Re: [Qemu-devel] [PATCH 2/10] Allow the monitor to be suspended during non-blocking op

Avi Kivity
2008-09-10T06:52:30Z

Anthony Liguori wrote:
> Live migration happens in the background, but it is useful to make the monitor
> command appear as if it's blocking. This allows a management tool to
> immediately know when the live migration has completed without having to poll
> the migration status.
>
> This patch allows the monitor to be suspended from a monitor callback which
> will prevent new monitor commands from being executed.
>
>

This means that migration is no longer transparent. While migration is
going on, you can't change the cdrom media, look at cpu registers, or do
anything that requires the monitor.

This both reduces the functionality and complicates management
applications. IMO migration should have asynchronous notification (and
no, I don't think multiple monitors is the correct solution).

--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.