Re: Relax CPU features sanity checking on heterogeneous architectures

[Stephen Boyd]

Quoting Sai Prakash Ranjan (2019-10-11 06:40:13)
> On 2019-10-11 19:04, Marc Zyngier wrote:
> > On Fri, 11 Oct 2019 18:47:39 +0530
> > Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx> wrote:
> > 
> >> Hi Mark,
> >> 
> >> Thanks a lot for the detailed explanations, I did have a look at all 
> >> the variations before posting this.
> >> 
> >> On 2019-10-11 16:20, Mark Rutland wrote:
> >> > Hi,
> >> >
> >> > On Fri, Oct 11, 2019 at 11:19:00AM +0530, Sai Prakash Ranjan wrote:
> >> >> On latest QCOM SoCs like SM8150 and SC7180 with big.LITTLE arch, below
> >> >> warnings are observed during bootup of big cpu cores.
> >> >
> >> > For reference, which CPUs are in those SoCs?
> >> >
> >> 
> >> SM8150 is based on Cortex-A55(little cores) and Cortex-A76(big cores). 
> >> I'm afraid I cannot give details about SC7180 yet.
> >> 
> >> >> SM8150:
> >> >> >> [    0.271177] CPU features: SANITY CHECK: Unexpected variation in
> >> >> SYS_ID_AA64PFR0_EL1. Boot CPU: 0x00000011112222, CPU4: >> 0x00000011111112
> >> >
> >> > The differing fields are EL3, EL2, and EL1: the boot CPU supports
> >> > AArch64 and AArch32 at those exception levels, while the secondary only
> >> > supports AArch64.
> >> >
> >> > Do we handle this variation in KVM?
> >> 
> >> We do not support KVM.
> > 
> > Mainline does. You don't get to pick and choose what is supported or
> > not.
> > 
> 
> Ok thats good.
> 

I want KVM on sc7180. How do I get it? Is something going to not work?