Re: [libvirt] Re: [Qemu-devel] [PATCH 1/6] Allow multiple monitor devices (v2)
On Tue, Apr 14, 2009 at 12:15:23PM +0300, Avi Kivity wrote:
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.
That is true, but we'd still be considering direct monitor access to
be a 'expert' user mode of use. If they wish to shoot themselves in
the foot by triggering a migration at same time they are hotplugging
I'm fine if their whole leg gets blown away.
Daniel
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