Re: [PATCH] x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h

[Borislav Petkov]

On Thu, Aug 15, 2019 at 09:59:03PM +0100, Andrew Cooper wrote:
> If you're virtualised, the write to MSR_AMD64_CPUID_FN_1 almost
> certainly won't take effect, which means userspace will still be able to
> see the bit.

msr_clear_bit() has a return value. We should check it before
doing anything further. I hope the HV actually signals the write
success/failure properly so that we get a correct return value.

-- 
Regards/Gruss,
    Boris.

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