x86: Detect Extended Feature Disable (XFD)

An extension called extended feature disable (XFD) is an extension added
for Intel AMX to the XSAVE feature set that allows an operating system
to enable a feature while preventing specific user threads from using
the feature.

diff --git a/sysdeps/x86/cpu-features.h b/sysdeps/x86/cpu-features.h
index f25df778cce90e5937f92648f19d7e205aca4491..bc425462d6401b862d0680f2d9fe941cc4041ba7 100644 (file)
--- a/sysdeps/x86/cpu-features.h
+++ b/sysdeps/x86/cpu-features.h
@@ -393,6 +393,7 @@ extern const struct cpu_features *__get_cpu_features (void)
 #define bit_cpu_XSAVEC         (1u << 1)
 #define bit_cpu_XGETBV_ECX_1   (1u << 2)
 #define bit_cpu_XSAVES         (1u << 3)
+#define bit_cpu_XFD            (1u << 4)
 
 /* COMMON_CPUID_INDEX_80000007.  */
 
@@ -578,6 +579,7 @@ extern const struct cpu_features *__get_cpu_features (void)
 #define index_cpu_XSAVEC       COMMON_CPUID_INDEX_D_ECX_1
 #define index_cpu_XGETBV_ECX_1 COMMON_CPUID_INDEX_D_ECX_1
 #define index_cpu_XSAVES       COMMON_CPUID_INDEX_D_ECX_1
+#define index_cpu_XFD          COMMON_CPUID_INDEX_D_ECX_1
 
 /* COMMON_CPUID_INDEX_80000007.  */
 
@@ -763,6 +765,7 @@ extern const struct cpu_features *__get_cpu_features (void)
 #define reg_XSAVEC             eax
 #define reg_XGETBV_ECX_1       eax
 #define reg_XSAVES             eax
+#define reg_XFD                        eax
 
 /* COMMON_CPUID_INDEX_80000007.  */
 

diff --git a/sysdeps/x86/tst-get-cpu-features.c b/sysdeps/x86/tst-get-cpu-features.c
index dafd66434c9ceb56a3e47239955d3956490bdb09..2cff2e86ba590ef8b831c228359d0e76b0bb2bd3 100644 (file)
--- a/sysdeps/x86/tst-get-cpu-features.c
+++ b/sysdeps/x86/tst-get-cpu-features.c
@@ -214,6 +214,7 @@ do_test (void)
   CHECK_CPU_FEATURE (XSAVEC);
   CHECK_CPU_FEATURE (XGETBV_ECX_1);
   CHECK_CPU_FEATURE (XSAVES);
+  CHECK_CPU_FEATURE (XFD);
   CHECK_CPU_FEATURE (INVARIANT_TSC);
   CHECK_CPU_FEATURE (WBNOINVD);
   CHECK_CPU_FEATURE (AVX512_BF16);