Re: [RFC 1/3] uapi: vhost: add vhost-net netfilter offload API

[Cindy Lu <lulu@redhat.com>]

s

On Mon, Feb 9, 2026 at 1:32 AM Michael S. Tsirkin <mst@redhat.com> wrote:
>
> On Sun, Feb 08, 2026 at 10:32:22PM +0800, Cindy Lu wrote:
> > Add VHOST_NET_SET_FILTER ioctl and the filter socket protocol used for
> > vhost-net filter offload.
> >
> > Signed-off-by: Cindy Lu <lulu@redhat.com>
> > ---
> >  include/uapi/linux/vhost.h | 20 ++++++++++++++++++++
> >  1 file changed, 20 insertions(+)
> >
> > diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
> > index c57674a6aa0d..d9a0ca7a3df0 100644
> > --- a/include/uapi/linux/vhost.h
> > +++ b/include/uapi/linux/vhost.h
> > @@ -131,6 +131,26 @@
> >   * device.  This can be used to stop the ring (e.g. for migration). */
> >  #define VHOST_NET_SET_BACKEND _IOW(VHOST_VIRTIO, 0x30, struct vhost_vring_file)
> >
> > +/* VHOST_NET filter offload (kernel vhost-net dataplane through QEMU netfilter) */
> > +struct vhost_net_filter {
> > +     __s32 fd;
> > +};
> > +
> > +enum {
> > +     VHOST_NET_FILTER_MSG_REQUEST = 1,
> > +};
> > +
> > +#define VHOST_NET_FILTER_DIRECTION_TX 1
> > +
> > +struct vhost_net_filter_msg {
> > +     __u16 type;
> > +     __u16 direction;
> > +     __u32 len;
> > +};
> > +
> > +
> > +#define VHOST_NET_SET_FILTER _IOW(VHOST_VIRTIO, 0x31, struct vhost_net_filter)
> > +
> >  /* VHOST_SCSI specific defines */
>
> can we get some info on what this is supposed to be doing, pls?
> it belongs here where userspace devs can find it, not hidden
> in code.
>
Hi Michael
We plan to add a new feature to support zero packet loss during live
migration, so we’re introducing this new UAPI. Thanks, I'll add more
information here.
Thanks
Cindy
>
> >
> >  #define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
> > --
> > 2.52.0
>