On Fri, Feb 21, 2025 at 8:08 PM Konstantin Shkolnyy <k...@linux.ibm.com> wrote:
>
> Add .set_vnet_le() function that always returns success, assuming that
> vDPA h/w always implements LE data format. Otherwise, QEMU disables vDPA and
> outputs the message:
> "backend does not support LE vnet headers; falling back on userspace virtio"
>
Acked-by: Eugenio Pérez <epere...@redhat.com>
> Signed-off-by: Konstantin Shkolnyy <k...@linux.ibm.com>
> ---
> Changes in V2: Add code comment.
>
> net/vhost-vdpa.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index 231b45246c..6e7cec4d45 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -270,6 +270,18 @@ static bool vhost_vdpa_has_ufo(NetClientState *nc)
>
> }
>
> +/*
> + * FIXME: vhost_vdpa doesn't have an API to "set h/w endianness". But it's
> + * reasonable to assume that h/w is LE by default, because LE is what
> + * virtio 1.0 and later ask for. So, this function just says "yes, the h/w is
> + * LE". Otherwise, on a BE machine, higher-level code would mistakely think
> + * the h/w is BE and can't support VDPA for a virtio 1.0 client.
> + */
> +static int vhost_vdpa_set_vnet_le(NetClientState *nc, bool enable)
> +{
> + return 0;
> +}
> +
> static bool vhost_vdpa_check_peer_type(NetClientState *nc, ObjectClass *oc,
> Error **errp)
> {
> @@ -437,6 +449,7 @@ static NetClientInfo net_vhost_vdpa_info = {
> .cleanup = vhost_vdpa_cleanup,
> .has_vnet_hdr = vhost_vdpa_has_vnet_hdr,
> .has_ufo = vhost_vdpa_has_ufo,
> + .set_vnet_le = vhost_vdpa_set_vnet_le,
> .check_peer_type = vhost_vdpa_check_peer_type,
> .set_steering_ebpf = vhost_vdpa_set_steering_ebpf,
> };
> --
> 2.34.1
>
