[PATCH 00/15] [v3] x86, fpu: XSAVE cleanups and sanity checks

[PATCH 00/15] [v3] x86, fpu: XSAVE cleanups and sanity checks

[Dave Hansen]

Changes in v3:
 * rework XSTATE_* macros using Ingo's suggested naming
 * change state size printk to be in decimal
 * add some more sanity-checking to detect and work around
   an undersized 'xregs_state'
 * remove "nr_" from some of the names used.

Changes in v2:
 * remove references to Processor Trace XSAVE state
   (will defer to another patch set)
 * Remove some cruft from last patch
 * move last_good_offset fix in to the patch that
   introduced it

These patches make some updates to the x86 XSAVE code.

They have been build and boot tested including on hardware
and/or simulators with AVX-512 and MPX.  It boots in all
of the tested configurations without hitting any of the
new warnings in this code.

There are basically 5 things going on here:
 * removal of the LWP (lightweight profiling) code
 * naming and type cleanups
 * removal of xfeatures_nr variable
 * addition of AVX-512 C structures
 * new sanity checks of XSAVE buffer sizing

Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org

[PATCH 01/15] x86, fpu: print xfeature buffer size in decimal

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

This is utterly a personal taste thing, but I find it way easier
to read structure sizes in decimal than in hex.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---

 b/arch/x86/kernel/fpu/xstate.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff -puN arch/x86/kernel/fpu/xstate.c~print-decimal arch/x86/kernel/fpu/xstate.c
--- a/arch/x86/kernel/fpu/xstate.c~print-decimal	2015-08-31 15:17:30.996727012 -0700
+++ b/arch/x86/kernel/fpu/xstate.c	2015-08-31 15:17:30.999727149 -0700
@@ -187,7 +187,7 @@ static void __init setup_xstate_features
 		xstate_offsets[leaf] = ebx;
 		xstate_sizes[leaf] = eax;
 
-		printk(KERN_INFO "x86/fpu: xstate_offset[%d]: %04x, xstate_sizes[%d]: %04x\n", leaf, ebx, leaf, eax);
+		printk(KERN_INFO "x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n", leaf, ebx, leaf, eax);
 	}
 }
 
@@ -357,7 +357,7 @@ void __init fpu__init_system_xstate(void
 	setup_init_fpu_buf();
 	setup_xstate_comp();
 
-	pr_info("x86/fpu: Enabled xstate features 0x%llx, context size is 0x%x bytes, using '%s' format.\n",
+	pr_info("x86/fpu: Enabled xstate features 0x%llx, context size is %d bytes, using '%s' format.\n",
 		xfeatures_mask,
 		xstate_size,
 		cpu_has_xsaves ? "compacted" : "standard");
_

[PATCH 02/15] x86, fpu: move XSAVE-disabling code to a helper

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

When we want to _completely_ disable XSAVE support as far as
the kernel is concerned, we have a big set of feature flags
to clear.  We currently only do this in cases where the user
asks for it to be disabled, but we are about to expand the
places where we do it to handle errors too.

Move the code in to xstate.c, and put it in the xstate.h
header.  We will use it in the next patch too.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---

 b/arch/x86/include/asm/fpu/xstate.h |    1 +
 b/arch/x86/kernel/fpu/init.c        |   12 +-----------
 b/arch/x86/kernel/fpu/xstate.c      |   19 +++++++++++++++++++
 3 files changed, 21 insertions(+), 11 deletions(-)

diff -puN arch/x86/include/asm/fpu/xstate.h~clear-all-xsave-cpu-caps arch/x86/include/asm/fpu/xstate.h
--- a/arch/x86/include/asm/fpu/xstate.h~clear-all-xsave-cpu-caps	2015-08-31 15:17:31.413746070 -0700
+++ b/arch/x86/include/asm/fpu/xstate.h	2015-08-31 15:17:31.419746345 -0700
@@ -40,6 +40,7 @@ extern u64 xstate_fx_sw_bytes[USER_XSTAT
 
 extern void update_regset_xstate_info(unsigned int size, u64 xstate_mask);
 
+void fpu__xstate_clear_all_cpu_caps(void);
 void *get_xsave_addr(struct xregs_state *xsave, int xstate);
 const void *get_xsave_field_ptr(int xstate_field);
 
diff -puN arch/x86/kernel/fpu/init.c~clear-all-xsave-cpu-caps arch/x86/kernel/fpu/init.c
--- a/arch/x86/kernel/fpu/init.c~clear-all-xsave-cpu-caps	2015-08-31 15:17:31.414746116 -0700
+++ b/arch/x86/kernel/fpu/init.c	2015-08-31 15:17:31.420746390 -0700
@@ -354,17 +354,7 @@ static int __init x86_noxsave_setup(char
 	if (strlen(s))
 		return 0;
 
-	setup_clear_cpu_cap(X86_FEATURE_XSAVE);
-	setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
-	setup_clear_cpu_cap(X86_FEATURE_XSAVEC);
-	setup_clear_cpu_cap(X86_FEATURE_XSAVES);
-	setup_clear_cpu_cap(X86_FEATURE_AVX);
-	setup_clear_cpu_cap(X86_FEATURE_AVX2);
-	setup_clear_cpu_cap(X86_FEATURE_AVX512F);
-	setup_clear_cpu_cap(X86_FEATURE_AVX512PF);
-	setup_clear_cpu_cap(X86_FEATURE_AVX512ER);
-	setup_clear_cpu_cap(X86_FEATURE_AVX512CD);
-	setup_clear_cpu_cap(X86_FEATURE_MPX);
+	fpu__xstate_clear_all_cpu_caps();
 
 	return 1;
 }
diff -puN arch/x86/kernel/fpu/xstate.c~clear-all-xsave-cpu-caps arch/x86/kernel/fpu/xstate.c
--- a/arch/x86/kernel/fpu/xstate.c~clear-all-xsave-cpu-caps	2015-08-31 15:17:31.416746208 -0700
+++ b/arch/x86/kernel/fpu/xstate.c	2015-08-31 15:17:31.420746390 -0700
@@ -39,6 +39,25 @@ static unsigned int xstate_comp_offsets[
 static unsigned int xfeatures_nr;
 
 /*
+ * Clear all of the X86_FEATURE_* bits that are unavailable
+ * when the CPU has no XSAVE support.
+ */
+void fpu__xstate_clear_all_cpu_caps(void)
+{
+	setup_clear_cpu_cap(X86_FEATURE_XSAVE);
+	setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
+	setup_clear_cpu_cap(X86_FEATURE_XSAVEC);
+	setup_clear_cpu_cap(X86_FEATURE_XSAVES);
+	setup_clear_cpu_cap(X86_FEATURE_AVX);
+	setup_clear_cpu_cap(X86_FEATURE_AVX2);
+	setup_clear_cpu_cap(X86_FEATURE_AVX512F);
+	setup_clear_cpu_cap(X86_FEATURE_AVX512PF);
+	setup_clear_cpu_cap(X86_FEATURE_AVX512ER);
+	setup_clear_cpu_cap(X86_FEATURE_AVX512CD);
+	setup_clear_cpu_cap(X86_FEATURE_MPX);
+}
+
+/*
  * Return whether the system supports a given xfeature.
  *
  * Also return the name of the (most advanced) feature that the caller requested:
_

[PATCH 03/15] x86, fpu: remove XSTATE_RESERVE

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

The original purpose of XSTATE_RESERVE was to carve out space
to store all of the possible extended state components that
get saved with the XSAVE instruction(s).

However, we are now almost entirely dynamically allocating
the buffers we use for XSAVE by placing them at the end of
the task_struct and them sizing them at boot.  The one
exception for that is the init_task.

The maximum extended state component size that we have today
is on systems with space for AVX-512 and Memory Protection
Keys: 2696 bytes.  We have reserved a PAGE_SIZE buffer in
the init_task via fpregs_state->__padding.

This check ensures that even if the component sizes or
layout were changed (which we do not expect), that we will
still not overflow the init_task's buffer.

In the case that we detect we might overflow the buffer,
we completely disable XSAVE support in the kernel and try
to boot as if we had 'legacy x87 FPU' support in place.
This is a crippled state without any of the XSAVE-enabled
features (MPX, AVX, etc...).  But, it at least let us
boot safely.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---

 b/arch/x86/include/asm/fpu/types.h |   15 ++++-----
 b/arch/x86/kernel/fpu/xstate.c     |   60 ++++++++++++++++++++++++++++++++-----
 2 files changed, 59 insertions(+), 16 deletions(-)

diff -puN arch/x86/include/asm/fpu/types.h~remove-xstate_reserve arch/x86/include/asm/fpu/types.h
--- a/arch/x86/include/asm/fpu/types.h~remove-xstate_reserve	2015-08-31 15:17:31.878767323 -0700
+++ b/arch/x86/include/asm/fpu/types.h	2015-08-31 15:17:31.883767551 -0700
@@ -159,22 +159,19 @@ struct xstate_header {
 	u64				reserved[6];
 } __attribute__((packed));
 
-/* New processor state extensions should be added here: */
-#define XSTATE_RESERVE			(sizeof(struct ymmh_struct) + \
-					 sizeof(struct lwp_struct)  + \
-					 sizeof(struct mpx_struct)  )
 /*
  * This is our most modern FPU state format, as saved by the XSAVE
  * and restored by the XRSTOR instructions.
  *
  * It consists of a legacy fxregs portion, an xstate header and
- * subsequent fixed size areas as defined by the xstate header.
- * Not all CPUs support all the extensions.
+ * subsequent areas as defined by the xstate header.  Not all CPUs
+ * support all the extensions, so the size of the extended area
+ * can vary quite a bit between CPUs.
  */
 struct xregs_state {
 	struct fxregs_state		i387;
 	struct xstate_header		header;
-	u8				__reserved[XSTATE_RESERVE];
+	u8				extended_state_area[0];
 } __attribute__ ((packed, aligned (64)));
 
 /*
@@ -182,7 +179,9 @@ struct xregs_state {
  * put together, so that we can pick the right one runtime.
  *
  * The size of the structure is determined by the largest
- * member - which is the xsave area:
+ * member - which is the xsave area.  The padding is there
+ * to ensure that statically-allocated task_structs (just
+ * the init_task today) have enough space.
  */
 union fpregs_state {
 	struct fregs_state		fsave;
diff -puN arch/x86/kernel/fpu/xstate.c~remove-xstate_reserve arch/x86/kernel/fpu/xstate.c
--- a/arch/x86/kernel/fpu/xstate.c~remove-xstate_reserve	2015-08-31 15:17:31.879767369 -0700
+++ b/arch/x86/kernel/fpu/xstate.c	2015-08-31 15:17:31.883767551 -0700
@@ -312,24 +312,64 @@ static void __init setup_init_fpu_buf(vo
 /*
  * Calculate total size of enabled xstates in XCR0/xfeatures_mask.
  */
-static void __init init_xstate_size(void)
+static unsigned int __init calculate_xstate_size(void)
 {
 	unsigned int eax, ebx, ecx, edx;
+	unsigned int calculated_xstate_size;
 	int i;
 
 	if (!cpu_has_xsaves) {
 		cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx);
-		xstate_size = ebx;
-		return;
+		calculated_xstate_size = ebx;
+		return calculated_xstate_size;
 	}
 
-	xstate_size = FXSAVE_SIZE + XSAVE_HDR_SIZE;
+	calculated_xstate_size = FXSAVE_SIZE + XSAVE_HDR_SIZE;
 	for (i = 2; i < 64; i++) {
 		if (test_bit(i, (unsigned long *)&xfeatures_mask)) {
 			cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
-			xstate_size += eax;
+			calculated_xstate_size += eax;
 		}
 	}
+	return calculated_xstate_size;
+}
+
+/*
+ * Will the runtime-enumerated 'xstate_size' fit in the init
+ * task's statically-allocated buffer?
+ */
+static bool is_supported_xstate_size(unsigned int test_xstate_size)
+{
+	if (test_xstate_size <= sizeof(union fpregs_state))
+		return true;
+
+	pr_warn("x86/fpu: xstate buffer too small (%ld < %d), disabling xsave\n",
+			sizeof(union fpregs_state), test_xstate_size);
+	return false;
+}
+
+static int init_xstate_size(void)
+{
+	/* Recompute the context size for enabled features: */
+	unsigned int possible_xstate_size = calculate_xstate_size();
+
+	/* Ensure we have the space to store all enabled: */
+	if (!is_supported_xstate_size(possible_xstate_size))
+		return -EINVAL;
+
+	/*
+	 * The size is OK, we are definitely going to use xsave,
+	 * make it known to the world that we need more space.
+	 */
+	xstate_size = possible_xstate_size;
+	return 0;
+}
+
+void fpu__init_disable_system_xstate(void)
+{
+	xfeatures_mask = 0;
+	cr4_clear_bits(X86_CR4_OSXSAVE);
+	fpu__xstate_clear_all_cpu_caps();
 }
 
 /*
@@ -340,6 +380,7 @@ void __init fpu__init_system_xstate(void
 {
 	unsigned int eax, ebx, ecx, edx;
 	static int on_boot_cpu = 1;
+	int err;
 
 	WARN_ON_FPU(!on_boot_cpu);
 	on_boot_cpu = 0;
@@ -367,9 +408,12 @@ void __init fpu__init_system_xstate(void
 
 	/* Enable xstate instructions to be able to continue with initialization: */
 	fpu__init_cpu_xstate();
-
-	/* Recompute the context size for enabled features: */
-	init_xstate_size();
+	err = init_xstate_size();
+	if (err) {
+		/* something went wrong, boot without any XSAVE support */
+		fpu__init_disable_system_xstate();
+		return;
+	}
 
 	update_regset_xstate_info(xstate_size, xfeatures_mask);
 	fpu__init_prepare_fx_sw_frame();
_

[PATCH 04/15] x86, fpu: kill LWP support

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

LightWeight Profiling was evidently an AMD profiling feature that
we never got around to implementing.  Remove the references to it.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---

 b/arch/x86/include/asm/fpu/types.h |    5 -----
 1 file changed, 5 deletions(-)

diff -puN arch/x86/include/asm/fpu/types.h~axe-lwp arch/x86/include/asm/fpu/types.h
--- a/arch/x86/include/asm/fpu/types.h~axe-lwp	2015-08-31 15:17:32.321787570 -0700
+++ b/arch/x86/include/asm/fpu/types.h	2015-08-31 15:17:32.324787707 -0700
@@ -132,11 +132,6 @@ struct ymmh_struct {
 	u8				ymmh_space[256];
 };
 
-/* We don't support LWP yet: */
-struct lwp_struct {
-	u8				reserved[128];
-};
-
 /* Intel MPX support: */
 struct bndreg {
 	u64				lower_bound;
_

[PATCH 06/15] x86, fpu: rename XFEATURES_NR_MAX

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

This is a logcal followon to the last patch.  It makes the
XFEATURE_MAX naming consistent with the other enum values.
This is what Ingo suggested.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---

 b/arch/x86/include/asm/fpu/types.h |    2 +-
 b/arch/x86/kernel/fpu/xstate.c     |    4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff -puN arch/x86/include/asm/fpu/types.h~rename-XFEATURES_NR_MAX arch/x86/include/asm/fpu/types.h
--- a/arch/x86/include/asm/fpu/types.h~rename-XFEATURES_NR_MAX	2015-08-31 15:17:33.710851053 -0700
+++ b/arch/x86/include/asm/fpu/types.h	2015-08-31 15:17:33.714851236 -0700
@@ -109,7 +109,7 @@ enum xfeature {
 	XFEATURE_ZMM_Hi256,
 	XFEATURE_Hi16_ZMM,
 
-	XFEATURES_NR_MAX,
+	XFEATURE_MAX,
 };
 
 #define XFEATURE_MASK_FP		(1 << XFEATURE_FP)
diff -puN arch/x86/kernel/fpu/xstate.c~rename-XFEATURES_NR_MAX arch/x86/kernel/fpu/xstate.c
--- a/arch/x86/kernel/fpu/xstate.c~rename-XFEATURES_NR_MAX	2015-08-31 15:17:33.711851099 -0700
+++ b/arch/x86/kernel/fpu/xstate.c	2015-08-31 15:17:33.715851281 -0700
@@ -31,8 +31,8 @@ static const char *xfeature_names[] =
  */
 u64 xfeatures_mask __read_mostly;
 
-static unsigned int xstate_offsets[XFEATURES_NR_MAX] = { [ 0 ... XFEATURES_NR_MAX - 1] = -1};
-static unsigned int xstate_sizes[XFEATURES_NR_MAX]   = { [ 0 ... XFEATURES_NR_MAX - 1] = -1};
+static unsigned int xstate_offsets[XFEATURE_MAX] = { [ 0 ... XFEATURE_MAX - 1] = -1};
+static unsigned int xstate_sizes[XFEATURE_MAX]   = { [ 0 ... XFEATURE_MAX - 1] = -1};
 static unsigned int xstate_comp_offsets[sizeof(xfeatures_mask)*8];
 
 /* The number of supported xfeatures in xfeatures_mask: */
_

[PATCH 05/15] x86, fpu: XSAVE macro renames

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

There are two concepts that have some confusing naming:
 1. Extended State Component numbers (currently called
    XFEATURE_BIT_*)
 2. Extended State Component masks (currently called XSTATE_*)

The numbers are (currently) from 0-9.  State component 3 is the
bounds registers for MPX, for instance.

But when we want to enable "state component 3", we go set a bit
in XCR0.  The bit we set is 1<<3.  We can check to see if a
state component feature is enabled by looking at its bit.

The current 'xfeature_bit's are at best xfeature bit _numbers_.
Calling them bits is at best inconsistent with ending the enum
list with 'XFEATURES_NR_MAX'.

This patch renames the enum to be 'xfeature'.  These also
happen to be what the Intel documentation calls a "state
component".

We also want to differentiate these from the "XSTATE_*" macros.
The "XSTATE_*" macros are a mask, and we rename them to match.

These macros are reasonably widely used so this patch is a
wee bit big, but this really is just a rename.

The only non-mechanical part of this is the

	s/XSTATE_EXTEND_MASK/XFEATURE_MASK_EXTEND/

We need a better name for it, but that's another patch.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---

 b/arch/x86/crypto/camellia_aesni_avx2_glue.c |    3 +
 b/arch/x86/crypto/camellia_aesni_avx_glue.c  |    3 +
 b/arch/x86/crypto/cast5_avx_glue.c           |    3 +
 b/arch/x86/crypto/cast6_avx_glue.c           |    3 +
 b/arch/x86/crypto/serpent_avx2_glue.c        |    3 +
 b/arch/x86/crypto/serpent_avx_glue.c         |    3 +
 b/arch/x86/crypto/sha1_ssse3_glue.c          |    2 -
 b/arch/x86/crypto/sha256_ssse3_glue.c        |    2 -
 b/arch/x86/crypto/sha512_ssse3_glue.c        |    2 -
 b/arch/x86/crypto/twofish_avx_glue.c         |    2 -
 b/arch/x86/include/asm/fpu/types.h           |   44 +++++++++++++++------------
 b/arch/x86/include/asm/fpu/xstate.h          |   14 +++++---
 b/arch/x86/kernel/fpu/init.c                 |    6 +--
 b/arch/x86/kernel/fpu/regset.c               |    4 +-
 b/arch/x86/kernel/fpu/signal.c               |    6 +--
 b/arch/x86/kernel/fpu/xstate.c               |   30 +++++++++---------
 b/arch/x86/kernel/traps.c                    |    2 -
 b/arch/x86/kvm/cpuid.c                       |    4 +-
 b/arch/x86/kvm/x86.c                         |   27 ++++++++--------
 b/arch/x86/kvm/x86.h                         |    6 +--
 b/arch/x86/mm/mpx.c                          |    6 +--
 21 files changed, 96 insertions(+), 79 deletions(-)

diff -puN arch/x86/crypto/camellia_aesni_avx2_glue.c~x86-fpu-rename-xfeature_bit arch/x86/crypto/camellia_aesni_avx2_glue.c
--- a/arch/x86/crypto/camellia_aesni_avx2_glue.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.743806857 -0700
+++ b/arch/x86/crypto/camellia_aesni_avx2_glue.c	2015-08-31 15:17:32.780808548 -0700
@@ -567,7 +567,8 @@ static int __init camellia_aesni_init(vo
 		return -ENODEV;
 	}
 
-	if (!cpu_has_xfeatures(XSTATE_SSE | XSTATE_YMM, &feature_name)) {
+	if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM,
+				&feature_name)) {
 		pr_info("CPU feature '%s' is not supported.\n", feature_name);
 		return -ENODEV;
 	}
diff -puN arch/x86/crypto/camellia_aesni_avx_glue.c~x86-fpu-rename-xfeature_bit arch/x86/crypto/camellia_aesni_avx_glue.c
--- a/arch/x86/crypto/camellia_aesni_avx_glue.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.745806948 -0700
+++ b/arch/x86/crypto/camellia_aesni_avx_glue.c	2015-08-31 15:17:32.780808548 -0700
@@ -554,7 +554,8 @@ static int __init camellia_aesni_init(vo
 {
 	const char *feature_name;
 
-	if (!cpu_has_xfeatures(XSTATE_SSE | XSTATE_YMM, &feature_name)) {
+	if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM,
+				&feature_name)) {
 		pr_info("CPU feature '%s' is not supported.\n", feature_name);
 		return -ENODEV;
 	}
diff -puN arch/x86/crypto/cast5_avx_glue.c~x86-fpu-rename-xfeature_bit arch/x86/crypto/cast5_avx_glue.c
--- a/arch/x86/crypto/cast5_avx_glue.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.746806994 -0700
+++ b/arch/x86/crypto/cast5_avx_glue.c	2015-08-31 15:17:32.781808594 -0700
@@ -469,7 +469,8 @@ static int __init cast5_init(void)
 {
 	const char *feature_name;
 
-	if (!cpu_has_xfeatures(XSTATE_SSE | XSTATE_YMM, &feature_name)) {
+	if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM,
+				&feature_name)) {
 		pr_info("CPU feature '%s' is not supported.\n", feature_name);
 		return -ENODEV;
 	}
diff -puN arch/x86/crypto/cast6_avx_glue.c~x86-fpu-rename-xfeature_bit arch/x86/crypto/cast6_avx_glue.c
--- a/arch/x86/crypto/cast6_avx_glue.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.748807085 -0700
+++ b/arch/x86/crypto/cast6_avx_glue.c	2015-08-31 15:17:32.781808594 -0700
@@ -591,7 +591,8 @@ static int __init cast6_init(void)
 {
 	const char *feature_name;
 
-	if (!cpu_has_xfeatures(XSTATE_SSE | XSTATE_YMM, &feature_name)) {
+	if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM,
+				&feature_name)) {
 		pr_info("CPU feature '%s' is not supported.\n", feature_name);
 		return -ENODEV;
 	}
diff -puN arch/x86/crypto/serpent_avx2_glue.c~x86-fpu-rename-xfeature_bit arch/x86/crypto/serpent_avx2_glue.c
--- a/arch/x86/crypto/serpent_avx2_glue.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.750807177 -0700
+++ b/arch/x86/crypto/serpent_avx2_glue.c	2015-08-31 15:17:32.782808639 -0700
@@ -542,7 +542,8 @@ static int __init init(void)
 		pr_info("AVX2 instructions are not detected.\n");
 		return -ENODEV;
 	}
-	if (!cpu_has_xfeatures(XSTATE_SSE | XSTATE_YMM, &feature_name)) {
+	if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM,
+				&feature_name)) {
 		pr_info("CPU feature '%s' is not supported.\n", feature_name);
 		return -ENODEV;
 	}
diff -puN arch/x86/crypto/serpent_avx_glue.c~x86-fpu-rename-xfeature_bit arch/x86/crypto/serpent_avx_glue.c
--- a/arch/x86/crypto/serpent_avx_glue.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.751807223 -0700
+++ b/arch/x86/crypto/serpent_avx_glue.c	2015-08-31 15:17:32.782808639 -0700
@@ -597,7 +597,8 @@ static int __init serpent_init(void)
 {
 	const char *feature_name;
 
-	if (!cpu_has_xfeatures(XSTATE_SSE | XSTATE_YMM, &feature_name)) {
+	if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM,
+				&feature_name)) {
 		pr_info("CPU feature '%s' is not supported.\n", feature_name);
 		return -ENODEV;
 	}
diff -puN arch/x86/crypto/sha1_ssse3_glue.c~x86-fpu-rename-xfeature_bit arch/x86/crypto/sha1_ssse3_glue.c
--- a/arch/x86/crypto/sha1_ssse3_glue.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.753807314 -0700
+++ b/arch/x86/crypto/sha1_ssse3_glue.c	2015-08-31 15:17:32.782808639 -0700
@@ -121,7 +121,7 @@ static struct shash_alg alg = {
 #ifdef CONFIG_AS_AVX
 static bool __init avx_usable(void)
 {
-	if (!cpu_has_xfeatures(XSTATE_SSE | XSTATE_YMM, NULL)) {
+	if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL)) {
 		if (cpu_has_avx)
 			pr_info("AVX detected but unusable.\n");
 		return false;
diff -puN arch/x86/crypto/sha256_ssse3_glue.c~x86-fpu-rename-xfeature_bit arch/x86/crypto/sha256_ssse3_glue.c
--- a/arch/x86/crypto/sha256_ssse3_glue.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.755807405 -0700
+++ b/arch/x86/crypto/sha256_ssse3_glue.c	2015-08-31 15:17:32.783808685 -0700
@@ -130,7 +130,7 @@ static struct shash_alg algs[] = { {
 #ifdef CONFIG_AS_AVX
 static bool __init avx_usable(void)
 {
-	if (!cpu_has_xfeatures(XSTATE_SSE | XSTATE_YMM, NULL)) {
+	if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL)) {
 		if (cpu_has_avx)
 			pr_info("AVX detected but unusable.\n");
 		return false;
diff -puN arch/x86/crypto/sha512_ssse3_glue.c~x86-fpu-rename-xfeature_bit arch/x86/crypto/sha512_ssse3_glue.c
--- a/arch/x86/crypto/sha512_ssse3_glue.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.756807451 -0700
+++ b/arch/x86/crypto/sha512_ssse3_glue.c	2015-08-31 15:17:32.783808685 -0700
@@ -129,7 +129,7 @@ static struct shash_alg algs[] = { {
 #ifdef CONFIG_AS_AVX
 static bool __init avx_usable(void)
 {
-	if (!cpu_has_xfeatures(XSTATE_SSE | XSTATE_YMM, NULL)) {
+	if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL)) {
 		if (cpu_has_avx)
 			pr_info("AVX detected but unusable.\n");
 		return false;
diff -puN arch/x86/crypto/twofish_avx_glue.c~x86-fpu-rename-xfeature_bit arch/x86/crypto/twofish_avx_glue.c
--- a/arch/x86/crypto/twofish_avx_glue.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.758807543 -0700
+++ b/arch/x86/crypto/twofish_avx_glue.c	2015-08-31 15:17:32.783808685 -0700
@@ -558,7 +558,7 @@ static int __init twofish_init(void)
 {
 	const char *feature_name;
 
-	if (!cpu_has_xfeatures(XSTATE_SSE | XSTATE_YMM, &feature_name)) {
+	if (!cpu_has_xfeatures(XSTATE_SSE | XSTATE_YMM, NULL)) {
 		pr_info("CPU feature '%s' is not supported.\n", feature_name);
 		return -ENODEV;
 	}
diff -puN arch/x86/include/asm/fpu/types.h~x86-fpu-rename-xfeature_bit arch/x86/include/asm/fpu/types.h
--- a/arch/x86/include/asm/fpu/types.h~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.760807634 -0700
+++ b/arch/x86/include/asm/fpu/types.h	2015-08-31 15:17:32.784808731 -0700
@@ -95,30 +95,36 @@ struct swregs_state {
 /*
  * List of XSAVE features Linux knows about:
  */
-enum xfeature_bit {
-	XSTATE_BIT_FP,
-	XSTATE_BIT_SSE,
-	XSTATE_BIT_YMM,
-	XSTATE_BIT_BNDREGS,
-	XSTATE_BIT_BNDCSR,
-	XSTATE_BIT_OPMASK,
-	XSTATE_BIT_ZMM_Hi256,
-	XSTATE_BIT_Hi16_ZMM,
+enum xfeature {
+	XFEATURE_FP,
+	XFEATURE_SSE,
+	/*
+	 * Values above here are "legacy states".
+	 * Those below are "extended states".
+	 */
+	XFEATURE_YMM,
+	XFEATURE_BNDREGS,
+	XFEATURE_BNDCSR,
+	XFEATURE_OPMASK,
+	XFEATURE_ZMM_Hi256,
+	XFEATURE_Hi16_ZMM,
 
 	XFEATURES_NR_MAX,
 };
 
-#define XSTATE_FP		(1 << XSTATE_BIT_FP)
-#define XSTATE_SSE		(1 << XSTATE_BIT_SSE)
-#define XSTATE_YMM		(1 << XSTATE_BIT_YMM)
-#define XSTATE_BNDREGS		(1 << XSTATE_BIT_BNDREGS)
-#define XSTATE_BNDCSR		(1 << XSTATE_BIT_BNDCSR)
-#define XSTATE_OPMASK		(1 << XSTATE_BIT_OPMASK)
-#define XSTATE_ZMM_Hi256	(1 << XSTATE_BIT_ZMM_Hi256)
-#define XSTATE_Hi16_ZMM		(1 << XSTATE_BIT_Hi16_ZMM)
+#define XFEATURE_MASK_FP		(1 << XFEATURE_FP)
+#define XFEATURE_MASK_SSE		(1 << XFEATURE_SSE)
+#define XFEATURE_MASK_YMM		(1 << XFEATURE_YMM)
+#define XFEATURE_MASK_BNDREGS		(1 << XFEATURE_BNDREGS)
+#define XFEATURE_MASK_BNDCSR		(1 << XFEATURE_BNDCSR)
+#define XFEATURE_MASK_OPMASK		(1 << XFEATURE_OPMASK)
+#define XFEATURE_MASK_ZMM_Hi256		(1 << XFEATURE_ZMM_Hi256)
+#define XFEATURE_MASK_Hi16_ZMM		(1 << XFEATURE_Hi16_ZMM)
 
-#define XSTATE_FPSSE		(XSTATE_FP | XSTATE_SSE)
-#define XSTATE_AVX512		(XSTATE_OPMASK | XSTATE_ZMM_Hi256 | XSTATE_Hi16_ZMM)
+#define XFEATURE_MASK_FPSSE		(XFEATURE_MASK_FP | XFEATURE_MASK_SSE)
+#define XFEATURE_MASK_AVX512		(XFEATURE_MASK_OPMASK \
+					 | XFEATURE_MASK_ZMM_Hi256 \
+					 | XFEATURE_MASK_Hi16_ZMM)
 
 /*
  * There are 16x 256-bit AVX registers named YMM0-YMM15.
diff -puN arch/x86/include/asm/fpu/xstate.h~x86-fpu-rename-xfeature_bit arch/x86/include/asm/fpu/xstate.h
--- a/arch/x86/include/asm/fpu/xstate.h~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.761807680 -0700
+++ b/arch/x86/include/asm/fpu/xstate.h	2015-08-31 15:17:32.784808731 -0700
@@ -6,7 +6,7 @@
 #include <linux/uaccess.h>
 
 /* Bit 63 of XCR0 is reserved for future expansion */
-#define XSTATE_EXTEND_MASK	(~(XSTATE_FPSSE | (1ULL << 63)))
+#define XFEATURE_MASK_EXTEND	(~(XFEATURE_MASK_FPSSE | (1ULL << 63)))
 
 #define XSTATE_CPUID		0x0000000d
 
@@ -19,14 +19,18 @@
 #define XSAVE_YMM_OFFSET    (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET)
 
 /* Supported features which support lazy state saving */
-#define XSTATE_LAZY	(XSTATE_FP | XSTATE_SSE | XSTATE_YMM		      \
-			| XSTATE_OPMASK | XSTATE_ZMM_Hi256 | XSTATE_Hi16_ZMM)
+#define XFEATURE_MASK_LAZY	(XFEATURE_MASK_FP | \
+	       			 XFEATURE_MASK_SSE | \
+				 XFEATURE_MASK_YMM | \
+				 XFEATURE_MASK_OPMASK |	\
+				 XFEATURE_MASK_ZMM_Hi256 | \
+				 XFEATURE_MASK_Hi16_ZMM)
 
 /* Supported features which require eager state saving */
-#define XSTATE_EAGER	(XSTATE_BNDREGS | XSTATE_BNDCSR)
+#define XFEATURE_MASK_EAGER	(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR)
 
 /* All currently supported features */
-#define XCNTXT_MASK	(XSTATE_LAZY | XSTATE_EAGER)
+#define XCNTXT_MASK	(XFEATURE_MASK_LAZY | XFEATURE_MASK_EAGER)
 
 #ifdef CONFIG_X86_64
 #define REX_PREFIX	"0x48, "
diff -puN arch/x86/kernel/fpu/init.c~x86-fpu-rename-xfeature_bit arch/x86/kernel/fpu/init.c
--- a/arch/x86/kernel/fpu/init.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.763807771 -0700
+++ b/arch/x86/kernel/fpu/init.c	2015-08-31 15:17:32.784808731 -0700
@@ -290,11 +290,11 @@ static void __init fpu__init_system_ctx_
 	if (cpu_has_xsaveopt && eagerfpu != DISABLE)
 		eagerfpu = ENABLE;
 
-	if (xfeatures_mask & XSTATE_EAGER) {
+	if (xfeatures_mask & XFEATURE_MASK_EAGER) {
 		if (eagerfpu == DISABLE) {
 			pr_err("x86/fpu: eagerfpu switching disabled, disabling the following xstate features: 0x%llx.\n",
-			       xfeatures_mask & XSTATE_EAGER);
-			xfeatures_mask &= ~XSTATE_EAGER;
+			       xfeatures_mask & XFEATURE_MASK_EAGER);
+			xfeatures_mask &= ~XFEATURE_MASK_EAGER;
 		} else {
 			eagerfpu = ENABLE;
 		}
diff -puN arch/x86/kernel/fpu/regset.c~x86-fpu-rename-xfeature_bit arch/x86/kernel/fpu/regset.c
--- a/arch/x86/kernel/fpu/regset.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.765807862 -0700
+++ b/arch/x86/kernel/fpu/regset.c	2015-08-31 15:17:32.785808777 -0700
@@ -66,7 +66,7 @@ int xfpregs_set(struct task_struct *targ
 	 * presence of FP and SSE state.
 	 */
 	if (cpu_has_xsave)
-		fpu->state.xsave.header.xfeatures |= XSTATE_FPSSE;
+		fpu->state.xsave.header.xfeatures |= XFEATURE_MASK_FPSSE;
 
 	return ret;
 }
@@ -326,7 +326,7 @@ int fpregs_set(struct task_struct *targe
 	 * presence of FP.
 	 */
 	if (cpu_has_xsave)
-		fpu->state.xsave.header.xfeatures |= XSTATE_FP;
+		fpu->state.xsave.header.xfeatures |= XFEATURE_MASK_FP;
 	return ret;
 }
 
diff -puN arch/x86/kernel/fpu/signal.c~x86-fpu-rename-xfeature_bit arch/x86/kernel/fpu/signal.c
--- a/arch/x86/kernel/fpu/signal.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.766807908 -0700
+++ b/arch/x86/kernel/fpu/signal.c	2015-08-31 15:17:32.785808777 -0700
@@ -107,7 +107,7 @@ static inline int save_xstate_epilog(voi
 	 * header as well as change any contents in the memory layout.
 	 * xrestore as part of sigreturn will capture all the changes.
 	 */
-	xfeatures |= XSTATE_FPSSE;
+	xfeatures |= XFEATURE_MASK_FPSSE;
 
 	err |= __put_user(xfeatures, (__u32 *)&x->header.xfeatures);
 
@@ -207,7 +207,7 @@ sanitize_restored_xstate(struct task_str
 		 * layout and not enabled by the OS.
 		 */
 		if (fx_only)
-			header->xfeatures = XSTATE_FPSSE;
+			header->xfeatures = XFEATURE_MASK_FPSSE;
 		else
 			header->xfeatures &= (xfeatures_mask & xfeatures);
 	}
@@ -230,7 +230,7 @@ static inline int copy_user_to_fpregs_ze
 {
 	if (use_xsave()) {
 		if ((unsigned long)buf % 64 || fx_only) {
-			u64 init_bv = xfeatures_mask & ~XSTATE_FPSSE;
+			u64 init_bv = xfeatures_mask & ~XFEATURE_MASK_FPSSE;
 			copy_kernel_to_xregs(&init_fpstate.xsave, init_bv);
 			return copy_user_to_fxregs(buf);
 		} else {
diff -puN arch/x86/kernel/fpu/xstate.c~x86-fpu-rename-xfeature_bit arch/x86/kernel/fpu/xstate.c
--- a/arch/x86/kernel/fpu/xstate.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.768807999 -0700
+++ b/arch/x86/kernel/fpu/xstate.c	2015-08-31 15:17:32.785808777 -0700
@@ -72,7 +72,7 @@ int cpu_has_xfeatures(u64 xfeatures_need
 		/*
 		 * So we use FLS here to be able to print the most advanced
 		 * feature that was requested but is missing. So if a driver
-		 * asks about "XSTATE_SSE | XSTATE_YMM" we'll print the
+		 * asks about "XFEATURE_MASK_SSE | XFEATURE_MASK_YMM" we'll print the
 		 * missing AVX feature - this is the most informative message
 		 * to users:
 		 */
@@ -131,7 +131,7 @@ void fpstate_sanitize_xstate(struct fpu
 	/*
 	 * FP is in init state
 	 */
-	if (!(xfeatures & XSTATE_FP)) {
+	if (!(xfeatures & XFEATURE_MASK_FP)) {
 		fx->cwd = 0x37f;
 		fx->swd = 0;
 		fx->twd = 0;
@@ -144,7 +144,7 @@ void fpstate_sanitize_xstate(struct fpu
 	/*
 	 * SSE is in init state
 	 */
-	if (!(xfeatures & XSTATE_SSE))
+	if (!(xfeatures & XFEATURE_MASK_SSE))
 		memset(&fx->xmm_space[0], 0, 256);
 
 	/*
@@ -223,14 +223,14 @@ static void __init print_xstate_feature(
  */
 static void __init print_xstate_features(void)
 {
-	print_xstate_feature(XSTATE_FP);
-	print_xstate_feature(XSTATE_SSE);
-	print_xstate_feature(XSTATE_YMM);
-	print_xstate_feature(XSTATE_BNDREGS);
-	print_xstate_feature(XSTATE_BNDCSR);
-	print_xstate_feature(XSTATE_OPMASK);
-	print_xstate_feature(XSTATE_ZMM_Hi256);
-	print_xstate_feature(XSTATE_Hi16_ZMM);
+	print_xstate_feature(XFEATURE_MASK_FP);
+	print_xstate_feature(XFEATURE_MASK_SSE);
+	print_xstate_feature(XFEATURE_MASK_YMM);
+	print_xstate_feature(XFEATURE_MASK_BNDREGS);
+	print_xstate_feature(XFEATURE_MASK_BNDCSR);
+	print_xstate_feature(XFEATURE_MASK_OPMASK);
+	print_xstate_feature(XFEATURE_MASK_ZMM_Hi256);
+	print_xstate_feature(XFEATURE_MASK_Hi16_ZMM);
 }
 
 /*
@@ -398,7 +398,7 @@ void __init fpu__init_system_xstate(void
 	cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx);
 	xfeatures_mask = eax + ((u64)edx << 32);
 
-	if ((xfeatures_mask & XSTATE_FPSSE) != XSTATE_FPSSE) {
+	if ((xfeatures_mask & XFEATURE_MASK_FPSSE) != XFEATURE_MASK_FPSSE) {
 		pr_err("x86/fpu: FP/SSE not present amongst the CPU's xstate features: 0x%llx.\n", xfeatures_mask);
 		BUG();
 	}
@@ -451,7 +451,7 @@ void fpu__resume_cpu(void)
  * Inputs:
  *	xstate: the thread's storage area for all FPU data
  *	xstate_feature: state which is defined in xsave.h (e.g.
- *	XSTATE_FP, XSTATE_SSE, etc...)
+ *	XFEATURE_MASK_FP, XFEATURE_MASK_SSE, etc...)
  * Output:
  *	address of the state in the xsave area, or NULL if the
  *	field is not present in the xsave buffer.
@@ -502,8 +502,8 @@ EXPORT_SYMBOL_GPL(get_xsave_addr);
  * Note that this only works on the current task.
  *
  * Inputs:
- *	@xsave_state: state which is defined in xsave.h (e.g. XSTATE_FP,
- *	XSTATE_SSE, etc...)
+ *	@xsave_state: state which is defined in xsave.h (e.g. XFEATURE_MASK_FP,
+ *	XFEATURE_MASK_SSE, etc...)
  * Output:
  *	address of the state in the xsave area or NULL if the state
  *	is not present or is in its 'init state'.
diff -puN arch/x86/kernel/traps.c~x86-fpu-rename-xfeature_bit arch/x86/kernel/traps.c
--- a/arch/x86/kernel/traps.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.770808091 -0700
+++ b/arch/x86/kernel/traps.c	2015-08-31 15:17:32.786808822 -0700
@@ -395,7 +395,7 @@ dotraplinkage void do_bounds(struct pt_r
 	 * which is all zeros which indicates MPX was not
 	 * responsible for the exception.
 	 */
-	bndcsr = get_xsave_field_ptr(XSTATE_BNDCSR);
+	bndcsr = get_xsave_field_ptr(XFEATURE_MASK_BNDCSR);
 	if (!bndcsr)
 		goto exit_trap;
 
diff -puN arch/x86/kvm/cpuid.c~x86-fpu-rename-xfeature_bit arch/x86/kvm/cpuid.c
--- a/arch/x86/kvm/cpuid.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.771808137 -0700
+++ b/arch/x86/kvm/cpuid.c	2015-08-31 15:17:32.786808822 -0700
@@ -30,7 +30,7 @@ static u32 xstate_required_size(u64 xsta
 	int feature_bit = 0;
 	u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
 
-	xstate_bv &= XSTATE_EXTEND_MASK;
+	xstate_bv &= XFEATURE_MASK_EXTEND;
 	while (xstate_bv) {
 		if (xstate_bv & 0x1) {
 		        u32 eax, ebx, ecx, edx, offset;
@@ -51,7 +51,7 @@ u64 kvm_supported_xcr0(void)
 	u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;
 
 	if (!kvm_x86_ops->mpx_supported())
-		xcr0 &= ~(XSTATE_BNDREGS | XSTATE_BNDCSR);
+		xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);
 
 	return xcr0;
 }
diff -puN arch/x86/kvm/x86.c~x86-fpu-rename-xfeature_bit arch/x86/kvm/x86.c
--- a/arch/x86/kvm/x86.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.773808228 -0700
+++ b/arch/x86/kvm/x86.c	2015-08-31 15:17:32.789808959 -0700
@@ -662,9 +662,9 @@ static int __kvm_set_xcr(struct kvm_vcpu
 	/* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now  */
 	if (index != XCR_XFEATURE_ENABLED_MASK)
 		return 1;
-	if (!(xcr0 & XSTATE_FP))
+	if (!(xcr0 & XFEATURE_MASK_FP))
 		return 1;
-	if ((xcr0 & XSTATE_YMM) && !(xcr0 & XSTATE_SSE))
+	if ((xcr0 & XFEATURE_MASK_YMM) && !(xcr0 & XFEATURE_MASK_SSE))
 		return 1;
 
 	/*
@@ -672,23 +672,24 @@ static int __kvm_set_xcr(struct kvm_vcpu
 	 * saving.  However, xcr0 bit 0 is always set, even if the
 	 * emulated CPU does not support XSAVE (see fx_init).
 	 */
-	valid_bits = vcpu->arch.guest_supported_xcr0 | XSTATE_FP;
+	valid_bits = vcpu->arch.guest_supported_xcr0 | XFEATURE_MASK_FP;
 	if (xcr0 & ~valid_bits)
 		return 1;
 
-	if ((!(xcr0 & XSTATE_BNDREGS)) != (!(xcr0 & XSTATE_BNDCSR)))
+	if ((!(xcr0 & XFEATURE_MASK_BNDREGS)) !=
+	    (!(xcr0 & XFEATURE_MASK_BNDCSR)))
 		return 1;
 
-	if (xcr0 & XSTATE_AVX512) {
-		if (!(xcr0 & XSTATE_YMM))
+	if (xcr0 & XFEATURE_MASK_AVX512) {
+		if (!(xcr0 & XFEATURE_MASK_YMM))
 			return 1;
-		if ((xcr0 & XSTATE_AVX512) != XSTATE_AVX512)
+		if ((xcr0 & XFEATURE_MASK_AVX512) != XFEATURE_MASK_AVX512)
 			return 1;
 	}
 	kvm_put_guest_xcr0(vcpu);
 	vcpu->arch.xcr0 = xcr0;
 
-	if ((xcr0 ^ old_xcr0) & XSTATE_EXTEND_MASK)
+	if ((xcr0 ^ old_xcr0) & XFEATURE_MASK_EXTEND)
 		kvm_update_cpuid(vcpu);
 	return 0;
 }
@@ -3108,7 +3109,7 @@ static void fill_xsave(u8 *dest, struct
 	 * Copy each region from the possibly compacted offset to the
 	 * non-compacted offset.
 	 */
-	valid = xstate_bv & ~XSTATE_FPSSE;
+	valid = xstate_bv & ~XFEATURE_MASK_FPSSE;
 	while (valid) {
 		u64 feature = valid & -valid;
 		int index = fls64(feature) - 1;
@@ -3146,7 +3147,7 @@ static void load_xsave(struct kvm_vcpu *
 	 * Copy each region from the non-compacted offset to the
 	 * possibly compacted offset.
 	 */
-	valid = xstate_bv & ~XSTATE_FPSSE;
+	valid = xstate_bv & ~XFEATURE_MASK_FPSSE;
 	while (valid) {
 		u64 feature = valid & -valid;
 		int index = fls64(feature) - 1;
@@ -3174,7 +3175,7 @@ static void kvm_vcpu_ioctl_x86_get_xsave
 			&vcpu->arch.guest_fpu.state.fxsave,
 			sizeof(struct fxregs_state));
 		*(u64 *)&guest_xsave->region[XSAVE_HDR_OFFSET / sizeof(u32)] =
-			XSTATE_FPSSE;
+			XFEATURE_MASK_FPSSE;
 	}
 }
 
@@ -3194,7 +3195,7 @@ static int kvm_vcpu_ioctl_x86_set_xsave(
 			return -EINVAL;
 		load_xsave(vcpu, (u8 *)guest_xsave->region);
 	} else {
-		if (xstate_bv & ~XSTATE_FPSSE)
+		if (xstate_bv & ~XFEATURE_MASK_FPSSE)
 			return -EINVAL;
 		memcpy(&vcpu->arch.guest_fpu.state.fxsave,
 			guest_xsave->region, sizeof(struct fxregs_state));
@@ -7251,7 +7252,7 @@ static void fx_init(struct kvm_vcpu *vcp
 	/*
 	 * Ensure guest xcr0 is valid for loading
 	 */
-	vcpu->arch.xcr0 = XSTATE_FP;
+	vcpu->arch.xcr0 = XFEATURE_MASK_FP;
 
 	vcpu->arch.cr0 |= X86_CR0_ET;
 }
diff -puN arch/x86/kvm/x86.h~x86-fpu-rename-xfeature_bit arch/x86/kvm/x86.h
--- a/arch/x86/kvm/x86.h~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.775808319 -0700
+++ b/arch/x86/kvm/x86.h	2015-08-31 15:17:32.789808959 -0700
@@ -175,9 +175,9 @@ int kvm_mtrr_get_msr(struct kvm_vcpu *vc
 bool kvm_mtrr_check_gfn_range_consistency(struct kvm_vcpu *vcpu, gfn_t gfn,
 					  int page_num);
 
-#define KVM_SUPPORTED_XCR0     (XSTATE_FP | XSTATE_SSE | XSTATE_YMM \
-				| XSTATE_BNDREGS | XSTATE_BNDCSR \
-				| XSTATE_AVX512)
+#define KVM_SUPPORTED_XCR0     (XFEATURE_MASK_FP | XFEATURE_MASK_SSE \
+				| XFEATURE_MASK_YMM | XFEATURE_MASK_BNDREGS \
+				| XFEATURE_MASK_BNDCSR | XFEATURE_MASK_AVX512)
 extern u64 host_xcr0;
 
 extern u64 kvm_supported_xcr0(void);
diff -puN arch/x86/mm/mpx.c~x86-fpu-rename-xfeature_bit arch/x86/mm/mpx.c
--- a/arch/x86/mm/mpx.c~x86-fpu-rename-xfeature_bit	2015-08-31 15:17:32.777808411 -0700
+++ b/arch/x86/mm/mpx.c	2015-08-31 15:17:32.790809005 -0700
@@ -295,7 +295,7 @@ siginfo_t *mpx_generate_siginfo(struct p
 		goto err_out;
 	}
 	/* get bndregs field from current task's xsave area */
-	bndregs = get_xsave_field_ptr(XSTATE_BNDREGS);
+	bndregs = get_xsave_field_ptr(XFEATURE_MASK_BNDREGS);
 	if (!bndregs) {
 		err = -EINVAL;
 		goto err_out;
@@ -352,7 +352,7 @@ static __user void *mpx_get_bounds_dir(v
 	 * The bounds directory pointer is stored in a register
 	 * only accessible if we first do an xsave.
 	 */
-	bndcsr = get_xsave_field_ptr(XSTATE_BNDCSR);
+	bndcsr = get_xsave_field_ptr(XFEATURE_MASK_BNDCSR);
 	if (!bndcsr)
 		return MPX_INVALID_BOUNDS_DIR;
 
@@ -529,7 +529,7 @@ static int do_mpx_bt_fault(void)
 	const struct bndcsr *bndcsr;
 	struct mm_struct *mm = current->mm;
 
-	bndcsr = get_xsave_field_ptr(XSTATE_BNDCSR);
+	bndcsr = get_xsave_field_ptr(XFEATURE_MASK_BNDCSR);
 	if (!bndcsr)
 		return -EINVAL;
 	/*
_

[PATCH 07/15] x86, fpu: rework XSTATE_* macros to remove magic '2'

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

The 'xstate.c' code has a bunch of references to '2'.  This
is because we have a lot more work to do for the "extended"
xstates than the "legacy" ones and state component 2 is the
first "extended" state.

This patch replaces all of the instances of '2' with
FIRST_EXTENDED_XFEATURE, which clearly explains what is
going on.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---

 b/arch/x86/include/asm/fpu/types.h |    2 ++
 b/arch/x86/kernel/fpu/xstate.c     |   13 +++++++------
 2 files changed, 9 insertions(+), 6 deletions(-)

diff -puN arch/x86/include/asm/fpu/types.h~remove-hard-coded-values arch/x86/include/asm/fpu/types.h
--- a/arch/x86/include/asm/fpu/types.h~remove-hard-coded-values	2015-08-31 15:17:34.150871163 -0700
+++ b/arch/x86/include/asm/fpu/types.h	2015-08-31 15:17:34.154871345 -0700
@@ -126,6 +126,8 @@ enum xfeature {
 					 | XFEATURE_MASK_ZMM_Hi256 \
 					 | XFEATURE_MASK_Hi16_ZMM)
 
+#define FIRST_EXTENDED_XFEATURE	XFEATURE_YMM
+
 /*
  * There are 16x 256-bit AVX registers named YMM0-YMM15.
  * The low 128 bits are aliased to the 16 SSE registers (XMM0-XMM15)
diff -puN arch/x86/kernel/fpu/xstate.c~remove-hard-coded-values arch/x86/kernel/fpu/xstate.c
--- a/arch/x86/kernel/fpu/xstate.c~remove-hard-coded-values	2015-08-31 15:17:34.151871208 -0700
+++ b/arch/x86/kernel/fpu/xstate.c	2015-08-31 15:17:34.155871391 -0700
@@ -200,7 +200,7 @@ static void __init setup_xstate_features
 
 	xfeatures_nr = fls64(xfeatures_mask);
 
-	for (leaf = 2; leaf < xfeatures_nr; leaf++) {
+	for (leaf = FIRST_EXTENDED_XFEATURE; leaf < xfeatures_nr; leaf++) {
 		cpuid_count(XSTATE_CPUID, leaf, &eax, &ebx, &ecx, &edx);
 
 		xstate_offsets[leaf] = ebx;
@@ -252,7 +252,7 @@ static void __init setup_xstate_comp(voi
 	xstate_comp_offsets[1] = offsetof(struct fxregs_state, xmm_space);
 
 	if (!cpu_has_xsaves) {
-		for (i = 2; i < xfeatures_nr; i++) {
+		for (i = FIRST_EXTENDED_XFEATURE; i < xfeatures_nr; i++) {
 			if (test_bit(i, (unsigned long *)&xfeatures_mask)) {
 				xstate_comp_offsets[i] = xstate_offsets[i];
 				xstate_comp_sizes[i] = xstate_sizes[i];
@@ -261,15 +261,16 @@ static void __init setup_xstate_comp(voi
 		return;
 	}
 
-	xstate_comp_offsets[2] = FXSAVE_SIZE + XSAVE_HDR_SIZE;
+	xstate_comp_offsets[FIRST_EXTENDED_XFEATURE] =
+	  	FXSAVE_SIZE + XSAVE_HDR_SIZE;
 
-	for (i = 2; i < xfeatures_nr; i++) {
+	for (i = FIRST_EXTENDED_XFEATURE; i < xfeatures_nr; i++) {
 		if (test_bit(i, (unsigned long *)&xfeatures_mask))
 			xstate_comp_sizes[i] = xstate_sizes[i];
 		else
 			xstate_comp_sizes[i] = 0;
 
-		if (i > 2)
+		if (i > FIRST_EXTENDED_XFEATURE)
 			xstate_comp_offsets[i] = xstate_comp_offsets[i-1]
 					+ xstate_comp_sizes[i-1];
 
@@ -325,7 +326,7 @@ static unsigned int __init calculate_xst
 	}
 
 	calculated_xstate_size = FXSAVE_SIZE + XSAVE_HDR_SIZE;
-	for (i = 2; i < 64; i++) {
+	for (i = FIRST_EXTENDED_XFEATURE; i < 64; i++) {
 		if (test_bit(i, (unsigned long *)&xfeatures_mask)) {
 			cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
 			calculated_xstate_size += eax;
_

[PATCH 08/15] x86, fpu: remove xfeature_nr

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

xfeature_nr ended up being initialized too late for me to
use it in the "xsave size sanity check" patch which is
later in the series.  I tried to move around its initialization
but realized that it was just as easy to get rid of it.

We only have 9 XFEATURES.  Instead of dynamically calculating
and storing the last feature, just use the compile-time max:
XFEATURES_NR_MAX.  Note that even with 'xfeatures_nr' we can
had "holes" in the xfeatures_mask that we had to deal with.

We also change a 'leaf' variable to be a plain 'i'.  Although
it is used to grab a cpuid leaf in this one loop, all of the
other loops just use an 'i' and I find it much more obvious
to keep the naming consistent across all the similar loops.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---

 b/arch/x86/kernel/fpu/xstate.c |   24 ++++++++----------------
 1 file changed, 8 insertions(+), 16 deletions(-)

diff -puN arch/x86/kernel/fpu/xstate.c~kill-xfeatures_nr arch/x86/kernel/fpu/xstate.c
--- a/arch/x86/kernel/fpu/xstate.c~kill-xfeatures_nr	2015-08-31 15:17:34.593891409 -0700
+++ b/arch/x86/kernel/fpu/xstate.c	2015-08-31 15:17:34.596891547 -0700
@@ -35,9 +35,6 @@ static unsigned int xstate_offsets[XFEAT
 static unsigned int xstate_sizes[XFEATURE_MAX]   = { [ 0 ... XFEATURE_MAX - 1] = -1};
 static unsigned int xstate_comp_offsets[sizeof(xfeatures_mask)*8];
 
-/* The number of supported xfeatures in xfeatures_mask: */
-static unsigned int xfeatures_nr;
-
 /*
  * Clear all of the X86_FEATURE_* bits that are unavailable
  * when the CPU has no XSAVE support.
@@ -190,23 +187,18 @@ void fpu__init_cpu_xstate(void)
 /*
  * Record the offsets and sizes of various xstates contained
  * in the XSAVE state memory layout.
- *
- * ( Note that certain features might be non-present, for them
- *   we'll have 0 offset and 0 size. )
  */
 static void __init setup_xstate_features(void)
 {
-	u32 eax, ebx, ecx, edx, leaf;
-
-	xfeatures_nr = fls64(xfeatures_mask);
+	u32 eax, ebx, ecx, edx, i;
 
-	for (leaf = FIRST_EXTENDED_XFEATURE; leaf < xfeatures_nr; leaf++) {
-		cpuid_count(XSTATE_CPUID, leaf, &eax, &ebx, &ecx, &edx);
+	for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
+		cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
 
-		xstate_offsets[leaf] = ebx;
-		xstate_sizes[leaf] = eax;
+		xstate_offsets[i] = ebx;
+		xstate_sizes[i] = eax;
 
-		printk(KERN_INFO "x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n", leaf, ebx, leaf, eax);
+		printk(KERN_INFO "x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n", i, ebx, i, eax);
 	}
 }
 
@@ -252,7 +244,7 @@ static void __init setup_xstate_comp(voi
 	xstate_comp_offsets[1] = offsetof(struct fxregs_state, xmm_space);
 
 	if (!cpu_has_xsaves) {
-		for (i = FIRST_EXTENDED_XFEATURE; i < xfeatures_nr; i++) {
+		for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
 			if (test_bit(i, (unsigned long *)&xfeatures_mask)) {
 				xstate_comp_offsets[i] = xstate_offsets[i];
 				xstate_comp_sizes[i] = xstate_sizes[i];
@@ -264,7 +256,7 @@ static void __init setup_xstate_comp(voi
 	xstate_comp_offsets[FIRST_EXTENDED_XFEATURE] =
 	  	FXSAVE_SIZE + XSAVE_HDR_SIZE;
 
-	for (i = FIRST_EXTENDED_XFEATURE; i < xfeatures_nr; i++) {
+	for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
 		if (test_bit(i, (unsigned long *)&xfeatures_mask))
 			xstate_comp_sizes[i] = xstate_sizes[i];
 		else
_

[PATCH 09/15] x86, fpu: add helper xfeature_enabled() instead of test_bit()

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

We currently use test_bit() in a few places to see if an xfeature
is enabled.  It ends up being a bit ugly because 'xfeatures_mask'
is a u64 and test_bit wants an 'unsigned long' so it requires a
cast.  The *_bit() functions are also techincally atomic, which
we have no need for here.

So, remove the test_bit()s and replace with the new
xfeature_enabled() helper.

This also provides a central place to add a comment about the
future need to support 'system xstates'.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---

 b/arch/x86/kernel/fpu/xstate.c |   16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff -puN arch/x86/kernel/fpu/xstate.c~use-xfeature_enabled arch/x86/kernel/fpu/xstate.c
--- a/arch/x86/kernel/fpu/xstate.c~use-xfeature_enabled	2015-08-31 15:17:35.008910377 -0700
+++ b/arch/x86/kernel/fpu/xstate.c	2015-08-31 15:17:35.011910514 -0700
@@ -226,6 +226,16 @@ static void __init print_xstate_features
 }
 
 /*
+ * Note that in the future we will likely need a pair of
+ * functions here: one for user xstates and the other for
+ * system xstates.  For now, they are the same.
+ */
+static int xfeature_enabled(enum xfeature xfeature)
+{
+	return !!(xfeatures_mask & (1UL << xfeature));
+}
+
+/*
  * This function sets up offsets and sizes of all extended states in
  * xsave area. This supports both standard format and compacted format
  * of the xsave aread.
@@ -245,7 +255,7 @@ static void __init setup_xstate_comp(voi
 
 	if (!cpu_has_xsaves) {
 		for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
-			if (test_bit(i, (unsigned long *)&xfeatures_mask)) {
+			if (xfeature_enabled(i)) {
 				xstate_comp_offsets[i] = xstate_offsets[i];
 				xstate_comp_sizes[i] = xstate_sizes[i];
 			}
@@ -257,7 +267,7 @@ static void __init setup_xstate_comp(voi
 	  	FXSAVE_SIZE + XSAVE_HDR_SIZE;
 
 	for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
-		if (test_bit(i, (unsigned long *)&xfeatures_mask))
+		if (xfeature_enabled(i))
 			xstate_comp_sizes[i] = xstate_sizes[i];
 		else
 			xstate_comp_sizes[i] = 0;
@@ -319,7 +329,7 @@ static unsigned int __init calculate_xst
 
 	calculated_xstate_size = FXSAVE_SIZE + XSAVE_HDR_SIZE;
 	for (i = FIRST_EXTENDED_XFEATURE; i < 64; i++) {
-		if (test_bit(i, (unsigned long *)&xfeatures_mask)) {
+		if (xfeature_enabled(i)) {
 			cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
 			calculated_xstate_size += eax;
 		}
_

[PATCH 10/15] x86, fpu: rework MPX 'xstate' types

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

MPX includes two separate "extended state components".  There is
no real need to have an 'mpx_struct' because we never really
manage the states together.

We also separate out the actual data in 'mpx_bndcsr_state' from
the padding.  We will shortly be checking the state sizes against
our structures and need them to match.  For consistency, we also
ensure to prefix these types with 'mpx_'.

Lastly, we add some comments to mirror some of the descriptions
in the Intel documents (SDM) of the various state components.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---

 b/arch/x86/include/asm/fpu/types.h |   33 +++++++++++++++++++++++++--------
 b/arch/x86/include/asm/trace/mpx.h |    7 ++++---
 b/arch/x86/kernel/traps.c          |    2 +-
 b/arch/x86/mm/mpx.c                |    9 +++++----
 4 files changed, 35 insertions(+), 16 deletions(-)

diff -puN arch/x86/include/asm/fpu/types.h~x86-fpu-rework-mpx-types arch/x86/include/asm/fpu/types.h
--- a/arch/x86/include/asm/fpu/types.h~x86-fpu-rework-mpx-types	2015-08-31 15:17:35.427929527 -0700
+++ b/arch/x86/include/asm/fpu/types.h	2015-08-31 15:17:35.436929938 -0700
@@ -141,20 +141,37 @@ struct ymmh_struct {
 };
 
 /* Intel MPX support: */
-struct bndreg {
+
+struct mpx_bndreg {
 	u64				lower_bound;
 	u64				upper_bound;
 } __packed;
+/*
+ * State component 3 is used for the 4 128-bit bounds registers
+ */
+struct mpx_bndreg_state {
+	struct mpx_bndreg		bndreg[4];
+} __packed;
 
-struct bndcsr {
-	u64				bndcfgu;
-	u64				bndstatus;
+/*
+ * State component 4 is used for the 64-bit user-mode MPX
+ * configuration register BNDCFGU and the 64-bit MPX status
+ * register BNDSTATUS.  We call the pair "BNDCSR".
+ */
+struct mpx_bndcsr {
+ 	u64				bndcfgu;
+ 	u64				bndstatus;
 } __packed;
 
-struct mpx_struct {
-	struct bndreg			bndreg[4];
-	struct bndcsr			bndcsr;
-};
+/*
+ * The BNDCSR state is padded out to be 64-bytes in size.
+ */
+struct mpx_bndcsr_state {
+	union {
+		struct mpx_bndcsr		bndcsr;
+		u8				pad_to_64_bytes[64];
+	};
+} __packed;
 
 struct xstate_header {
 	u64				xfeatures;
diff -puN arch/x86/include/asm/trace/mpx.h~x86-fpu-rework-mpx-types arch/x86/include/asm/trace/mpx.h
--- a/arch/x86/include/asm/trace/mpx.h~x86-fpu-rework-mpx-types	2015-08-31 15:17:35.429929618 -0700
+++ b/arch/x86/include/asm/trace/mpx.h	2015-08-31 15:17:35.436929938 -0700
@@ -11,7 +11,7 @@
 TRACE_EVENT(mpx_bounds_register_exception,
 
 	TP_PROTO(void *addr_referenced,
-		 const struct bndreg *bndreg),
+		 const struct mpx_bndreg *bndreg),
 	TP_ARGS(addr_referenced, bndreg),
 
 	TP_STRUCT__entry(
@@ -44,7 +44,7 @@ TRACE_EVENT(mpx_bounds_register_exceptio
 
 TRACE_EVENT(bounds_exception_mpx,
 
-	TP_PROTO(const struct bndcsr *bndcsr),
+	TP_PROTO(const struct mpx_bndcsr *bndcsr),
 	TP_ARGS(bndcsr),
 
 	TP_STRUCT__entry(
@@ -116,7 +116,8 @@ TRACE_EVENT(mpx_new_bounds_table,
 /*
  * This gets used outside of MPX-specific code, so we need a stub.
  */
-static inline void trace_bounds_exception_mpx(const struct bndcsr *bndcsr)
+static inline
+void trace_bounds_exception_mpx(const struct mpx_bndcsr *bndcsr)
 {
 }
 
diff -puN arch/x86/kernel/traps.c~x86-fpu-rework-mpx-types arch/x86/kernel/traps.c
--- a/arch/x86/kernel/traps.c~x86-fpu-rework-mpx-types	2015-08-31 15:17:35.431929709 -0700
+++ b/arch/x86/kernel/traps.c	2015-08-31 15:17:35.437929984 -0700
@@ -372,7 +372,7 @@ dotraplinkage void do_double_fault(struc
 dotraplinkage void do_bounds(struct pt_regs *regs, long error_code)
 {
 	enum ctx_state prev_state;
-	const struct bndcsr *bndcsr;
+	const struct mpx_bndcsr *bndcsr;
 	siginfo_t *info;
 
 	prev_state = exception_enter();
diff -puN arch/x86/mm/mpx.c~x86-fpu-rework-mpx-types arch/x86/mm/mpx.c
--- a/arch/x86/mm/mpx.c~x86-fpu-rework-mpx-types	2015-08-31 15:17:35.432929755 -0700
+++ b/arch/x86/mm/mpx.c	2015-08-31 15:17:35.437929984 -0700
@@ -274,7 +274,8 @@ bad_opcode:
  */
 siginfo_t *mpx_generate_siginfo(struct pt_regs *regs)
 {
-	const struct bndreg *bndregs, *bndreg;
+	const struct mpx_bndreg_state *bndregs;
+	const struct mpx_bndreg *bndreg;
 	siginfo_t *info = NULL;
 	struct insn insn;
 	uint8_t bndregno;
@@ -301,7 +302,7 @@ siginfo_t *mpx_generate_siginfo(struct p
 		goto err_out;
 	}
 	/* now go select the individual register in the set of 4 */
-	bndreg = &bndregs[bndregno];
+	bndreg = &bndregs->bndreg[bndregno];
 
 	info = kzalloc(sizeof(*info), GFP_KERNEL);
 	if (!info) {
@@ -343,7 +344,7 @@ err_out:
 
 static __user void *mpx_get_bounds_dir(void)
 {
-	const struct bndcsr *bndcsr;
+	const struct mpx_bndcsr *bndcsr;
 
 	if (!cpu_feature_enabled(X86_FEATURE_MPX))
 		return MPX_INVALID_BOUNDS_DIR;
@@ -526,7 +527,7 @@ out_unmap:
 static int do_mpx_bt_fault(void)
 {
 	unsigned long bd_entry, bd_base;
-	const struct bndcsr *bndcsr;
+	const struct mpx_bndcsr *bndcsr;
 	struct mm_struct *mm = current->mm;
 
 	bndcsr = get_xsave_field_ptr(XFEATURE_MASK_BNDCSR);
_

[PATCH 13/15] x86, fpu: correct and check XSAVE xstate size calculations

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

Note: our xsaves support is currently broken and disabled.  This
patch does not fix it, but it is an incremental improvement.
This might be useful to someone backporting the entire set of
XSAVES patches at some point, but it should not be backported
alone.

Ingo said he wanted something like this (bullets 2 and 3):

	http://lkml.kernel.org/r/20150808091508.GB32641@gmail.com

There are currently two xsave buffer formats: standard and
compacted.  The standard format is waht 'XSAVE' and 'XSAVEOPT'
produce while 'XSAVES' and 'XSAVEC' produce a compacted-formet
buffer.  (The kernel never uses XSAVEC)

But, the XSAVES buffer *ALSO* contains "system state components"
which are never saved by a plain XSAVE.  So, XSAVES has two
things that might make its buffer differently-sized from an
XSAVE-produced one.

The current code assumes that an XSAVES buffer's size is simply
the sum of the sizes of the (user) states which are supported.
This seems to work in most cases, but it is not consistent with
what the SDM says, and it breaks if we 'align' a component in the
buffer.  The calculation is also unnecessary work since the CPU
*tells* us the size of the buffer directly.

This patch just reads the size of the buffer right out of the
CPUID leaf instead of trying to derive it.

But, blindly trusting the CPU like this is dangerous.  We add
a verification pass in do_extra_xstate_size_checks() to ensure
that the size we calculate matches with what we see from the
hardware.  When it comes down to it, we trust but verify the
CPU.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---

 b/arch/x86/kernel/fpu/xstate.c |  184 ++++++++++++++++++++++++++++++++++++++---
 1 file changed, 174 insertions(+), 10 deletions(-)

diff -puN arch/x86/kernel/fpu/xstate.c~fix-xstate_size-calculation arch/x86/kernel/fpu/xstate.c
--- a/arch/x86/kernel/fpu/xstate.c~fix-xstate_size-calculation	2015-08-31 15:17:36.752990085 -0700
+++ b/arch/x86/kernel/fpu/xstate.c	2015-08-31 15:17:36.755990222 -0700
@@ -312,27 +312,190 @@ static void __init setup_init_fpu_buf(vo
 	copy_xregs_to_kernel_booting(&init_fpstate.xsave);
 }
 
+static int xfeature_is_supervisor(int xfeature_nr)
+{
+	/*
+	 * We currently do not support supervisor states, but if
+	 * we did, we could find out like this.
+	 *
+	 * SDM says: If state component i is a user state component,
+	 * ECX[0] return 0; if state component i is a supervisor
+	 * state component, ECX[0] returns 1.
+	u32 eax, ebx, ecx, edx;
+	cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx;
+	return !!(ecx & 1);
+	*/
+	return 0;
+}
+/*
+static int xfeature_is_user(int xfeature_nr)
+{
+	return !xfeature_is_supervisor(xfeature_nr);
+}
+*/
+
+/*
+ * This check is important because it is easy to get XSTATE_*
+ * confused with XSTATE_BIT_*.
+ */
+#define CHECK_XFEATURE(nr) do {		\
+	WARN_ON(nr < FIRST_EXTENDED_XFEATURE);	\
+	WARN_ON(nr >= XFEATURE_MAX);	\
+} while (0)
+
+/*
+ * We could cache this like xstate_size[], but we only use
+ * it here, so it would be a waste of space.
+ */
+static int xfeature_is_aligned(int xfeature_nr)
+{
+	u32 eax, ebx, ecx, edx;
+
+	CHECK_XFEATURE(xfeature_nr);
+	cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
+	/*
+	 * The value returned by ECX[1] indicates the alignment
+	 * of state component i when the compacted format
+	 * of the extended region of an XSAVE area is used
+	 */
+	return !!(ecx & 2);
+}
+
+static int xfeature_uncompacted_offset(int xfeature_nr)
+{
+	u32 eax, ebx, ecx, edx;
+
+	CHECK_XFEATURE(xfeature_nr);
+	cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
+	return ebx;
+}
+
+static int xfeature_size(int xfeature_nr)
+{
+	u32 eax, ebx, ecx, edx;
+
+	CHECK_XFEATURE(xfeature_nr);
+	cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
+	return eax;
+}
+
+/*
+ * 'XSAVES' implies two different things:
+ * 1. saving of supervisor/system state
+ * 2. using the compacted format
+ *
+ * Use this function when dealing with the compacted format so
+ * that it is obvious which aspect of 'XSAVES' is being handled
+ * by the calling code.
+ */
+static int using_compacted_format(void)
+{
+	return cpu_has_xsaves;
+}
+
+static void __xstate_dump_leaves(void)
+{
+	int i;
+	u32 eax, ebx, ecx, edx;
+	static int should_dump = 1;
+
+	if (!should_dump)
+		return;
+	should_dump = 0;
+	/*
+	 * Dump out a few leaves past the ones that we support
+	 * just in case there are some goodies up there
+	 */
+	for (i = 0; i < XFEATURE_MAX + 10; i++) {
+		cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
+		pr_warn("CPUID[%02x, %02x]: eax=%08x ebx=%08x ecx=%08x edx=%08x\n",
+			XSTATE_CPUID, i, eax, ebx, ecx, edx);
+	}
+}
+
+#define XSTATE_WARN_ON(x) do {							\
+	if (WARN_ONCE(x, "XSAVE consistency problem, dumping leaves")) {	\
+		__xstate_dump_leaves();						\
+	}									\
+} while (0)
+
+/*
+ * This essentially double-checks what the cpu told us about
+ * how large the XSAVE buffer needs to be.  We are recalculating
+ * it to be safe.
+ */
+static void do_extra_xstate_size_checks(void)
+{
+	int paranoid_xstate_size = FXSAVE_SIZE + XSAVE_HDR_SIZE;
+	int i;
+
+	for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
+		if (!xfeature_enabled(i))
+			continue;
+		/*
+		 * Supervisor state components can be managed only by
+		 * XSAVES, which is compacted-format only.
+		 */
+		if (!using_compacted_format())
+			XSTATE_WARN_ON(xfeature_is_supervisor(i));
+
+		/* Align from the end of the previous feature */
+		if (xfeature_is_aligned(i))
+			paranoid_xstate_size = ALIGN(paranoid_xstate_size, 64);
+		/*
+		 * The offset of a given state in the non-compacted
+		 * format is given to us in a CPUID leaf.  We check
+		 * them for being ordered (increasing offsets) in
+		 * setup_xstate_features().
+		 */
+		if (!using_compacted_format())
+			paranoid_xstate_size = xfeature_uncompacted_offset(i);
+		/*
+		 * The compacted-format offset always depends on where
+		 * the previous state ended.
+		 */
+		paranoid_xstate_size += xfeature_size(i);
+	}
+	XSTATE_WARN_ON(paranoid_xstate_size != xstate_size);
+}
+
 /*
  * Calculate total size of enabled xstates in XCR0/xfeatures_mask.
+ *
+ * Note the SDM's wording here.  "sub-function 0" only enumerates
+ * the size of the *user* states.  If we use it to size a buffer
+ * that we use 'XSAVES' on, we could potentially overflow the
+ * buffer because 'XSAVES' saves system states too.
+ *
+ * Note that we do not currently set any bits on IA32_XSS so
+ * 'XCR0 | IA32_XSS == XCR0' for now.
  */
 static unsigned int __init calculate_xstate_size(void)
 {
 	unsigned int eax, ebx, ecx, edx;
 	unsigned int calculated_xstate_size;
-	int i;
 
 	if (!cpu_has_xsaves) {
+		/*
+		 * - CPUID function 0DH, sub-function 0:
+		 *    EBX enumerates the size (in bytes) required by
+		 *    the XSAVE instruction for an XSAVE area
+		 *    containing all the *user* state components
+		 *    corresponding to bits currently set in XCR0.
+		 */
 		cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx);
 		calculated_xstate_size = ebx;
-		return calculated_xstate_size;
-	}
-
-	calculated_xstate_size = FXSAVE_SIZE + XSAVE_HDR_SIZE;
-	for (i = FIRST_EXTENDED_XFEATURE; i < 64; i++) {
-		if (xfeature_enabled(i)) {
-			cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
-			calculated_xstate_size += eax;
-		}
+	} else {
+		/*
+		 * - CPUID function 0DH, sub-function 1:
+		 *    EBX enumerates the size (in bytes) required by
+		 *    the XSAVES instruction for an XSAVE area
+		 *    containing all the state components
+		 *    corresponding to bits currently set in
+		 *    XCR0 | IA32_XSS.
+		 */
+		cpuid_count(XSTATE_CPUID, 1, &eax, &ebx, &ecx, &edx);
+		calculated_xstate_size = ebx;
 	}
 	return calculated_xstate_size;
 }
@@ -365,6 +528,7 @@ static int init_xstate_size(void)
 	 * make it known to the world that we need more space.
 	 */
 	xstate_size = possible_xstate_size;
+	do_extra_xstate_size_checks();
 	return 0;
 }
 
_

[PATCH 11/15] x86, fpu: rework YMM definition

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

We are about to rework all of the "extended state" definitions.
This makes the 'ymm' naming consistent with the AVX-512 types
we will introduce later.

We also add a convenience type: "reg_128_bit" so that we do
not have to spell out our arithmetic.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---

 b/arch/x86/include/asm/fpu/types.h |   16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff -puN arch/x86/include/asm/fpu/types.h~x86-fpu-rework-ymm-types arch/x86/include/asm/fpu/types.h
--- a/arch/x86/include/asm/fpu/types.h~x86-fpu-rework-ymm-types	2015-08-31 15:17:35.919952013 -0700
+++ b/arch/x86/include/asm/fpu/types.h	2015-08-31 15:17:35.922952150 -0700
@@ -128,17 +128,23 @@ enum xfeature {
 
 #define FIRST_EXTENDED_XFEATURE	XFEATURE_YMM
 
+struct reg_128_bit {
+	u8      regbytes[128/8];
+};
+
 /*
+ * State component 2:
+ *
  * There are 16x 256-bit AVX registers named YMM0-YMM15.
  * The low 128 bits are aliased to the 16 SSE registers (XMM0-XMM15)
- * and are stored in 'struct fxregs_state::xmm_space[]'.
+ * and are stored in 'struct fxregs_state::xmm_space[]' in the
+ * "legacy" area.
  *
- * The high 128 bits are stored here:
- *    16x 128 bits == 256 bytes.
+ * The high 128 bits are stored here.
  */
 struct ymmh_struct {
-	u8				ymmh_space[256];
-};
+	struct reg_128_bit              hi_ymm[16];
+} __packed;
 
 /* Intel MPX support: */
 
_

[PATCH 12/15] x86, fpu: add C structures for AVX-512 state components

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

AVX-512 has 3 separate state components:
1. opmask registers
2. zmm upper half of registers 0-15
3. new zmm registers (16-31)

This patch adds C structures for the three components along with
a few comments mostly lifted from the SDM to explain what they
do.  This will allow us to check our structures against what the
hardware tells us about the sizes of the components.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---

 b/arch/x86/include/asm/fpu/types.h |   33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff -puN arch/x86/include/asm/fpu/types.h~avx-512-structs arch/x86/include/asm/fpu/types.h
--- a/arch/x86/include/asm/fpu/types.h~avx-512-structs	2015-08-31 15:17:36.334970980 -0700
+++ b/arch/x86/include/asm/fpu/types.h	2015-08-31 15:17:36.337971117 -0700
@@ -131,6 +131,12 @@ enum xfeature {
 struct reg_128_bit {
 	u8      regbytes[128/8];
 };
+struct reg_256_bit {
+	u8	regbytes[256/8];
+};
+struct reg_512_bit {
+	u8	regbytes[512/8];
+};
 
 /*
  * State component 2:
@@ -179,6 +185,33 @@ struct mpx_bndcsr_state {
 	};
 } __packed;
 
+/* AVX-512 Components: */
+
+/*
+ * State component 5 is used for the 8 64-bit opmask registers
+ * k0-k7 (opmask state).
+ */
+struct avx_512_opmask_state {
+	u64 				opmask_reg[8];
+} __packed;
+
+/*
+ * State component 6 is used for the upper 256 bits of the
+ * registers ZMM0-ZMM15. These 16 256-bit values are denoted
+ * ZMM0_H-ZMM15_H (ZMM_Hi256 state).
+ */
+struct avx_512_zmm_uppers_state {
+	struct reg_256_bit		zmm_upper[16];
+} __packed;
+
+/*
+ * State component 7 is used for the 16 512-bit registers
+ * ZMM16-ZMM31 (Hi16_ZMM state).
+ */
+struct avx_512_hi16_state {
+	struct reg_512_bit		hi16_zmm[16];
+} __packed;
+
 struct xstate_header {
 	u64				xfeatures;
 	u64				xcomp_bv;
_

[PATCH 14/15] x86, fpu: check to ensure increasing-offset xstate offsets

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

The xstate CPUID leaves enumerate where each state component is
inside the XSAVE buffer, along with the size of the entire
buffer.  Our new XSAVE sanity-checking code extrapolates an
expected _total_ buffer size by looking at the last component
that it encounters.

That method requires that the highest-numbered component also
be the one with the highest offset.  This is a pretty safe
assumption, but let's add some code to ensure it stays true.

To make this check work correctly, we also need to ensure we
only consider the offsets from enabled features because the
offset register (ebx) will return 0 on unsupported features.

This also means that we will preserve the -1's that we
initialized xstate_offsets/sizes[] with.  That will help
find bugs.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---

 b/arch/x86/kernel/fpu/xstate.c |   35 ++++++++++++++++++++++++-----------
 1 file changed, 24 insertions(+), 11 deletions(-)

diff -puN arch/x86/kernel/fpu/xstate.c~x86-fpu-increasing-offset-assumption arch/x86/kernel/fpu/xstate.c
--- a/arch/x86/kernel/fpu/xstate.c~x86-fpu-increasing-offset-assumption	2015-08-31 15:17:37.174009326 -0700
+++ b/arch/x86/kernel/fpu/xstate.c	2015-08-31 15:17:37.177009463 -0700
@@ -185,18 +185,41 @@ void fpu__init_cpu_xstate(void)
 }
 
 /*
+ * Note that in the future we will likely need a pair of
+ * functions here: one for user xstates and the other for
+ * system xstates.  For now, they are the same.
+ */
+static int xfeature_enabled(enum xfeature xfeature)
+{
+	return !!(xfeatures_mask & (1UL << xfeature));
+}
+
+/*
  * Record the offsets and sizes of various xstates contained
  * in the XSAVE state memory layout.
  */
 static void __init setup_xstate_features(void)
 {
 	u32 eax, ebx, ecx, edx, i;
+	/* start at the beginnning of the "extended state" */
+	unsigned int last_good_offset = offsetof(struct xregs_state,
+						 extended_state_area);
 
 	for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
-		cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
+		if (!xfeature_enabled(i))
+			continue;
 
+		cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
 		xstate_offsets[i] = ebx;
 		xstate_sizes[i] = eax;
+		/*
+		 * In our xstate size checks, we assume that the
+		 * highest-numbered xstate feature has the
+		 * highest offset in the buffer.  Ensure it does.
+		 */
+		WARN_ONCE(last_good_offset > xstate_offsets[i],
+			"x86/fpu: misordered xstate at %d\n", last_good_offset);
+		last_good_offset = xstate_offsets[i];
 
 		printk(KERN_INFO "x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n", i, ebx, i, eax);
 	}
@@ -226,16 +249,6 @@ static void __init print_xstate_features
 }
 
 /*
- * Note that in the future we will likely need a pair of
- * functions here: one for user xstates and the other for
- * system xstates.  For now, they are the same.
- */
-static int xfeature_enabled(enum xfeature xfeature)
-{
-	return !!(xfeatures_mask & (1UL << xfeature));
-}
-
-/*
  * This function sets up offsets and sizes of all extended states in
  * xsave area. This supports both standard format and compacted format
  * of the xsave aread.
_

[PATCH 15/15] x86, fpu: check CPU-provided sizes against struct declarations

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

Changes from v2:
 * remove XSTATE_RESERVED check, since it is gone now

--

From: Dave Hansen <dave.hansen@linux.intel.com>

We now have C structures defined for each of the XSAVE state
components that we support.  This patch adds checks during our
verification pass to ensure that the CPU-provided data
enumerated in CPUID leaves matches our C structures.

If not, we warn and dump all the XSAVE CPUID leaves.

Note: this *actually* found an inconsistency with the MPX
'bndcsr' state.  The hardware pads it out differently from
our C structures.  This patch caught it and warned.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---

 b/arch/x86/kernel/fpu/xstate.c |   45 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff -puN arch/x86/kernel/fpu/xstate.c~x86-fpu-check-against-struct-declarations arch/x86/kernel/fpu/xstate.c
--- a/arch/x86/kernel/fpu/xstate.c~x86-fpu-check-against-struct-declarations	2015-08-31 15:17:37.593028476 -0700
+++ b/arch/x86/kernel/fpu/xstate.c	2015-08-31 15:17:37.597028659 -0700
@@ -432,6 +432,49 @@ static void __xstate_dump_leaves(void)
 	}									\
 } while (0)
 
+#define XCHECK_SZ(sz, nr, nr_macro, __struct) do {			\
+	if ((nr == nr_macro) &&						\
+	    WARN_ONCE(sz != sizeof(__struct),				\
+		"%s: struct is %ld bytes, cpu state %d bytes\n",	\
+		__stringify(nr_macro), sizeof(__struct), sz)) {		\
+		__xstate_dump_leaves();					\
+	}								\
+} while (0)
+
+/*
+ * We have a C struct for each 'xstate'.  We need to ensure
+ * that our software representation matches what the CPU
+ * tells us about the state's size.
+ */
+static void check_xstate_against_struct(int nr)
+{
+	/*
+	 * Ask the CPU for the size of the state.
+	 */
+	int sz = xfeature_size(nr);
+	/*
+	 * Match each CPU state with the corresponding software
+	 * structure.
+	 */
+	XCHECK_SZ(sz, nr, XFEATURE_YMM,       struct ymmh_struct);
+	XCHECK_SZ(sz, nr, XFEATURE_BNDREGS,   struct mpx_bndreg_state);
+	XCHECK_SZ(sz, nr, XFEATURE_BNDCSR,    struct mpx_bndcsr_state);
+	XCHECK_SZ(sz, nr, XFEATURE_OPMASK,    struct avx_512_opmask_state);
+	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);
+
+	/*
+	 * Make *SURE* to add any feature numbers in below if
+	 * there are "holes" in the xsave state component
+	 * numbers.
+	 */
+	if ((nr < XFEATURE_YMM) ||
+	    (nr >= XFEATURE_MAX)) {
+		WARN_ONCE(1, "no structure for xstate: %d\n", nr);
+		XSTATE_WARN_ON(1);
+	}
+}
+
 /*
  * This essentially double-checks what the cpu told us about
  * how large the XSAVE buffer needs to be.  We are recalculating
@@ -445,6 +488,8 @@ static void do_extra_xstate_size_checks(
 	for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
 		if (!xfeature_enabled(i))
 			continue;
+
+		check_xstate_against_struct(i);
 		/*
 		 * Supervisor state components can be managed only by
 		 * XSAVES, which is compacted-format only.
_

Re: [PATCH 05/15] x86, fpu: XSAVE macro renames

[Dave Hansen]

On 08/31/2015 03:20 PM, Dave Hansen wrote:
> -	if (!cpu_has_xfeatures(XSTATE_SSE | XSTATE_YMM, &feature_name)) {
> +	if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM,
> +				&feature_name)) {
>  		pr_info("CPU feature '%s' is not supported.\n", feature_name);
>  		return -ENODEV;
>  	}

I posted theses a bit too quickly.  0day found one of these spots that I
missed renaming XSTATE_*.

Review of the rest of the set would be appreciated, but I'll need to
post at least one more version before they can get applied anywhere.

[PATCH 14/15] x86, fpu: check to ensure increasing-offset xstate offsets

[Dave Hansen]

From: Dave Hansen <dave.hansen@linux.intel.com>

The xstate CPUID leaves enumerate where each state component is
inside the XSAVE buffer, along with the size of the entire
buffer.  Our new XSAVE sanity-checking code extrapolates an
expected _total_ buffer size by looking at the last component
that it encounters.

That method requires that the highest-numbered component also
be the one with the highest offset.  This is a pretty safe
assumption, but let's add some code to ensure it stays true.

To make this check work correctly, we also need to ensure we
only consider the offsets from enabled features because the
offset register (ebx) will return 0 on unsupported features.

This also means that we will preserve the -1's that we
initialized xstate_offsets/sizes[] with.  That will help
find bugs.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---

 b/arch/x86/kernel/fpu/xstate.c |   35 ++++++++++++++++++++++++-----------
 1 file changed, 24 insertions(+), 11 deletions(-)

diff -puN arch/x86/kernel/fpu/xstate.c~x86-fpu-increasing-offset-assumption arch/x86/kernel/fpu/xstate.c
--- a/arch/x86/kernel/fpu/xstate.c~x86-fpu-increasing-offset-assumption	2015-09-02 16:23:52.556530877 -0700
+++ b/arch/x86/kernel/fpu/xstate.c	2015-09-02 16:23:52.560531059 -0700
@@ -185,18 +185,41 @@ void fpu__init_cpu_xstate(void)
 }
 
 /*
+ * Note that in the future we will likely need a pair of
+ * functions here: one for user xstates and the other for
+ * system xstates.  For now, they are the same.
+ */
+static int xfeature_enabled(enum xfeature xfeature)
+{
+	return !!(xfeatures_mask & (1UL << xfeature));
+}
+
+/*
  * Record the offsets and sizes of various xstates contained
  * in the XSAVE state memory layout.
  */
 static void __init setup_xstate_features(void)
 {
 	u32 eax, ebx, ecx, edx, i;
+	/* start at the beginnning of the "extended state" */
+	unsigned int last_good_offset = offsetof(struct xregs_state,
+						 extended_state_area);
 
 	for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
-		cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
+		if (!xfeature_enabled(i))
+			continue;
 
+		cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
 		xstate_offsets[i] = ebx;
 		xstate_sizes[i] = eax;
+		/*
+		 * In our xstate size checks, we assume that the
+		 * highest-numbered xstate feature has the
+		 * highest offset in the buffer.  Ensure it does.
+		 */
+		WARN_ONCE(last_good_offset > xstate_offsets[i],
+			"x86/fpu: misordered xstate at %d\n", last_good_offset);
+		last_good_offset = xstate_offsets[i];
 
 		printk(KERN_INFO "x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n", i, ebx, i, eax);
 	}
@@ -226,16 +249,6 @@ static void __init print_xstate_features
 }
 
 /*
- * Note that in the future we will likely need a pair of
- * functions here: one for user xstates and the other for
- * system xstates.  For now, they are the same.
- */
-static int xfeature_enabled(enum xfeature xfeature)
-{
-	return !!(xfeatures_mask & (1UL << xfeature));
-}
-
-/*
  * This function sets up offsets and sizes of all extended states in
  * xsave area. This supports both standard format and compacted format
  * of the xsave aread.
_