vhost user: add rarp sending after live migration for legacy guest

A new vhost user message is added to allow QEMU to ask to vhost user backend to
broadcast a fake RARP after live migration for guest without GUEST_ANNOUNCE
capability.

This new message is sent only if the backend supports the new
VHOST_USER_PROTOCOL_F_RARP protocol feature.
The payload of this new message is the MAC address of the guest (not known by
the backend). The MAC address is copied in the first 6 bytes of a u64 to avoid
to create a new payload message type.

This new message has no equivalent ioctl so a new callback is added in the
userOps structure to send the request.

Upon reception of this new message the vhost user backend must generate and
broadcast a fake RARP request to notify the migration is terminated.

Signed-off-by: Thibaut Collet <thibaut.collet@6wind.com>
[Rebased and fixed checkpatch errors - Marc-André]
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
This commit is contained in:
Thibaut Collet 2015-10-09 17:17:32 +02:00 committed by Michael S. Tsirkin
parent f6f56291de
commit 3e866365e1
6 changed files with 89 additions and 3 deletions

View file

@ -106,9 +106,29 @@ err:
static ssize_t vhost_user_receive(NetClientState *nc, const uint8_t *buf,
size_t size)
{
/* Discard the request that is received and managed by backend
* by an other way.
/* In case of RARP (message size is 60) notify backup to send a fake RARP.
This fake RARP will be sent by backend only for guest
without GUEST_ANNOUNCE capability.
*/
if (size == 60) {
VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
int r;
static int display_rarp_failure = 1;
char mac_addr[6];
/* extract guest mac address from the RARP message */
memcpy(mac_addr, &buf[6], 6);
r = vhost_net_notify_migration_done(s->vhost_net, mac_addr);
if ((r != 0) && (display_rarp_failure)) {
fprintf(stderr,
"Vhost user backend fails to broadcast fake RARP\n");
fflush(stderr);
display_rarp_failure = 0;
}
}
return size;
}