Re: [PATCH 5.10 38/58] KVM: arm64: Allow indirect vectors to be used without SPECTRE_V3A

James Morse
2022-03-15T12:27:45Z

On 3/15/22 12:20 PM, James Morse wrote:
> On 3/11/22 6:42 AM, Greg Kroah-Hartman wrote:
>> On Fri, Mar 11, 2022 at 12:48:59AM +0100, Pavel Machek wrote:
>>> What is going on here?
>>>
>>>> commit 5bdf3437603d4af87f9c7f424b0c8aeed2420745 upstream.
>>>
>>> Upstream commit 5bdf is very different from this. In particular,
>>>
>>>>   arch/arm64/kvm/hyp/smccc_wa.S    |   66 +++++++++++++++++++++++++++++++++++++++
>>>
>>> I can't find smccc_wa.S, neither in mainline, nor in -next. And it
>>> looks buggy. I suspect loop_k24 should loop 24 times, but it does 8
>>> loops AFAICT. Same problem with loop_k32.
>
> Yup, that's a bug. Thanks for spotting it!
> I'll post a replacement for this patch.

Looking more closely at this: when I originally did this the 'new' code for stable was
in a separate patch to make it clear it was new code. Here it looks like Greg has merged
it into this patch.
I'm not sure what the 'rules' are for this sort of thing, obviously Greg gets the last say.

I'll try and restructure the other backports to look like this, it is certainly simpler
than trrying to pull all the prerequisites for all the upstream patches in.

Thanks,

James