[v8,1/8] x86/cpu, kvm: Add support for CPUID_80000021_EAX

Message ID 20230123225700.2224063-2-kim.phillips@amd.com
State New
Headers
Series x86/cpu, kvm: Support AMD Automatic IBRS |

Commit Message

Kim Phillips Jan. 23, 2023, 10:56 p.m. UTC
  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>
---
 arch/x86/include/asm/cpufeature.h        | 7 +++++--
 arch/x86/include/asm/cpufeatures.h       | 2 +-
 arch/x86/include/asm/disabled-features.h | 3 ++-
 arch/x86/include/asm/required-features.h | 3 ++-
 arch/x86/kernel/cpu/common.c             | 3 +++
 arch/x86/kvm/reverse_cpuid.h             | 1 +
 6 files changed, 14 insertions(+), 5 deletions(-)
  

Comments

Sean Christopherson Jan. 23, 2023, 11:54 p.m. UTC | #1
On Mon, Jan 23, 2023, Kim Phillips wrote:
> 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.

Nit, "KVM guests", not "VM guests".
  

Patch

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 1a85e1fb0922..ce0c8f7d3218 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -32,6 +32,7 @@  enum cpuid_leafs
 	CPUID_8000_0007_EBX,
 	CPUID_7_EDX,
 	CPUID_8000_001F_EAX,
+	CPUID_8000_0021_EAX,
 };
 
 #define X86_CAP_FMT_NUM "%d:%d"
@@ -94,8 +95,9 @@  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) ||	\
@@ -118,8 +120,9 @@  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 6cfa7143c316..a84536876794 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			1	   /* N 32-bit bug flags */
 
 /*
diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
index c44b56f7ffba..5dfa4fb76f4b 100644
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h
@@ -124,6 +124,7 @@ 
 #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 aff774775c67..7ba1726b71c7 100644
--- a/arch/x86/include/asm/required-features.h
+++ b/arch/x86/include/asm/required-features.h
@@ -98,6 +98,7 @@ 
 #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 5fe56f0ec9d7..094dbcd63f2a 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1093,6 +1093,9 @@  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);
 
diff --git a/arch/x86/kvm/reverse_cpuid.h b/arch/x86/kvm/reverse_cpuid.h
index 042d0aca3c92..81f4e9ce0c77 100644
--- a/arch/x86/kvm/reverse_cpuid.h
+++ b/arch/x86/kvm/reverse_cpuid.h
@@ -68,6 +68,7 @@  static const struct cpuid_reg reverse_cpuid[] = {
 	[CPUID_12_EAX]        = {0x00000012, 0, CPUID_EAX},
 	[CPUID_8000_001F_EAX] = {0x8000001f, 0, CPUID_EAX},
 	[CPUID_7_1_EDX]       = {         7, 1, CPUID_EDX},
+	[CPUID_8000_0021_EAX] = {0x80000021, 0, CPUID_EAX},
 };
 
 /*