What were you trying to do that didn't work?

Live-migration with VDUSE devices bound to vhost-vdpa may fail because of VIRTIO_NET_F_GSO feature not being part of vdpa_svq_device_features bitmask (net/vhost-vdpa.c).

With a workaround disabling VIRTIO_NET_F_GSO in the VDUSE application, it later fails because of missing VIRTIO_F_IN_ORDER and VIRTIO_F_INDIRECT_DESC features (hw/virtio/vhost_shadow_virtqueue.c, vhost_svq_vqlid_features()).

While I think there should be no issue in advertizing VIRTIO_F_IN_ORDER with SVQs, VIRTIO_F_INDIRECT_DESC support might require more investigations.

What is the impact of this issue to you?

Guest cannot live-migrate:

# virsh migrate --live fc41-1 qemu+ssh://wsfd-advnetlab03.anl.eng.rdu2.dc.redhat.com/system
error: Requested operation is not valid: cannot migrate domain: SVQ Invalid device feature flags, offer: 0xb38009f83, ok: 0x328009f83