[PATCH][kvmtool] virtio/pci: Signal INTx interrupts as level instead of edge

[Ard Biesheuvel]

On Mon, 31 Jan 2022 at 17:03, Marc Zyngier <maz at kernel.org> wrote:
>
> It appears that the way INTx is emulated is "slightly" out of spec
> in kvmtool. We happily inject an edge interrupt, even if the spec
> mandates a level.
>
> This doesn't change much for either the guest or userspace (only
> KVM will have a bit more work tracking the EOI), but at least
> this is correct.
>
> Reported-by: Pierre Gondois <pierre.gondois at arm.com>
> Signed-off-by: Marc Zyngier <maz at kernel.org>
> Cc: Ard Biesheuvel <ardb at kernel.org>
> Cc: Sami Mujawar <sami.mujawar at arm.com>
> Cc: Will Deacon <will at kernel.org>

Acked-by: Ard Biesheuvel <ardb at kernel.org>

> ---
>  pci.c        | 2 +-
>  virtio/pci.c | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/pci.c b/pci.c
> index e5930331..a769ae27 100644
> --- a/pci.c
> +++ b/pci.c
> @@ -61,7 +61,7 @@ int pci__assign_irq(struct pci_device_header *pci_hdr)
>         pci_hdr->irq_line       = irq__alloc_line();
>
>         if (!pci_hdr->irq_type)
> -               pci_hdr->irq_type = IRQ_TYPE_EDGE_RISING;
> +               pci_hdr->irq_type = IRQ_TYPE_LEVEL_HIGH;
>
>         return pci_hdr->irq_line;
>  }
> diff --git a/virtio/pci.c b/virtio/pci.c
> index 41085291..2777d1c8 100644
> --- a/virtio/pci.c
> +++ b/virtio/pci.c
> @@ -413,7 +413,7 @@ int virtio_pci__signal_vq(struct kvm *kvm, struct virtio_device *vdev, u32 vq)
>                         kvm__irq_trigger(kvm, vpci->gsis[vq]);
>         } else {
>                 vpci->isr = VIRTIO_IRQ_HIGH;
> -               kvm__irq_trigger(kvm, vpci->legacy_irq_line);
> +               kvm__irq_line(kvm, vpci->legacy_irq_line, VIRTIO_IRQ_HIGH);
>         }
>         return 0;
>  }
> --
> 2.34.1
>