[PATCH] x86, fpu: rename XCR0 access macro

From: Dave Hansen
Date: Fri Apr 24 2015 - 19:00:31 EST



From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>

The SDM says that the xgetbv instruction:

Reads the contents of the extended control register (XCR)
specified in the ECX register into registers EDX:EAX.

In other words, xgetbv(0) gets the thing that the SDM calls XCR0.
We have a macro for that "0" and we call it
XCR_XFEATURE_ENABLED_MASK. That's a bit unfortunate because it
is not a mask nor does the "0" have much to do with the features
we have enabled. It's an index if anything.

Rename the macro to what it means: "XCR0".

Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>

---

b/arch/x86/crypto/camellia_aesni_avx2_glue.c | 2 +-
b/arch/x86/crypto/camellia_aesni_avx_glue.c | 2 +-
b/arch/x86/crypto/cast5_avx_glue.c | 2 +-
b/arch/x86/crypto/cast6_avx_glue.c | 2 +-
b/arch/x86/crypto/serpent_avx2_glue.c | 2 +-
b/arch/x86/crypto/serpent_avx_glue.c | 2 +-
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/xcr.h | 6 +++++-
b/arch/x86/kernel/xsave.c | 2 +-
b/arch/x86/kvm/x86.c | 16 ++++++++--------
b/arch/x86/power/cpu.c | 2 +-
14 files changed, 25 insertions(+), 21 deletions(-)

diff -puN arch/x86/kvm/x86.c~x86-fpu-rename-xcr0-macro arch/x86/kvm/x86.c
--- a/arch/x86/kvm/x86.c~x86-fpu-rename-xcr0-macro 2015-04-24 15:55:10.454089347 -0700
+++ b/arch/x86/kvm/x86.c 2015-04-24 15:59:42.193345311 -0700
@@ -634,7 +634,7 @@ static void kvm_load_guest_xcr0(struct k
if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE) &&
!vcpu->guest_xcr0_loaded) {
/* kvm_set_xcr() also depends on this */
- xsetbv(XCR_XFEATURE_ENABLED_MASK, vcpu->arch.xcr0);
+ xsetbv(XCR0, vcpu->arch.xcr0);
vcpu->guest_xcr0_loaded = 1;
}
}
@@ -643,7 +643,7 @@ static void kvm_put_guest_xcr0(struct kv
{
if (vcpu->guest_xcr0_loaded) {
if (vcpu->arch.xcr0 != host_xcr0)
- xsetbv(XCR_XFEATURE_ENABLED_MASK, host_xcr0);
+ xsetbv(XCR0, host_xcr0);
vcpu->guest_xcr0_loaded = 0;
}
}
@@ -654,8 +654,8 @@ static int __kvm_set_xcr(struct kvm_vcpu
u64 old_xcr0 = vcpu->arch.xcr0;
u64 valid_bits;

- /* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now */
- if (index != XCR_XFEATURE_ENABLED_MASK)
+ /* Only support XCR0 now */
+ if (index != XCR0)
return 1;
if (!(xcr0 & XSTATE_FP))
return 1;
@@ -3295,7 +3295,7 @@ static void kvm_vcpu_ioctl_x86_get_xcrs(

guest_xcrs->nr_xcrs = 1;
guest_xcrs->flags = 0;
- guest_xcrs->xcrs[0].xcr = XCR_XFEATURE_ENABLED_MASK;
+ guest_xcrs->xcrs[0].xcr = XCR0;
guest_xcrs->xcrs[0].value = vcpu->arch.xcr0;
}

@@ -3312,8 +3312,8 @@ static int kvm_vcpu_ioctl_x86_set_xcrs(s

for (i = 0; i < guest_xcrs->nr_xcrs; i++)
/* Only support XCR0 currently */
- if (guest_xcrs->xcrs[i].xcr == XCR_XFEATURE_ENABLED_MASK) {
- r = __kvm_set_xcr(vcpu, XCR_XFEATURE_ENABLED_MASK,
+ if (guest_xcrs->xcrs[i].xcr == XCR0) {
+ r = __kvm_set_xcr(vcpu, XCR0,
guest_xcrs->xcrs[i].value);
break;
}
@@ -5809,7 +5809,7 @@ int kvm_arch_init(void *opaque)
perf_register_guest_info_callbacks(&kvm_guest_cbs);

if (cpu_has_xsave)
- host_xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+ host_xcr0 = xgetbv(XCR0);

kvm_lapic_init();
#ifdef CONFIG_X86_64
diff -puN arch/x86/include/asm/xcr.h~x86-fpu-rename-xcr0-macro arch/x86/include/asm/xcr.h
--- a/arch/x86/include/asm/xcr.h~x86-fpu-rename-xcr0-macro 2015-04-24 15:55:10.456089437 -0700
+++ b/arch/x86/include/asm/xcr.h 2015-04-24 15:55:10.483090655 -0700
@@ -17,13 +17,17 @@
#ifndef _ASM_X86_XCR_H
#define _ASM_X86_XCR_H

-#define XCR_XFEATURE_ENABLED_MASK 0x00000000
+#define XCR0 0x00000000

#ifdef __KERNEL__
# ifndef __ASSEMBLY__

#include <linux/types.h>

+/*
+ * Reads the contents of the extended control register (XCR)
+ * specified in the ECX register into registers EDX:EAX.
+ */
static inline u64 xgetbv(u32 index)
{
u32 eax, edx;
diff -puN arch/x86/crypto/camellia_aesni_avx2_glue.c~x86-fpu-rename-xcr0-macro arch/x86/crypto/camellia_aesni_avx2_glue.c
--- a/arch/x86/crypto/camellia_aesni_avx2_glue.c~x86-fpu-rename-xcr0-macro 2015-04-24 15:55:10.458089527 -0700
+++ b/arch/x86/crypto/camellia_aesni_avx2_glue.c 2015-04-24 15:55:10.484090700 -0700
@@ -568,7 +568,7 @@ static int __init camellia_aesni_init(vo
return -ENODEV;
}

- xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+ xcr0 = xgetbv(XCR0);
if ((xcr0 & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM)) {
pr_info("AVX2 detected but unusable.\n");
return -ENODEV;
diff -puN arch/x86/crypto/camellia_aesni_avx_glue.c~x86-fpu-rename-xcr0-macro arch/x86/crypto/camellia_aesni_avx_glue.c
--- a/arch/x86/crypto/camellia_aesni_avx_glue.c~x86-fpu-rename-xcr0-macro 2015-04-24 15:55:10.460089618 -0700
+++ b/arch/x86/crypto/camellia_aesni_avx_glue.c 2015-04-24 15:55:10.484090700 -0700
@@ -560,7 +560,7 @@ static int __init camellia_aesni_init(vo
return -ENODEV;
}

- xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+ xcr0 = xgetbv(XCR0);
if ((xcr0 & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM)) {
pr_info("AVX detected but unusable.\n");
return -ENODEV;
diff -puN arch/x86/crypto/cast5_avx_glue.c~x86-fpu-rename-xcr0-macro arch/x86/crypto/cast5_avx_glue.c
--- a/arch/x86/crypto/cast5_avx_glue.c~x86-fpu-rename-xcr0-macro 2015-04-24 15:55:10.462089708 -0700
+++ b/arch/x86/crypto/cast5_avx_glue.c 2015-04-24 15:55:10.485090745 -0700
@@ -475,7 +475,7 @@ static int __init cast5_init(void)
return -ENODEV;
}

- xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+ xcr0 = xgetbv(XCR0);
if ((xcr0 & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM)) {
pr_info("AVX detected but unusable.\n");
return -ENODEV;
diff -puN arch/x86/crypto/cast6_avx_glue.c~x86-fpu-rename-xcr0-macro arch/x86/crypto/cast6_avx_glue.c
--- a/arch/x86/crypto/cast6_avx_glue.c~x86-fpu-rename-xcr0-macro 2015-04-24 15:55:10.463089753 -0700
+++ b/arch/x86/crypto/cast6_avx_glue.c 2015-04-24 15:55:10.485090745 -0700
@@ -597,7 +597,7 @@ static int __init cast6_init(void)
return -ENODEV;
}

- xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+ xcr0 = xgetbv(XCR0);
if ((xcr0 & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM)) {
pr_info("AVX detected but unusable.\n");
return -ENODEV;
diff -puN arch/x86/crypto/serpent_avx2_glue.c~x86-fpu-rename-xcr0-macro arch/x86/crypto/serpent_avx2_glue.c
--- a/arch/x86/crypto/serpent_avx2_glue.c~x86-fpu-rename-xcr0-macro 2015-04-24 15:55:10.465089843 -0700
+++ b/arch/x86/crypto/serpent_avx2_glue.c 2015-04-24 15:55:10.485090745 -0700
@@ -544,7 +544,7 @@ static int __init init(void)
return -ENODEV;
}

- xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+ xcr0 = xgetbv(XCR0);
if ((xcr0 & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM)) {
pr_info("AVX detected but unusable.\n");
return -ENODEV;
diff -puN arch/x86/crypto/serpent_avx_glue.c~x86-fpu-rename-xcr0-macro arch/x86/crypto/serpent_avx_glue.c
--- a/arch/x86/crypto/serpent_avx_glue.c~x86-fpu-rename-xcr0-macro 2015-04-24 15:55:10.467089933 -0700
+++ b/arch/x86/crypto/serpent_avx_glue.c 2015-04-24 15:55:10.486090790 -0700
@@ -603,7 +603,7 @@ static int __init serpent_init(void)
return -ENODEV;
}

- xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+ xcr0 = xgetbv(XCR0);
if ((xcr0 & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM)) {
printk(KERN_INFO "AVX detected but unusable.\n");
return -ENODEV;
diff -puN arch/x86/crypto/sha1_ssse3_glue.c~x86-fpu-rename-xcr0-macro arch/x86/crypto/sha1_ssse3_glue.c
--- a/arch/x86/crypto/sha1_ssse3_glue.c~x86-fpu-rename-xcr0-macro 2015-04-24 15:55:10.469090024 -0700
+++ b/arch/x86/crypto/sha1_ssse3_glue.c 2015-04-24 15:55:10.486090790 -0700
@@ -128,7 +128,7 @@ static bool __init avx_usable(void)
if (!cpu_has_avx || !cpu_has_osxsave)
return false;

- xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+ xcr0 = xgetbv(XCR0);
if ((xcr0 & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM)) {
pr_info("AVX detected but unusable.\n");

diff -puN arch/x86/crypto/sha256_ssse3_glue.c~x86-fpu-rename-xcr0-macro arch/x86/crypto/sha256_ssse3_glue.c
--- a/arch/x86/crypto/sha256_ssse3_glue.c~x86-fpu-rename-xcr0-macro 2015-04-24 15:55:10.471090114 -0700
+++ b/arch/x86/crypto/sha256_ssse3_glue.c 2015-04-24 15:55:10.486090790 -0700
@@ -137,7 +137,7 @@ static bool __init avx_usable(void)
if (!cpu_has_avx || !cpu_has_osxsave)
return false;

- xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+ xcr0 = xgetbv(XCR0);
if ((xcr0 & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM)) {
pr_info("AVX detected but unusable.\n");

diff -puN arch/x86/crypto/sha512_ssse3_glue.c~x86-fpu-rename-xcr0-macro arch/x86/crypto/sha512_ssse3_glue.c
--- a/arch/x86/crypto/sha512_ssse3_glue.c~x86-fpu-rename-xcr0-macro 2015-04-24 15:55:10.472090159 -0700
+++ b/arch/x86/crypto/sha512_ssse3_glue.c 2015-04-24 15:55:10.487090836 -0700
@@ -136,7 +136,7 @@ static bool __init avx_usable(void)
if (!cpu_has_avx || !cpu_has_osxsave)
return false;

- xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+ xcr0 = xgetbv(XCR0);
if ((xcr0 & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM)) {
pr_info("AVX detected but unusable.\n");

diff -puN arch/x86/crypto/twofish_avx_glue.c~x86-fpu-rename-xcr0-macro arch/x86/crypto/twofish_avx_glue.c
--- a/arch/x86/crypto/twofish_avx_glue.c~x86-fpu-rename-xcr0-macro 2015-04-24 15:55:10.474090249 -0700
+++ b/arch/x86/crypto/twofish_avx_glue.c 2015-04-24 15:55:10.487090836 -0700
@@ -565,7 +565,7 @@ static int __init twofish_init(void)
return -ENODEV;
}

- xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+ xcr0 = xgetbv(XCR0);
if ((xcr0 & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM)) {
printk(KERN_INFO "AVX detected but unusable.\n");
return -ENODEV;
diff -puN arch/x86/kernel/xsave.c~x86-fpu-rename-xcr0-macro arch/x86/kernel/xsave.c
--- a/arch/x86/kernel/xsave.c~x86-fpu-rename-xcr0-macro 2015-04-24 15:55:10.476090339 -0700
+++ b/arch/x86/kernel/xsave.c 2015-04-24 15:55:10.487090836 -0700
@@ -456,7 +456,7 @@ static void prepare_fx_sw_frame(void)
static inline void xstate_enable(void)
{
cr4_set_bits(X86_CR4_OSXSAVE);
- xsetbv(XCR_XFEATURE_ENABLED_MASK, pcntxt_mask);
+ xsetbv(XCR0, pcntxt_mask);
}

/*
diff -puN arch/x86/power/cpu.c~x86-fpu-rename-xcr0-macro arch/x86/power/cpu.c
--- a/arch/x86/power/cpu.c~x86-fpu-rename-xcr0-macro 2015-04-24 15:55:10.478090430 -0700
+++ b/arch/x86/power/cpu.c 2015-04-24 15:55:10.488090881 -0700
@@ -225,7 +225,7 @@ static void notrace __restore_processor_
* restore XCR0 for xsave capable cpu's.
*/
if (cpu_has_xsave)
- xsetbv(XCR_XFEATURE_ENABLED_MASK, pcntxt_mask);
+ xsetbv(XCR0, pcntxt_mask);

fix_processor_context();

_
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