On 11/25/20 4:02 AM, Markus Armbruster wrote:
> CLI -netdev accumulates in option group "netdev".
>
> Before commit 08712fcb85 "net: Track netdevs in NetClientState rather
> than QemuOpt", netdev_add added to the option group, and netdev_del
> removed from it, both HMP and QMP. Thus, every netdev had a
> corresponding QemuOpts in this option group.
>
> Commit 08712fcb85 dropped this for QMP netdev_add and both netdev_del.
> Now a netdev has a corresponding QemuOpts only when it was created
> with CLI or HMP. Two issues:
>
> * QMP and HMP netdev_del can leave QemuOpts behind, breaking HMP
> netdev_add. Reproducer:
>
> $ qemu-system-x86_64 -S -display none -nodefaults -monitor stdio
> QEMU 5.1.92 monitor - type 'help' for more information
> (qemu) netdev_add user,id=net0
> (qemu) info network
> net0: index=0,type=user,net=10.0.2.0,restrict=off
> (qemu) netdev_del net0
> (qemu) info network
> (qemu) netdev_add user,id=net0
> upstream-qemu: Duplicate ID 'net0' for netdev
> Try "help netdev_add" for more information
>
> Fix by restoring the QemuOpts deletion in qmp_netdev_del(), but with
> a guard, because the QemuOpts need not exist.
>
> * QMP netdev_add loses its "no duplicate ID" check. Reproducer:
>
> $ qemu-system-x86_64 -S -display none -qmp stdio
> {"QMP": {"version": {"qemu": {"micro": 92, "minor": 1, "major": 5},
> "package": "v5.2.0-rc2-1-g02c1f0142c"}, "capabilities": ["oob"]}}
> {"execute": "qmp_capabilities"}
> {"return": {}}
> {"execute": "netdev_add", "arguments": {"type": "user", "id":"net0"}}
> {"return": {}}
> {"execute": "netdev_add", "arguments": {"type": "user", "id":"net0"}}
> {"return": {}}
>
> Fix by adding a duplicate ID check to net_client_init1() to replace
> the lost one. The check is redundant for callers where QemuOpts
> still checks, i.e. for CLI and HMP.
>
> Reported-by: Andrew Melnichenko <and...@daynix.com>
> Fixes: 08712fcb851034228b61f75bd922863a984a4f60
> Cc: qemu-sta...@nongnu.org
> Signed-off-by: Markus Armbruster <arm...@redhat.com>
> ---
> net/net.c | 20 ++++++++++++++++++--
> 1 file changed, 18 insertions(+), 2 deletions(-)
The adventure in QAPIfication of netdev_add has been long. Thanks for
working on this.
Reviewed-by: Eric Blake <ebl...@redhat.com>
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
