[PATCH v3 01/17] virtio_pci: struct virtio_pci_common_cfg add queue_notify_data

Jason Wang
Mon, 07 Feb 2022 08:06:15 -0000

On Mon, Feb 7, 2022 at 2:07 PM Xuan Zhuo <xuanzhuo at linux.alibaba.com>
wrote:
>
> On Mon, 7 Feb 2022 11:41:06 +0800, Jason Wang <jasowang at
redhat.com> wrote:
> >
> > ? 2022/1/26 ??3:35, Xuan Zhuo ??:
> > > Add queue_notify_data in struct virtio_pci_common_cfg, which
comes from
> > > here https://github.com/oasis-tcs/virtio-spec/issues/89
> > >
> > > Since I want to add queue_reset after it, I submitted this patch
first.
> > >
> > > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
> > > ---
> > >   include/uapi/linux/virtio_pci.h | 1 +
> > >   1 file changed, 1 insertion(+)
> > >
> > > diff --git a/include/uapi/linux/virtio_pci.h
b/include/uapi/linux/virtio_pci.h
> > > index 3a86f36d7e3d..492c89f56c6a 100644
> > > --- a/include/uapi/linux/virtio_pci.h
> > > +++ b/include/uapi/linux/virtio_pci.h
> > > @@ -164,6 +164,7 @@ struct virtio_pci_common_cfg {
> > >     __le32 queue_avail_hi;          /* read-write */
> > >     __le32 queue_used_lo;           /* read-write */
> > >     __le32 queue_used_hi;           /* read-write */
> > > +   __le16 queue_notify_data;       /* read-write */
> > >   };
> >
> >
> > So I had the same concern as previous version.
> >
> > This breaks uABI where program may try to use sizeof(struct
> > virtio_pci_common_cfg).
> >
> > We probably need a container structure here.
>
> I see, I plan to add a struct like this, do you think it's appropriate?
>
> struct virtio_pci_common_cfg_v1 {
>         struct virtio_pci_common_cfg cfg;
>         __le16 queue_notify_data;       /* read-write */
> }

Something like this but we probably need a better name.

Thanks

>
> Thanks.
>
> >
> > THanks
> >
> >
> > >
> > >   /* Fields in VIRTIO_PCI_CAP_PCI_CFG: */
> >
>