[PATCH RFC v2 6/9] target/loongarch: Implement kvm_arch_init_vcpu

[Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>]

Implement kvm_arch_init_vcpu interface for loongarch,
in this function, we register VM change state handler.
And when VM state changes to running, the counter value
should be put into kvm to keep consistent with kvm,
and when state change to stop, counter value should be
refreshed from kvm.

Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
---
 target/loongarch/cpu.h        |  1 +
 target/loongarch/kvm.c        | 23 +++++++++++++++++++++++
 target/loongarch/trace-events |  2 ++
 3 files changed, 26 insertions(+)

diff --git a/target/loongarch/cpu.h b/target/loongarch/cpu.h
index 86b9f26d60..473d9986f3 100644
--- a/target/loongarch/cpu.h
+++ b/target/loongarch/cpu.h
@@ -350,6 +350,7 @@ struct ArchCPU {
 
     /* 'compatible' string for this CPU for Linux device trees */
     const char *dtb_compatible;
+    uint64_t counter_value;
 };
 
 #define TYPE_LOONGARCH_CPU "loongarch-cpu"
diff --git a/target/loongarch/kvm.c b/target/loongarch/kvm.c
index 8dea294930..59d7e35490 100644
--- a/target/loongarch/kvm.c
+++ b/target/loongarch/kvm.c
@@ -393,8 +393,31 @@ int kvm_arch_put_registers(CPUState *cs, int level)
     return ret;
 }
 
+static void kvm_loongarch_vm_stage_change(void *opaque, bool running,
+                                          RunState state)
+{
+    int ret;
+    CPUState *cs = opaque;
+    LoongArchCPU *cpu = LOONGARCH_CPU(cs);
+
+    if (running) {
+        ret = kvm_larch_putq(cs, KVM_REG_LOONGARCH_COUNTER,
+                             &cpu->counter_value);
+        if (ret < 0) {
+            trace_kvm_failed_put_counter(strerror(errno));
+        }
+    } else {
+        ret = kvm_larch_getq(cs, KVM_REG_LOONGARCH_COUNTER,
+                             &cpu->counter_value);
+        if (ret < 0) {
+            trace_kvm_failed_get_counter(strerror(errno));
+        }
+    }
+}
+
 int kvm_arch_init_vcpu(CPUState *cs)
 {
+    qemu_add_vm_change_state_handler(kvm_loongarch_vm_stage_change, cs);
     return 0;
 }
 
diff --git a/target/loongarch/trace-events b/target/loongarch/trace-events
index 67817fee67..6926bbe399 100644
--- a/target/loongarch/trace-events
+++ b/target/loongarch/trace-events
@@ -9,3 +9,5 @@ kvm_failed_get_fpu(const char *msg) "Failed to get fpu from KVM: %s"
 kvm_failed_put_fpu(const char *msg) "Failed to put fpu into KVM: %s"
 kvm_failed_get_mpstate(const char *msg) "Failed to get mp_state from KVM: %s"
 kvm_failed_put_mpstate(const char *msg) "Failed to put mp_state into KVM: %s"
+kvm_failed_get_counter(const char *msg) "Failed to get counter from KVM: %s"
+kvm_failed_put_counter(const char *msg) "Failed to put counter into KVM: %s"
-- 
2.31.1