diff options
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 62593b740c82..203d42340fc1 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1020,11 +1020,35 @@ static u32 msr_based_features[] = { static unsigned int num_msr_based_features; +u64 kvm_get_arch_capabilities(void) +{ + u64 data; + + rdmsrl_safe(MSR_IA32_ARCH_CAPABILITIES, &data); + + /* + * If we're doing cache flushes (either "always" or "cond") + * we will do one whenever the guest does a vmlaunch/vmresume. + * If an outer hypervisor is doing the cache flush for us + * (VMENTER_L1D_FLUSH_NESTED_VM), we can safely pass that + * capability to the guest too, and if EPT is disabled we're not + * vulnerable. Overall, only VMENTER_L1D_FLUSH_NEVER will + * require a nested hypervisor to do a flush of its own. + */ + if (l1tf_vmx_mitigation != VMENTER_L1D_FLUSH_NEVER) + data |= ARCH_CAP_SKIP_VMENTRY_L1DFLUSH; + + return data; +} +EXPORT_SYMBOL_GPL(kvm_get_arch_capabilities); + static int kvm_get_msr_feature(struct kvm_msr_entry *msr) { switch (msr->index) { - case MSR_IA32_UCODE_REV: case MSR_IA32_ARCH_CAPABILITIES: + msr->data = kvm_get_arch_capabilities(); + break; + case MSR_IA32_UCODE_REV: rdmsrl_safe(msr->index, &msr->data); break; default: |