When I tried chardev-change, it reports this error:
{
"error": {
"class": "GenericError",
"desc": "Chardev user does not support chardev hotswap"
}
}
On Fri, Apr 16, 2021 at 11:33 AM Markus Armbruster <[email protected]> wrote:
>
> Li Zhang <[email protected]> writes:
>
> > On Tue, Apr 13, 2021 at 8:41 AM Markus Armbruster <[email protected]> wrote:
> >>
> >> Li Zhang <[email protected]> writes:
> >>
> >> > From: Li Zhang <[email protected]>
> >> >
> >> > For some scenarios, it needs to hot-add a monitor device.
> >> > But QEMU doesn't support hotplug yet. It also works by adding
> >> > a monitor with null backend by default and then change its
> >> > backend to socket by QMP command "chardev-change".
> >> >
> >> > So this patch is to support monitor chardev hotswap with QMP.
> >> >
> >> > Signed-off-by: Li Zhang <[email protected]>
> >>
> >> I think what what you're trying to say is that chardev-change does not
> >> work when the character device changes is used by a QMP monitor.
> >> Correct?
> >>
> > I mean that when the character device is a monitor device, it doesn't
> > work with a QMP monitor.
> > For example, I add 2 QMP monitors and change one of the monitor's
> > backends from socket to a null device.
> > It doesn't work because it needs the monitor device to support
> > chardev-change.
> >
> >> If yes, how exactly does it misbehave?
> > This command chardev-change needs specific device's change callback
> > function.
>
> Yes, but what happens if you try anyway? I'm asking, because I'd like
> the answer to be worked into the commit message.
>
> >> Does it work with an HMP monitor?
> > No, it doesn't work.
>
--
Best Regards
-Li
