x86/cpu, kvm: Add support for CPUID_80000021_EAX

commit 8415a74852d7c24795007ee9862d25feb519007c upstream.

Add support for CPUID leaf 80000021, EAX. The majority of the features will be
used in the kernel and thus a separate leaf is appropriate.

Include KVM's reverse_cpuid entry because features are used by VM guests, too.

  [ bp: Massage commit message. ]

Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20230124163319.2277355-2-kim.phillips@amd.com
[bwh: Backported to 6.1: adjust context]
Signed-off-by: Ben Hutchings <benh@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

6 files changed, 14 insertions, 5 deletions

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 00d329a990e5..4466a47b7608 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -31,6 +31,7 @@ enum cpuid_leafs
 	CPUID_8000_0007_EBX,
 	CPUID_7_EDX,
 	CPUID_8000_001F_EAX,
+	CPUID_8000_0021_EAX,
 };
 
 #ifdef CONFIG_X86_FEATURE_NAMES
@@ -90,8 +91,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
 	   CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) ||	\
 	   CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) ||	\
 	   CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 19, feature_bit) ||	\
+	   CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 20, feature_bit) ||	\
 	   REQUIRED_MASK_CHECK					  ||	\
-	   BUILD_BUG_ON_ZERO(NCAPINTS != 20))
+	   BUILD_BUG_ON_ZERO(NCAPINTS != 21))
 
 #define DISABLED_MASK_BIT_SET(feature_bit)				\
 	 ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  0, feature_bit) ||	\
@@ -114,8 +116,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
 	   CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) ||	\
 	   CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) ||	\
 	   CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 19, feature_bit) ||	\
+	   CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 20, feature_bit) ||	\
 	   DISABLED_MASK_CHECK					  ||	\
-	   BUILD_BUG_ON_ZERO(NCAPINTS != 20))
+	   BUILD_BUG_ON_ZERO(NCAPINTS != 21))
 
 #define cpu_has(c, bit)							\
 	(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :	\
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 09aed77becc8..f42286e9a2b1 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -13,7 +13,7 @@
 /*
  * Defines x86 CPU feature bits
  */
-#define NCAPINTS			20	   /* N 32-bit words worth of info */
+#define NCAPINTS			21	   /* N 32-bit words worth of info */
 #define NBUGINTS			2	   /* N 32-bit bug flags */
 
 /*
diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
index f0f935f8d917..8453260f6d9f 100644
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h
@@ -85,6 +85,7 @@
 #define DISABLED_MASK17	0
 #define DISABLED_MASK18	0
 #define DISABLED_MASK19	0
-#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 20)
+#define DISABLED_MASK20	0
+#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 21)
 
 #endif /* _ASM_X86_DISABLED_FEATURES_H */
diff --git a/arch/x86/include/asm/required-features.h b/arch/x86/include/asm/required-features.h
index fa5700097f64..fb3d81347e33 100644
--- a/arch/x86/include/asm/required-features.h
+++ b/arch/x86/include/asm/required-features.h
@@ -102,6 +102,7 @@
 #define REQUIRED_MASK17	0
 #define REQUIRED_MASK18	0
 #define REQUIRED_MASK19	0
-#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 20)
+#define REQUIRED_MASK20	0
+#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 21)
 
 #endif /* _ASM_X86_REQUIRED_FEATURES_H */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 423119c1eb54..fdc727972f1b 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -970,6 +970,9 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
 	if (c->extended_cpuid_level >= 0x8000001f)
 		c->x86_capability[CPUID_8000_001F_EAX] = cpuid_eax(0x8000001f);
 
+	if (c->extended_cpuid_level >= 0x80000021)
+		c->x86_capability[CPUID_8000_0021_EAX] = cpuid_eax(0x80000021);
+
 	init_scattered_cpuid_features(c);
 	init_speculation_control(c);
 	init_cqm(c);
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index 7dec43b2c420..defae8082789 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -53,6 +53,7 @@ static const struct cpuid_reg reverse_cpuid[] = {
 	[CPUID_7_ECX]         = {         7, 0, CPUID_ECX},
 	[CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX},
 	[CPUID_7_EDX]         = {         7, 0, CPUID_EDX},
+	[CPUID_8000_0021_EAX] = {0x80000021, 0, CPUID_EAX},
 };
 
 static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned x86_feature)