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

[Pierre Gondois]

On 1/31/22 5:04 PM, Ard Biesheuvel wrote:
> 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>

Hi,
Just to confirm, I tried the patch and everything is working for me,
Regards,
Pierre

> 
>> ---
>>   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
>>