Re: [Qemu-devel] [PATCH] xen: make xen-platform a default device

[Fabio Fantoni <fabio.fantoni@m2r.biz>]

Il 23/05/2014 16:30, Stefano Stabellini ha scritto:
> On Fri, 23 May 2014, Fabio Fantoni wrote:
>>> One issue is that -M pc didn't always work with Xen. Now it does and we
>>> are already relying on it in libxl since
>>> 2bc047635b51abd41c917aa2b813211ee0de2c38. It is safe because all QEMU
>>> releases from 1.6 onward work well with Xen and -M pc. Older QEMU
>>> releases are considered ancient and unmaintained. This is what I was
>>> referring to in my last reply. I really meant "we should move away from
>>> xenfv and use a pc.* machine that does not create xen-platform by
>>> default".
>>>
>>> As you say the other issue is the version of the pc machine, especially
>>> in relation to save/restore. However since:
>>>
>>> commit 2bc047635b51abd41c917aa2b813211ee0de2c38
>>> Author: Anthony PERARD <address@hidden>
>>> Date:   Wed Nov 27 18:21:34 2013 +0000
>>>
>>>       libxl: Handle xen_platform_pci=0 case with qemu-xen.
>>>
>>> we are simply calling QEMU with -M pc if xen_platform_pci=0. I think we
>>> should change that too and backport the patch to 4.4. pc-i440fx-1.6
>>> seems like a good choice to me.
>> Use "-M pc" as default seems a good idea.
>> Use specific version maybe too.
>> This way the base hardware should stay the same even if updating qemu, is
>> right?
> Yep
>
>
>> If yes, this should also solve possible problem like windows
>> reactivation request for different hardware, right?
> Right
>
>
>> How about create also xl parameter to select the "pc" model?
> Having a VM config parameter for it is OK. In the past I argued against
> relying on such a parameter to solve all compatibility issues with QEMU
> because I would like libxl to be able to select the right QEMU machine
> automatically, without user intervention.  But the option could still be
> useful for debugging.
>

Excellent