Re: [patch 13/31] x86/fpu: Move KVMs FPU swapping to FPU core

Thomas Gleixner
2021-10-12T18:27:08Z

On Tue, Oct 12 2021 at 20:25, Thomas Gleixner wrote:

> On Tue, Oct 12 2021 at 18:53, Borislav Petkov wrote:
>> On Tue, Oct 12, 2021 at 02:00:17AM +0200, Thomas Gleixner wrote:
>>> /*
>>> - * Guests with protected state can't have it set by the hypervisor,
>>> - * so skip trying to set it.
>>> + * Guest with protected state have guest_fpu == NULL which makes
>>
>> "Guests ... "
>>
>>> + * the swap only safe the host state. Exclude PKRU from restore as
>>
>> "save"
>
> No I meant safe, but let me rephrase it, Swap does both save and
> restore. But it's not safe to dereference a NULL pointer :)
>
> .... makes the swap only handle the host state. Exclude PKRU from restore as

Gah. I should have looked at the context first. "save" is correct
here. Oh well...