linmiaohe <linmiaohe@xxxxxxxxxx> writes:
> From: Miaohe Lin <linmiaohe@xxxxxxxxxx>
>
> Commit 13db77347db1 ("KVM: x86: don't notify userspace IOAPIC on edge
> EOI") said, edge-triggered interrupts don't set a bit in TMR, which means
> that IOAPIC isn't notified on EOI. And var level indicates level-triggered
> interrupt.
> But commit 3159d36ad799 ("KVM: x86: use generic function for MSI parsing")
> replace var level with irq.level by mistake. Fix it by changing irq.level
> to irq.trig_mode.
>
> Fixes: 3159d36ad799 ("KVM: x86: use generic function for MSI parsing")
> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
> ---
> arch/x86/kvm/irq_comm.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/irq_comm.c b/arch/x86/kvm/irq_comm.c
> index 79afa0bb5f41..c47d2acec529 100644
> --- a/arch/x86/kvm/irq_comm.c
> +++ b/arch/x86/kvm/irq_comm.c
> @@ -417,7 +417,7 @@ void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu,
>
> kvm_set_msi_irq(vcpu->kvm, entry, &irq);
>
> - if (irq.level &&
> + if (irq.trig_mode &&
> kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
> irq.dest_id, irq.dest_mode))
> __set_bit(irq.vector, ioapic_handled_vectors);
Assuming Radim's comment (13db77347db1) is correct, the change in
3159d36ad799 looks wrong and your patch restores the status
quo. Actually, kvm_set_msi_irq() always sets irq->level = 1 so checking
it is pointless.
Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
(but it is actually possible that there's a buggy userspace out there
which expects EOI notifications; we won't find out unless we try to fix
the bug).
--
Vitaly
