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[PULL 46/46] accel: introduce AccelCPUClass extending CPUClass

Richard Henderson posted 46 patches 4 years, 2 months ago
Maintainers: "Hervé Poussineau" <hpoussin@reactos.org>, "Edgar E. Iglesias" <edgar.iglesias@gmail.com>, Laurent Vivier <laurent@vivier.eu>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Greg Kurz <groug@kaod.org>, Guan Xuetao <gxt@mprc.pku.edu.cn>, "Philippe Mathieu-Daudé" <f4bug@amsat.org>, Jiaxun Yang <jiaxun.yang@flygoat.com>, Richard Henderson <richard.henderson@linaro.org>, Artyom Tarasenko <atar4qemu@gmail.com>, Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>, Sagar Karandikar <sagark@eecs.berkeley.edu>, Colin Xu <colin.xu@intel.com>, Anthony Perard <anthony.perard@citrix.com>, Bastian Koppelmann <kbastian@mail.uni-paderborn.de>, Cornelia Huck <cohuck@redhat.com>, Laurent Vivier <lvivier@redhat.com>, Riku Voipio <riku.voipio@iki.fi>, Sarah Harris <S.E.Harris@kent.ac.uk>, Thomas Huth <thuth@redhat.com>, Wenchao Wang <wenchao.wang@intel.com>, Aleksandar Rikalo <aleksandar.rikalo@syrmia.com>, Michael Rolnik <mrolnik@gmail.com>, Yoshinori Sato <ysato@users.sourceforge.jp>, Aurelien Jarno <aurelien@aurel32.net>, Palmer Dabbelt <palmer@dabbelt.com>, Alistair Francis <Alistair.Francis@wdc.com>, Chris Wulff <crwulff@gmail.com>, Paul Durrant <paul@xen.org>, Peter Maydell <peter.maydell@linaro.org>, Cameron Esfahani <dirty@apple.com>, Max Filippov <jcmvbkbc@gmail.com>, Marek Vasut <marex@denx.de>, Eduardo Habkost <ehabkost@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Stefano Stabellini <sstabellini@kernel.org>, Michael Walle <michael@walle.cc>, Roman Bolshakov <r.bolshakov@yadro.com>, Stafford Horne <shorne@gmail.com>, Sunil Muthuswamy <sunilmut@microsoft.com>, David Gibson <david@gibson.dropbear.id.au>, Anthony Green <green@moxielogic.com>, David Hildenbrand <david@redhat.com>
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[PULL 46/46] accel: introduce AccelCPUClass extending CPUClass
Posted by Richard Henderson 4 years, 2 months ago 
From: Claudio Fontana <cfontana@suse.de>

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 <cfontana@suse.de>
Message-Id: <20210204163931.7358-19-cfontana@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/hw/core/accel-cpu.h | 38 ++++++++++++++++++++++++++++++++
 include/hw/core/cpu.h       |  4 ++++
 accel/accel-common.c        | 44 +++++++++++++++++++++++++++++++++++++
 MAINTAINERS                 |  1 +
 4 files changed, 87 insertions(+)
 create mode 100644 include/hw/core/accel-cpu.h

diff --git a/include/hw/core/accel-cpu.h b/include/hw/core/accel-cpu.h
new file mode 100644
index 0000000000..24a6697412
--- /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 4f6c6b18c9..38d813c389 100644
--- 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;
diff --git a/accel/accel-common.c b/accel/accel-common.c
index 6b59873419..9901b0531c 100644
--- 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/MAINTAINERS b/MAINTAINERS
index 2e63561ad0..8d8b0bf966 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -440,6 +440,7 @@ R: Paolo Bonzini <pbonzini@redhat.com>
 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
-- 
2.25.1
Re: [PULL 46/46] accel: introduce AccelCPUClass extending CPUClass
Posted by Philippe Mathieu-Daudé 4 years ago 
Hi Claudio,

+Eduardo/Paolo

On 2/5/21 11:56 PM, Richard Henderson wrote:
> From: Claudio Fontana <cfontana@suse.de>
> 
> 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 <cfontana@suse.de>
> Message-Id: <20210204163931.7358-19-cfontana@suse.de>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  include/hw/core/accel-cpu.h | 38 ++++++++++++++++++++++++++++++++
>  include/hw/core/cpu.h       |  4 ++++
>  accel/accel-common.c        | 44 +++++++++++++++++++++++++++++++++++++
>  MAINTAINERS                 |  1 +
>  4 files changed, 87 insertions(+)
>  create mode 100644 include/hw/core/accel-cpu.h
> 
> diff --git a/include/hw/core/accel-cpu.h b/include/hw/core/accel-cpu.h
> new file mode 100644
> index 0000000000..24a6697412
> --- /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);

We could use a const pointer to const AccelCPUOps.

> +} AccelCPUClass;
> +
> +#endif /* ACCEL_CPU_H */
> diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
> index 4f6c6b18c9..38d813c389 100644
> --- 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;

(so here AccelCPUOps)

>  
>      /* when TCG is not available, this pointer is NULL */
>      struct TCGCPUOps *tcg_ops;
> diff --git a/accel/accel-common.c b/accel/accel-common.c
> index 6b59873419..9901b0531c 100644
> --- 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,

I'm not convince the abstract QOM parent has to be
per target. All methods in AccelCPUClass use pointers,
so we should be fine with opaque CPU* pointer declarations,
and have one common type for all targets.

> +    .class_size = sizeof(AccelCPUClass),
> +};
> +
>  static void register_accel_types(void)
>  {
>      type_register_static(&accel_type);
> +    type_register_static(&accel_cpu_type);
>  }

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