Re: [Qemu-devel] [PATCH] virtio: Fix no interrupt when not creating msi controller

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Jan 20, 2017 at 10:50:49AM +0800, Shannon Zhao wrote:
> From: Shannon Zhao <shannon.zhao@linaro.org>
> 
> For ARM virt machine, if we use virt-2.7 which will not create ITS node,
> the virtio-net can not recieve interrupts so it can't get ip address
> through dhcp.
> This fixes commit 83d768b(virtio: set ISR on dataplane notifications).
> 
> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
> ---
>  hw/virtio/virtio.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index aa4f38f..709b718 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -2082,6 +2082,7 @@ static void virtio_queue_guest_notifier_read(EventNotifier *n)
>  {
>      VirtQueue *vq = container_of(n, VirtQueue, guest_notifier);
>      if (event_notifier_test_and_clear(n)) {
> +        virtio_set_isr(vq->vdev, 0x1);
>          virtio_notify_vector(vq->vdev, vq->vector);
>      }
>  }

Then you should bring back virtio_irq, to avoid duplicating
code from virtio_notify.



> -- 
> 2.0.4
>