[v8,21/21] i386/cpu: Use CPUCacheInfo.share_level to encode CPUID[0x8000001D].EAX[bits 25:14]

Commit Message

Zhao Liu Jan. 31, 2024, 10:13 a.m. UTC

From: Zhao Liu <[e-mail]>

CPUID[0x8000001D].EAX[bits 25:14] NumSharingCache: number of logical
processors sharing cache.

The number of logical processors sharing this cache is
NumSharingCache + 1.

After cache models have topology information, we can use
CPUCacheInfo.share_level to decide which topology level to be encoded
into CPUID[0x8000001D].EAX[bits 25:14].

Cc: Babu Moger <[e-mail]>
Tested-by: Yongwei Ma <[e-mail]>
Signed-off-by: Zhao Liu <[e-mail]>
---
Changes since v7:
 * Renamed max_processor_ids_for_cache() to max_thread_ids_for_cache().
 * Dropped Michael/Babu's ACKed/Tested tags since the code change.
 * Re-added Yongwei's Tested tag For his re-testing.

Changes since v3:
 * Explained what "CPUID[0x8000001D].EAX[bits 25:14]" means in the
   commit message. (Babu)

Changes since v1:
 * Used cache->share_level as the parameter in
   max_processor_ids_for_cache().
---
 target/i386/cpu.c | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

Patch

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index fbfebdc2caf3..763de2b93c28 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -481,20 +481,12 @@  static void encode_cache_cpuid8000001d(CPUCacheInfo *cache,
                                        uint32_t *eax, uint32_t *ebx,
                                        uint32_t *ecx, uint32_t *edx)
 {
-    uint32_t num_sharing_cache;
     assert(cache->size == cache->line_size * cache->associativity *
                           cache->partitions * cache->sets);
 
     *eax = CACHE_TYPE(cache->type) | CACHE_LEVEL(cache->level) |
                (cache->self_init ? CACHE_SELF_INIT_LEVEL : 0);
-
-    /* L3 is shared among multiple cores */
-    if (cache->level == 3) {
-        num_sharing_cache = 1 << apicid_die_offset(topo_info);
-    } else {
-        num_sharing_cache = 1 << apicid_core_offset(topo_info);
-    }
-    *eax |= (num_sharing_cache - 1) << 14;
+    *eax |= max_thread_ids_for_cache(topo_info, cache->share_level) << 14;
 
     assert(cache->line_size > 0);
     assert(cache->partitions > 0);