accel: replace struct CpusAccel with AccelOpsClass

This will allow us to centralize the registration of
the cpus.c module accelerator operations (in accel/accel-softmmu.c),
and trigger it automatically using object hierarchy lookup from the
new accel_init_interfaces() initialization step, depending just on
which accelerators are available in the code.

Rename all tcg-cpus.c, kvm-cpus.c, etc to tcg-accel-ops.c,
kvm-accel-ops.c, etc, matching the object type names.

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20210204163931.7358-18-cfontana@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

MAINTAINERS

@@ -439,7 +439,8 @@ M: Richard Henderson <richard.henderson@linaro.org>
 R: Paolo Bonzini <pbonzini@redhat.com>
 S: Maintained
 F: include/qemu/accel.h
-F: accel/accel.c
+F: include/sysemu/accel-ops.h
+F: accel/accel-*.c
 F: accel/Makefile.objs
 F: accel/stubs/Makefile.objs
 

accel/accel-common.c

@@ -26,6 +26,10 @@
 #include "qemu/osdep.h"
 #include "qemu/accel.h"
 
+#ifndef CONFIG_USER_ONLY
+#include "accel-softmmu.h"
+#endif /* !CONFIG_USER_ONLY */
+
 static const TypeInfo accel_type = {
     .name = TYPE_ACCEL,
     .parent = TYPE_OBJECT,
@@ -42,6 +46,13 @@ AccelClass *accel_find(const char *opt_name)
     return ac;
 }
 
+void accel_init_interfaces(AccelClass *ac)
+{
+#ifndef CONFIG_USER_ONLY
+    accel_init_ops_interfaces(ac);
+#endif /* !CONFIG_USER_ONLY */
+}
+
 static void register_accel_types(void)
 {
     type_register_static(&accel_type);

accel/accel-softmmu.c

@@ -26,9 +26,9 @@
 #include "qemu/osdep.h"
 #include "qemu/accel.h"
 #include "hw/boards.h"
-#include "sysemu/arch_init.h"
+#include "sysemu/cpus.h"
-#include "sysemu/sysemu.h"
+
-#include "qom/object.h"
+#include "accel-softmmu.h"
 
 int accel_init_machine(AccelState *accel, MachineState *ms)
 {
@@ -60,3 +60,41 @@ void accel_setup_post(MachineState *ms)
         acc->setup_post(ms, accel);
     }
 }
+
+/* initialize the arch-independent accel operation interfaces */
+void accel_init_ops_interfaces(AccelClass *ac)
+{
+    const char *ac_name;
+    char *ops_name;
+    AccelOpsClass *ops;
+
+    ac_name = object_class_get_name(OBJECT_CLASS(ac));
+    g_assert(ac_name != NULL);
+
+    ops_name = g_strdup_printf("%s" ACCEL_OPS_SUFFIX, ac_name);
+    ops = ACCEL_OPS_CLASS(object_class_by_name(ops_name));
+    g_free(ops_name);
+
+    /*
+     * all accelerators need to define ops, providing at least a mandatory
+     * non-NULL create_vcpu_thread operation.
+     */
+    g_assert(ops != NULL);
+    if (ops->ops_init) {
+        ops->ops_init(ops);
+    }
+    cpus_register_accel(ops);
+}
+
+static const TypeInfo accel_ops_type_info = {
+    .name = TYPE_ACCEL_OPS,
+    .parent = TYPE_OBJECT,
+    .abstract = true,
+    .class_size = sizeof(AccelOpsClass),
+};
+
+static void accel_softmmu_register_types(void)
+{
+    type_register_static(&accel_ops_type_info);
+}
+type_init(accel_softmmu_register_types);

accel/accel-softmmu.h

@@ -0,0 +1,15 @@
+/*
+ * QEMU System Emulation accel internal functions
+ *
+ * Copyright 2021 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 ACCEL_SOFTMMU_H
+#define ACCEL_SOFTMMU_H
+
+void accel_init_ops_interfaces(AccelClass *ac);
+
+#endif /* ACCEL_SOFTMMU_H */

accel/kvm/kvm-accel-ops.c

@@ -74,11 +74,27 @@ static void kvm_start_vcpu_thread(CPUState *cpu)
                        cpu, QEMU_THREAD_JOINABLE);
 }
 
-const CpusAccel kvm_cpus = {
+static void kvm_accel_ops_class_init(ObjectClass *oc, void *data)
-    .create_vcpu_thread = kvm_start_vcpu_thread,
+{
+    AccelOpsClass *ops = ACCEL_OPS_CLASS(oc);
 
-    .synchronize_post_reset = kvm_cpu_synchronize_post_reset,
+    ops->create_vcpu_thread = kvm_start_vcpu_thread;
-    .synchronize_post_init = kvm_cpu_synchronize_post_init,
+    ops->synchronize_post_reset = kvm_cpu_synchronize_post_reset;
-    .synchronize_state = kvm_cpu_synchronize_state,
+    ops->synchronize_post_init = kvm_cpu_synchronize_post_init;
-    .synchronize_pre_loadvm = kvm_cpu_synchronize_pre_loadvm,
+    ops->synchronize_state = kvm_cpu_synchronize_state;
+    ops->synchronize_pre_loadvm = kvm_cpu_synchronize_pre_loadvm;
+}
+
+static const TypeInfo kvm_accel_ops_type = {
+    .name = ACCEL_OPS_NAME("kvm"),
+
+    .parent = TYPE_ACCEL_OPS,
+    .class_init = kvm_accel_ops_class_init,
+    .abstract = true,
 };
+
+static void kvm_accel_ops_register_types(void)
+{
+    type_register_static(&kvm_accel_ops_type);
+}
+type_init(kvm_accel_ops_register_types);

accel/kvm/kvm-all.c

@@ -2256,8 +2256,6 @@ static int kvm_init(MachineState *ms)
         ret = ram_block_discard_disable(true);
         assert(!ret);
     }
-
-    cpus_register_accel(&kvm_cpus);
     return 0;
 
 err:

accel/kvm/kvm-cpus.h

@@ -12,8 +12,6 @@
 
 #include "sysemu/cpus.h"
 
-extern const CpusAccel kvm_cpus;
-
 int kvm_init_vcpu(CPUState *cpu, Error **errp);
 int kvm_cpu_exec(CPUState *cpu);
 void kvm_destroy_vcpu(CPUState *cpu);

accel/kvm/meson.build

@@ -1,7 +1,7 @@
 kvm_ss = ss.source_set()
 kvm_ss.add(files(
   'kvm-all.c',
-  'kvm-cpus.c',
+  'kvm-accel-ops.c',
 ))
 kvm_ss.add(when: 'CONFIG_SEV', if_false: files('sev-stub.c'))
 

accel/qtest/qtest.c

@@ -25,14 +25,8 @@
 #include "qemu/main-loop.h"
 #include "hw/core/cpu.h"
 
-const CpusAccel qtest_cpus = {
-    .create_vcpu_thread = dummy_start_vcpu_thread,
-    .get_virtual_clock = qtest_get_virtual_clock,
-};
-
 static int qtest_init_accel(MachineState *ms)
 {
-    cpus_register_accel(&qtest_cpus);
     return 0;
 }
 
@@ -52,9 +46,26 @@ static const TypeInfo qtest_accel_type = {
     .class_init = qtest_accel_class_init,
 };
 
+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;
+};
+
+static const TypeInfo qtest_accel_ops_type = {
+    .name = ACCEL_OPS_NAME("qtest"),
+
+    .parent = TYPE_ACCEL_OPS,
+    .class_init = qtest_accel_ops_class_init,
+    .abstract = true,
+};
+
 static void qtest_type_init(void)
 {
     type_register_static(&qtest_accel_type);
+    type_register_static(&qtest_accel_ops_type);
 }
 
 type_init(qtest_type_init);

accel/tcg/meson.build

@@ -15,8 +15,8 @@ specific_ss.add_all(when: 'CONFIG_TCG', if_true: tcg_ss)
 
 specific_ss.add(when: ['CONFIG_SOFTMMU', 'CONFIG_TCG'], if_true: files(
   'cputlb.c',
-  'tcg-cpus.c',
+  'tcg-accel-ops.c',
-  'tcg-cpus-mttcg.c',
+  'tcg-accel-ops-mttcg.c',
-  'tcg-cpus-icount.c',
+  'tcg-accel-ops-icount.c',
-  'tcg-cpus-rr.c'
+  'tcg-accel-ops-rr.c'
 ))

accel/tcg/tcg-accel-ops-icount.c

@@ -32,9 +32,9 @@
 #include "exec/exec-all.h"
 #include "hw/boards.h"
 
-#include "tcg-cpus.h"
+#include "tcg-accel-ops.h"
-#include "tcg-cpus-icount.h"
+#include "tcg-accel-ops-icount.h"
-#include "tcg-cpus-rr.h"
+#include "tcg-accel-ops-rr.h"
 
 static int64_t icount_get_limit(void)
 {
@@ -93,7 +93,7 @@ void icount_prepare_for_run(CPUState *cpu)
     /*
      * These should always be cleared by icount_process_data after
      * each vCPU execution. However u16.high can be raised
-     * asynchronously by cpu_exit/cpu_interrupt/tcg_cpus_handle_interrupt
+     * asynchronously by cpu_exit/cpu_interrupt/tcg_handle_interrupt
      */
     g_assert(cpu_neg(cpu)->icount_decr.u16.low == 0);
     g_assert(cpu->icount_extra == 0);
@@ -125,23 +125,14 @@ void icount_process_data(CPUState *cpu)
     replay_mutex_unlock();
 }
 
-static void icount_handle_interrupt(CPUState *cpu, int mask)
+void icount_handle_interrupt(CPUState *cpu, int mask)
 {
     int old_mask = cpu->interrupt_request;
 
-    tcg_cpus_handle_interrupt(cpu, mask);
+    tcg_handle_interrupt(cpu, mask);
     if (qemu_cpu_is_self(cpu) &&
         !cpu->can_do_io
         && (mask & ~old_mask) != 0) {
         cpu_abort(cpu, "Raised interrupt while not in I/O function");
     }
 }
-
-const CpusAccel tcg_cpus_icount = {
-    .create_vcpu_thread = rr_start_vcpu_thread,
-    .kick_vcpu_thread = rr_kick_vcpu_thread,
-
-    .handle_interrupt = icount_handle_interrupt,
-    .get_virtual_clock = icount_get,
-    .get_elapsed_ticks = icount_get,
-};

accel/tcg/tcg-accel-ops-icount.h

@@ -14,4 +14,6 @@ void icount_handle_deadline(void);
 void icount_prepare_for_run(CPUState *cpu);
 void icount_process_data(CPUState *cpu);
 
+void icount_handle_interrupt(CPUState *cpu, int mask);
+
 #endif /* TCG_CPUS_ICOUNT_H */

accel/tcg/tcg-accel-ops-mttcg.c

@@ -32,7 +32,8 @@
 #include "exec/exec-all.h"
 #include "hw/boards.h"
 
-#include "tcg-cpus.h"
+#include "tcg-accel-ops.h"
+#include "tcg-accel-ops-mttcg.h"
 
 /*
  * In the multi-threaded case each vCPU has its own thread. The TLS
@@ -103,12 +104,12 @@ static void *mttcg_cpu_thread_fn(void *arg)
     return NULL;
 }
 
-static void mttcg_kick_vcpu_thread(CPUState *cpu)
+void mttcg_kick_vcpu_thread(CPUState *cpu)
 {
     cpu_exit(cpu);
 }
 
-static void mttcg_start_vcpu_thread(CPUState *cpu)
+void mttcg_start_vcpu_thread(CPUState *cpu)
 {
     char thread_name[VCPU_THREAD_NAME_SIZE];
 
@@ -131,10 +132,3 @@ static void mttcg_start_vcpu_thread(CPUState *cpu)
     cpu->hThread = qemu_thread_get_handle(cpu->thread);
 #endif
 }
-
-const CpusAccel tcg_cpus_mttcg = {
-    .create_vcpu_thread = mttcg_start_vcpu_thread,
-    .kick_vcpu_thread = mttcg_kick_vcpu_thread,
-
-    .handle_interrupt = tcg_cpus_handle_interrupt,
-};

accel/tcg/tcg-accel-ops-mttcg.h

@@ -0,0 +1,19 @@
+/*
+ * QEMU TCG Multi Threaded vCPUs implementation
+ *
+ * Copyright 2021 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 TCG_CPUS_MTTCG_H
+#define TCG_CPUS_MTTCG_H
+
+/* kick MTTCG vCPU thread */
+void mttcg_kick_vcpu_thread(CPUState *cpu);
+
+/* start an mttcg vCPU thread */
+void mttcg_start_vcpu_thread(CPUState *cpu);
+
+#endif /* TCG_CPUS_MTTCG_H */

accel/tcg/tcg-accel-ops-rr.c

@@ -32,9 +32,9 @@
 #include "exec/exec-all.h"
 #include "hw/boards.h"
 
-#include "tcg-cpus.h"
+#include "tcg-accel-ops.h"
-#include "tcg-cpus-rr.h"
+#include "tcg-accel-ops-rr.h"
-#include "tcg-cpus-icount.h"
+#include "tcg-accel-ops-icount.h"
 
 /* Kick all RR vCPUs */
 void rr_kick_vcpu_thread(CPUState *unused)
@@ -296,10 +296,3 @@ void rr_start_vcpu_thread(CPUState *cpu)
         cpu->created = true;
     }
 }
-
-const CpusAccel tcg_cpus_rr = {
-    .create_vcpu_thread = rr_start_vcpu_thread,
-    .kick_vcpu_thread = rr_kick_vcpu_thread,
-
-    .handle_interrupt = tcg_cpus_handle_interrupt,
-};

accel/tcg/tcg-accel-ops.c

@@ -34,7 +34,10 @@
 #include "exec/exec-all.h"
 #include "hw/boards.h"
 
-#include "tcg-cpus.h"
+#include "tcg-accel-ops.h"
+#include "tcg-accel-ops-mttcg.h"
+#include "tcg-accel-ops-rr.h"
+#include "tcg-accel-ops-icount.h"
 
 /* common functionality among all TCG variants */
 
@@ -64,7 +67,7 @@ int tcg_cpus_exec(CPUState *cpu)
 }
 
 /* mask must never be zero, except for A20 change call */
-void tcg_cpus_handle_interrupt(CPUState *cpu, int mask)
+void tcg_handle_interrupt(CPUState *cpu, int mask)
 {
     g_assert(qemu_mutex_iothread_locked());
 
@@ -80,3 +83,43 @@ void tcg_cpus_handle_interrupt(CPUState *cpu, int mask)
         qatomic_set(&cpu_neg(cpu)->icount_decr.u16.high, -1);
     }
 }
+
+static void tcg_accel_ops_init(AccelOpsClass *ops)
+{
+    if (qemu_tcg_mttcg_enabled()) {
+        ops->create_vcpu_thread = mttcg_start_vcpu_thread;
+        ops->kick_vcpu_thread = mttcg_kick_vcpu_thread;
+        ops->handle_interrupt = tcg_handle_interrupt;
+    } else if (icount_enabled()) {
+        ops->create_vcpu_thread = rr_start_vcpu_thread;
+        ops->kick_vcpu_thread = rr_kick_vcpu_thread;
+        ops->handle_interrupt = icount_handle_interrupt;
+        ops->get_virtual_clock = icount_get;
+        ops->get_elapsed_ticks = icount_get;
+    } else {
+        ops->create_vcpu_thread = rr_start_vcpu_thread;
+        ops->kick_vcpu_thread = rr_kick_vcpu_thread;
+        ops->handle_interrupt = tcg_handle_interrupt;
+    }
+}
+
+static void tcg_accel_ops_class_init(ObjectClass *oc, void *data)
+{
+    AccelOpsClass *ops = ACCEL_OPS_CLASS(oc);
+
+    ops->ops_init = tcg_accel_ops_init;
+}
+
+static const TypeInfo tcg_accel_ops_type = {
+    .name = ACCEL_OPS_NAME("tcg"),
+
+    .parent = TYPE_ACCEL_OPS,
+    .class_init = tcg_accel_ops_class_init,
+    .abstract = true,
+};
+
+static void tcg_accel_ops_register_types(void)
+{
+    type_register_static(&tcg_accel_ops_type);
+}
+type_init(tcg_accel_ops_register_types);

accel/tcg/tcg-accel-ops.h

@@ -14,12 +14,8 @@
 
 #include "sysemu/cpus.h"
 
-extern const CpusAccel tcg_cpus_mttcg;
-extern const CpusAccel tcg_cpus_icount;
-extern const CpusAccel tcg_cpus_rr;
-
 void tcg_cpus_destroy(CPUState *cpu);
 int tcg_cpus_exec(CPUState *cpu);
-void tcg_cpus_handle_interrupt(CPUState *cpu, int mask);
+void tcg_handle_interrupt(CPUState *cpu, int mask);
 
 #endif /* TCG_CPUS_H */

accel/tcg/tcg-all.c

@@ -33,10 +33,6 @@
 #include "qemu/accel.h"
 #include "qapi/qapi-builtin-visit.h"
 
-#ifndef CONFIG_USER_ONLY
-#include "tcg-cpus.h"
-#endif /* CONFIG_USER_ONLY */
-
 struct TCGState {
     AccelState parent_obj;
 
@@ -124,14 +120,6 @@ static int tcg_init(MachineState *ms)
      */
 #ifndef CONFIG_USER_ONLY
     tcg_region_init();
-
-    if (mttcg_enabled) {
-        cpus_register_accel(&tcg_cpus_mttcg);
-    } else if (icount_enabled()) {
-        cpus_register_accel(&tcg_cpus_icount);
-    } else {
-        cpus_register_accel(&tcg_cpus_rr);
-    }
 #endif /* !CONFIG_USER_ONLY */
 
     return 0;

accel/xen/xen-all.c

@@ -154,10 +154,6 @@ static void xen_setup_post(MachineState *ms, AccelState *accel)
     }
 }
 
-const CpusAccel xen_cpus = {
-    .create_vcpu_thread = dummy_start_vcpu_thread,
-};
-
 static int xen_init(MachineState *ms)
 {
     MachineClass *mc = MACHINE_GET_CLASS(ms);
@@ -185,9 +181,6 @@ static int xen_init(MachineState *ms)
      * opt out of system RAM being allocated by generic code
      */
     mc->default_ram_id = NULL;
-
-    cpus_register_accel(&xen_cpus);
-
     return 0;
 }
 
@@ -222,9 +215,24 @@ static const TypeInfo xen_accel_type = {
     .class_init = xen_accel_class_init,
 };
 
+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;
+}
+
+static const TypeInfo xen_accel_ops_type = {
+    .name = ACCEL_OPS_NAME("xen"),
+
+    .parent = TYPE_ACCEL_OPS,
+    .class_init = xen_accel_ops_class_init,
+    .abstract = true,
+};
+
 static void xen_type_init(void)
 {
     type_register_static(&xen_accel_type);
+    type_register_static(&xen_accel_ops_type);
 }
-
 type_init(xen_type_init);