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authorMichael S. Tsirkin <mst@redhat.com>2010-09-20 18:08:41 +0200
committerAnthony Liguori <aliguori@us.ibm.com>2010-10-12 16:09:19 -0500
commit456496e22556203f5f9c3ff02faa7d75ef3face9 (patch)
tree24ce7a02b11f89b5c3a3ba9606cad374cf31c600
parentMerge remote branch 'qmp/for-stable-0.13' into stable-0.13 (diff)
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net: delay freeing peer host device
With -netdev, virtio devices present offload features to guest, depending on the backend used. Thus, removing host netdev peer while guest is active leads to guest-visible inconsistency and/or crashes. As a solution, while guest (NIC) peer device exists, we prevent the host peer from being deleted. This patch does this by adding peer_deleted flag in nic state: if host device is going away while guest device is around, set this flag and keep a shell of the host device around for as long as guest device exists. The link is put down so all packets will get discarded. At the moment, management can detect that device deletion is delayed by doing info net. As a next step, we shall add commands that control hotplug/unplug without removing the device, and an event to report that guest has responded to the hotplug event. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> (cherry picked from commit a083a89d7277f3268a251ce635d9aae5559242bd)
-rw-r--r--net.c49
-rw-r--r--net.h1
2 files changed, 43 insertions, 7 deletions
diff --git a/net.c b/net.c
index 8ddf872a6..eb8226b59 100644
--- a/net.c
+++ b/net.c
@@ -281,29 +281,64 @@ NICState *qemu_new_nic(NetClientInfo *info,
return nic;
}
-void qemu_del_vlan_client(VLANClientState *vc)
+static void qemu_cleanup_vlan_client(VLANClientState *vc)
{
if (vc->vlan) {
QTAILQ_REMOVE(&vc->vlan->clients, vc, next);
} else {
- if (vc->send_queue) {
- qemu_del_net_queue(vc->send_queue);
- }
QTAILQ_REMOVE(&non_vlan_clients, vc, next);
- if (vc->peer) {
- vc->peer->peer = NULL;
- }
}
if (vc->info->cleanup) {
vc->info->cleanup(vc);
}
+}
+static void qemu_free_vlan_client(VLANClientState *vc)
+{
+ if (!vc->vlan) {
+ if (vc->send_queue) {
+ qemu_del_net_queue(vc->send_queue);
+ }
+ if (vc->peer) {
+ vc->peer->peer = NULL;
+ }
+ }
qemu_free(vc->name);
qemu_free(vc->model);
qemu_free(vc);
}
+void qemu_del_vlan_client(VLANClientState *vc)
+{
+ /* If there is a peer NIC, delete and cleanup client, but do not free. */
+ if (!vc->vlan && vc->peer && vc->peer->info->type == NET_CLIENT_TYPE_NIC) {
+ NICState *nic = DO_UPCAST(NICState, nc, vc->peer);
+ if (nic->peer_deleted) {
+ return;
+ }
+ nic->peer_deleted = true;
+ /* Let NIC know peer is gone. */
+ vc->peer->link_down = true;
+ if (vc->peer->info->link_status_changed) {
+ vc->peer->info->link_status_changed(vc->peer);
+ }
+ qemu_cleanup_vlan_client(vc);
+ return;
+ }
+
+ /* If this is a peer NIC and peer has already been deleted, free it now. */
+ if (!vc->vlan && vc->peer && vc->info->type == NET_CLIENT_TYPE_NIC) {
+ NICState *nic = DO_UPCAST(NICState, nc, vc);
+ if (nic->peer_deleted) {
+ qemu_free_vlan_client(vc->peer);
+ }
+ }
+
+ qemu_cleanup_vlan_client(vc);
+ qemu_free_vlan_client(vc);
+}
+
VLANClientState *
qemu_find_vlan_client_by_name(Monitor *mon, int vlan_id,
const char *client_str)
diff --git a/net.h b/net.h
index 518cf9c1f..44c31a9b3 100644
--- a/net.h
+++ b/net.h
@@ -72,6 +72,7 @@ typedef struct NICState {
VLANClientState nc;
NICConf *conf;
void *opaque;
+ bool peer_deleted;
} NICState;
struct VLANState {