From: Zide Chen <zide.chen@intel.com>
To: qemu-devel@nongnu.org, kvm@vger.kernel.org,
Paolo Bonzini <pbonzini@redhat.com>,
Zhao Liu <zhao1.liu@intel.com>, Peter Xu <peterx@redhat.com>,
Fabiano Rosas <farosas@suse.de>
Cc: Xiaoyao Li <xiaoyao.li@intel.com>,
Dongli Zhang <dongli.zhang@oracle.com>,
Dapeng Mi <dapeng1.mi@linux.intel.com>,
Zide Chen <zide.chen@intel.com>
Subject: [PATCH V2 06/11] target/i386: Save/Restore DS based PEBS specfic MSRs
Date: Wed, 28 Jan 2026 15:09:43 -0800 [thread overview]
Message-ID: <20260128231003.268981-7-zide.chen@intel.com> (raw)
In-Reply-To: <20260128231003.268981-1-zide.chen@intel.com>
From: Dapeng Mi <dapeng1.mi@linux.intel.com>
DS-based PEBS introduces three MSRs: MSR_IA32_DS_AREA, MSR_PEBS_DATA_CFG,
and MSR_IA32_PEBS_ENABLE. Save and restore these MSRs when legacy DS
PEBS is enabled.
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
---
V2:
- No changes.
target/i386/cpu.h | 9 +++++++++
target/i386/kvm/kvm.c | 25 +++++++++++++++++++++++++
target/i386/machine.c | 27 ++++++++++++++++++++++++++-
3 files changed, 60 insertions(+), 1 deletion(-)
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 812d53e22c41..3e2222e105bc 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -422,6 +422,7 @@ typedef enum X86Seg {
#define MSR_IA32_PERF_CAPABILITIES 0x345
#define PERF_CAP_LBR_FMT 0x3f
#define PERF_CAP_FULL_WRITE (1U << 13)
+#define PERF_CAP_PEBS_BASELINE (1U << 14)
#define MSR_IA32_TSX_CTRL 0x122
#define MSR_IA32_TSCDEADLINE 0x6e0
@@ -512,6 +513,11 @@ typedef enum X86Seg {
#define MSR_CORE_PERF_GLOBAL_CTRL 0x38f
#define MSR_CORE_PERF_GLOBAL_OVF_CTRL 0x390
+/* Legacy DS based PEBS MSRs */
+#define MSR_IA32_PEBS_ENABLE 0x3f1
+#define MSR_PEBS_DATA_CFG 0x3f2
+#define MSR_IA32_DS_AREA 0x600
+
#define MSR_MC0_CTL 0x400
#define MSR_MC0_STATUS 0x401
#define MSR_MC0_ADDR 0x402
@@ -2089,6 +2095,9 @@ typedef struct CPUArchState {
uint64_t msr_fixed_ctr_ctrl;
uint64_t msr_global_ctrl;
uint64_t msr_global_status;
+ uint64_t msr_ds_area;
+ uint64_t msr_pebs_data_cfg;
+ uint64_t msr_pebs_enable;
uint64_t msr_fixed_counters[MAX_FIXED_COUNTERS];
uint64_t msr_gp_counters[MAX_GP_COUNTERS];
uint64_t msr_gp_evtsel[MAX_GP_COUNTERS];
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index a2cf9b5df35d..a72e4d60dfa2 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -4143,6 +4143,15 @@ static int kvm_put_msrs(X86CPU *cpu, KvmPutState level)
kvm_msr_entry_add(cpu, MSR_CORE_PERF_GLOBAL_CTRL, 0);
}
+ if (env->features[FEAT_1_EDX] & CPUID_DTS) {
+ kvm_msr_entry_add(cpu, MSR_IA32_DS_AREA, env->msr_ds_area);
+ }
+
+ if (env->features[FEAT_PERF_CAPABILITIES] & PERF_CAP_PEBS_BASELINE) {
+ kvm_msr_entry_add(cpu, MSR_IA32_PEBS_ENABLE, env->msr_pebs_enable);
+ kvm_msr_entry_add(cpu, MSR_PEBS_DATA_CFG, env->msr_pebs_data_cfg);
+ }
+
/* Set the counter values. */
for (i = 0; i < num_architectural_pmu_fixed_counters; i++) {
kvm_msr_entry_add(cpu, MSR_CORE_PERF_FIXED_CTR0 + i,
@@ -4688,6 +4697,13 @@ static int kvm_get_msrs(X86CPU *cpu)
kvm_msr_entry_add(cpu, perf_cntr_base + i, 0);
kvm_msr_entry_add(cpu, MSR_P6_EVNTSEL0 + i, 0);
}
+ if (env->features[FEAT_1_EDX] & CPUID_DTS) {
+ kvm_msr_entry_add(cpu, MSR_IA32_DS_AREA, 0);
+ }
+ if (env->features[FEAT_PERF_CAPABILITIES] & PERF_CAP_PEBS_BASELINE) {
+ kvm_msr_entry_add(cpu, MSR_IA32_PEBS_ENABLE, 0);
+ kvm_msr_entry_add(cpu, MSR_PEBS_DATA_CFG, 0);
+ }
}
if (env->mcg_cap) {
@@ -5013,6 +5029,15 @@ static int kvm_get_msrs(X86CPU *cpu)
case MSR_P6_EVNTSEL0 ... MSR_P6_EVNTSEL0 + MAX_GP_COUNTERS - 1:
env->msr_gp_evtsel[index - MSR_P6_EVNTSEL0] = msrs[i].data;
break;
+ case MSR_IA32_DS_AREA:
+ env->msr_ds_area = msrs[i].data;
+ break;
+ case MSR_PEBS_DATA_CFG:
+ env->msr_pebs_data_cfg = msrs[i].data;
+ break;
+ case MSR_IA32_PEBS_ENABLE:
+ env->msr_pebs_enable = msrs[i].data;
+ break;
case HV_X64_MSR_HYPERCALL:
env->msr_hv_hypercall = msrs[i].data;
break;
diff --git a/target/i386/machine.c b/target/i386/machine.c
index 7d08a05835fc..7f45db1247b1 100644
--- a/target/i386/machine.c
+++ b/target/i386/machine.c
@@ -659,6 +659,27 @@ static const VMStateDescription vmstate_msr_ia32_feature_control = {
}
};
+static bool ds_pebs_enabled(void *opaque)
+{
+ X86CPU *cpu = opaque;
+ CPUX86State *env = &cpu->env;
+
+ return (env->msr_ds_area || env->msr_pebs_enable ||
+ env->msr_pebs_data_cfg);
+}
+
+static const VMStateDescription vmstate_msr_ds_pebs = {
+ .name = "cpu/msr_ds_pebs",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = ds_pebs_enabled,
+ .fields = (const VMStateField[]){
+ VMSTATE_UINT64(env.msr_ds_area, X86CPU),
+ VMSTATE_UINT64(env.msr_pebs_data_cfg, X86CPU),
+ VMSTATE_UINT64(env.msr_pebs_enable, X86CPU),
+ VMSTATE_END_OF_LIST()}
+};
+
static bool pmu_enable_needed(void *opaque)
{
X86CPU *cpu = opaque;
@@ -697,7 +718,11 @@ static const VMStateDescription vmstate_msr_architectural_pmu = {
VMSTATE_UINT64_ARRAY(env.msr_gp_counters, X86CPU, MAX_GP_COUNTERS),
VMSTATE_UINT64_ARRAY(env.msr_gp_evtsel, X86CPU, MAX_GP_COUNTERS),
VMSTATE_END_OF_LIST()
- }
+ },
+ .subsections = (const VMStateDescription * const []) {
+ &vmstate_msr_ds_pebs,
+ NULL,
+ },
};
static bool mpx_needed(void *opaque)
--
2.52.0
next prev parent reply other threads:[~2026-01-28 23:17 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-28 23:09 [PATCH V2 00/11] target/i386: Misc PMU, PEBS, and MSR fixes and improvements Zide Chen
2026-01-28 23:09 ` [PATCH V2 01/11] target/i386: Disable unsupported BTS for guest Zide Chen
2026-02-10 6:31 ` Mi, Dapeng
2026-02-11 6:14 ` Xiaoyao Li
2026-03-04 18:22 ` Chen, Zide
2026-01-28 23:09 ` [PATCH V2 02/11] target/i386: Don't save/restore PERF_GLOBAL_OVF_CTRL MSR Zide Chen
2026-01-28 23:09 ` [PATCH V2 03/11] target/i386: Gate enable_pmu on kvm_enabled() Zide Chen
2026-01-28 23:09 ` [PATCH V2 04/11] target/i386: Support full-width writes for perf counters Zide Chen
2026-01-28 23:09 ` [PATCH V2 05/11] target/i386: Increase MSR_BUF_SIZE and split KVM_[GET/SET]_MSRS calls Zide Chen
2026-02-10 6:57 ` Mi, Dapeng
2026-02-10 17:23 ` Chen, Zide
2026-01-28 23:09 ` Zide Chen [this message]
2026-01-28 23:09 ` [PATCH V2 07/11] target/i386: Make some PEBS features user-visible Zide Chen
2026-02-10 7:02 ` Mi, Dapeng
2026-01-28 23:09 ` [PATCH V2 08/11] target/i386: Clean up LBR format handling Zide Chen
2026-02-10 7:07 ` Mi, Dapeng
2026-01-28 23:09 ` [PATCH V2 09/11] target/i386: Refactor " Zide Chen
2026-02-10 7:14 ` Mi, Dapeng
2026-01-28 23:09 ` [PATCH V2 10/11] target/i386: Add pebs-fmt CPU option Zide Chen
2026-01-28 23:09 ` [PATCH V2 11/11] target/i386: Disable guest PEBS capability when not enabled Zide Chen
2026-02-10 7:30 ` Mi, Dapeng
2026-02-10 19:05 ` Chen, Zide
2026-02-11 1:20 ` Mi, Dapeng
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