vdpa: Allow vDPA to work on big-endian machine

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"

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Konstantin Shkolnyy <kshk@linux.ibm.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Konstantin Shkolnyy 2025-02-21 13:07:33 -06:00 committed by Jason Wang
parent aa90f1161b
commit b027f55a99

View file

@ -262,6 +262,18 @@ 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)
{
@ -429,6 +441,7 @@ 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,
};