From: Dongli Zhang <dongli.zhang@oracle.com>
Date: Fri, 9 Jan 2026 07:53:57 +0000 (-0800)
Subject: target/i386/kvm: extract unrelated code out of kvm_x86_build_cpuid()
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7b5d7096294c2594411dc4cbb527a716e9efbba7;p=thirdparty%2Fqemu.git

target/i386/kvm: extract unrelated code out of kvm_x86_build_cpuid()

The initialization of 'has_architectural_pmu_version',
'num_architectural_pmu_gp_counters', and
'num_architectural_pmu_fixed_counters' is unrelated to the process of
building the CPUID.

Extract them out of kvm_x86_build_cpuid().

In addition, use cpuid_find_entry() instead of cpu_x86_cpuid(), because
CPUID has already been filled at this stage.

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Reviewed-by: Zide Chen <zide.chen@intel.com>
Link: https://lore.kernel.org/r/20260109075508.113097-3-dongli.zhang@oracle.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 69748420fd..31e8ef87aa 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -1985,33 +1985,6 @@ uint32_t kvm_x86_build_cpuid(CPUX86State *env, struct kvm_cpuid_entry2 *entries,
         }
     }
 
-    if (limit >= 0x0a) {
-        uint32_t eax, edx;
-
-        cpu_x86_cpuid(env, 0x0a, 0, &eax, &unused, &unused, &edx);
-
-        has_architectural_pmu_version = eax & 0xff;
-        if (has_architectural_pmu_version > 0) {
-            num_architectural_pmu_gp_counters = (eax & 0xff00) >> 8;
-
-            /* Shouldn't be more than 32, since that's the number of bits
-             * available in EBX to tell us _which_ counters are available.
-             * Play it safe.
-             */
-            if (num_architectural_pmu_gp_counters > MAX_GP_COUNTERS) {
-                num_architectural_pmu_gp_counters = MAX_GP_COUNTERS;
-            }
-
-            if (has_architectural_pmu_version > 1) {
-                num_architectural_pmu_fixed_counters = edx & 0x1f;
-
-                if (num_architectural_pmu_fixed_counters > MAX_FIXED_COUNTERS) {
-                    num_architectural_pmu_fixed_counters = MAX_FIXED_COUNTERS;
-                }
-            }
-        }
-    }
-
     cpu_x86_cpuid(env, 0x80000000, 0, &limit, &unused, &unused, &unused);
 
     for (i = 0x80000000; i <= limit; i++) {
@@ -2115,6 +2088,39 @@ int kvm_arch_pre_create_vcpu(CPUState *cpu, Error **errp)
     return 0;
 }
 
+static void kvm_init_pmu_info(struct kvm_cpuid2 *cpuid)
+{
+    struct kvm_cpuid_entry2 *c;
+
+    c = cpuid_find_entry(cpuid, 0xa, 0);
+
+    if (!c) {
+        return;
+    }
+
+    has_architectural_pmu_version = c->eax & 0xff;
+    if (has_architectural_pmu_version > 0) {
+        num_architectural_pmu_gp_counters = (c->eax & 0xff00) >> 8;
+
+        /*
+         * Shouldn't be more than 32, since that's the number of bits
+         * available in EBX to tell us _which_ counters are available.
+         * Play it safe.
+         */
+        if (num_architectural_pmu_gp_counters > MAX_GP_COUNTERS) {
+            num_architectural_pmu_gp_counters = MAX_GP_COUNTERS;
+        }
+
+        if (has_architectural_pmu_version > 1) {
+            num_architectural_pmu_fixed_counters = c->edx & 0x1f;
+
+            if (num_architectural_pmu_fixed_counters > MAX_FIXED_COUNTERS) {
+                num_architectural_pmu_fixed_counters = MAX_FIXED_COUNTERS;
+            }
+        }
+    }
+}
+
 int kvm_arch_init_vcpu(CPUState *cs)
 {
     struct {
@@ -2305,6 +2311,8 @@ int kvm_arch_init_vcpu(CPUState *cs)
     cpuid_i = kvm_x86_build_cpuid(env, cpuid_data.entries, cpuid_i);
     cpuid_data.cpuid.nent = cpuid_i;
 
+    kvm_init_pmu_info(&cpuid_data.cpuid);
+
     if (x86_cpu_family(env->cpuid_version) >= 6
         && (env->features[FEAT_1_EDX] & (CPUID_MCE | CPUID_MCA)) ==
            (CPUID_MCE | CPUID_MCA)) {