accel: Add missing AccelOpsClass::has_work() and drop SysemuCPUOps one

cpu_common_has_work() is the default has_work() implementation
and returns 'false'.

Explicit it for the QTest / HAX / HVF / NVMM / Xen accelerators
and remove cpu_common_has_work().

Since there are no more implementations of SysemuCPUOps::has_work,
remove it along with the assertion in cpu_has_work().

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Paul Durrant <paul@xen.org>
Message-Id: <20210912172731.789788-31-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

accel/hvf/hvf-accel-ops.c

@@ -446,6 +446,11 @@ static void hvf_start_vcpu_thread(CPUState *cpu)
                        cpu, QEMU_THREAD_JOINABLE);
 }
 
+static bool hvf_cpu_has_work(CPUState *cpu)
+{
+    return false;
+}
+
 static void hvf_accel_ops_class_init(ObjectClass *oc, void *data)
 {
     AccelOpsClass *ops = ACCEL_OPS_CLASS(oc);
@@ -456,6 +461,7 @@ static void hvf_accel_ops_class_init(ObjectClass *oc, void *data)
     ops->synchronize_post_init = hvf_cpu_synchronize_post_init;
     ops->synchronize_state = hvf_cpu_synchronize_state;
     ops->synchronize_pre_loadvm = hvf_cpu_synchronize_pre_loadvm;
+    ops->has_work = hvf_cpu_has_work;
 };
 static const TypeInfo hvf_accel_ops_type = {
     .name = ACCEL_OPS_NAME("hvf"),

accel/qtest/qtest.c

@@ -47,12 +47,18 @@ static const TypeInfo qtest_accel_type = {
 };
 module_obj(TYPE_QTEST_ACCEL);
 
+static bool qtest_cpu_has_work(CPUState *cpu)
+{
+    return false;
+}
+
 static void qtest_accel_ops_class_init(ObjectClass *oc, void *data)
 {
     AccelOpsClass *ops = ACCEL_OPS_CLASS(oc);
 
     ops->create_vcpu_thread = dummy_start_vcpu_thread;
     ops->get_virtual_clock = qtest_get_virtual_clock;
+    ops->has_work = qtest_cpu_has_work;
 };
 
 static const TypeInfo qtest_accel_ops_type = {

accel/xen/xen-all.c

@@ -215,11 +215,17 @@ static const TypeInfo xen_accel_type = {
     .class_init = xen_accel_class_init,
 };
 
+static bool xen_cpu_has_work(CPUState *cpu)
+{
+    return false;
+}
+
 static void xen_accel_ops_class_init(ObjectClass *oc, void *data)
 {
     AccelOpsClass *ops = ACCEL_OPS_CLASS(oc);
 
     ops->create_vcpu_thread = dummy_start_vcpu_thread;
+    ops->has_work = xen_cpu_has_work;
 }
 
 static const TypeInfo xen_accel_ops_type = {

hw/core/cpu-common.c

@@ -143,11 +143,6 @@ static void cpu_common_reset(DeviceState *dev)
     }
 }
 
-static bool cpu_common_has_work(CPUState *cs)
-{
-    return false;
-}
-
 ObjectClass *cpu_class_by_name(const char *typename, const char *cpu_model)
 {
     CPUClass *cc = CPU_CLASS(object_class_by_name(typename));
@@ -279,7 +274,6 @@ static void cpu_class_init(ObjectClass *klass, void *data)
 
     k->parse_features = cpu_common_parse_features;
     k->get_arch_id = cpu_common_get_arch_id;
-    k->has_work = cpu_common_has_work;
     k->gdb_read_register = cpu_common_gdb_read_register;
     k->gdb_write_register = cpu_common_gdb_write_register;
     set_bit(DEVICE_CATEGORY_CPU, dc->categories);

include/hw/core/cpu.h

@@ -89,7 +89,6 @@ struct SysemuCPUOps;
  * instantiatable CPU type.
  * @parse_features: Callback to parse command line arguments.
  * @reset_dump_flags: #CPUDumpFlags to use for reset logging.
- * @has_work: Callback for checking if there is work to do.
  * @memory_rw_debug: Callback for GDB memory access.
  * @dump_state: Callback for dumping state.
  * @get_arch_id: Callback for getting architecture-dependent CPU ID.
@@ -132,7 +131,6 @@ struct CPUClass {
     void (*parse_features)(const char *typename, char *str, Error **errp);
 
     int reset_dump_flags;
-    bool (*has_work)(CPUState *cpu);
     int (*memory_rw_debug)(CPUState *cpu, vaddr addr,
                            uint8_t *buf, int len, bool is_write);
     void (*dump_state)(CPUState *cpu, FILE *, int flags);

softmmu/cpus.c

@@ -251,13 +251,8 @@ void cpu_interrupt(CPUState *cpu, int mask)
 
 bool cpu_has_work(CPUState *cpu)
 {
-    CPUClass *cc = CPU_GET_CLASS(cpu);
-
-    if (cpus_accel->has_work) {
-        return cpus_accel->has_work(cpu);
-    }
-    g_assert(cc->has_work);
-    return cc->has_work(cpu);
+    g_assert(cpus_accel->has_work);
+    return cpus_accel->has_work(cpu);
 }
 
 static int do_vm_stop(RunState state, bool send_stop)

target/i386/hax/hax-accel-ops.c

@@ -74,6 +74,11 @@ static void hax_start_vcpu_thread(CPUState *cpu)
 #endif
 }
 
+static bool hax_cpu_has_work(CPUState *cpu)
+{
+    return false;
+}
+
 static void hax_accel_ops_class_init(ObjectClass *oc, void *data)
 {
     AccelOpsClass *ops = ACCEL_OPS_CLASS(oc);
@@ -85,6 +90,7 @@ static void hax_accel_ops_class_init(ObjectClass *oc, void *data)
     ops->synchronize_post_init = hax_cpu_synchronize_post_init;
     ops->synchronize_state = hax_cpu_synchronize_state;
     ops->synchronize_pre_loadvm = hax_cpu_synchronize_pre_loadvm;
+    ops->has_work = hax_cpu_has_work;
 }
 
 static const TypeInfo hax_accel_ops_type = {

target/i386/nvmm/nvmm-accel-ops.c

@@ -83,6 +83,11 @@ static void nvmm_kick_vcpu_thread(CPUState *cpu)
     cpus_kick_thread(cpu);
 }
 
+static bool nvmm_cpu_has_work(CPUState *cpu)
+{
+    return false;
+}
+
 static void nvmm_accel_ops_class_init(ObjectClass *oc, void *data)
 {
     AccelOpsClass *ops = ACCEL_OPS_CLASS(oc);
@@ -94,6 +99,7 @@ static void nvmm_accel_ops_class_init(ObjectClass *oc, void *data)
     ops->synchronize_post_init = nvmm_cpu_synchronize_post_init;
     ops->synchronize_state = nvmm_cpu_synchronize_state;
     ops->synchronize_pre_loadvm = nvmm_cpu_synchronize_pre_loadvm;
+    ops->has_work = nvmm_cpu_has_work;
 }
 
 static const TypeInfo nvmm_accel_ops_type = {