[RFC 07/13] KVM: arm64: ITS: Change entry_size and indirect bit in BASER

[Auger Eric]

Hi Marc,

On 12/01/2017 18:05, Marc Zyngier wrote:
> On 12/01/17 15:56, Eric Auger wrote:
>> Change the device table entry_size to 16 bytes instead of 8.
>> We also Store the device and collection device in the its
>> struct.
>>
>> The patch also clears the indirect bit for the device BASER.
>> The indirect bit is set as read-only.
> 
> Err... Why? We *really* want to continue supporting indirect tables, as
> this is a massive memory saver for the guest.
> 
>>
>> Signed-off-by: Eric Auger <eric.auger at redhat.com>
>>
>> ---
>>
>> TODO: investigate support of 2 level tables, ie. enabling
>> Indirect = 1. Support of 2 level tables is implementation
>> defined.
> 
> Clearly, that's a regression. What exactly is the issue that decided you
> to disable it?
Well no valuable reason besides I saw it was optional, lack of
time/knowledge and a bit of laziness. I will address this requirement in
my next respin.

For my curiosity why did we choose not allowing the feature for
collections. Is that just because we think their number if going
sufficiently small compared to devices?

Thanks

Eric
> 
> Thanks,
> 
> 	M.
>