Re: [RFC PATCH v4 02/27] x86/fpu/xstate: Change some names to separate XSAVES system and user states

[Peter Zijlstra]

On Fri, Sep 21, 2018 at 08:03:26AM -0700, Yu-cheng Yu wrote:

> diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
> index a38bf5a1e37a..f1f9bf91a0ab 100644
> --- a/arch/x86/include/asm/fpu/internal.h
> +++ b/arch/x86/include/asm/fpu/internal.h
> @@ -93,7 +93,8 @@ static inline void fpstate_init_xstate(struct xregs_state *xsave)
>  	 * XRSTORS requires these bits set in xcomp_bv, or it will
>  	 * trigger #GP:
>  	 */
> -	xsave->header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT | xfeatures_mask;
> +	xsave->header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT |
> +			xfeatures_mask_user;

I would be OK with that line extending to 82 characters..

>  }
>  
>  static inline void fpstate_init_fxstate(struct fxregs_state *fx)

> diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
> index 87a57b7642d3..19f8df54c72a 100644
> --- a/arch/x86/kernel/fpu/xstate.c
> +++ b/arch/x86/kernel/fpu/xstate.c

> @@ -421,7 +421,8 @@ static void __init setup_init_fpu_buf(void)
>  	print_xstate_features();
>  
>  	if (boot_cpu_has(X86_FEATURE_XSAVES))
> -		init_fpstate.xsave.header.xcomp_bv = (u64)1 << 63 | xfeatures_mask;
> +		init_fpstate.xsave.header.xcomp_bv =
> +			BIT_ULL(63) | xfeatures_mask_user;

If you do that, the if () needs { } per coding style.

>  
>  	/*
>  	 * Init all the features state with header.xfeatures being 0x0