Re: [PATCH] virtio: update queue size on guest write

[Stefano Garzarella]

On Fri, Dec 13, 2019 at 09:24:03AM -0500, Michael S. Tsirkin wrote:
> Some guests read back queue size after writing it.
> Update the size immediatly upon write otherwise
> they get confused.
> 
> Signed-off-by: Michael S. Tsirkin <address@hidden>
> ---
>  hw/virtio/virtio-pci.c | 2 ++
>  1 file changed, 2 insertions(+)

Reviewed-by: Stefano Garzarella <address@hidden>


Just a question, should we do the same in virtio-mmio?

Maybe doing virtio_queue_set_num() in any case (legacy and non-legacy)
during VIRTIO_MMIO_QUEUE_NUM writing.

Thanks,
Stefano

> 
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index c6b47a9c73..e5c759e19e 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -1256,6 +1256,8 @@ static void virtio_pci_common_write(void *opaque, 
> hwaddr addr,
>          break;
>      case VIRTIO_PCI_COMMON_Q_SIZE:
>          proxy->vqs[vdev->queue_sel].num = val;
> +        virtio_queue_set_num(vdev, vdev->queue_sel,
> +                             proxy->vqs[vdev->queue_sel].num);
>          break;
>      case VIRTIO_PCI_COMMON_Q_MSIX:
>          msix_vector_unuse(&proxy->pci_dev,
> -- 
> MST
> 
> 

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