Re: [PATCH 1/8] virtio: add request_vqs/free_vqs operations

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

On Mon, May 04, 2009 at 09:02:20PM +0930, Rusty Russell wrote:
> On Mon, 27 Apr 2009 10:01:53 pm Michael S. Tsirkin wrote:
> > This adds 2 new optional virtio operations: request_vqs/free_vqs. They will be
> > used for MSI support, because MSI needs to know the total number of vectors
> > upfront.
> > 
> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> 
> Hi Michael,

Hi Rusty,

>   Thanks for this work!  But this interface is horrible.  Either probe for the
> number of vqs in virtio_pci, or change find_vq to
> 
> 	int (*find_vqs)(struct virtio_device *, unsigned max,
> 						     struct virtqueue *vqs[]);

I'm happier with the later option: it's easy for a host to expose
support for a very large number of vqs, and I don't want them to
waste resources if guest does not use them.

Thanks for the feedback!

> Thanks,
> Rusty.

-- 
MST