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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


  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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