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From: Alexander Graf <agraf@suse.de>
To: Avi Kivity <avi@redhat.com>
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Subject: Re: [PATCH 08/26] KVM: PPC: Add PV guest critical sections
Date: Sun, 27 Jun 2010 13:49:36 +0200
Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	KVM list <kvm@vger.kernel.org>,
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Am 27.06.2010 um 12:59 schrieb Avi Kivity <avi@redhat.com>:

> 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)

Alex
>