On Fri, Jun 05, 2015 at 03:24:12PM +0200, Thibaut Collet wrote:
> Add VIRTIO_NET_F_GUEST_ANNOUNCE capability to vhost-net when netdev backend is
> vhost-user.
>
> For netdev backend using virtio-net NIC the self announce is managed directly
> by the virtio-net NIC and not by the netdev backend itself.
> To avoid duplication of announces (once from the guest and once from QEMU) a
> bitfield is added in the NetClientState structure.
> If this bit is set self announce does not send message to the guest to request
> gratuitous ARP but let virtio-net NIC set the VIRTIO_NET_S_ANNOUNCE for
> gratuitous ARP.
>
> Signed-off-by: Thibaut Collet <thibaut.col...@6wind.com>
> ---
> v2: do not discard anymore packets send to vhost-user: it is GARP request
> after
> live migration.
> As suggested by S. Hajnoczi qemu_announce_self skips virtio-net NIC that
> already send GARP.
>
> hw/net/vhost_net.c | 2 ++
> include/net/net.h | 1 +
> net/vhost-user.c | 2 ++
> savevm.c | 11 ++++++++---
> 4 files changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index 426b23e..a745f97 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -82,6 +82,8 @@ static const int user_feature_bits[] = {
> VIRTIO_NET_F_CTRL_MAC_ADDR,
> VIRTIO_NET_F_CTRL_GUEST_OFFLOADS,
>
> + VIRTIO_NET_F_GUEST_ANNOUNCE,
> +
> VIRTIO_NET_F_MQ,
>
> VHOST_INVALID_FEATURE_BIT
> diff --git a/include/net/net.h b/include/net/net.h
> index e66ca03..a78e9df 100644
> --- a/include/net/net.h
> +++ b/include/net/net.h
> @@ -85,6 +85,7 @@ struct NetClientState {
> char *name;
> char info_str[256];
> unsigned receive_disabled : 1;
> + unsigned self_announce_disabled : 1;
> NetClientDestructor *destructor;
> unsigned int queue_index;
> unsigned rxfilter_notify_enabled:1;
> diff --git a/net/vhost-user.c b/net/vhost-user.c
> index 8d26728..b345446 100644
> --- a/net/vhost-user.c
> +++ b/net/vhost-user.c
> @@ -147,6 +147,8 @@ static int net_vhost_user_init(NetClientState *peer,
> const char *device,
>
> s = DO_UPCAST(VhostUserState, nc, nc);
>
> + /* Self announce is managed directly by virtio-net NIC */
> + s->nc.self_announce_disabled = 1;
> /* We don't provide a receive callback */
> s->nc.receive_disabled = 1;
> s->chr = chr;
> diff --git a/savevm.c b/savevm.c
> index 3b0e222..7a134b1 100644
> --- a/savevm.c
> +++ b/savevm.c
> @@ -80,11 +80,16 @@ static void qemu_announce_self_iter(NICState *nic, void
> *opaque)
> {
> uint8_t buf[60];
> int len;
> + NetClientState *nc;
>
> - trace_qemu_announce_self_iter(qemu_ether_ntoa(&nic->conf->macaddr));
> - len = announce_self_create(buf, nic->conf->macaddr.a);
> + nc = qemu_get_queue(nic);
>
> - qemu_send_packet_raw(qemu_get_queue(nic), buf, len);
> + if (!nc->peer->self_announce_disabled) {
> + trace_qemu_announce_self_iter(qemu_ether_ntoa(&nic->conf->macaddr));
> + len = announce_self_create(buf, nic->conf->macaddr.a);
> +
> + qemu_send_packet_raw(nc, buf, len);
> + }
> }
>
I don't think qemu_send_packet_raw can ever work for vhost user.
What happens if you merely add VIRTIO_NET_F_GUEST_ANNOUNCE
to the feature list, and drop the rest of the patch?
> --
> 1.7.10.4
