Commit b454feb9 authored by Yu-cheng Yu's avatar Yu-cheng Yu Committed by Borislav Petkov
Browse files

x86/fpu/xstate: Add supervisor PASID state for ENQCMD 



The ENQCMD instruction reads a PASID from the IA32_PASID MSR. The
MSR is stored in the task's supervisor XSAVE* PASID state and is
context-switched by XSAVES/XRSTORS.

 [ bp: Add (in-)definite articles and massage. ]

Signed-off-by: default avatarYu-cheng Yu <yu-cheng.yu@intel.com>
Co-developed-by: default avatarFenghua Yu <fenghua.yu@intel.com>
Signed-off-by: default avatarFenghua Yu <fenghua.yu@intel.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarTony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/1600187413-163670-6-git-send-email-fenghua.yu@intel.com
parent ff4f8281

arch/x86/include/asm/fpu/types.h

+10 −1
Original line number Diff line number Diff line
@@ -114,7 +114,7 @@ enum xfeature { 
	XFEATURE_Hi16_ZMM,

	XFEATURE_PT_UNIMPLEMENTED_SO_FAR,

	XFEATURE_PKRU,

	XFEATURE_RSRVD_COMP_10,

	XFEATURE_PASID,

	XFEATURE_RSRVD_COMP_11,

	XFEATURE_RSRVD_COMP_12,

	XFEATURE_RSRVD_COMP_13,
@@ -134,6 +134,7 @@ enum xfeature { 
#define XFEATURE_MASK_Hi16_ZMM		(1 << XFEATURE_Hi16_ZMM)

#define XFEATURE_MASK_PT		(1 << XFEATURE_PT_UNIMPLEMENTED_SO_FAR)

#define XFEATURE_MASK_PKRU		(1 << XFEATURE_PKRU)

#define XFEATURE_MASK_PASID		(1 << XFEATURE_PASID)

#define XFEATURE_MASK_LBR		(1 << XFEATURE_LBR)



#define XFEATURE_MASK_FPSSE		(XFEATURE_MASK_FP | XFEATURE_MASK_SSE)
@@ -256,6 +257,14 @@ struct arch_lbr_state { 
	struct lbr_entry		entries[];

} __packed;



/*

 * State component 10 is supervisor state used for context-switching the

 * PASID state.

 */

struct ia32_pasid_state {

	u64 pasid;

} __packed;



struct xstate_header {

	u64				xfeatures;

	u64				xcomp_bv;

arch/x86/include/asm/fpu/xstate.h

+1 −1
Original line number Diff line number Diff line
@@ -35,7 +35,7 @@ 
				      XFEATURE_MASK_BNDCSR)



/* All currently supported supervisor features */

#define XFEATURE_MASK_SUPERVISOR_SUPPORTED (0)

#define XFEATURE_MASK_SUPERVISOR_SUPPORTED (XFEATURE_MASK_PASID)



/*

 * A supervisor state component may not always contain valuable information,

arch/x86/kernel/fpu/xstate.c

+5 −1
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ static const char *xfeature_names[] = 
	"AVX-512 ZMM_Hi256"		,

	"Processor Trace (unused)"	,

	"Protection Keys User registers",

	"PASID state",

	"unknown xstate feature"	,

};
@@ -51,6 +52,7 @@ static short xsave_cpuid_features[] __initdata = { 
	X86_FEATURE_AVX512F,

	X86_FEATURE_INTEL_PT,

	X86_FEATURE_PKU,

	X86_FEATURE_ENQCMD,

};



/*
@@ -318,6 +320,7 @@ static void __init print_xstate_features(void) 
	print_xstate_feature(XFEATURE_MASK_ZMM_Hi256);

	print_xstate_feature(XFEATURE_MASK_Hi16_ZMM);

	print_xstate_feature(XFEATURE_MASK_PKRU);

	print_xstate_feature(XFEATURE_MASK_PASID);

}



/*
@@ -592,6 +595,7 @@ static void check_xstate_against_struct(int nr) 
	XCHECK_SZ(sz, nr, XFEATURE_ZMM_Hi256, struct avx_512_zmm_uppers_state);

	XCHECK_SZ(sz, nr, XFEATURE_Hi16_ZMM,  struct avx_512_hi16_state);

	XCHECK_SZ(sz, nr, XFEATURE_PKRU,      struct pkru_state);

	XCHECK_SZ(sz, nr, XFEATURE_PASID,     struct ia32_pasid_state);



	/*

	 * Make *SURE* to add any feature numbers in below if
@@ -601,7 +605,7 @@ static void check_xstate_against_struct(int nr) 
	if ((nr < XFEATURE_YMM) ||

	    (nr >= XFEATURE_MAX) ||

	    (nr == XFEATURE_PT_UNIMPLEMENTED_SO_FAR) ||

	    ((nr >= XFEATURE_RSRVD_COMP_10) && (nr <= XFEATURE_LBR))) {

	    ((nr >= XFEATURE_RSRVD_COMP_11) && (nr <= XFEATURE_LBR))) {

		WARN_ONCE(1, "no structure for xstate: %d\n", nr);

		XSTATE_WARN_ON(1);

	}

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