[RFC,v3,5/8] cpus: extract out kvm-specific code to accel/kvm

diff --git a/accel/kvm/Makefile.objs b/accel/kvm/Makefile.objs
index fdfa481578..ce0f492b8d 100644
--- a/accel/kvm/Makefile.objs
+++ b/accel/kvm/Makefile.objs
@@ -1,2 +1,4 @@ 
 obj-y += kvm-all.o
+obj-y += kvm-cpus.o
+
 obj-$(call lnot,$(CONFIG_SEV)) += sev-stub.o
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 63ef6af9a1..fbd82cb444 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -44,6 +44,9 @@ 
 #include "qapi/qapi-types-common.h"
 #include "qapi/qapi-visit-common.h"
 #include "sysemu/reset.h"
+#include "qemu/guest-random.h"
+#include "sysemu/hw_accel.h"
+#include "kvm-cpus.h"
 
 #include "hw/boards.h"
 
@@ -378,7 +381,7 @@  err:
     return ret;
 }
 
-int kvm_destroy_vcpu(CPUState *cpu)
+static int do_kvm_destroy_vcpu(CPUState *cpu)
 {
     KVMState *s = kvm_state;
     long mmap_size;
@@ -412,6 +415,14 @@  err:
     return ret;
 }
 
+void kvm_destroy_vcpu(CPUState *cpu)
+{
+    if (do_kvm_destroy_vcpu(cpu) < 0) {
+        error_report("kvm_destroy_vcpu failed");
+        exit(EXIT_FAILURE);
+    }
+}
+
 static int kvm_get_vcpu(KVMState *s, unsigned long vcpu_id)
 {
     struct KVMParkedVcpu *cpu;
@@ -2232,6 +2243,7 @@  static int kvm_init(MachineState *ms)
         assert(!ret);
     }
 
+    cpus_register_accel(&kvm_cpus);
     return 0;
 
 err:
diff --git a/accel/kvm/kvm-cpus.c b/accel/kvm/kvm-cpus.c
new file mode 100644
index 0000000000..7866a2e9c3
--- /dev/null
+++ b/accel/kvm/kvm-cpus.c
@@ -0,0 +1,88 @@ 
+/*
+ * QEMU KVM support
+ *
+ * Copyright IBM, Corp. 2008
+ *           Red Hat, Inc. 2008
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *  Glauber Costa     <gcosta@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "qemu/main-loop.h"
+#include "sysemu/kvm_int.h"
+#include "sysemu/runstate.h"
+#include "sysemu/cpus.h"
+#include "qemu/guest-random.h"
+
+#include "kvm-cpus.h"
+
+static void *kvm_vcpu_thread_fn(void *arg)
+{
+    CPUState *cpu = arg;
+    int r;
+
+    rcu_register_thread();
+
+    qemu_mutex_lock_iothread();
+    qemu_thread_get_self(cpu->thread);
+    cpu->thread_id = qemu_get_thread_id();
+    cpu->can_do_io = 1;
+    current_cpu = cpu;
+
+    r = kvm_init_vcpu(cpu);
+    if (r < 0) {
+        error_report("kvm_init_vcpu failed: %s", strerror(-r));
+        exit(1);
+    }
+
+    kvm_init_cpu_signals(cpu);
+
+    /* signal CPU creation */
+    cpu_thread_signal_created(cpu);
+    qemu_guest_random_seed_thread_part2(cpu->random_seed);
+
+    do {
+        if (cpu_can_run(cpu)) {
+            r = kvm_cpu_exec(cpu);
+            if (r == EXCP_DEBUG) {
+                cpu_handle_guest_debug(cpu);
+            }
+        }
+        qemu_wait_io_event(cpu);
+    } while (!cpu->unplug || cpu_can_run(cpu));
+
+    kvm_destroy_vcpu(cpu);
+    cpu_thread_signal_destroyed(cpu);
+    qemu_mutex_unlock_iothread();
+    rcu_unregister_thread();
+    return NULL;
+}
+
+static void kvm_start_vcpu_thread(CPUState *cpu)
+{
+    char thread_name[VCPU_THREAD_NAME_SIZE];
+
+    cpu->thread = g_malloc0(sizeof(QemuThread));
+    cpu->halt_cond = g_malloc0(sizeof(QemuCond));
+    qemu_cond_init(cpu->halt_cond);
+    snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "CPU %d/KVM",
+             cpu->cpu_index);
+    qemu_thread_create(cpu->thread, thread_name, kvm_vcpu_thread_fn,
+                       cpu, QEMU_THREAD_JOINABLE);
+}
+
+CpusAccel kvm_cpus = {
+    .create_vcpu_thread = kvm_start_vcpu_thread,
+
+    .synchronize_post_reset = kvm_cpu_synchronize_post_reset,
+    .synchronize_post_init = kvm_cpu_synchronize_post_init,
+    .synchronize_state = kvm_cpu_synchronize_state,
+    .synchronize_pre_loadvm = kvm_cpu_synchronize_pre_loadvm,
+};
diff --git a/accel/kvm/kvm-cpus.h b/accel/kvm/kvm-cpus.h
new file mode 100644
index 0000000000..62fbc911d9
--- /dev/null
+++ b/accel/kvm/kvm-cpus.h
@@ -0,0 +1,17 @@ 
+/*
+ * Accelerator CPUS Interface
+ *
+ * Copyright 2020 SUSE LLC
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef KVM_CPUS_H
+#define KVM_CPUS_H
+
+#include "sysemu/cpus.h"
+
+extern CpusAccel kvm_cpus;
+
+#endif /* KVM_CPUS_H */
diff --git a/accel/stubs/kvm-stub.c b/accel/stubs/kvm-stub.c
index 82f118d2df..69f8a842da 100644
--- a/accel/stubs/kvm-stub.c
+++ b/accel/stubs/kvm-stub.c
@@ -32,9 +32,8 @@  bool kvm_readonly_mem_allowed;
 bool kvm_ioeventfd_any_length_allowed;
 bool kvm_msi_use_devid;
 
-int kvm_destroy_vcpu(CPUState *cpu)
+void kvm_destroy_vcpu(CPUState *cpu)
 {
-    return -ENOSYS;
 }
 
 int kvm_init_vcpu(CPUState *cpu)
diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index b4174d941c..7a5f973b6f 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -218,7 +218,7 @@  int kvm_has_intx_set_mask(void);
 
 int kvm_init_vcpu(CPUState *cpu);
 int kvm_cpu_exec(CPUState *cpu);
-int kvm_destroy_vcpu(CPUState *cpu);
+void kvm_destroy_vcpu(CPUState *cpu);
 
 /**
  * kvm_arm_supports_user_irq
diff --git a/softmmu/cpus.c b/softmmu/cpus.c
index 9b4c59f6f5..f4cc05128b 100644
--- a/softmmu/cpus.c
+++ b/softmmu/cpus.c
@@ -179,9 +179,6 @@  void cpu_synchronize_state(CPUState *cpu)
     if (cpus_accel && cpus_accel->synchronize_state) {
         cpus_accel->synchronize_state(cpu);
     }
-    if (kvm_enabled()) {
-        kvm_cpu_synchronize_state(cpu);
-    }
     if (hax_enabled()) {
         hax_cpu_synchronize_state(cpu);
     }
@@ -195,9 +192,6 @@  void cpu_synchronize_post_reset(CPUState *cpu)
     if (cpus_accel && cpus_accel->synchronize_post_reset) {
         cpus_accel->synchronize_post_reset(cpu);
     }
-    if (kvm_enabled()) {
-        kvm_cpu_synchronize_post_reset(cpu);
-    }
     if (hax_enabled()) {
         hax_cpu_synchronize_post_reset(cpu);
     }
@@ -211,9 +205,6 @@  void cpu_synchronize_post_init(CPUState *cpu)
     if (cpus_accel && cpus_accel->synchronize_post_init) {
         cpus_accel->synchronize_post_init(cpu);
     }
-    if (kvm_enabled()) {
-        kvm_cpu_synchronize_post_init(cpu);
-    }
     if (hax_enabled()) {
         hax_cpu_synchronize_post_init(cpu);
     }
@@ -227,9 +218,6 @@  void cpu_synchronize_pre_loadvm(CPUState *cpu)
     if (cpus_accel && cpus_accel->synchronize_pre_loadvm) {
         cpus_accel->synchronize_pre_loadvm(cpu);
     }
-    if (kvm_enabled()) {
-        kvm_cpu_synchronize_pre_loadvm(cpu);
-    }
     if (hax_enabled()) {
         hax_cpu_synchronize_pre_loadvm(cpu);
     }
@@ -384,14 +372,6 @@  void run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data data)
     do_run_on_cpu(cpu, func, data, &qemu_global_mutex);
 }
 
-static void qemu_kvm_destroy_vcpu(CPUState *cpu)
-{
-    if (kvm_destroy_vcpu(cpu) < 0) {
-        error_report("kvm_destroy_vcpu failed");
-        exit(EXIT_FAILURE);
-    }
-}
-
 static void qemu_cpu_stop(CPUState *cpu, bool exit)
 {
     g_assert(qemu_cpu_is_self(cpu));
@@ -437,48 +417,6 @@  void qemu_wait_io_event(CPUState *cpu)
     qemu_wait_io_event_common(cpu);
 }
 
-static void *qemu_kvm_cpu_thread_fn(void *arg)
-{
-    CPUState *cpu = arg;
-    int r;
-
-    rcu_register_thread();
-
-    qemu_mutex_lock_iothread();
-    qemu_thread_get_self(cpu->thread);
-    cpu->thread_id = qemu_get_thread_id();
-    cpu->can_do_io = 1;
-    current_cpu = cpu;
-
-    r = kvm_init_vcpu(cpu);
-    if (r < 0) {
-        error_report("kvm_init_vcpu failed: %s", strerror(-r));
-        exit(1);
-    }
-
-    kvm_init_cpu_signals(cpu);
-
-    /* signal CPU creation */
-    cpu_thread_signal_created(cpu);
-    qemu_guest_random_seed_thread_part2(cpu->random_seed);
-
-    do {
-        if (cpu_can_run(cpu)) {
-            r = kvm_cpu_exec(cpu);
-            if (r == EXCP_DEBUG) {
-                cpu_handle_guest_debug(cpu);
-            }
-        }
-        qemu_wait_io_event(cpu);
-    } while (!cpu->unplug || cpu_can_run(cpu));
-
-    qemu_kvm_destroy_vcpu(cpu);
-    cpu_thread_signal_destroyed(cpu);
-    qemu_mutex_unlock_iothread();
-    rcu_unregister_thread();
-    return NULL;
-}
-
 static void *qemu_hax_cpu_thread_fn(void *arg)
 {
     CPUState *cpu = arg;
@@ -802,19 +740,6 @@  static void qemu_hax_start_vcpu(CPUState *cpu)
 #endif
 }
 
-static void qemu_kvm_start_vcpu(CPUState *cpu)
-{
-    char thread_name[VCPU_THREAD_NAME_SIZE];
-
-    cpu->thread = g_malloc0(sizeof(QemuThread));
-    cpu->halt_cond = g_malloc0(sizeof(QemuCond));
-    qemu_cond_init(cpu->halt_cond);
-    snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "CPU %d/KVM",
-             cpu->cpu_index);
-    qemu_thread_create(cpu->thread, thread_name, qemu_kvm_cpu_thread_fn,
-                       cpu, QEMU_THREAD_JOINABLE);
-}
-
 static void qemu_hvf_start_vcpu(CPUState *cpu)
 {
     char thread_name[VCPU_THREAD_NAME_SIZE];
@@ -876,8 +801,6 @@  void qemu_init_vcpu(CPUState *cpu)
     if (cpus_accel) {
         /* accelerator already implements the CpusAccel interface */
         cpus_accel->create_vcpu_thread(cpu);
-    } else if (kvm_enabled()) {
-        qemu_kvm_start_vcpu(cpu);
     } else if (hax_enabled()) {
         qemu_hax_start_vcpu(cpu);
     } else if (hvf_enabled()) {