Re: [Qemu-devel] [PATCH] Introduce -accel command option.

[Alexander Graf]

On 16.11.2010, at 17:55, Daniel P. Berrange wrote:

> On Tue, Nov 16, 2010 at 10:41:25AM -0600, Anthony Liguori wrote:
>> On 11/16/2010 10:10 AM, Anthony PERARD wrote:
>>> On Mon, 15 Nov 2010, Anthony Liguori wrote:
>>> 
>>> 
>>>> On 11/15/2010 09:45 AM, address@hidden wrote:
>>>> 
>>>>> From: Anthony PERARD<address@hidden>
>>>>> 
>>>>> This option gives the ability to switch one "accelerator" like kvm, xen
>>>>> or the default one tcg. We can specify more than one accelerator by
>>>>> separate them by a comma. QEMU will try each one and use the first whose
>>>>> works.
>>>>> 
>>>>> So,
>>>>> 
>>>>> -accel xen,kvm,tcg
>>>>> 
>>>>> which would try Xen support first, then KVM and finaly tcg if none of
>>>>> the other works.
>>>>> 
>>>>> 
>>>> Should use QemuOpts instead of parsing by hand.
>>>> 
>>> Ok for that.
>>> 
>>> 
>>>> I'd rather it be
>>>> presented as a -machine option too with accel=xen:kvm:tcg to specify 
>>>> order.
>>>> 
>>> This is not clear to me, did you mean that you prefer to have both
>>> "-accel accels" and "-machine accel=accels" options?
>>> 
>> 
>> Just -machine accel=accels.
>> 
>> Part of my rational is that accelerator is a machine property.  If you 
>> do -M xenpv it ought to imply -machine accel=xen.
> 
> Surely, only if it is running on a Xen Dom0. If you use -M xenpv on a KVM
> host, then -M xenpv should imply -machine accel=kvm (ie it would be using
> xenner)

Actually, it should imply -machine accel=kvm,tcg :). Accelerators really are 
not a machine property. In an ideal world, -M pc would just work with xen hvm 
if -accel xen is given.


Alex