From b074ea6f3d6d717e8429971708276d2e87af72cf Mon Sep 17 00:00:00 2001 From: Xiao Wang Date: Mon, 1 Nov 2010 09:15:07 -0200 Subject: [RHEL6 qemu-kvm PATCH 1/2] net: delay freeing peer host device RH-Author: Xiao Wang Message-id: <20101101091507.9347.81139.stgit@dhcp-91-158.nay.redhat.com> Patchwork-id: 13098 O-Subject: [RHEL6.1 and RHEL6.0Z PATCH] net: delay freeing peer host device Bugzilla: 634661 RH-Acked-by: Alex Williamson RH-Acked-by: Jes Sorensen RH-Acked-by: Michael S. Tsirkin From: Michael S. Tsirkin Bugzilla: 634661 Brew Build: https://brewweb.devel.redhat.com/taskinfo?taskID=2863328 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. Test status: Tested with my own machine and got ack from qe. Signed-off-by: Michael S. Tsirkin Acked-by: Alex Williamson (cherry picked from commit a083a89d7277f3268a251ce635d9aae5559242bd) --- net.c | 49 ++++++++++++++++++++++++++++++++++++++++++------- net.h | 1 + 2 files changed, 43 insertions(+), 7 deletions(-) Signed-off-by: Eduardo Habkost --- net.c | 49 ++++++++++++++++++++++++++++++++++++++++++------- net.h | 1 + 2 files changed, 43 insertions(+), 7 deletions(-) diff --git a/net.c b/net.c index 985099e..037c699 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 9f3c82f..b7857cd 100644 --- a/net.h +++ b/net.h @@ -73,6 +73,7 @@ typedef struct NICState { VLANClientState nc; NICConf *conf; void *opaque; + bool peer_deleted; } NICState; struct VLANState { -- 1.7.3.2