From: Dongli Zhang <dongli.zhang@oracle.com>
To: qemu-devel@nongnu.org, kvm@vger.kernel.org
Cc: pbonzini@redhat.com, zhao1.liu@intel.com, mtosatti@redhat.com,
sandipan.das@amd.com, babu.moger@amd.com, likexu@tencent.com,
like.xu.linux@gmail.com, groug@kaod.org, khorenko@virtuozzo.com,
alexander.ivanov@virtuozzo.com, den@virtuozzo.com,
davydov-max@yandex-team.ru, xiaoyao.li@intel.com,
dapeng1.mi@linux.intel.com, joe.jin@oracle.com,
ewanhai-oc@zhaoxin.com, ewanhai@zhaoxin.com
Subject: [PATCH v6 4/9] target/i386/kvm: extract unrelated code out of kvm_x86_build_cpuid()
Date: Tue, 24 Jun 2025 00:43:23 -0700 [thread overview]
Message-ID: <20250624074421.40429-5-dongli.zhang@oracle.com> (raw)
In-Reply-To: <20250624074421.40429-1-dongli.zhang@oracle.com>
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>
---
Changed since v1:
- Still extract the code, but call them for all CPUs.
Changed since v2:
- Use cpuid_find_entry() instead of cpu_x86_cpuid().
- Didn't add Reviewed-by from Dapeng as the change isn't minor.
target/i386/kvm/kvm.c | 62 ++++++++++++++++++++++++-------------------
1 file changed, 35 insertions(+), 27 deletions(-)
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 15155b79b5..4baaa069b8 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -1968,33 +1968,6 @@ 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++) {
@@ -2098,6 +2071,39 @@ 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 {
@@ -2288,6 +2294,8 @@ 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 (((env->cpuid_version >> 8)&0xF) >= 6
&& (env->features[FEAT_1_EDX] & (CPUID_MCE | CPUID_MCA)) ==
(CPUID_MCE | CPUID_MCA)) {
--
2.43.5
next prev parent reply other threads:[~2025-06-24 7:50 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-24 7:43 [PATCH v6 0/9] target/i386/kvm/pmu: PMU Enhancement, Bugfix and Cleanup Dongli Zhang
2025-06-24 7:43 ` [PATCH v6 1/9] target/i386: disable PerfMonV2 when PERFCORE unavailable Dongli Zhang
2025-06-24 7:43 ` [PATCH v6 2/9] target/i386: disable PERFCORE when "-pmu" is configured Dongli Zhang
2025-06-24 7:43 ` [PATCH v6 3/9] target/i386/kvm: set KVM_PMU_CAP_DISABLE if " Dongli Zhang
2025-07-02 3:47 ` Mi, Dapeng
2025-06-24 7:43 ` Dongli Zhang [this message]
2025-07-02 3:52 ` [PATCH v6 4/9] target/i386/kvm: extract unrelated code out of kvm_x86_build_cpuid() Mi, Dapeng
2025-06-24 7:43 ` [PATCH v6 5/9] target/i386/kvm: rename architectural PMU variables Dongli Zhang
2025-08-13 9:18 ` Sandipan Das
2025-06-24 7:43 ` [PATCH v6 6/9] target/i386/kvm: query kvm.enable_pmu parameter Dongli Zhang
2025-07-02 5:10 ` Mi, Dapeng
2025-06-24 7:43 ` [PATCH v6 7/9] target/i386/kvm: reset AMD PMU registers during VM reset Dongli Zhang
2025-07-02 5:38 ` Mi, Dapeng
2025-06-24 7:43 ` [PATCH v6 8/9] target/i386/kvm: support perfmon-v2 for reset Dongli Zhang
2025-06-24 7:43 ` [PATCH v6 9/9] target/i386/kvm: don't stop Intel PMU counters Dongli Zhang
2025-07-02 5:42 ` Mi, Dapeng
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