree | 376f26be8d3040cf36a25c3762595c072de715b7 /arch/x86/kvm/vmx/nested.c | |
| parent | KVM: nVMX: Rename nested.vmcs01_* fields to nested.pre_vmenter_* (diff) | |
| download | linux-dev-308a4fffeb361af90f17837c1bcace3139d1f677.tar.xz linux-dev-308a4fffeb361af90f17837c1bcace3139d1f677.zip | |
KVM: nVMX: Save BNDCFGS to vmcs12 iff relevant controls are exposed to L1
Save BNDCFGS to vmcs12 (from vmcs02) if and only if at least of one of
the load-on-entry or clear-on-exit fields for BNDCFGS is enumerated as an
allowed-1 bit in vmcs12. Skipping the field avoids an unnecessary VMREAD
when MPX is supported but not exposed to L1.
Per Intel's SDM:
If the processor supports either the 1-setting of the "load IA32_BNDCFGS"
VM-entry control or that of the "clear IA32_BNDCFGS" VM-exit control, the
contents of the IA32_BNDCFGS MSR are saved into the corresponding field.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220614215831.3762138-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx/nested.c')
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 38015f4ecc54..496981b86f94 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -4104,7 +4104,8 @@ static void sync_vmcs02_to_vmcs12_rare(struct kvm_vcpu *vcpu, vmcs12->guest_idtr_base = vmcs_readl(GUEST_IDTR_BASE); vmcs12->guest_pending_dbg_exceptions = vmcs_readl(GUEST_PENDING_DBG_EXCEPTIONS); - if (kvm_mpx_supported()) + if ((vmx->nested.msrs.entry_ctls_high & VM_ENTRY_LOAD_BNDCFGS) || + (vmx->nested.msrs.exit_ctls_high & VM_EXIT_CLEAR_BNDCFGS)) vmcs12->guest_bndcfgs = vmcs_read64(GUEST_BNDCFGS); vmx->nested.need_sync_vmcs02_to_vmcs12_rare = false; |