From: Zhao Liu <zhao1.liu@intel.com>

Linux kernel (from v6.4, with commit edc0a2b595765 ("x86/topology: Fix
erroneous smp_num_siblings on Intel Hybrid platforms") is able to
handle platforms with Module level enumerated via CPUID.1F.

Expose the module level in CPUID[0x1F] if the machine has more than 1
modules.

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>
Message-ID: <20240424154929.1487382-15-zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 include/hw/i386/topology.h | 6 ++++--
 target/i386/cpu.h          | 1 +
 hw/i386/x86-common.c       | 2 +-
 target/i386/cpu.c          | 6 ++++++
 4 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/include/hw/i386/topology.h b/include/hw/i386/topology.h
index 7622d806932..ea871045779 100644
--- a/include/hw/i386/topology.h
+++ b/include/hw/i386/topology.h
@@ -71,6 +71,7 @@ enum CPUTopoLevel {
     CPU_TOPO_LEVEL_INVALID,
     CPU_TOPO_LEVEL_SMT,
     CPU_TOPO_LEVEL_CORE,
+    CPU_TOPO_LEVEL_MODULE,
     CPU_TOPO_LEVEL_DIE,
     CPU_TOPO_LEVEL_PACKAGE,
     CPU_TOPO_LEVEL_MAX,
@@ -198,11 +199,12 @@ static inline apic_id_t x86_apicid_from_cpu_idx(X86CPUTopoInfo *topo_info,
 }
 
 /*
- * Check whether there's extended topology level (die)?
+ * Check whether there's extended topology level (module or die)?
  */
 static inline bool x86_has_extended_topo(unsigned long *topo_bitmap)
 {
-    return test_bit(CPU_TOPO_LEVEL_DIE, topo_bitmap);
+    return test_bit(CPU_TOPO_LEVEL_MODULE, topo_bitmap) ||
+           test_bit(CPU_TOPO_LEVEL_DIE, topo_bitmap);
 }
 
 #endif /* HW_I386_TOPOLOGY_H */
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index e79293158a0..196b068614c 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1024,6 +1024,7 @@ uint64_t x86_cpu_get_supported_feature_word(FeatureWord w,
 #define CPUID_1F_ECX_TOPO_LEVEL_INVALID  CPUID_B_ECX_TOPO_LEVEL_INVALID
 #define CPUID_1F_ECX_TOPO_LEVEL_SMT      CPUID_B_ECX_TOPO_LEVEL_SMT
 #define CPUID_1F_ECX_TOPO_LEVEL_CORE     CPUID_B_ECX_TOPO_LEVEL_CORE
+#define CPUID_1F_ECX_TOPO_LEVEL_MODULE   3
 #define CPUID_1F_ECX_TOPO_LEVEL_DIE      5
 
 /* MSR Feature Bits */
diff --git a/hw/i386/x86-common.c b/hw/i386/x86-common.c
index 994f8424889..34dfa894879 100644
--- a/hw/i386/x86-common.c
+++ b/hw/i386/x86-common.c
@@ -273,7 +273,7 @@ void x86_cpu_pre_plug(HotplugHandler *hotplug_dev,
 
     if (ms->smp.modules > 1) {
         env->nr_modules = ms->smp.modules;
-        /* TODO: Expose module level in CPUID[0x1F]. */
+        set_bit(CPU_TOPO_LEVEL_MODULE, env->avail_cpu_topo);
     }
 
     if (ms->smp.dies > 1) {
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 92aa4498551..4aea6e3dd24 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -277,6 +277,8 @@ static uint32_t num_threads_by_topo_level(X86CPUTopoInfo *topo_info,
         return 1;
     case CPU_TOPO_LEVEL_CORE:
         return topo_info->threads_per_core;
+    case CPU_TOPO_LEVEL_MODULE:
+        return topo_info->threads_per_core * topo_info->cores_per_module;
     case CPU_TOPO_LEVEL_DIE:
         return topo_info->threads_per_core * topo_info->cores_per_module *
                topo_info->modules_per_die;
@@ -297,6 +299,8 @@ static uint32_t apicid_offset_by_topo_level(X86CPUTopoInfo *topo_info,
         return 0;
     case CPU_TOPO_LEVEL_CORE:
         return apicid_core_offset(topo_info);
+    case CPU_TOPO_LEVEL_MODULE:
+        return apicid_module_offset(topo_info);
     case CPU_TOPO_LEVEL_DIE:
         return apicid_die_offset(topo_info);
     case CPU_TOPO_LEVEL_PACKAGE:
@@ -316,6 +320,8 @@ static uint32_t cpuid1f_topo_type(enum CPUTopoLevel topo_level)
         return CPUID_1F_ECX_TOPO_LEVEL_SMT;
     case CPU_TOPO_LEVEL_CORE:
         return CPUID_1F_ECX_TOPO_LEVEL_CORE;
+    case CPU_TOPO_LEVEL_MODULE:
+        return CPUID_1F_ECX_TOPO_LEVEL_MODULE;
     case CPU_TOPO_LEVEL_DIE:
         return CPUID_1F_ECX_TOPO_LEVEL_DIE;
     default:
-- 
2.45.1