From b56cf56ccfe6bec17d9ba253eefcbcdad3503907 Mon Sep 17 00:00:00 2001 From: Michael S. Tsirkin Date: Wed, 9 Feb 2011 14:40:56 -0200 Subject: [PATCH 03/10] net: notify peer about link status change RH-Author: Michael S. Tsirkin Message-id: Patchwork-id: 17907 O-Subject: [PATCHv2 RHEL6.1 1/2] net: notify peer about link status change Bugzilla: 676015 RH-Acked-by: Xiao Wang RH-Acked-by: Glauber Costa RH-Acked-by: Alex Williamson qemu makes it possible to disable link at tap which is not communicated to the guest but causes all packets to be dropped. This works for virtio userspace, as qemu stops giving it packets, but not for virtio-net connected to vhost-net as that does not get notified about this change. Notify peer when this happens, which will then be used by the follow-up patch to stop/start vhost-net. Note: it might be a good idea to make peer link status match tap in this case, so the guest gets an event and updates the carrier state. For now stay bug for bug compatible with what we used to have in userspace. Signed-off-by: Michael S. Tsirkin Reported-by: pradeep --- net.c | 11 +++++++++++ 1 files changed, 11 insertions(+), 0 deletions(-) Signed-off-by: Luiz Capitulino --- net.c | 11 +++++++++++ 1 files changed, 11 insertions(+), 0 deletions(-) diff --git a/net.c b/net.c index f62a9e9..3fc9c9f 100644 --- a/net.c +++ b/net.c @@ -1320,6 +1320,17 @@ done: if (vc->info->link_status_changed) { vc->info->link_status_changed(vc); } + + /* Notify peer. Don't update peer link status: this makes it possible to + * disconnect from host network without notifying the guest. + * FIXME: is disconnected link status change operation useful? + * + * Current behaviour is compatible with qemu vlans where there could be + * multiple clients that can still communicate with each other in + * disconnected mode. For now maintain this compatibility. */ + if (vc->peer && vc->peer->info->link_status_changed) { + vc->peer->info->link_status_changed(vc->peer); + } return 0; } -- 1.7.4.rc1.16.gd2f15e