From 57db061a63243c64c07624740fc039ddcc4777a2 Mon Sep 17 00:00:00 2001
From: Song Gao <gaosong@loongson.cn>
Date: Fri, 22 Mar 2024 19:26:35 +0800
Subject: [PATCH] target/loongarch/kvm: Add pmu support

This patch adds PMU support
  e.g
    '...  -cpu max,pmu=on,pmnum=[1-16]';
    '...  -cpu max,pmu=on' (default pmnum = 4);
    '...  -cpu max,pmu=off' (disable PMU)

Signed-off-by: Song Gao <gaosong@loongson.cn>
---
 target/loongarch/cpu.c                | 64 +++++++++++++++++++++++++++
 target/loongarch/cpu.h                |  2 +
 target/loongarch/kvm/kvm.c            | 55 ++++++++++++++++++++++-
 target/loongarch/loongarch-qmp-cmds.c |  2 +-
 4 files changed, 121 insertions(+), 2 deletions(-)

diff --git a/target/loongarch/cpu.c b/target/loongarch/cpu.c
index fdb819c2cf..bc557f207b 100644
--- a/target/loongarch/cpu.c
+++ b/target/loongarch/cpu.c
@@ -8,6 +8,7 @@
 #include "qemu/osdep.h"
 #include "qemu/log.h"
 #include "qemu/qemu-print.h"
+#include "qemu/error-report.h"
 #include "qapi/error.h"
 #include "qemu/module.h"
 #include "sysemu/qtest.h"
@@ -19,6 +20,7 @@
 #include "internals.h"
 #include "fpu/softfloat-helpers.h"
 #include "cpu-csr.h"
+#include "qapi/visitor.h"
 #include "sysemu/reset.h"
 #include "vec.h"
 #ifdef CONFIG_KVM
@@ -426,6 +428,14 @@ static void loongarch_la464_initfn(Object *obj)
     data = FIELD_DP32(data, CPUCFG5, CC_DIV, 1);
     env->cpucfg[5] = data;
 
+    if (kvm_enabled()) {
+        data = 0;
+        data = FIELD_DP32(data, CPUCFG6, PMP, 1);
+        data = FIELD_DP32(data, CPUCFG6, PMNUM, 3);
+        data = FIELD_DP32(data, CPUCFG6, PMBITS, 63);
+        env->cpucfg[6] = data;
+    }
+
     data = 0;
     data = FIELD_DP32(data, CPUCFG16, L1_IUPRE, 1);
     data = FIELD_DP32(data, CPUCFG16, L1_DPRE, 1);
@@ -660,6 +670,48 @@ static void loongarch_set_lasx(Object *obj, bool value, Error **errp)
     }
 }
 
+static bool loongarch_get_pmu(Object *obj, Error **errp)
+{
+    LoongArchCPU *cpu = LOONGARCH_CPU(obj);
+
+    return  !!(FIELD_EX32(cpu->env.cpucfg[6], CPUCFG6, PMP));
+}
+
+static void loongarch_set_pmu(Object *obj, bool value,  Error **errp)
+{
+    LoongArchCPU *cpu = LOONGARCH_CPU(obj);
+
+    cpu->env.cpucfg[6] = FIELD_DP32(cpu->env.cpucfg[6], CPUCFG6, PMP, value);
+}
+
+static void loongarch_get_pmnum(Object *obj, Visitor *v,
+                                const char *name, void *opaque,
+                                Error **errp)
+{
+    LoongArchCPU *cpu = LOONGARCH_CPU(obj);
+    uint32_t value = FIELD_EX32(cpu->env.cpucfg[6], CPUCFG6, PMNUM);
+
+    visit_type_uint32(v, name, &value, errp);
+}
+
+static void loongarch_set_pmnum(Object *obj, Visitor *v,
+                                const char *name, void *opaque,
+                                Error **errp)
+{
+    LoongArchCPU *cpu = LOONGARCH_CPU(obj);
+    uint32_t *value= opaque;
+
+    if (!visit_type_uint32(v, name, value, errp)) {
+        return;
+    }
+    if ((*value <= PMNUM_MAX) && (*value > 0)) {
+        cpu->env.cpucfg[6] = FIELD_DP32(cpu->env.cpucfg[6], CPUCFG6, PMNUM, *value -1);
+    } else {
+        error_report("Performance counter number need be in [1- %d]\n", PMNUM_MAX);
+        exit(EXIT_FAILURE);
+    }
+}
+
 void loongarch_cpu_post_init(Object *obj)
 {
     LoongArchCPU *cpu = LOONGARCH_CPU(obj);
@@ -672,6 +724,18 @@ void loongarch_cpu_post_init(Object *obj)
         object_property_add_bool(obj, "lasx", loongarch_get_lasx,
                                  loongarch_set_lasx);
     }
+
+    if (kvm_enabled()) {
+        object_property_add_bool(obj, "pmu", loongarch_get_pmu,
+                                 loongarch_set_pmu);
+        if (FIELD_EX32(cpu->env.cpucfg[6], CPUCFG6, PMP)) {
+            uint32_t value = 4;
+            object_property_add(obj, "pmnum", "uint32",
+                                loongarch_get_pmnum,
+                                loongarch_set_pmnum, NULL,
+                                (void *)&value);
+        }
+    }
 }
 
 static void loongarch_cpu_init(Object *obj)
diff --git a/target/loongarch/cpu.h b/target/loongarch/cpu.h
index 4749d41c8c..80cad24fa1 100644
--- a/target/loongarch/cpu.h
+++ b/target/loongarch/cpu.h
@@ -186,6 +186,8 @@ FIELD(CPUCFG6, PMNUM, 4, 4)
 FIELD(CPUCFG6, PMBITS, 8, 6)
 FIELD(CPUCFG6, UPM, 14, 1)
 
+#define PMNUM_MAX 16
+
 /* cpucfg[16] bits */
 FIELD(CPUCFG16, L1_IUPRE, 0, 1)
 FIELD(CPUCFG16, L1_IUUNIFY, 1, 1)
diff --git a/target/loongarch/kvm/kvm.c b/target/loongarch/kvm/kvm.c
index 49d02076ad..5dda631b2b 100644
--- a/target/loongarch/kvm/kvm.c
+++ b/target/loongarch/kvm/kvm.c
@@ -573,6 +573,53 @@ static int kvm_check_cpucfg2(CPUState *cs)
     return ret;
 }
 
+static int kvm_check_cpucfg6(CPUState *cs)
+{
+    int ret;
+    uint64_t val;
+    struct kvm_device_attr attr = {
+        .group = KVM_LOONGARCH_VCPU_CPUCFG,
+        .attr = 6,
+        .addr = (uint64_t)&val,
+    };
+    LoongArchCPU *cpu = LOONGARCH_CPU(cs);
+    CPULoongArchState *env = &cpu->env;
+
+    ret = kvm_vcpu_ioctl(cs, KVM_HAS_DEVICE_ATTR, &attr);
+    if (!ret) {
+        kvm_vcpu_ioctl(cs, KVM_GET_DEVICE_ATTR, &attr);
+
+        if (FIELD_EX32(env->cpucfg[6], CPUCFG6, PMP)) {
+             /* Check PMP */
+             if (!FIELD_EX32(val, CPUCFG6, PMP)) {
+                 error_report("'pmu' feature not supported by KVM on this host"
+                              " Please disable 'pmu' with "
+                              "'... -cpu XXX,pmu=off ...'\n");
+                 exit(EXIT_FAILURE);
+             }
+             /* Check PMNUM */
+             int guest_pmnum = FIELD_EX32(env->cpucfg[6], CPUCFG6, PMNUM);
+             int host_pmnum = FIELD_EX32(val, CPUCFG6, PMNUM);
+             if (guest_pmnum > host_pmnum){
+                 warn_report("The guest pmnum %d larger than KVM support %d\n",
+                              guest_pmnum, host_pmnum);
+                 env->cpucfg[6] = FIELD_DP32(env->cpucfg[6], CPUCFG6,
+                                             PMNUM, host_pmnum);
+             }
+             /* Check PMBITS */
+             int guest_pmbits = FIELD_EX32(env->cpucfg[6], CPUCFG6, PMBITS);
+             int host_pmbits = FIELD_EX32(val, CPUCFG6, PMBITS);
+             if (guest_pmbits != host_pmbits) {
+                 warn_report("The host not support PMBITS %d\n", guest_pmbits);
+                 env->cpucfg[6] = FIELD_DP32(env->cpucfg[6], CPUCFG6,
+                                             PMBITS, host_pmbits);
+             }
+        }
+    }
+
+    return ret;
+}
+
 static int kvm_loongarch_put_cpucfg(CPUState *cs)
 {
     int i, ret = 0;
@@ -586,7 +633,13 @@ static int kvm_loongarch_put_cpucfg(CPUState *cs)
             if (ret) {
                 return ret;
             }
-	}
+        }
+        if (i == 6) {
+            ret = kvm_check_cpucfg6(cs);
+            if (ret) {
+                return ret;
+            }
+        }
         val = env->cpucfg[i];
         ret = kvm_set_one_reg(cs, KVM_IOC_CPUCFG(i), &val);
         if (ret < 0) {
diff --git a/target/loongarch/loongarch-qmp-cmds.c b/target/loongarch/loongarch-qmp-cmds.c
index 645672ff59..2612f43de9 100644
--- a/target/loongarch/loongarch-qmp-cmds.c
+++ b/target/loongarch/loongarch-qmp-cmds.c
@@ -42,7 +42,7 @@ CpuDefinitionInfoList *qmp_query_cpu_definitions(Error **errp)
 }
 
 static const char *cpu_model_advertised_features[] = {
-    "lsx", "lasx", NULL
+    "lsx", "lasx", "pmu", "pmnum", NULL
 };
 
 CpuModelExpansionInfo *qmp_query_cpu_model_expansion(CpuModelExpansionType type,
-- 
2.33.0