Re: [Qemu-devel] Bug in option parsing

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2012-08-22 17:58, Martin Kletzander wrote:
> On 08/22/2012 05:15 PM, Jan Kiszka wrote:
>> On 2012-08-22 17:05, Martin Kletzander wrote:
>>> Hi everybody,
>>>
>>> while coding the support for Jason's dump-guest-core option I realized
>>> there is (probably) a problem with the way QEMU parses additional
>>> machine options ('dump-guest-core', 'kvm_shadow_mem' etc.). Running QEMU
>>> with option to -machine works ok, but using '-M' (as libvirt does) works
>>> only w/o additional options, otherwise it ends in an error (the whole
>>> string is probably parsed as a machine name).
>>>
>>> Is '-M' so obsolete it shouldn't be used at all or is it just an bug? We
>>> still use '-M' everywhere I know and '-machine' isn't compatible with
>>> older versions and different builds of QEMU.
>>>
>>> Should I file a bug or do we have to drop '-M' for this situations?
>>
>> If libvirt uses -M just like -machine, i.e. with more than a machine
>> name, that would be a libvirt bug (but that would have been noticed much
>> earlier - did you patch something?). QEMU only keeps -M <machine-name>
>> around to please existing users that didn't switch yet. It is NOT an
>> alias for -machine.
>>
> 
> There is no option *yet* that libvirt would like to use as an additional
> option for machine type, but I'm working on the first one and I've hit this.
> 
> So your suggestion would be to use -machine wherever it's possible and
> fallback to -M only when -machine is not supported?

Yep.

Jan

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