[PATCH v3 3/6] i386: Introduce new struct "MultiBitFeatureInfo" for multi-bit features

[Lei Wang]

Some features use multiple CPUID bits to form a value to be used, e.g.,
CPUID(0x1E,0):EBX[23:08] is regarded as the tmul_maxn value for AMX.
Introduce a new struct "MultiBitFeatureInfo" to hold the information for
those features and create a corresponding member in struct FeatureWordInfo,
so that the infomation can be assigned for each item in feature_word_info
array and used in the future.

Signed-off-by: Lei Wang <lei4.wang@intel.com>
---
 target/i386/cpu-internal.h |  9 +++++++
 target/i386/cpu.c          | 54 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+)

diff --git a/target/i386/cpu-internal.h b/target/i386/cpu-internal.h
index 9baac5c0b4..66b3d66cb4 100644
--- a/target/i386/cpu-internal.h
+++ b/target/i386/cpu-internal.h
@@ -25,6 +25,13 @@ typedef enum FeatureWordType {
    MSR_FEATURE_WORD,
 } FeatureWordType;
 
+typedef struct MultiBitFeatureInfo {
+    const char *feat_name;
+    uint64_t mask;
+    unsigned high_bit_position;
+    unsigned low_bit_position;
+} MultiBitFeatureInfo;
+
 typedef struct FeatureWordInfo {
     FeatureWordType type;
     /* feature flags names are taken from "Intel Processor Identification and
@@ -51,6 +58,8 @@ typedef struct FeatureWordInfo {
     uint64_t migratable_flags; /* Feature flags known to be migratable */
     /* Features that shouldn't be auto-enabled by "-cpu host" */
     uint64_t no_autoenable_flags;
+    unsigned num_multi_bit_features;
+    MultiBitFeatureInfo *multi_bit_features;
 } FeatureWordInfo;
 
 extern FeatureWordInfo feature_word_info[];
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 883098bc5a..88aa780566 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -1011,6 +1011,21 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
         },
         .migratable_flags = CPUID_AMX_PALETTE_1_TOTAL_TILE_BYTES_MASK |
             CPUID_AMX_PALETTE_1_BYTES_PER_TILE_MASK,
+        .num_multi_bit_features = 2,
+        .multi_bit_features = (MultiBitFeatureInfo[]){
+            {
+                .feat_name = "total_tile_bytes",
+                .mask = CPUID_AMX_PALETTE_1_TOTAL_TILE_BYTES_MASK,
+                .high_bit_position = 15,
+                .low_bit_position = 0,
+            },
+            {
+                .feat_name = "bytes_per_tile",
+                .mask = CPUID_AMX_PALETTE_1_BYTES_PER_TILE_MASK,
+                .high_bit_position = 31,
+                .low_bit_position = 16,
+            },
+        },
     },
     [FEAT_1D_1_EBX] = {
         .type = CPUID_FEATURE_WORD,
@@ -1021,6 +1036,21 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
         },
         .migratable_flags = CPUID_AMX_PALETTE_1_BYTES_PER_ROW_MASK |
             CPUID_AMX_PALETTE_1_MAX_NAMES_MASK,
+        .num_multi_bit_features = 2,
+        .multi_bit_features = (MultiBitFeatureInfo[]){
+            {
+                .feat_name = "bytes_per_row",
+                .mask = CPUID_AMX_PALETTE_1_BYTES_PER_ROW_MASK,
+                .high_bit_position = 15,
+                .low_bit_position = 0,
+            },
+            {
+                .feat_name = "max_names",
+                .mask = CPUID_AMX_PALETTE_1_MAX_NAMES_MASK,
+                .high_bit_position = 31,
+                .low_bit_position = 16,
+            },
+        },
     },
     [FEAT_1D_1_ECX] = {
         .type = CPUID_FEATURE_WORD,
@@ -1030,6 +1060,15 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
             .reg = R_ECX,
         },
         .migratable_flags = CPUID_AMX_PALETTE_1_MAX_ROWS_MASK,
+        .num_multi_bit_features = 1,
+        .multi_bit_features = (MultiBitFeatureInfo[]){
+            {
+                .feat_name = "max_rows",
+                .mask = CPUID_AMX_PALETTE_1_MAX_ROWS_MASK,
+                .high_bit_position = 15,
+                .low_bit_position = 0,
+            },
+        },
     },
     [FEAT_1E_0_EBX] = {
         .type = CPUID_FEATURE_WORD,
@@ -1040,6 +1079,21 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
         },
         .migratable_flags = CPUID_AMX_TMUL_MAX_K_MASK |
             CPUID_AMX_TMUL_MAX_N_MASK,
+        .num_multi_bit_features = 2,
+        .multi_bit_features = (MultiBitFeatureInfo[]){
+            {
+                .feat_name = "tmul_maxk",
+                .mask = CPUID_AMX_TMUL_MAX_K_MASK,
+                .high_bit_position = 7,
+                .low_bit_position = 0,
+            },
+            {
+                .feat_name = "tmul_maxn",
+                .mask = CPUID_AMX_TMUL_MAX_N_MASK,
+                .high_bit_position = 23,
+                .low_bit_position = 8,
+            },
+        },
     },
     /*Below are MSR exposed features*/
     [FEAT_ARCH_CAPABILITIES] = {
-- 
2.34.1