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| author |   Paolo Bonzini <pbonzini@redhat.com> | 2021-11-22 19:43:10 -0500 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-11-30 03:52:39 -0500 |
| commit | 37c4dbf337c5c2cdb24365ffae6ed70ac1e74d7a (patch) | |
| tree | dec097ef78d23a930833dd41a25278f3865cc9d7 /arch/x86/kvm/lapic.c | |
| parent | KVM: VMX: prepare sync_pir_to_irr for running with APICv disabled (diff) | |
| download | linux-dev-37c4dbf337c5c2cdb24365ffae6ed70ac1e74d7a.tar.xz linux-dev-37c4dbf337c5c2cdb24365ffae6ed70ac1e74d7a.zip | |
KVM: x86: check PIR even for vCPUs with disabled APICv
The IRTE for an assigned device can trigger a POSTED_INTR_VECTOR even
if APICv is disabled on the vCPU that receives it. In that case, the
interrupt will just cause a vmexit and leave the ON bit set together
with the PIR bit corresponding to the interrupt.
Right now, the interrupt would not be delivered until APICv is re-enabled.
However, fixing this is just a matter of always doing the PIR->IRR
synchronization, even if the vCPU has temporarily disabled APICv.
This is not a problem for performance, or if anything it is an
improvement. First, in the common case where vcpu->arch.apicv_active is
true, one fewer check has to be performed. Second, static_call_cond will
elide the function call if APICv is not present or disabled. Finally,
in the case for AMD hardware we can remove the sync_pir_to_irr callback:
it is only needed for apic_has_interrupt_for_ppr, and that function
already has a fallback for !APICv.
Cc: stable@vger.kernel.org
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Message-Id: <20211123004311.2954158-4-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/lapic.c')
| -rw-r--r-- | arch/x86/kvm/lapic.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 759952dd1222..f206fc35deff 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -707,7 +707,7 @@ static void pv_eoi_clr_pending(struct kvm_vcpu *vcpu) static int apic_has_interrupt_for_ppr(struct kvm_lapic *apic, u32 ppr) { int highest_irr; - if (apic->vcpu->arch.apicv_active) + if (kvm_x86_ops.sync_pir_to_irr) highest_irr = static_call(kvm_x86_sync_pir_to_irr)(apic->vcpu); else highest_irr = apic_find_highest_irr(apic); |