[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command l
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command line |
Date: |
Thu, 29 Jan 2015 15:46:35 +0000 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
* Daniel P. Berrange (address@hidden) wrote:
> On Thu, Jan 29, 2015 at 03:22:55PM +0000, Dr. David Alan Gilbert wrote:
> > * Daniel P. Berrange (address@hidden) wrote:
> > > On Thu, Jan 29, 2015 at 03:06:37PM +0000, Dr. David Alan Gilbert (git)
> > > wrote:
> > > > From: "Dr. David Alan Gilbert" <address@hidden>
> > > >
> > > > For an incoming migration it's potentially useful to be able to set
> > > > capabilities and parameters prior to opening the connection, while
> > > > a separate option for that would have been possible it seems better
> > > > to give access to all the existing migration capabilities, parameters
> > > > etc. The least restrictive way of doing this is to allow arbitrary
> > > > QMP commands to be executed prior to the -incoming being processed.
> > > >
> > > > As an example:
> > > >
> > > > ./bin/qemu-system-x86_64 -nographic -nodefaults -qmp-command
> > > > '{"execute": "migrate-set-capabilities",
> > > > "arguments":{"capabilities":[{"capability":"xbzrle","state":true}]}}'
> > > > -qmp-command '{"execute": "query-migrate-capabilities"}' -incoming
> > > > tcp::444
> > >
> > > I'm unclear how we'd easily deal with the response from commands
> > > invoked this way, to get replies and/or errors. Also, it might
> > > be the case that we need to conditionally run certain commands
> > > depending on the result of earlier commands.
> > >
> > > Wouldn't it make more sense to simply add a 'migrate_incoming' QMP
> > > command, and stop using -incoming altogether, so we just have normal
> > > QMP access ?
> > >
> > > eg,
> > >
> > > # qemu-system-x86_64 ....device args... -S
> > > (qmp) ....arbitrary QMP commands ..
> > > (qmp) {"execute":"migrate-incoming", "arguments": { "uri": "tcp::44"
> > > }}
> >
> > I'm a bit worried about whether starting an incoming migrate afterwards is
> > different in any subtle way. I can see there are a handful of devices that
> > have 'runstate_check(RUN_STATE_INMIGRATE)' calls in, and thus I'm not sure
> > that starting a paused VM and then flipping to RUN_STATE_INMIGRATE would
> > be quite the same.
> >
> > Having said that, we do have 'loadvm' that's similar to an incoming
> > migration.
>
> Yep, existance of 'loadvm' does give confidence that this should work with
> migration, hopefully only needing a few cleanups for the state check you
> mention above.
Hmm I'm not sure; I've had a dig and the tests for INMIGRATE do a lot of random
things; qxl, usb, and blockdev for starters, and the block stuff sets a flag
that is then passed to qcow and other backends that do stuff all over with it.
Howver, something like:
-incoming pause
followed by the monitor command later should work - how do you feel
about that?
Dave
>
>
> Regards,
> Daniel
> --
> |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :|
> |: http://libvirt.org -o- http://virt-manager.org :|
> |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :|
> |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK
- Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command line, (continued)
- Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command line, Daniel P. Berrange, 2015/01/30
- Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command line, Markus Armbruster, 2015/01/30
- Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command line, Dr. David Alan Gilbert, 2015/01/30
- Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command line, Markus Armbruster, 2015/01/30
- Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command line, Markus Armbruster, 2015/01/30
- Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command line, Dr. David Alan Gilbert, 2015/01/29
- Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command line, Daniel P. Berrange, 2015/01/29
- Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command line,
Dr. David Alan Gilbert <=
- Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command line, Eric Blake, 2015/01/29
- Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command line, Dr. David Alan Gilbert, 2015/01/29
- Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command line, Daniel P. Berrange, 2015/01/29
- Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command line, Paolo Bonzini, 2015/01/30
- Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command line, Dr. David Alan Gilbert, 2015/01/30
- Re: [Qemu-devel] [RFC 1/1] Execute arbitrary QMP commands from command line, Paolo Bonzini, 2015/01/30
Re: [Qemu-devel] [RFC 0/1] Incoming migration vs early monitor commands, Eric Blake, 2015/01/29
Re: [Qemu-devel] [RFC 0/1] Incoming migration vs early monitor commands, Paolo Bonzini, 2015/01/29