Re: [Qemu-devel] [PATCH V2 08/11] virtio-pci: switch to use bus specific queue limit

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

On Thu, Feb 26, 2015 at 03:04:43PM +0800, Jason Wang wrote:
> Instead of depending on a macro, switch to use a bus specific queue
> limit.
> 
> Cc: Anthony Liguori <aliguori@amazon.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>  hw/virtio/virtio-pci.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index 7fa8141..23c4649 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -215,7 +215,7 @@ static void virtio_pci_start_ioeventfd(VirtIOPCIProxy *proxy)
>          return;
>      }
>  
> -    for (n = 0; n < VIRTIO_PCI_QUEUE_MAX; n++) {
> +    for (n = 0; n < virtio_get_queue_max(vdev); n++) {
>          if (!virtio_queue_get_num(vdev, n)) {
>              continue;
>          }

This is done on guest IO, and I think after applying the
next patch which increases the number to >500 for pci, it's too much
work: VCPU is blocked meanwhile. Same applies to other places.

At minimum, we'll need a faster way to locate active VQs.


-- 
MST