| Message ID | 20220714091327.1085353-7-vkuznets@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: VMX: Support updated eVMCSv1 revision + use vmcs_config for L1 VMX MSRs | expand |
On Thu, 2022-07-14 at 11:13 +0200, Vitaly Kuznetsov wrote: > KVM has to check guest visible HYPERV_CPUID_NESTED_FEATURES.EBX CPUID > leaf to know which Enlightened VMCS definition to use (original or 2022 > update). Cache the leaf along with other Hyper-V CPUID feature leaves > to make the check quick. > > While on it, wipe the whole 'hv_vcpu->cpuid_cache' with memset() instead > of having to zero each particular member when the corresponding CPUID entry > was not found. > > Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> > --- > arch/x86/include/asm/kvm_host.h | 2 ++ > arch/x86/kvm/hyperv.c | 17 ++++++++--------- > 2 files changed, 10 insertions(+), 9 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index de5a149d0971..077ec9cf3169 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -616,6 +616,8 @@ struct kvm_vcpu_hv { > u32 enlightenments_eax; /* HYPERV_CPUID_ENLIGHTMENT_INFO.EAX */ > u32 enlightenments_ebx; /* HYPERV_CPUID_ENLIGHTMENT_INFO.EBX */ > u32 syndbg_cap_eax; /* HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES.EAX */ > + u32 nested_eax; /* HYPERV_CPUID_NESTED_FEATURES.EAX */ > + u32 nested_ebx; /* HYPERV_CPUID_NESTED_FEATURES.EBX */ > } cpuid_cache; > }; > > diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c > index e08189211d9a..a8e4944ca110 100644 > --- a/arch/x86/kvm/hyperv.c > +++ b/arch/x86/kvm/hyperv.c > @@ -2005,31 +2005,30 @@ void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu) > > hv_vcpu = to_hv_vcpu(vcpu); > > + memset(&hv_vcpu->cpuid_cache, 0, sizeof(hv_vcpu->cpuid_cache)); > + > entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_FEATURES, 0); > if (entry) { > hv_vcpu->cpuid_cache.features_eax = entry->eax; > hv_vcpu->cpuid_cache.features_ebx = entry->ebx; > hv_vcpu->cpuid_cache.features_edx = entry->edx; > - } else { > - hv_vcpu->cpuid_cache.features_eax = 0; > - hv_vcpu->cpuid_cache.features_ebx = 0; > - hv_vcpu->cpuid_cache.features_edx = 0; > } > > entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_ENLIGHTMENT_INFO, 0); > if (entry) { > hv_vcpu->cpuid_cache.enlightenments_eax = entry->eax; > hv_vcpu->cpuid_cache.enlightenments_ebx = entry->ebx; > - } else { > - hv_vcpu->cpuid_cache.enlightenments_eax = 0; > - hv_vcpu->cpuid_cache.enlightenments_ebx = 0; > } > > entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES, 0); > if (entry) > hv_vcpu->cpuid_cache.syndbg_cap_eax = entry->eax; > - else > - hv_vcpu->cpuid_cache.syndbg_cap_eax = 0; > + > + entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_NESTED_FEATURES, 0); > + if (entry) { > + hv_vcpu->cpuid_cache.nested_eax = entry->eax; > + hv_vcpu->cpuid_cache.nested_ebx = entry->ebx; > + } > } > > int kvm_hv_set_enforce_cpuid(struct kvm_vcpu *vcpu, bool enforce) Makes sense, looks good. Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Best regards, Maxim Levitsky
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index de5a149d0971..077ec9cf3169 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -616,6 +616,8 @@ struct kvm_vcpu_hv { u32 enlightenments_eax; /* HYPERV_CPUID_ENLIGHTMENT_INFO.EAX */ u32 enlightenments_ebx; /* HYPERV_CPUID_ENLIGHTMENT_INFO.EBX */ u32 syndbg_cap_eax; /* HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES.EAX */ + u32 nested_eax; /* HYPERV_CPUID_NESTED_FEATURES.EAX */ + u32 nested_ebx; /* HYPERV_CPUID_NESTED_FEATURES.EBX */ } cpuid_cache; }; diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index e08189211d9a..a8e4944ca110 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -2005,31 +2005,30 @@ void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu) hv_vcpu = to_hv_vcpu(vcpu); + memset(&hv_vcpu->cpuid_cache, 0, sizeof(hv_vcpu->cpuid_cache)); + entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_FEATURES, 0); if (entry) { hv_vcpu->cpuid_cache.features_eax = entry->eax; hv_vcpu->cpuid_cache.features_ebx = entry->ebx; hv_vcpu->cpuid_cache.features_edx = entry->edx; - } else { - hv_vcpu->cpuid_cache.features_eax = 0; - hv_vcpu->cpuid_cache.features_ebx = 0; - hv_vcpu->cpuid_cache.features_edx = 0; } entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_ENLIGHTMENT_INFO, 0); if (entry) { hv_vcpu->cpuid_cache.enlightenments_eax = entry->eax; hv_vcpu->cpuid_cache.enlightenments_ebx = entry->ebx; - } else { - hv_vcpu->cpuid_cache.enlightenments_eax = 0; - hv_vcpu->cpuid_cache.enlightenments_ebx = 0; } entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES, 0); if (entry) hv_vcpu->cpuid_cache.syndbg_cap_eax = entry->eax; - else - hv_vcpu->cpuid_cache.syndbg_cap_eax = 0; + + entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_NESTED_FEATURES, 0); + if (entry) { + hv_vcpu->cpuid_cache.nested_eax = entry->eax; + hv_vcpu->cpuid_cache.nested_ebx = entry->ebx; + } } int kvm_hv_set_enforce_cpuid(struct kvm_vcpu *vcpu, bool enforce)
KVM has to check guest visible HYPERV_CPUID_NESTED_FEATURES.EBX CPUID leaf to know which Enlightened VMCS definition to use (original or 2022 update). Cache the leaf along with other Hyper-V CPUID feature leaves to make the check quick. While on it, wipe the whole 'hv_vcpu->cpuid_cache' with memset() instead of having to zero each particular member when the corresponding CPUID entry was not found. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> --- arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/hyperv.c | 17 ++++++++--------- 2 files changed, 10 insertions(+), 9 deletions(-)