x86/cpu: Add cpu_type to struct x86_cpu_id

In addition to matching vendor/family/model/feature, for hybrid variants it is
required to also match cpu-type. For example, some CPU vulnerabilities like
RFDS only affect a specific cpu-type.

To be able to also match CPUs based on their type, add a new field "type" to
struct x86_cpu_id which is used by the CPU-matching tables. Introduce
X86_CPU_TYPE_ANY for the cases that don't care about the cpu-type.

  [ bp: Massage commit message. ]

Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/20250311-add-cpu-type-v8-3-e8514dcaaff2@linux.intel.com

2 files changed, 25 insertions, 9 deletions

diff --git a/arch/x86/include/asm/cpu_device_id.h b/arch/x86/include/asm/cpu_device_id.h
index 45489b034cd6..6be777a06944 100644
--- a/arch/x86/include/asm/cpu_device_id.h
+++ b/arch/x86/include/asm/cpu_device_id.h
@@ -74,13 +74,14 @@
  * into another macro at the usage site for good reasons, then please
  * start this local macro with X86_MATCH to allow easy grepping.
  */
-#define X86_MATCH_CPU(_vendor, _family, _model, _steppings, _feature, _data) { \
+#define X86_MATCH_CPU(_vendor, _family, _model, _steppings, _feature, _type, _data) { \
 	.vendor		= _vendor,					\
 	.family		= _family,					\
 	.model		= _model,					\
 	.steppings	= _steppings,					\
 	.feature	= _feature,					\
 	.flags		= X86_CPU_ID_FLAG_ENTRY_VALID,			\
+	.type		= _type,					\
 	.driver_data	= (unsigned long) _data				\
 }
 
@@ -96,7 +97,7 @@
  */
 #define X86_MATCH_VENDOR_FAM_FEATURE(vendor, family, feature, data)		\
 	X86_MATCH_CPU(X86_VENDOR_##vendor, family, X86_MODEL_ANY,		\
-		      X86_STEPPING_ANY, feature, data)
+		      X86_STEPPING_ANY, feature, X86_CPU_TYPE_ANY, data)
 
 /**
  * X86_MATCH_VENDOR_FEATURE - Macro for matching vendor and CPU feature
@@ -109,7 +110,7 @@
  */
 #define X86_MATCH_VENDOR_FEATURE(vendor, feature, data)				\
 	X86_MATCH_CPU(X86_VENDOR_##vendor, X86_FAMILY_ANY, X86_MODEL_ANY,	\
-		      X86_STEPPING_ANY, feature, data)
+		      X86_STEPPING_ANY, feature, X86_CPU_TYPE_ANY, data)
 
 /**
  * X86_MATCH_FEATURE - Macro for matching a CPU feature
@@ -120,7 +121,7 @@
  */
 #define X86_MATCH_FEATURE(feature, data)					\
 	X86_MATCH_CPU(X86_VENDOR_ANY, X86_FAMILY_ANY, X86_MODEL_ANY,		\
-		      X86_STEPPING_ANY, feature, data)
+		      X86_STEPPING_ANY, feature, X86_CPU_TYPE_ANY, data)
 
 /**
  * X86_MATCH_VENDOR_FAM_MODEL - Match vendor, family and model
@@ -134,7 +135,7 @@
  */
 #define X86_MATCH_VENDOR_FAM_MODEL(vendor, family, model, data)			\
 	X86_MATCH_CPU(X86_VENDOR_##vendor, family, model, X86_STEPPING_ANY,	\
-		      X86_FEATURE_ANY, data)
+		      X86_FEATURE_ANY, X86_CPU_TYPE_ANY, data)
 
 /**
  * X86_MATCH_VENDOR_FAM - Match vendor and family
@@ -147,7 +148,7 @@
  */
 #define X86_MATCH_VENDOR_FAM(vendor, family, data)				\
 	X86_MATCH_CPU(X86_VENDOR_##vendor, family, X86_MODEL_ANY,		\
-		      X86_STEPPING_ANY, X86_FEATURE_ANY, data)
+		      X86_STEPPING_ANY, X86_FEATURE_ANY, X86_CPU_TYPE_ANY, data)
 
 /**
  * X86_MATCH_VFM - Match encoded vendor/family/model
@@ -158,7 +159,7 @@
  */
 #define X86_MATCH_VFM(vfm, data)						\
 	X86_MATCH_CPU(VFM_VENDOR(vfm), VFM_FAMILY(vfm),	VFM_MODEL(vfm),		\
-		      X86_STEPPING_ANY, X86_FEATURE_ANY, data)
+		      X86_STEPPING_ANY, X86_FEATURE_ANY, X86_CPU_TYPE_ANY, data)
 
 #define __X86_STEPPINGS(mins, maxs)    GENMASK(maxs, mins)
 /**
@@ -173,7 +174,8 @@
  */
 #define X86_MATCH_VFM_STEPS(vfm, min_step, max_step, data)			\
 	X86_MATCH_CPU(VFM_VENDOR(vfm), VFM_FAMILY(vfm), VFM_MODEL(vfm),		\
-		      __X86_STEPPINGS(min_step, max_step), X86_FEATURE_ANY, data)
+		      __X86_STEPPINGS(min_step, max_step), X86_FEATURE_ANY,	\
+		      X86_CPU_TYPE_ANY, data)
 
 /**
  * X86_MATCH_VFM_FEATURE - Match encoded vendor/family/model/feature
@@ -185,7 +187,19 @@
  */
 #define X86_MATCH_VFM_FEATURE(vfm, feature, data)				\
 	X86_MATCH_CPU(VFM_VENDOR(vfm), VFM_FAMILY(vfm), VFM_MODEL(vfm),		\
-		      X86_STEPPING_ANY, feature, data)
+		      X86_STEPPING_ANY, feature, X86_CPU_TYPE_ANY, data)
+
+/**
+ * X86_MATCH_VFM_CPU_TYPE - Match encoded vendor/family/model/type
+ * @vfm:	Encoded 8-bits each for vendor, family, model
+ * @type:	CPU type e.g. P-core, E-core
+ * @data:	Driver specific data or NULL. The internal storage
+ *		format is unsigned long. The supplied value, pointer
+ *		etc. is cast to unsigned long internally.
+ */
+#define X86_MATCH_VFM_CPU_TYPE(vfm, type, data)				\
+	X86_MATCH_CPU(VFM_VENDOR(vfm), VFM_FAMILY(vfm), VFM_MODEL(vfm),	\
+		      X86_STEPPING_ANY, X86_FEATURE_ANY, type, data)
 
 extern const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match);
 extern bool x86_match_min_microcode_rev(const struct x86_cpu_id *table);
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index d67614f7b7f1..bd7e60c0b72f 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -692,6 +692,7 @@ struct x86_cpu_id {
 	__u16 feature;	/* bit index */
 	/* Solely for kernel-internal use: DO NOT EXPORT to userspace! */
 	__u16 flags;
+	__u8  type;
 	kernel_ulong_t driver_data;
 };
 
@@ -703,6 +704,7 @@ struct x86_cpu_id {
 #define X86_STEP_MIN 0
 #define X86_STEP_MAX 0xf
 #define X86_FEATURE_ANY 0	/* Same as FPU, you can't test for that */
+#define X86_CPU_TYPE_ANY 0
 
 /*
  * Generic table type for matching CPU features.