Re: [Qemu-devel] [PATCH v5 04/36] ppc/xive: introduce the XiveRouter model

[Cédric Le Goater]

On 11/22/18 7:50 AM, Benjamin Herrenschmidt wrote:
> On Thu, 2018-11-22 at 15:44 +1100, David Gibson wrote:
>>
>> Sorry, didn't think of this in my first reply.
>>
>> 1) Does the hardware ever actually write back to the EAS?  I know it
>> does for the END, but it's not clear why it would need to for the
>> EAS.  If not, we don't need the setter.
> 
> Nope, though the PAPR model will via hcalls

Indeed. The H_INT_SET_SOURCE_CONFIG hcall updates the EAT.

>> 2) The signatures are a bit odd here.  For the setter, a value would
>> make sense than a (XiveEAS *), since it's just a word.  For the getter
>> you could return the EAS value directly rather than using a pointer -
>> there's already a valid bit in the EAS so you can construct a value
>> with that cleared if the lisn is out of bounds.

Yes we could. I think I made it that way to be consistent with the 
other XIVE internal structures which are bigger : END, NVT

There might be other reasons in Pnv. One was to use generic accessors 
to the guest RAM but I didn't do it finally. Take a look at the Pnv
model and we might decide to change the prototype then. I don't 
think it's a major change.

Thanks,

C.