Re: [PATCH v2 9/9] x86/xsaves: Re-enable XSAVES

From: Yu-cheng Yu
Date: Thu Feb 25 2016 - 16:05:32 EST


On Thu, Feb 25, 2016 at 12:34:59PM -0800, Dave Hansen wrote:
> On 02/25/2016 12:26 PM, Yu-cheng Yu wrote:
> > - * ( This is easy to backport while we are fixing
> > - * XSAVES* support. )
> > + * Most recent CPUs supporting XSAVES can run 64-bit mode.
> > + * Enable XSAVES for 64-bit.
> > */
> > - setup_clear_cpu_cap(X86_FEATURE_XSAVES);
> > + if (!config_enabled(CONFIG_X86_64))
> > + setup_clear_cpu_cap(X86_FEATURE_XSAVES);
> > }
>
> Is this intended to be permanent? If so, we would not be able to
> support any future supervisor features on 32-bit.

I was thinking of the 64-bit-only change, but then decided to put it out
for discussion.

Yu-cheng