From mboxrd@z Thu Jan  1 00:00:00 1970
From: Scott Wood <scottwood@freescale.com>
Subject: Re: [PATCH 08/50] KVM: PPC: Add support for explicit HIOR setting
Date: Thu, 5 Jan 2012 11:16:15 -0600
Message-ID: <4F05DADF.4010403@freescale.com>
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Cc: <kvm-ppc@vger.kernel.org>, kvm list <kvm@vger.kernel.org>,
	Avi Kivity <avi@redhat.com>,
	Marcelo Tosatti <mtosatti@redhat.com>
To: Alexander Graf <agraf@suse.de>
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On 01/04/2012 08:36 PM, Alexander Graf wrote:
> 
> On 04.01.2012, at 21:12, Scott Wood wrote:
> 
>> On 01/03/2012 07:10 PM, Alexander Graf wrote:
>>> diff --git a/arch/powerpc/include/asm/kvm.h b/arch/powerpc/include/asm/kvm.h
>>> index 25964ee..fb3fddc 100644
>>> --- a/arch/powerpc/include/asm/kvm.h
>>> +++ b/arch/powerpc/include/asm/kvm.h
>>> @@ -327,4 +327,6 @@ struct kvm_book3e_206_tlb_params {
>>> 	__u32 reserved[8];
>>> };
>>>
>>> +#define KVM_ONE_REG_PPC_HIOR	KVM_ONE_REG_PPC | 0x100
>>
>> Where does 0x100 come from?
> 
> I quite frankly don't remember :). This could just as well be 0 or 1.
> 
>> There should probaly be some structure to the register space, with a
>> subarch field distinguishing between "common SPR", "book3s SPR", "book3e
>> SPR", along with others for non-SPR registers, KVM inventions, etc.
> 
> Not sure we really need this. I would very much prefer to just always
> use the textual representation. What would we do if something book3s
> specific suddenly becomes generic (like Altivec for example, or
> FPU)?

Good point... A plain enumeration should be fine.  0x100 was strange
enough that it left me wondering what the value should be for the next
register to be added -- I didn't want it to turn into something like the
booke regs->trap mess, where some exceptions re-use the classic offsets,
and other exceptions have numbers that seem to be pulled from out of
nowhere.

-Scott