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Commit 69496e10 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86/fpu: Print supported xstate features in human readable way 



Inform the user/admin about which xstate features the kernel supports.

Reviewed-by: default avatarBorislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 32d4d9cc

arch/x86/kernel/fpu/xsave.c

+25 −0
Original line number Diff line number Diff line
@@ -482,6 +482,30 @@ static void __init setup_xstate_features(void) 
	} while (1);

}



static void print_xstate_feature(u64 xstate_mask, const char *desc)

{

	if (pcntxt_mask & xstate_mask) {

		int xstate_feature = fls64(xstate_mask)-1;



		pr_info("x86/fpu: Supporting XSAVE feature %2d: '%s'\n", xstate_feature, desc);

	}

}



/*

 * Print out all the supported xstate features:

 */

static void print_xstate_features(void)

{

	print_xstate_feature(XSTATE_FP,		"x87 floating point registers");

	print_xstate_feature(XSTATE_SSE,	"SSE registers");

	print_xstate_feature(XSTATE_YMM,	"AVX registers");

	print_xstate_feature(XSTATE_BNDREGS,	"MPX bounds registers");

	print_xstate_feature(XSTATE_BNDCSR,	"MPX CSR");

	print_xstate_feature(XSTATE_OPMASK,	"AVX-512 opmask");

	print_xstate_feature(XSTATE_ZMM_Hi256,	"AVX-512 Hi256");

	print_xstate_feature(XSTATE_Hi16_ZMM,	"AVX-512 ZMM_Hi256");

}



/*

 * This function sets up offsets and sizes of all extended states in

 * xsave area. This supports both standard format and compacted format
@@ -545,6 +569,7 @@ static void __init setup_init_fpu_buf(void) 
		return;



	setup_xstate_features();

	print_xstate_features();



	if (cpu_has_xsaves) {

		init_xstate_buf->xsave_hdr.xcomp_bv =