On Thu, May 30, 2024 at 11:59:36 +0200, Michal Privoznik wrote:
> In one of my recent commits, I've introduced
> virDomainInterfaceClearQoS() which is a helper that either calls
> virNetDevBandwidthClear() ('tc' implementation) or
> virNetDevOpenvswitchInterfaceClearQos() (for ovs ifaces). But I
> made a micro optimization which leads to a bug: the function
> checks whether passed iface has any QoS set and returns early if
> it has none. In majority of cases this is right thing to do, but
> when removing QoS on virDomainUpdateDeviceFlags() this is
> problematic. The new definition (passed as argument to
> virDomainInterfaceClearQoS()) contains no QoS (because user
> requested its removal) and thus instead of removing the old QoS
> setting nothing is done.
>
> Fortunately, the fix is simple - pass olddev which contains the
> old QoS setting.
>
> Fixes: 812a146dfe784315edece43d09f8d9e432f8230e
> Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx>
> ---
> src/qemu/qemu_hotplug.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
> index 4739beead8..c98b0b5d52 100644
> --- a/src/qemu/qemu_hotplug.c
> +++ b/src/qemu/qemu_hotplug.c
> @@ -4071,7 +4071,7 @@ qemuDomainChangeNet(virQEMUDriver *driver,
> goto cleanup;
> }
> } else {
> - if (virDomainInterfaceClearQoS(vm->def, newdev) < 0)
> + if (virDomainInterfaceClearQoS(vm->def, olddev) < 0)
> goto cleanup;
> }
>
Reviewed-by: Jiri Denemark <jdenemar@xxxxxxxxxx>
