Re: KVM guest sometimes failed to boot because of kernel stack overflow if KPTI is enabled on a hisilicon ARM64 platform.

[James Morse]

Hi Wei,

On 20/06/18 16:52, Wei Xu wrote:
> On 2018/6/20 22:42, Will Deacon wrote:
>> Hmm, I wonder if this is at all related to RAS, since we've just enabled
>> that and if we take a fault whilst rewriting swapper then we're going to
>> get stuck. What happens if you set CONFIG_ARM64_RAS_EXTN=n in the guest?
> 
> I will try it now.

It's not just the Kconfig symbol, could you also revert:

f751daa4f9d3 ("arm64: Unconditionally enable IESB on exception entry/return for
firmware-first")


(reverts and build cleanly on 4.17)


Thanks,

James