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From: Yu-cheng Yu <yu-cheng.yu@intel.com>
Date: Tue, 15 Sep 2020 09:30:09 -0700
Subject: x86/fpu/xstate: Add supervisor PASID state for ENQCMD
Git-commit: b454feb9abc1a9ee876fb84bfea0fc8d726f5bc4
Patch-mainline: v5.10-rc1
References: jsc#13318

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: Yu-cheng Yu <yu-cheng.yu@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/1600187413-163670-6-git-send-email-fenghua.yu@intel.com
---
 arch/x86/include/asm/fpu/types.h  |   11 ++++++++++-
 arch/x86/include/asm/fpu/xstate.h |    2 +-
 arch/x86/kernel/fpu/xstate.c      |    4 ++++
 3 files changed, 15 insertions(+), 2 deletions(-)

--- a/arch/x86/include/asm/fpu/types.h
+++ b/arch/x86/include/asm/fpu/types.h
@@ -114,7 +114,7 @@ enum xfeature {
 	XFEATURE_Hi16_ZMM,
 	XFEATURE_PT_UNIMPLEMENTED_SO_FAR,
 	XFEATURE_PKRU,
-
+	XFEATURE_PASID,
 	XFEATURE_MAX,
 };
 
@@ -128,6 +128,7 @@ 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_FPSSE		(XFEATURE_MASK_FP | XFEATURE_MASK_SSE)
 #define XFEATURE_MASK_AVX512		(XFEATURE_MASK_OPMASK \
@@ -229,6 +230,14 @@ struct pkru_state {
 	u32				pad;
 } __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;
--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -33,7 +33,7 @@
 				      XFEATURE_MASK_BNDCSR)
 
 /* All currently supported supervisor features */
-#define XFEATURE_MASK_SUPERVISOR_SUPPORTED (0)
+#define XFEATURE_MASK_SUPERVISOR_SUPPORTED (XFEATURE_MASK_PASID)
 
 /*
  * Unsupported supervisor features. When a supervisor feature in this mask is
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -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[] __in
 	X86_FEATURE_AVX512F,
 	X86_FEATURE_INTEL_PT,
 	X86_FEATURE_PKU,
+	X86_FEATURE_ENQCMD,
 };
 
 /*
@@ -314,6 +316,7 @@ static void __init print_xstate_features
 	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);
 }
 
 /*
@@ -580,6 +583,7 @@ static void check_xstate_against_struct(
 	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