On Thu, Oct 20, 2022 at 12:34:22PM +0200, Eugenio Pérez wrote:
> A gratuitous ARP is recommended after a live migration to reduce the amount of
> time needed by the network links to be aware of the new location. A hypervisor
> may not have the knowledge of the guest network configuration, and this is
> especially true on passthrough devices, so its simpler to ask the guest to
> do it.
>
> However, the device control part of this feature can be totally emulated by
> qemu and shadow virtqueue, not needing any special feature from the actual
> vdpa device.
>
> VIRTIO_NET_F_STATUS is also needed for the guest to access the status of
> virtio net config where announcement status bit is set. Emulating it as
> always active in case backend does not support it.
>
> This series need two fixes applied:
> * https://lists.nongnu.org/archive/html/qemu-devel/2022-10/msg03242.html
> * https://lists.nongnu.org/archive/html/qemu-devel/2022-10/msg03241.html
Jason you seem to have queued these so you will have to take
this patchset too.
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> v1:
> * Move code from vhost_net_get_config to virtio_net_get_config.
>
> RFC v2:
> * Add VIRTIO_NET_F_STATUS emulation.
>
> Eugenio Pérez (7):
> vdpa: Save emulated features list in vhost_vdpa
> virtio_net: Modify virtio_net_get_config to early return
> virtio_net: Handle _F_STATUS emulation in virtio_net_get_config
> vdpa: Expose VIRTIO_NET_F_STATUS unconditionally
> vdpa: handle VIRTIO_NET_CTRL_ANNOUNCE in
> vhost_vdpa_net_handle_ctrl_avail
> virtio_net: copy VIRTIO_NET_S_ANNOUNCE if device model has it
> vdpa: Offer VIRTIO_NET_F_GUEST_ANNOUNCE feature if SVQ is enabled
>
> include/hw/virtio/vhost-vdpa.h | 2 ++
> hw/net/virtio-net.c | 40 +++++++++++++++++++++-------------
> hw/virtio/vhost-vdpa.c | 8 +++----
> net/vhost-vdpa.c | 25 ++++++++++++++++++---
> 4 files changed, 53 insertions(+), 22 deletions(-)
>
> --
> 2.31.1
>