Re: [libvirt] Re: [Qemu-devel] [PATCH 1/6] Allow multiple monitor devices (v2)
Daniel P. Berrange wrote:
Yes indeed its a little crazy :-) As anthony mentioned if libvirt
were
able to be notified of changes a user makes in the monitor, there's no
reason we could not allow end users to access the monitor of a VM
libvirt is managing. We just need to make sure libvirt doesn't miss
changes like attaching or detaching block devices, etc, because that'll
cause crash/data loss later when libvirt migrates or does save/restore,
etc because it'll launch QEMU with wrong args
You still have an inherent race here.
user: plug in disk
libvirt: start migration, still without disk
qemu: libvirt, a disk has been plugged in.
> I don't see how adding those low-level monitory things to
libvirt is
> an improvement - debugging and scripted keystrokes are not the sort of
> functionality libvirt is for - or is it?
>
I think it could probably be argued that sending fake keystrokes could
be within scope. Random ad-hoc debugging probably out of scope.
That means that to debug a problem in the field you have to locate a
guest's host, and follow it around as it migrates (or disable migration).
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.