[Qemu-devel] [PATCH v2 2/2] kvm: migrate vPMU state

[Paolo Bonzini <pbonzini@redhat.com>]

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target-i386/cpu.h     | 23 +++++++++++++
 target-i386/kvm.c     | 93 ++++++++++++++++++++++++++++++++++++++++++++++++---
 target-i386/machine.c | 44 ++++++++++++++++++++++++
 3 files changed, 155 insertions(+), 5 deletions(-)

diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index d19d111..15d6d6a 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -304,6 +304,8 @@
 #define MSR_TSC_ADJUST                  0x0000003b
 #define MSR_IA32_TSCDEADLINE            0x6e0
 
+#define MSR_P6_PERFCTR0                 0xc1
+
 #define MSR_MTRRcap                     0xfe
 #define MSR_MTRRcap_VCNT                8
 #define MSR_MTRRcap_FIXRANGE_SUPPORT    (1 << 8)
@@ -317,6 +319,8 @@
 #define MSR_MCG_STATUS                  0x17a
 #define MSR_MCG_CTL                     0x17b
 
+#define MSR_P6_EVNTSEL0                 0x186
+
 #define MSR_IA32_PERF_STATUS            0x198
 
 #define MSR_IA32_MISC_ENABLE            0x1a0
@@ -342,6 +346,14 @@
 
 #define MSR_MTRRdefType                 0x2ff
 
+#define MSR_CORE_PERF_FIXED_CTR0        0x309
+#define MSR_CORE_PERF_FIXED_CTR1        0x30a
+#define MSR_CORE_PERF_FIXED_CTR2        0x30b
+#define MSR_CORE_PERF_FIXED_CTR_CTRL    0x38d
+#define MSR_CORE_PERF_GLOBAL_STATUS     0x38e
+#define MSR_CORE_PERF_GLOBAL_CTRL       0x38f
+#define MSR_CORE_PERF_GLOBAL_OVF_CTRL   0x390
+
 #define MSR_MC0_CTL                     0x400
 #define MSR_MC0_STATUS                  0x401
 #define MSR_MC0_ADDR                    0x402
@@ -720,6 +732,9 @@ typedef struct {
 #define CPU_NB_REGS CPU_NB_REGS32
 #endif
 
+#define MAX_FIXED_COUNTERS 3
+#define MAX_GP_COUNTERS    (MSR_IA32_PERF_STATUS - MSR_P6_EVNTSEL0)
+
 #define NB_MMU_MODES 3
 
 typedef enum TPRAccess {
@@ -814,6 +829,14 @@ typedef struct CPUX86State {
     uint64_t mcg_status;
     uint64_t msr_ia32_misc_enable;
 
+    uint64_t msr_fixed_ctr_ctrl;
+    uint64_t msr_global_ctrl;
+    uint64_t msr_global_status;
+    uint64_t msr_global_ovf_ctrl;
+    uint64_t msr_fixed_counters[MAX_FIXED_COUNTERS];
+    uint64_t msr_gp_counters[MAX_GP_COUNTERS];
+    uint64_t msr_gp_evtsel[MAX_GP_COUNTERS];
+
     /* exception/interrupt handling */
     int error_code;
     int exception_is_int;
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 3c9d10a..96ec1f4 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -71,6 +71,9 @@ static bool has_msr_misc_enable;
 static bool has_msr_kvm_steal_time;
 static int lm_capable_kernel;
 
+static bool has_msr_architectural_pmu;
+static uint32_t num_architectural_pmu_counters;
+
 bool kvm_allows_irq0_override(void)
 {
     return !kvm_irqchip_in_kernel() || kvm_has_gsi_routing();
@@ -581,6 +584,25 @@ int kvm_arch_init_vcpu(CPUState *cs)
             break;
         }
     }
+
+    if (limit >= 0x0a) {
+        uint32_t ver;
+
+        cpu_x86_cpuid(env, 0x0a, 0, &ver, &unused, &unused, &unused);
+        if ((ver & 0xff) > 0) {
+            has_msr_architectural_pmu = true;
+            num_architectural_pmu_counters = (ver & 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_counters > MAX_GP_COUNTERS) {
+                num_architectural_pmu_counters = MAX_GP_COUNTERS;
+            }
+        }
+    }
+
     cpu_x86_cpuid(env, 0x80000000, 0, &limit, &unused, &unused, &unused);
 
     for (i = 0x80000000; i <= limit; i++) {
@@ -1052,7 +1074,7 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
         struct kvm_msr_entry entries[100];
     } msr_data;
     struct kvm_msr_entry *msrs = msr_data.entries;
-    int n = 0;
+    int n = 0, i;
 
     kvm_msr_entry_set(&msrs[n++], MSR_IA32_SYSENTER_CS, env->sysenter_cs);
     kvm_msr_entry_set(&msrs[n++], MSR_IA32_SYSENTER_ESP, env->sysenter_esp);
@@ -1094,9 +1116,8 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
         }
     }
     /*
-     * The following paravirtual MSRs have side effects on the guest or are
-     * too heavy for normal writeback. Limit them to reset or full state
-     * updates.
+     * The following MSRs have side effects on the guest or are too heavy
+     * for normal writeback. Limit them to reset or full state updates.
      */
     if (level >= KVM_PUT_RESET_STATE) {
         kvm_msr_entry_set(&msrs[n++], MSR_KVM_SYSTEM_TIME,
@@ -1114,6 +1135,33 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
             kvm_msr_entry_set(&msrs[n++], MSR_KVM_STEAL_TIME,
                               env->steal_time_msr);
         }
+        if (has_msr_architectural_pmu) {
+            /* Stop the counter.  */
+            kvm_msr_entry_set(&msrs[n++], MSR_CORE_PERF_FIXED_CTR_CTRL, 0);
+            kvm_msr_entry_set(&msrs[n++], MSR_CORE_PERF_GLOBAL_CTRL, 0);
+
+            /* Set the counter values.  */
+            for (i = 0; i < MAX_FIXED_COUNTERS; i++) {
+                kvm_msr_entry_set(&msrs[n++], MSR_CORE_PERF_FIXED_CTR0 + i,
+                                  env->msr_fixed_counters[i]);
+            }
+            for (i = 0; i < num_architectural_pmu_counters; i++) {
+                kvm_msr_entry_set(&msrs[n++], MSR_P6_PERFCTR0 + i,
+                                  env->msr_gp_counters[i]);
+                kvm_msr_entry_set(&msrs[n++], MSR_P6_EVNTSEL0 + i,
+                                  env->msr_gp_evtsel[i]);
+            }
+            kvm_msr_entry_set(&msrs[n++], MSR_CORE_PERF_GLOBAL_STATUS,
+                              env->msr_global_status);
+            kvm_msr_entry_set(&msrs[n++], MSR_CORE_PERF_GLOBAL_OVF_CTRL,
+                              env->msr_global_ovf_ctrl);
+
+            /* Now start the PMU.  */
+            kvm_msr_entry_set(&msrs[n++], MSR_CORE_PERF_FIXED_CTR_CTRL,
+                              env->msr_fixed_ctr_ctrl);
+            kvm_msr_entry_set(&msrs[n++], MSR_CORE_PERF_GLOBAL_CTRL,
+                              env->msr_global_ctrl);
+        }
         if (hyperv_hypercall_available()) {
             kvm_msr_entry_set(&msrs[n++], HV_X64_MSR_GUEST_OS_ID, 0);
             kvm_msr_entry_set(&msrs[n++], HV_X64_MSR_HYPERCALL, 0);
@@ -1370,6 +1418,19 @@ static int kvm_get_msrs(X86CPU *cpu)
     if (has_msr_kvm_steal_time) {
         msrs[n++].index = MSR_KVM_STEAL_TIME;
     }
+    if (has_msr_architectural_pmu) {
+        msrs[n++].index = MSR_CORE_PERF_FIXED_CTR_CTRL;
+        msrs[n++].index = MSR_CORE_PERF_GLOBAL_CTRL;
+        msrs[n++].index = MSR_CORE_PERF_GLOBAL_STATUS;
+        msrs[n++].index = MSR_CORE_PERF_GLOBAL_OVF_CTRL;
+        for (i = 0; i < MAX_FIXED_COUNTERS; i++) {
+            msrs[n++].index = MSR_CORE_PERF_FIXED_CTR0 + i;
+        }
+        for (i = 0; i < num_architectural_pmu_counters; i++) {
+            msrs[n++].index = MSR_P6_PERFCTR0 + i;
+            msrs[n++].index = MSR_P6_EVNTSEL0 + i;
+        }
+    }
 
     if (env->mcg_cap) {
         msrs[n++].index = MSR_MCG_STATUS;
@@ -1386,7 +1447,8 @@ static int kvm_get_msrs(X86CPU *cpu)
     }
 
     for (i = 0; i < ret; i++) {
-        switch (msrs[i].index) {
+        uint32_t index = msrs[i].index;
+        switch (index) {
         case MSR_IA32_SYSENTER_CS:
             env->sysenter_cs = msrs[i].data;
             break;
@@ -1458,6 +1520,27 @@ static int kvm_get_msrs(X86CPU *cpu)
         case MSR_KVM_STEAL_TIME:
             env->steal_time_msr = msrs[i].data;
             break;
+        case MSR_CORE_PERF_FIXED_CTR_CTRL:
+            env->msr_fixed_ctr_ctrl = msrs[i].data;
+            break;
+        case MSR_CORE_PERF_GLOBAL_CTRL:
+            env->msr_global_ctrl = msrs[i].data;
+            break;
+        case MSR_CORE_PERF_GLOBAL_STATUS:
+            env->msr_global_status = msrs[i].data;
+            break;
+        case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
+            env->msr_global_ovf_ctrl = msrs[i].data;
+            break;
+        case MSR_CORE_PERF_FIXED_CTR0 ... MSR_CORE_PERF_FIXED_CTR0 + MAX_FIXED_COUNTERS - 1:
+            env->msr_fixed_counters[index - MSR_CORE_PERF_FIXED_CTR0] = msrs[i].data;
+            break;
+        case MSR_P6_PERFCTR0 ... MSR_P6_PERFCTR0 + MAX_GP_COUNTERS - 1:
+            env->msr_gp_counters[index - MSR_P6_PERFCTR0] = msrs[i].data;
+            break;
+        case MSR_P6_EVNTSEL0 ... MSR_P6_EVNTSEL0 + MAX_GP_COUNTERS - 1:
+            env->msr_gp_evtsel[index - MSR_P6_EVNTSEL0] = msrs[i].data;
+            break;
         }
     }
 
diff --git a/target-i386/machine.c b/target-i386/machine.c
index f9ec581..076a39d 100644
--- a/target-i386/machine.c
+++ b/target-i386/machine.c
@@ -446,6 +446,47 @@ static const VMStateDescription vmstate_msr_ia32_misc_enable = {
     }
 };
 
+static bool pmu_enable_needed(void *opaque)
+{
+    X86CPU *cpu = opaque;
+    CPUX86State *env = &cpu->env;
+    int i;
+
+    if (env->msr_fixed_ctr_ctrl || env->msr_global_ctrl ||
+        env->msr_global_status || env->msr_global_ovf_ctrl) {
+        return true;
+    }
+    for (i = 0; i < MAX_FIXED_COUNTERS; i++) {
+        if (env->msr_fixed_counters[i]) {
+            return true;
+        }
+    }
+    for (i = 0; i < MAX_GP_COUNTERS; i++) {
+        if (env->msr_gp_counters[i] || env->msr_gp_evtsel[i]) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+static const VMStateDescription vmstate_msr_architectural_pmu = {
+    .name = "cpu/msr_architectural_pmu",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .fields      = (VMStateField []) {
+        VMSTATE_UINT64(env.msr_fixed_ctr_ctrl, X86CPU),
+        VMSTATE_UINT64(env.msr_global_ctrl, X86CPU),
+        VMSTATE_UINT64(env.msr_global_status, X86CPU),
+        VMSTATE_UINT64(env.msr_global_ovf_ctrl, X86CPU),
+        VMSTATE_UINT64_ARRAY(env.msr_fixed_counters, X86CPU, MAX_FIXED_COUNTERS),
+        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()
+    }
+};
+
 const VMStateDescription vmstate_x86_cpu = {
     .name = "cpu",
     .version_id = 12,
@@ -571,6 +612,9 @@ const VMStateDescription vmstate_x86_cpu = {
         }, {
             .vmsd = &vmstate_msr_ia32_misc_enable,
             .needed = misc_enable_needed,
+        }, {
+            .vmsd = &vmstate_msr_architectural_pmu,
+            .needed = pmu_enable_needed,
         } , {
             /* empty */
         }
-- 
1.8.3.1