Re: [PATCH v9 1/8] net/virtio: vring init for packed queues

[Tiwei Bie <tiwei.bie@intel.com>]

On Thu, Oct 25, 2018 at 05:12:48PM +0200, Jens Freimann wrote:
> On Thu, Oct 25, 2018 at 03:51:19PM +0200, Maxime Coquelin wrote:
> > 
> > 
> > On 10/25/18 3:48 PM, Jens Freimann wrote:
> > > On Thu, Oct 25, 2018 at 05:21:15PM +0800, Tiwei Bie wrote:
> > > > On Wed, Oct 24, 2018 at 04:32:29PM +0200, Jens Freimann wrote:
> > > > > Signed-off-by: Jens Freimann <jfreimann@redhat.com>
> > > > > ??struct vring {
> > > > > ???????? unsigned int num;
> > > > > -?????? struct vring_desc?? *desc;
> > > > > -?????? struct vring_avail *avail;
> > > > > -?????? struct vring_used?? *used;
> > > > > +?????? union {
> > > > > +?????????????? struct vring_desc_packed *desc_packed;
> > > > > +?????????????? struct vring_desc *desc;
> > > > > +?????? };
> > > > > +?????? union {
> > > > > +?????????????? struct vring_avail *avail;
> > > > > +?????????????? struct vring_packed_desc_event *driver_event;
> > > > > +?????? };
> > > > > +?????? union {
> > > > > +?????????????? struct vring_used?? *used;
> > > > > +?????????????? struct vring_packed_desc_event *device_event;
> > > > > +?????? };
> > > > > ??};
> > > > > 
> > > > 
> > > > We should define a new `vring` structure for packed ring.
> > > 
> > > I think it was requested to have it as a union before, but I can do
> > > it.
> > 
> > I guess oyu vcan have a union between struct vring and struct
> > vring_packed?
> 
> Like this?
> 
> struct vring {
>          unsigned int num;
>          union {
>                 struct vring_split *split;
> _                struct vring_packed *packed;
>          };
>  };
> 
> We will have to write vq->vq_ring.split.avail->flags and
> vq->vq_ring.packed.desc[xx] and similar things in a lot of places, no?
> 
> Should we just add both vring_split and vring_packed to struct
> virtqueue instead? Only one of them will have memory allocated per virtqueue
> anyway.

Yeah, we can add both to struct virtqueue.