Re: [Qemu-devel] [RESEND][PATCH v3] Generalize -machine command line option

[Markus Armbruster <armbru@redhat.com>]

Jan Kiszka <jan.kiszka@siemens.com> writes:

> On 2011-07-25 12:45, Richard W.M. Jones wrote:
>> On Mon, Jul 25, 2011 at 12:33:01PM +0200, Jan Kiszka wrote:
>>> On 2011-07-25 11:41, Richard W.M. Jones wrote:
>>>> On Sat, Jul 23, 2011 at 12:38:37PM +0200, Jan Kiszka wrote:
>>>>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>>>>
>>>>> -machine somehow suggests that it selects the machine, but it doesn't.
>>>>> Fix that before this command is set in stone.
>>>>>
>>>>> Actually, -machine should supersede -M and allow to introduce arbitrary
>>>>> per-machine options to the command line. That will change the internal
>>>>> realization again, but we will be able to keep the user interface
>>>>> stable.
>>>>
>>>> This breaks libguestfs which was doing:
>>>>
>>>>   qemu -machine accel=kvm:tcg ...
>>>>
>>>> We are not passing any -M option at all.  We don't particularly care
>>>> about the machine type since we're not that performance sensitive and
>>>> we don't need to serialize the machine state.
>>>>
>>>> I have checked, and this works:
>>>>
>>>>   qemu -machine pc,accel=kvm:tcg ...
>>>>
>>>> "pc" is the default, right?  What about for other architectures?
>>>
>>> Yes, pc is the right default. Other arch have other defaults.
>> 
>> So what you're saying is we have to parse qemu -machine \? output by
>> looking for the string '(default)'?  eg:
>> 
>> $ ./arm-softmmu/qemu-system-arm -machine \?|fgrep '(default)'
>> integratorcp ARM Integrator/CP (ARM926EJ-S) (default)
>> 
>> $ ./i386-softmmu/qemu -machine \?|fgrep '(default)'
>> pc-0.14    Standard PC (default)
>
> I understand, this is clumsy. Will see if we can do better.

Is there a technical reason why type isn't optional with -machine?

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