Re: [Qemu-devel] [PATCH v4] virtio dataplane: adapt dataplane for virtio Version 1

[Pierre Morel]

On 09/07/2015 12:20 PM, Stefan Hajnoczi wrote:
> On Wed, Sep 02, 2015 at 06:53:44PM +0200, Pierre Morel wrote:
> > +    addr = virtio_queue_get_desc_addr(vdev, n);
> > +    size = virtio_queue_get_desc_size(vdev, n);
> > +    ptr = vring_map(&vring->mr_desc, addr, size, true);
> > +    if (!ptr) {
> > +        error_report("Failed to map 0x%16lx byte for vring desc at %16lx",
> > +                      size, addr);
> > +        goto out_err_desc;
> >       }
> > -
> > -    vring_init(&vring->vr, virtio_queue_get_num(vdev, n), vring_ptr, 4096);
> > +    vr->desc = ptr;
> > +
> > +    addr = virtio_queue_get_avail_addr(vdev, n);
> > +    size = virtio_queue_get_avail_size(vdev, n);
> > +    size += sizeof(__virtio16);
> Please add a comment explaining what these 2 bytes are for.

ok, I send an v5 with this and including the remarks from Greg on 
read/write access

> > +    ptr = vring_map(&vring->mr_avail, addr, size, true);
> > +    if (!ptr) {
> > +        error_report("Failed to map 0x%16lx byte for vring avail at %16lx",
> > +                      size, addr);
> > +        goto out_err_avail;
> > +    }
> > +    vr->avail = ptr;
> > +
> > +    addr = virtio_queue_get_used_addr(vdev, n);
> > +    size = virtio_queue_get_used_size(vdev, n);
> > +    size += sizeof(__virtio16);
> Here too.
Here too too