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| author | Paolo Bonzini <pbonzini@redhat.com> | 2021-11-30 15:37:45 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-12-02 12:12:11 +0300 |
| commit | ef8b4b7203682cc9adb37c8336d3f0f3b80bc382 (patch) | |
| tree | c669580c30f5a082940b346cb4ed1260c640fc86 /arch/x86/kvm/svm | |
| parent | cb1d220da0faa5ca0deb93449aff953f0c2cce6d (diff) | |
| download | linux-ef8b4b7203682cc9adb37c8336d3f0f3b80bc382.tar.xz | |
KVM: ensure APICv is considered inactive if there is no APIC
kvm_vcpu_apicv_active() returns false if a virtual machine has no in-kernel
local APIC, however kvm_apicv_activated might still be true if there are
no reasons to disable APICv; in fact it is quite likely that there is none
because APICv is inhibited by specific configurations of the local APIC
and those configurations cannot be programmed. This triggers a WARN:
WARN_ON_ONCE(kvm_apicv_activated(vcpu->kvm) != kvm_vcpu_apicv_active(vcpu));
To avoid this, introduce another cause for APICv inhibition, namely the
absence of an in-kernel local APIC. This cause is enabled by default,
and is dropped by either KVM_CREATE_IRQCHIP or the enabling of
KVM_CAP_IRQCHIP_SPLIT.
Reported-by: Ignat Korchagin <ignat@cloudflare.com>
Fixes: ee49a8932971 ("KVM: x86: Move SVM's APICv sanity check to common x86", 2021-10-22)
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Tested-by: Ignat Korchagin <ignat@cloudflare.com>
Message-Id: <20211130123746.293379-1-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/svm')
| -rw-r--r-- | arch/x86/kvm/svm/avic.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index 9d6066eb7c10..8f9af7b7dbbe 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -900,6 +900,7 @@ out: bool svm_check_apicv_inhibit_reasons(ulong bit) { ulong supported = BIT(APICV_INHIBIT_REASON_DISABLE) | + BIT(APICV_INHIBIT_REASON_ABSENT) | BIT(APICV_INHIBIT_REASON_HYPERV) | BIT(APICV_INHIBIT_REASON_NESTED) | BIT(APICV_INHIBIT_REASON_IRQWIN) | |