[PATCH 1/2] KVM: x86: ioapic: Set remote_irr only after successful delivery
Hao Zhang <[email protected]>
| Newsgroups | org.kernel.vger.kvm |
|---|---|
| Message-ID | <[email protected]> |
From: Hao Zhang <[email protected]> The I/O APIC sets remote_irr for level-triggered interrupts to track that the interrupt has been accepted by a local APIC and that the I/O APIC must wait for the corresponding EOI before delivering the interrupt again. But ioapic_service() currently sets remote_irr for any non-zero return from kvm_irq_delivery_to_apic(). The delivery helper can return -1 when no destination is found. Treating -1 as success causes KVM to set remote_irr even though no interrupt was delivered and no EOI will ever be generated, leaving the pin blocked. Set remote_irr only when the delivery result is positive, i.e. when at least one local APIC accepted the interrupt. Fixes: 4925663a079c ("KVM: Report IRQ injection status to userspace.") Signed-off-by: Hao Zhang <[email protected]> --- arch/x86/kvm/ioapic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c index 757667fb2bfa..24a7cc3b8b7e 100644 --- a/arch/x86/kvm/ioapic.c +++ b/arch/x86/kvm/ioapic.c @@ -491,7 +491,7 @@ static int ioapic_service(struct kvm_ioapic *ioapic, int irq, bool line_status) } else ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe); - if (ret && irqe.trig_mode == IOAPIC_LEVEL_TRIG) + if (ret > 0 && irqe.trig_mode == IOAPIC_LEVEL_TRIG) entry->fields.remote_irr = 1; return ret; base-commit: c21bb4193868a8de71fc4693fa741e195fdf5d86 -- 2.15.0