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

From: "Michael S. Tsirkin" <[email-masked]>
Date: Sun, 8 Feb 2026 12:32:11 -0500

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 <[email-masked]>
> ---
>  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.

>  
>  #define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
> -- 
> 2.52.0