Re: [PATCH 08/26] KVM: PPC: Add PV guest critical sections

Alexander Graf
2010-06-27T12:06:01Z

Am 27.06.2010 um 13:53 schrieb Avi Kivity <avi-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>:

> On 06/27/2010 02:49 PM, Alexander Graf wrote:
>>
>> Am 27.06.2010 um 12:59 schrieb Avi Kivity <avi-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>:
>>
>>> On 06/27/2010 01:33 PM, Alexander Graf wrote:
>>>>> Or inc/dec...
>>>>
>>>>
>>>> Uh - huh? How would that help?
>>>
>>> inc shared->critical # disable interrupts
>>
>> There is no opcode in the ppc isa that acts on momery without
>> involving a register.
>>
>> An inc would be:
>>
>> ld rX, A(0)
>> addi rX, rX, 1
>> std rX, A(0)
>
> Right, I was agreeing with you. I meant there was no inc/dec mem
> insns.

Ah, I see :). I think that's really the only point where I deem the
x86 isa superior :).

Alex