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[Qemu-devel] [PATCH 2/2] Fix netdev name lookup in -device, device_add,
From: |
Markus Armbruster |
Subject: |
[Qemu-devel] [PATCH 2/2] Fix netdev name lookup in -device, device_add, netdev_del |
Date: |
Thu, 16 Jun 2011 18:45:37 +0200 |
qemu_find_netdev() looks up members of non_vlan_clients by name. It
happily returns the first match. Trouble is the names need not be
unique.
non_vlan_clients contains host parts (netdevs) and guest parts (NICs).
Netdevs have unique names: a netdev's name is a (mandatory)
qemu_netdev_opts ID, and these are unique.
NIC names are not unique. If a NIC has a qdev ID (which is unique),
that's its name. Else, we make up a name. The made-up names are
unique, but they can clash with qdev IDs. Even if NICs had unique
names, they could still clash with netdev names.
Callers of qemu_find_netdev():
* net_init_nic() wants a netdev. It happens to work because it runs
before NICs get added to non_vlan_clients.
* do_netdev_del() wants a netdev. If it gets a NIC, it complains and
fails. Bug: a netdev with the same name that comes later in
non_vlan_clients can't be deleted:
$ qemu-system-x86_64 -nodefaults -vnc :0 -S -monitor stdio -netdev
user,id=hostnet0 -device virtio-net-pci,netdev=hostnet0,id=virtio1
[...]
(qemu) netdev_add user,id=virtio1
(qemu) info network
Devices not on any VLAN:
hostnet0: net=10.0.2.0, restricted=n peer=virtio1
virtio1: model=virtio-net-pci,macaddr=52:54:00:12:34:56 peer=hostnet0
virtio1: net=10.0.2.0, restricted=n
(qemu) netdev_del virtio1
Device 'virtio1' not found
* parse_netdev() wants a netdev. If it gets a NIC, it gets confused.
With the test setup above:
(qemu) device_add virtio-net-pci,netdev=virtio1
Property 'virtio-net-pci.netdev' can't take value 'virtio1', it's in use
You can even connect two NICs to each other:
$ qemu-system-x86_64 -nodefaults -vnc :0 -S -monitor stdio -device
virtio-net-pci,id=virtio1 -device e1000,netdev=virtio1
[...]
Devices not on any VLAN:
virtio1: model=virtio-net-pci,macaddr=52:54:00:12:34:56 peer=e1000.0
e1000.0: model=e1000,macaddr=52:54:00:12:34:57 peer=virtio1
(qemu) q
Segmentation fault (core dumped)
* do_set_link() works fine for both netdevs and NICs. Whether it
really makes sense for netdevs is debatable, but that's outside this
patch's scope.
Change qemu_find_netdev() to return only netdevs. This fixes the
netdev_del and device_add/-device bugs demonstrated above.
To avoid changing set_link, make do_set_link() search non_vlan_clients
by hand instead of calling qemu_find_netdev().
Signed-off-by: Markus Armbruster <address@hidden>
---
net.c | 10 ++++++++--
1 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/net.c b/net.c
index 8754627..c5c4b6b 100644
--- a/net.c
+++ b/net.c
@@ -658,6 +658,8 @@ VLANClientState *qemu_find_netdev(const char *id)
VLANClientState *vc;
QTAILQ_FOREACH(vc, &non_vlan_clients, next) {
+ if (vc->info->type == NET_CLIENT_TYPE_NIC)
+ continue;
if (!strcmp(vc->name, id)) {
return vc;
}
@@ -1217,7 +1219,7 @@ int do_netdev_del(Monitor *mon, const QDict *qdict,
QObject **ret_data)
VLANClientState *vc;
vc = qemu_find_netdev(id);
- if (!vc || vc->info->type == NET_CLIENT_TYPE_NIC) {
+ if (!vc) {
qerror_report(QERR_DEVICE_NOT_FOUND, id);
return -1;
}
@@ -1262,7 +1264,11 @@ int do_set_link(Monitor *mon, const QDict *qdict,
QObject **ret_data)
}
}
}
- vc = qemu_find_netdev(name);
+ QTAILQ_FOREACH(vc, &non_vlan_clients, next) {
+ if (!strcmp(vc->name, name)) {
+ goto done;
+ }
+ }
done:
if (!vc) {
--
1.7.2.3