From: H.J. Lu <hjl.tools@gmail.com>
Date: Mon, 6 Jul 2020 13:57:08 +0000 (-0700)
Subject: x86: Detect Extended Feature Disable (XFD)
X-Git-Tag: glibc-2.32~137
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=28c13ae5bbc81aa2ae67890ce53e65257d4703a4;p=thirdparty%2Fglibc.git

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 f25df778cce..bc425462d64 100644
--- 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 dafd66434c9..2cff2e86ba5 100644
--- 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);