diff options
| author | Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> | 2019-11-14 14:15:14 -0600 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-02-05 15:17:43 +0100 |
| commit | 9a0bf05430699dc94b7ced940f6270c7cf1d77ef (patch) | |
| tree | 5c88a9e9a81cbf399dcc2eb6a9458aeadc5f9ce2 /arch | |
| parent | f4fdc0a2edf48f16f7b10cceaf4781fc56ab7fd9 (diff) | |
svm: Deactivate AVIC when launching guest with nested SVM support
Since AVIC does not currently work w/ nested virtualization,
deactivate AVIC for the guest if setting CPUID Fn80000001_ECX[SVM]
(i.e. indicate support for SVM, which is needed for nested virtualization).
Also, introduce a new APICV_INHIBIT_REASON_NESTED bit to be used for
this reason.
Suggested-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/svm.c | 11 |
2 files changed, 11 insertions, 1 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 90bfe8becc56..ce19dea5f2dd 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -877,6 +877,7 @@ enum kvm_irqchip_mode { #define APICV_INHIBIT_REASON_DISABLE 0 #define APICV_INHIBIT_REASON_HYPERV 1 +#define APICV_INHIBIT_REASON_NESTED 2 struct kvm_arch { unsigned long n_used_mmu_pages; diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 3b87ccd320d1..af90f83d7123 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -5988,6 +5988,14 @@ static void svm_cpuid_update(struct kvm_vcpu *vcpu) return; guest_cpuid_clear(vcpu, X86_FEATURE_X2APIC); + + /* + * Currently, AVIC does not work with nested virtualization. + * So, we disable AVIC when cpuid for SVM is set in the L1 guest. + */ + if (nested && guest_cpuid_has(vcpu, X86_FEATURE_SVM)) + kvm_request_apicv_update(vcpu->kvm, false, + APICV_INHIBIT_REASON_NESTED); } #define F feature_bit @@ -7319,7 +7327,8 @@ static bool svm_apic_init_signal_blocked(struct kvm_vcpu *vcpu) static bool svm_check_apicv_inhibit_reasons(ulong bit) { ulong supported = BIT(APICV_INHIBIT_REASON_DISABLE) | - BIT(APICV_INHIBIT_REASON_HYPERV); + BIT(APICV_INHIBIT_REASON_HYPERV) | + BIT(APICV_INHIBIT_REASON_NESTED); return supported & BIT(bit); } |