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| author |  Vitaly Kuznetsov <vkuznets@redhat.com>
| 2021-05-21 11:51:37 +0200 |
|---|---|---|
| committer |  Paolo Bonzini <pbonzini@redhat.com>
| 2021-06-17 13:09:38 -0400 |
| commit | 10d7bf1e46dc19d964f0f67d2a6d20df907742d1 (patch) | |
| tree | 206e1f232352ee6aff49bdb5e72c4a4e52342cb5 /arch/x86/kvm | |
| parent | KVM: x86: hyper-v: Introduce KVM_CAP_HYPERV_ENFORCE_CPUID (diff) | |
| download | linux-10d7bf1e46dc.tar.gz linux-10d7bf1e46dc.tar.bz2 linux-10d7bf1e46dc.zip | |
KVM: x86: hyper-v: Cache guest CPUID leaves determining features availability
Limiting exposed Hyper-V features requires a fast way to check if the
particular feature is exposed in guest visible CPUIDs or not. To aboid
looping through all CPUID entries on every hypercall/MSR access cache
the required leaves on CPUID update.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-4-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/hyperv.c | 49 |
1 files changed, 39 insertions, 10 deletions
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 02b0ee189f82..7e7928fc77ef 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -274,15 +274,10 @@ static int synic_set_msr(struct kvm_vcpu_hv_synic *synic, static bool kvm_hv_is_syndbg_enabled(struct kvm_vcpu *vcpu) { - struct kvm_cpuid_entry2 *entry; - - entry = kvm_find_cpuid_entry(vcpu, - HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES, - 0); - if (!entry) - return false; + struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu); - return entry->eax & HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING; + return hv_vcpu->cpuid_cache.syndbg_cap_eax & + HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING; } static int kvm_hv_syndbg_complete_userspace(struct kvm_vcpu *vcpu) @@ -1845,12 +1840,46 @@ ret_success: void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu) { struct kvm_cpuid_entry2 *entry; + struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu); entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_INTERFACE, 0); - if (entry && entry->eax == HYPERV_CPUID_SIGNATURE_EAX) + if (entry && entry->eax == HYPERV_CPUID_SIGNATURE_EAX) { vcpu->arch.hyperv_enabled = true; - else + } else { vcpu->arch.hyperv_enabled = false; + return; + } + + if (!to_hv_vcpu(vcpu) && kvm_hv_vcpu_init(vcpu)) + return; + + hv_vcpu = to_hv_vcpu(vcpu); + + 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; } int kvm_hv_set_enforce_cpuid(struct kvm_vcpu *vcpu, bool enforce) |