Re: [Qemu-devel] [PATCH 2/5] virtio: increase VIRITO_QUEUE_MAX to 513

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

On Fri, Feb 06, 2015 at 03:54:10PM +0800, Jason Wang wrote:
> Recent linux kernel supports up to 256 tap queues. Increase the limit
> to 513 (256 * 2 + 1(ctrl vq)).
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>

We have a bunch of loops over all possible VQ numbers in virtio pci.
Doing this for 1000 VQs when most of them are inactive seems extreme - I
suspect we need a list of active VQs now.

> ---
>  include/hw/virtio/virtio.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
> index 220c09d..21bb30f 100644
> --- a/include/hw/virtio/virtio.h
> +++ b/include/hw/virtio/virtio.h
> @@ -92,7 +92,7 @@ typedef struct VirtQueueElement
>      struct iovec out_sg[VIRTQUEUE_MAX_SIZE];
>  } VirtQueueElement;
>  
> -#define VIRTIO_QUEUE_MAX 64
> +#define VIRTIO_QUEUE_MAX 513
>  
>  #define VIRTIO_NO_VECTOR 0xffff
>  
> -- 
> 1.9.1