accel: introduce AccelCPUClass extending CPUClass

add a new optional interface to CPUClass, which allows accelerators
to extend the CPUClass with additional accelerator-specific
initializations.

This will allow to separate the target cpu code that is specific
to each accelerator, and register it automatically with object
hierarchy lookup depending on accelerator code availability,
as part of the accel_init_interfaces() initialization step.

Signed-off-by: Claudio Fontana <[email protected]>
Message-Id: <20210204163931[email protected]>
Signed-off-by: Richard Henderson <[email protected]>

diff --git a/MAINTAINERS b/MAINTAINERS
index 2e63561ad053b7e8a07d363e5ab7857d6b050f45..8d8b0bf966d68036f7f3b387a8e0716737c5f835 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -440,6 +440,7 @@ R: Paolo Bonzini <[email protected]>
 S: Maintained
 F: include/qemu/accel.h
 F: include/sysemu/accel-ops.h
+F: include/hw/core/accel-cpu.h
 F: accel/accel-*.c
 F: accel/Makefile.objs
 F: accel/stubs/Makefile.objs

diff --git a/accel/accel-common.c b/accel/accel-common.c
index 6b59873419953f471b080a8d378782aa1d974ff1..9901b0531c42f3c77cedfe7011d61563e8fa5f7f 100644 (file)
--- a/accel/accel-common.c
+++ b/accel/accel-common.c
@@ -26,6 +26,9 @@
 #include "qemu/osdep.h"
 #include "qemu/accel.h"
 
+#include "cpu.h"
+#include "hw/core/accel-cpu.h"
+
 #ifndef CONFIG_USER_ONLY
 #include "accel-softmmu.h"
 #endif /* !CONFIG_USER_ONLY */
@@ -46,16 +49,57 @@ AccelClass *accel_find(const char *opt_name)
     return ac;
 }
 
+static void accel_init_cpu_int_aux(ObjectClass *klass, void *opaque)
+{
+    CPUClass *cc = CPU_CLASS(klass);
+    AccelCPUClass *accel_cpu = opaque;
+
+    cc->accel_cpu = accel_cpu;
+    if (accel_cpu->cpu_class_init) {
+        accel_cpu->cpu_class_init(cc);
+    }
+}
+
+/* initialize the arch-specific accel CpuClass interfaces */
+static void accel_init_cpu_interfaces(AccelClass *ac)
+{
+    const char *ac_name; /* AccelClass name */
+    char *acc_name;      /* AccelCPUClass name */
+    ObjectClass *acc;    /* AccelCPUClass */
+
+    ac_name = object_class_get_name(OBJECT_CLASS(ac));
+    g_assert(ac_name != NULL);
+
+    acc_name = g_strdup_printf("%s-%s", ac_name, CPU_RESOLVING_TYPE);
+    acc = object_class_by_name(acc_name);
+    g_free(acc_name);
+
+    if (acc) {
+        object_class_foreach(accel_init_cpu_int_aux,
+                             CPU_RESOLVING_TYPE, false, acc);
+    }
+}
+
 void accel_init_interfaces(AccelClass *ac)
 {
 #ifndef CONFIG_USER_ONLY
     accel_init_ops_interfaces(ac);
 #endif /* !CONFIG_USER_ONLY */
+
+    accel_init_cpu_interfaces(ac);
 }
 
+static const TypeInfo accel_cpu_type = {
+    .name = TYPE_ACCEL_CPU,
+    .parent = TYPE_OBJECT,
+    .abstract = true,
+    .class_size = sizeof(AccelCPUClass),
+};
+
 static void register_accel_types(void)
 {
     type_register_static(&accel_type);
+    type_register_static(&accel_cpu_type);
 }
 
 type_init(register_accel_types);

diff --git a/include/hw/core/accel-cpu.h b/include/hw/core/accel-cpu.h
new file mode 100644 (file)
index 0000000..24a6697
--- /dev/null
+++ b/include/hw/core/accel-cpu.h
@@ -0,0 +1,38 @@
+/*
+ * Accelerator interface, specializes CPUClass
+ * This header is used only by target-specific code.
+ *
+ * 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_CPU_H
+#define ACCEL_CPU_H
+
+/*
+ * This header is used to define new accelerator-specific target-specific
+ * accelerator cpu subclasses.
+ * It uses CPU_RESOLVING_TYPE, so this is clearly target-specific.
+ *
+ * Do not try to use for any other purpose than the implementation of new
+ * subclasses in target/, or the accel implementation itself in accel/
+ */
+
+#define TYPE_ACCEL_CPU "accel-" CPU_RESOLVING_TYPE
+#define ACCEL_CPU_NAME(name) (name "-" TYPE_ACCEL_CPU)
+typedef struct AccelCPUClass AccelCPUClass;
+DECLARE_CLASS_CHECKERS(AccelCPUClass, ACCEL_CPU, TYPE_ACCEL_CPU)
+
+typedef struct AccelCPUClass {
+    /*< private >*/
+    ObjectClass parent_class;
+    /*< public >*/
+
+    void (*cpu_class_init)(CPUClass *cc);
+    void (*cpu_instance_init)(CPUState *cpu);
+    void (*cpu_realizefn)(CPUState *cpu, Error **errp);
+} AccelCPUClass;
+
+#endif /* ACCEL_CPU_H */

diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index 4f6c6b18c95ffd973d4c1b61a553ed869a2b1569..38d813c389b1e088ccdf235d6904589cfa184018 100644 (file)
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -79,6 +79,9 @@ struct TranslationBlock;
 /* see tcg-cpu-ops.h */
 struct TCGCPUOps;
 
+/* see accel-cpu.h */
+struct AccelCPUClass;
+
 /**
  * CPUClass:
  * @class_by_name: Callback to map -cpu command line model name to an
@@ -187,6 +190,7 @@ struct CPUClass {
     /* Keep non-pointer data at the end to minimize holes.  */
     int gdb_num_core_regs;
     bool gdb_stop_before_watchpoint;
+    struct AccelCPUClass *accel_cpu;
 
     /* when TCG is not available, this pointer is NULL */
     struct TCGCPUOps *tcg_ops;