Some vhost client/backend are able to support live migration.
To provide this service the following features must be added:
1. Add the VIRTIO_NET_F_GUEST_ANNOUNCE capability to vhost-net when netdev
backend is vhost-user.
2. Provide a nop receive callback to vhost-user. This callback is for RARP
packets automatically send by qemu_announce_self after a migration.
These packets are useless for vhost user and just discarded.
Signed-off-by: Thibaut Collet <thibaut.col...@6wind.com>
---
hw/net/vhost_net.c | 2 ++
net/vhost-user.c | 21 +++++++++++++++++++--
2 files changed, 21 insertions(+), 2 deletions(-)
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 9bd360b..668c422 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -85,6 +85,8 @@ 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/net/vhost-user.c b/net/vhost-user.c
index b51bc04..20778a1 100644
--- a/net/vhost-user.c
+++ b/net/vhost-user.c
@@ -65,6 +65,24 @@ static void vhost_user_stop(VhostUserState *s)
s->vhost_net = 0;
}
+static ssize_t vhost_user_receive(NetClientState *nc, const uint8_t *buf,
+ size_t size)
+{
+ /* A live migration is done. Display an error if the packet is not a RARP.
+ * RARP are just discarded: guest is already notified of live migration
+ * by the virtio-net NIC or by the vhost-user backend */
+ if (size != 60) {
+ static int display_trace = 1;
+
+ if (display_trace) {
+ fprintf(stderr,"Vhost user receives unexpected packets\n");
+ fflush(stderr);
+ display_trace = 0;
+ }
+ }
+ return size;
+}
+
static void vhost_user_cleanup(NetClientState *nc)
{
VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
@@ -90,6 +108,7 @@ static bool vhost_user_has_ufo(NetClientState *nc)
static NetClientInfo net_vhost_user_info = {
.type = NET_CLIENT_OPTIONS_KIND_VHOST_USER,
.size = sizeof(VhostUserState),
+ .receive = vhost_user_receive,
.cleanup = vhost_user_cleanup,
.has_vnet_hdr = vhost_user_has_vnet_hdr,
.has_ufo = vhost_user_has_ufo,
@@ -146,8 +165,6 @@ static int net_vhost_user_init(NetClientState *peer, const
char *device,
s = DO_UPCAST(VhostUserState, nc, nc);
- /* We don't provide a receive callback */
- s->nc.receive_disabled = 1;
s->chr = chr;
s->nc.queue_index = i;
--
1.7.10.4
