Re: [Qemu-devel] [SeaBIOS] [PATCH] don't expose pvpanic device in the UI

[Gleb Natapov]

On Tue, Aug 06, 2013 at 03:05:52PM +0300, Michael S. Tsirkin wrote:
> On Tue, Aug 06, 2013 at 03:00:06PM +0300, Gleb Natapov wrote:
> > On Tue, Aug 06, 2013 at 01:23:49PM +0200, Andreas Färber wrote:
> > > Am 06.08.2013 13:00, schrieb Gleb Natapov:
> > > > On Tue, Aug 06, 2013 at 12:35:10PM +0200, Andreas Färber wrote:
> > > >> I wonder if IPMI might be such an alternative in the future, in which
> > > >> case we should come up with some way to fully disable pvpanic device
> > > >> creation. CC'ing Corey.
> > > >>
> > > > IPMI was considered, to complicated for what was needed.
> > > 
> > > Sorry? There's nothing wrong with going for pvpanic as a simple
> > > implementation.
> > > 
> > Sure, why "sorry" then? :) PV has its benefits.
> 
> PV always seems easier. It sometimes becomes a maintainance problem
> down the way though.
> 
If it is modelled as proper device, why? What PV devices we have that are pain?

> > > There have been IPMI patchsets on qemu-devel though, and SUSE will be
> > > investigating adding some IPMI support too (not sure if identical to the
> > > scope of those patchsets), whether IPMI is complicated or not. It's a
> > > standard present on physical servers, facilitating unified management of
> > > virtual and physical servers, and there's OpenIPMI as implementation.
> > > 
> > Of course, there is nothing wrong with implementing IPMI either. Many
> > problems that IPMI solves are much simpler to solve in virtualized
> > environment with management software and pvpanic closes one gap
> > between what IPMI provides and virtual machine management can do.
> > 
> > > My point was, there may be alternative, non-PV implementations to suck
> > > such information out of a guest, IPMI being one example of a management
> > > interface that exists for physical servers. So it's not necessarily
> > > black-or-white, but choices similar to virtio vs. IDE vs. AHCI vs. SCSI.
> > > 
> > pvpanic not meant to replace IPMI though.
> 
> But will you want pvpanic if you have IPMI?
> 
Why not? They report to different components.

--
                        Gleb.