Re: [PATCH 1/4] X86: Intel MPX definiation

[Paolo Bonzini <pbonzini@redhat.com>]

Il 02/12/2013 17:43, Liu, Jinsong ha scritto:
> From fbfa537f690eca139a96c6b2636ab5130bf57716 Mon Sep 17 00:00:00 2001
> From: Liu Jinsong <jinsong.liu@intel.com>
> Date: Fri, 29 Nov 2013 01:27:00 +0800
> Subject: [PATCH 1/4] X86: Intel MPX definiation
> 
> Signed-off-by: Xudong Hao <xudong.hao@intel.com>
> Signed-off-by: Liu Jinsong <jinsong.liu@intel.com>
> ---
>  arch/x86/include/asm/cpufeature.h |    2 ++
>  arch/x86/include/asm/xsave.h      |    5 ++++-
>  2 files changed, 6 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
> index 89270b4..1b00b01 100644
> --- a/arch/x86/include/asm/cpufeature.h
> +++ b/arch/x86/include/asm/cpufeature.h
> @@ -216,6 +216,7 @@
>  #define X86_FEATURE_ERMS	(9*32+ 9) /* Enhanced REP MOVSB/STOSB */
>  #define X86_FEATURE_INVPCID	(9*32+10) /* Invalidate Processor Context ID */
>  #define X86_FEATURE_RTM		(9*32+11) /* Restricted Transactional Memory */
> +#define X86_FEATURE_MPX		(9*32+14) /* Memory Protection Extension */
>  #define X86_FEATURE_RDSEED	(9*32+18) /* The RDSEED instruction */
>  #define X86_FEATURE_ADX		(9*32+19) /* The ADCX and ADOX instructions */
>  #define X86_FEATURE_SMAP	(9*32+20) /* Supervisor Mode Access Prevention */
> @@ -330,6 +331,7 @@ extern const char * const x86_power_flags[32];
>  #define cpu_has_perfctr_l2	boot_cpu_has(X86_FEATURE_PERFCTR_L2)
>  #define cpu_has_cx8		boot_cpu_has(X86_FEATURE_CX8)
>  #define cpu_has_cx16		boot_cpu_has(X86_FEATURE_CX16)
> +#define cpu_has_mpx		boot_cpu_has(X86_FEATURE_MPX)
>  #define cpu_has_eager_fpu	boot_cpu_has(X86_FEATURE_EAGER_FPU)
>  #define cpu_has_topoext		boot_cpu_has(X86_FEATURE_TOPOEXT)
>  
> diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h
> index 0415cda..d3e3ea5 100644
> --- a/arch/x86/include/asm/xsave.h
> +++ b/arch/x86/include/asm/xsave.h
> @@ -9,6 +9,8 @@
>  #define XSTATE_FP	0x1
>  #define XSTATE_SSE	0x2
>  #define XSTATE_YMM	0x4
> +#define XSTATE_BNDREGS	0x8
> +#define XSTATE_BNDCSR	0x10
>  
>  #define XSTATE_FPSSE	(XSTATE_FP | XSTATE_SSE)
>  
> @@ -23,7 +25,8 @@
>  /*
>   * These are the features that the OS can handle currently.
>   */
> -#define XCNTXT_MASK	(XSTATE_FP | XSTATE_SSE | XSTATE_YMM)
> +#define XCNTXT_MASK	(XSTATE_FP | XSTATE_SSE | XSTATE_YMM | \
> +			XSTATE_BNDREGS | XSTATE_BNDCSR)
>  
>  #ifdef CONFIG_X86_64
>  #define REX_PREFIX	"0x48, "
> 

hpa/Ingo/Thomas, can you give your Acked-by for this patch?

I'm not sure of the consequences of changing XCNTXT_MASK.  This series
(which was submitted with the wrong threading) wants it so that KVM can
use fpu_save_init and fpu_restore_checking to save and restore the MPX
state of the guest.

Paolo