target/i386: Add CPUID.1F generation support for multi-dies PCMachine

The CPUID.1F as Intel V2 Extended Topology Enumeration Leaf would be
exposed if guests want to emulate multiple software-visible die within
each package. Per Intel's SDM, the 0x1f is a superset of 0xb, thus they
can be generated by almost same code as 0xb except die_offset setting.

If the number of dies per package is greater than 1, the cpuid_min_level
would be adjusted to 0x1f regardless of whether the host supports CPUID.1F.
Likewise, the CPUID.1F wouldn't be exposed if env->nr_dies < 2.

Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Message-Id: <20190620054525.37188-2-like.xu@linux.intel.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

1 files changed, 41 insertions, 0 deletions

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index b9d6f32945..296ef6c918 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -4416,6 +4416,42 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
         assert(!(*eax & ~0x1f));
         *ebx &= 0xffff; /* The count doesn't need to be reliable. */
         break;
+    case 0x1F:
+        /* V2 Extended Topology Enumeration Leaf */
+        if (env->nr_dies < 2) {
+            *eax = *ebx = *ecx = *edx = 0;
+            break;
+        }
+
+        *ecx = count & 0xff;
+        *edx = cpu->apic_id;
+        switch (count) {
+        case 0:
+            *eax = apicid_core_offset(env->nr_dies, cs->nr_cores,
+                                                    cs->nr_threads);
+            *ebx = cs->nr_threads;
+            *ecx |= CPUID_TOPOLOGY_LEVEL_SMT;
+            break;
+        case 1:
+            *eax = apicid_die_offset(env->nr_dies, cs->nr_cores,
+                                                   cs->nr_threads);
+            *ebx = cs->nr_cores * cs->nr_threads;
+            *ecx |= CPUID_TOPOLOGY_LEVEL_CORE;
+            break;
+        case 2:
+            *eax = apicid_pkg_offset(env->nr_dies, cs->nr_cores,
+                                                   cs->nr_threads);
+            *ebx = env->nr_dies * cs->nr_cores * cs->nr_threads;
+            *ecx |= CPUID_TOPOLOGY_LEVEL_DIE;
+            break;
+        default:
+            *eax = 0;
+            *ebx = 0;
+            *ecx |= CPUID_TOPOLOGY_LEVEL_INVALID;
+        }
+        assert(!(*eax & ~0x1f));
+        *ebx &= 0xffff; /* The count doesn't need to be reliable. */
+        break;
     case 0xD: {
         /* Processor Extended State */
         *eax = 0;
@@ -5094,6 +5130,11 @@ static void x86_cpu_expand_features(X86CPU *cpu, Error **errp)
             x86_cpu_adjust_level(cpu, &cpu->env.cpuid_min_level, 0x14);
         }
 
+        /* CPU topology with multi-dies support requires CPUID[0x1F] */
+        if (env->nr_dies > 1) {
+            x86_cpu_adjust_level(cpu, &env->cpuid_min_level, 0x1F);
+        }
+
         /* SVM requires CPUID[0x8000000A] */
         if (env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_SVM) {
             x86_cpu_adjust_level(cpu, &env->cpuid_min_xlevel, 0x8000000A);