[Skiboot] [PATCH v5 02/10] xive: Set the fused core mode properly

[Cédric Le Goater]

Hello Vaidy,

On 5/6/20 1:49 PM, Vaidyanathan Srinivasan wrote:
> * C?dric Le Goater <clg at kaod.org> [2020-04-25 15:14:32]:
> 
>> On 4/22/20 7:04 AM, Vaidyanathan Srinivasan wrote:
>>> From: Benjamin Herrenschmidt <benh at kernel.crashing.org>
>>>
>>> Set or clear the fused core mode bit in the XIVE inits
>>> properly. While HostBoot is supposed to do it, I prefer
>>> not depending on it doing the right thing, since we already
>>> configure that register ourselves anyway.
>>>
>>> Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
>>> Signed-off-by: Michael Neuling <mikey at neuling.org>
>>
>> I suppose that the thread enablement in the presenter is correct ? 
>> This was never tested AFAICT.
> 
> Hi Cedric,
> 
> General host stability with interrupts tested ok.  KVM guests are also
> ok.  

Great. 

We have done fixes recently to increase the maximum number of guests. 
We were limited to 128 in the past, so much less that the number of 
available HW threads. Have you tried to push the limits ? 

> Is there a specific test that we should run and observe to verify this
> enablement?

Nah. It's just that the fused cored initialization is not used very
often in XIVE driver. It should be fine with the above. 

Thanks,
C.