[PULL 22/23] i386/cpu: Use CPUCacheInfo.share_level to encode CPUID[0x8000001D].EAX[bits 25:14]

Paolo Bonzini posted 23 patches 6 months ago
Maintainers: "Michael S. Tsirkin" <mst@redhat.com>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Paolo Bonzini <pbonzini@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Eduardo Habkost <eduardo@habkost.net>, Marcelo Tosatti <mtosatti@redhat.com>
[PULL 22/23] i386/cpu: Use CPUCacheInfo.share_level to encode CPUID[0x8000001D].EAX[bits 25:14]
Posted by Paolo Bonzini 6 months ago
From: Zhao Liu <zhao1.liu@intel.com>

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].

Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Message-ID: <20240424154929.1487382-22-zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/cpu.c | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index f91e1500266..bc2dceb647f 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -478,20 +478,12 @@ 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);
-- 
2.45.1