Re: [Qemu-devel] [PATCH qom-cpu v4 09/18] cpu: Turn cpu_get_memory_mapping() into a CPUState hook

[Luiz Capitulino <lcapitulino@redhat.com>]

On Sun,  9 Jun 2013 18:10:38 +0200
Andreas Färber <afaerber@suse.de> wrote:

> Change error reporting from return value to Error argument.
> 
> Signed-off-by: Andreas Färber <afaerber@suse.de>
> ---
>  include/qom/cpu.h                 | 14 ++++++++++++++
>  include/sysemu/memory_mapping.h   |  2 --
>  memory_mapping-stub.c             |  6 ------
>  memory_mapping.c                  |  7 ++++---
>  qom/cpu.c                         | 16 ++++++++++++++++
>  target-i386/arch_memory_mapping.c | 12 +++++++-----
>  target-i386/cpu-qom.h             |  3 +++
>  target-i386/cpu.c                 |  1 +
>  8 files changed, 45 insertions(+), 16 deletions(-)
> 
> diff --git a/include/qom/cpu.h b/include/qom/cpu.h
> index 1f70240..254be2e 100644
> --- a/include/qom/cpu.h
> +++ b/include/qom/cpu.h
> @@ -23,6 +23,7 @@
>  #include <signal.h>
>  #include "hw/qdev-core.h"
>  #include "qemu/thread.h"
> +#include "qemu/typedefs.h"
>  
>  typedef int (*WriteCoreDumpFunction)(void *buf, size_t size, void *opaque);
>  
> @@ -49,6 +50,7 @@ typedef struct CPUState CPUState;
>   * @do_interrupt: Callback for interrupt handling.
>   * @get_arch_id: Callback for getting architecture-dependent CPU ID.
>   * @get_paging_enabled: Callback for inquiring whether paging is enabled.
> + * @get_memory_mapping: Callback for obtaining the memory mappings.
>   * @vmsd: State description for migration.
>   *
>   * Represents a CPU family or model.
> @@ -64,6 +66,8 @@ typedef struct CPUClass {
>      void (*do_interrupt)(CPUState *cpu);
>      int64_t (*get_arch_id)(CPUState *cpu);
>      bool (*get_paging_enabled)(const CPUState *cpu);
> +    void (*get_memory_mapping)(CPUState *cpu, MemoryMappingList *list,
> +                               Error **errp);
>  
>      const struct VMStateDescription *vmsd;
>      int (*write_elf64_note)(WriteCoreDumpFunction f, CPUState *cpu,
> @@ -148,6 +152,16 @@ struct CPUState {
>  bool cpu_paging_enabled(const CPUState *cpu);
>  
>  /**
> + * @cpu: The CPU whose memory mappings are to be obtained.
> + * @list: Where to write the memory mappings to.
> + * @errp: Pointer for reporting an #Error.
> + *
> + * Returns: 0 if successful.
> + */

It turns void now, but you can add:

Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>

When you respin.

> +void cpu_get_memory_mapping(CPUState *cpu, MemoryMappingList *list,
> +                            Error **errp);
> +
> +/**
>   * cpu_write_elf64_note:
>   * @f: pointer to a function that writes memory to a file
>   * @cpu: The CPU whose memory is to be dumped
> diff --git a/include/sysemu/memory_mapping.h b/include/sysemu/memory_mapping.h
> index 1f71c32..c47e6ee 100644
> --- a/include/sysemu/memory_mapping.h
> +++ b/include/sysemu/memory_mapping.h
> @@ -31,8 +31,6 @@ struct MemoryMappingList {
>      QTAILQ_HEAD(, MemoryMapping) head;
>  };
>  
> -int cpu_get_memory_mapping(MemoryMappingList *list, CPUArchState *env);
> -
>  /*
>   * add or merge the memory region [phys_addr, phys_addr + length) into the
>   * memory mapping's list. The region's virtual address starts with virt_addr,
> diff --git a/memory_mapping-stub.c b/memory_mapping-stub.c
> index 6c0dfeb..989dc00 100644
> --- a/memory_mapping-stub.c
> +++ b/memory_mapping-stub.c
> @@ -19,9 +19,3 @@ int qemu_get_guest_memory_mapping(MemoryMappingList *list)
>  {
>      return -2;
>  }
> -
> -int cpu_get_memory_mapping(MemoryMappingList *list,
> -					                                          CPUArchState *env)
> -{
> -    return -1;
> -}
> diff --git a/memory_mapping.c b/memory_mapping.c
> index 0790aac..9bd24ce 100644
> --- a/memory_mapping.c
> +++ b/memory_mapping.c
> @@ -183,13 +183,14 @@ int qemu_get_guest_memory_mapping(MemoryMappingList *list)
>      CPUArchState *env, *first_paging_enabled_cpu;
>      RAMBlock *block;
>      ram_addr_t offset, length;
> -    int ret;
>  
>      first_paging_enabled_cpu = find_paging_enabled_cpu(first_cpu);
>      if (first_paging_enabled_cpu) {
>          for (env = first_paging_enabled_cpu; env != NULL; env = env->next_cpu) {
> -            ret = cpu_get_memory_mapping(list, env);
> -            if (ret < 0) {
> +            Error *err = NULL;
> +            cpu_get_memory_mapping(ENV_GET_CPU(env), list, &err);
> +            if (err) {
> +                error_free(err);
>                  return -1;
>              }
>          }
> diff --git a/qom/cpu.c b/qom/cpu.c
> index 9f6da0f..b25fbc9 100644
> --- a/qom/cpu.c
> +++ b/qom/cpu.c
> @@ -62,6 +62,21 @@ static bool cpu_common_get_paging_enabled(const CPUState *cpu)
>      return true;
>  }
>  
> +void cpu_get_memory_mapping(CPUState *cpu, MemoryMappingList *list,
> +                            Error **errp)
> +{
> +    CPUClass *cc = CPU_GET_CLASS(cpu);
> +
> +    return cc->get_memory_mapping(cpu, list, errp);
> +}
> +
> +static void cpu_common_get_memory_mapping(CPUState *cpu,
> +                                          MemoryMappingList *list,
> +                                          Error **errp)
> +{
> +    error_setg(errp, "Obtaining memory mappings is unsupported on this CPU.");
> +}
> +
>  /* CPU hot-plug notifiers */
>  static NotifierList cpu_added_notifiers =
>      NOTIFIER_LIST_INITIALIZER(cpu_add_notifiers);
> @@ -189,6 +204,7 @@ static void cpu_class_init(ObjectClass *klass, void *data)
>      k->reset = cpu_common_reset;
>      k->get_arch_id = cpu_common_get_arch_id;
>      k->get_paging_enabled = cpu_common_get_paging_enabled;
> +    k->get_memory_mapping = cpu_common_get_memory_mapping;
>      k->write_elf32_qemunote = cpu_common_write_elf32_qemunote;
>      k->write_elf32_note = cpu_common_write_elf32_note;
>      k->write_elf64_qemunote = cpu_common_write_elf64_qemunote;
> diff --git a/target-i386/arch_memory_mapping.c b/target-i386/arch_memory_mapping.c
> index c5a10ec..2566a04 100644
> --- a/target-i386/arch_memory_mapping.c
> +++ b/target-i386/arch_memory_mapping.c
> @@ -239,11 +239,15 @@ static void walk_pml4e(MemoryMappingList *list,
>  }
>  #endif
>  
> -int cpu_get_memory_mapping(MemoryMappingList *list, CPUArchState *env)
> +void x86_cpu_get_memory_mapping(CPUState *cs, MemoryMappingList *list,
> +                                Error **errp)
>  {
> -    if (!cpu_paging_enabled(ENV_GET_CPU(env))) {
> +    X86CPU *cpu = X86_CPU(cs);
> +    CPUX86State *env = &cpu->env;
> +
> +    if (!cpu_paging_enabled(cs)) {
>          /* paging is disabled */
> -        return 0;
> +        return;
>      }
>  
>      if (env->cr[4] & CR4_PAE_MASK) {
> @@ -269,7 +273,5 @@ int cpu_get_memory_mapping(MemoryMappingList *list, CPUArchState *env)
>          pse = !!(env->cr[4] & CR4_PSE_MASK);
>          walk_pde2(list, pde_addr, env->a20_mask, pse);
>      }
> -
> -    return 0;
>  }
>  
> diff --git a/target-i386/cpu-qom.h b/target-i386/cpu-qom.h
> index 849cedf..e0ac072 100644
> --- a/target-i386/cpu-qom.h
> +++ b/target-i386/cpu-qom.h
> @@ -98,4 +98,7 @@ int x86_cpu_write_elf64_qemunote(WriteCoreDumpFunction f, CPUState *cpu,
>  int x86_cpu_write_elf32_qemunote(WriteCoreDumpFunction f, CPUState *cpu,
>                                   void *opaque);
>  
> +void x86_cpu_get_memory_mapping(CPUState *cpu, MemoryMappingList *list,
> +                                Error **errp);
> +
>  #endif
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index f6fa7fa..a7154af 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -2529,6 +2529,7 @@ static void x86_cpu_common_class_init(ObjectClass *oc, void *data)
>      cc->get_arch_id = x86_cpu_get_arch_id;
>      cc->get_paging_enabled = x86_cpu_get_paging_enabled;
>  #ifndef CONFIG_USER_ONLY
> +    cc->get_memory_mapping = x86_cpu_get_memory_mapping;
>      cc->write_elf64_note = x86_cpu_write_elf64_note;
>      cc->write_elf64_qemunote = x86_cpu_write_elf64_qemunote;
>      cc->write_elf32_note = x86_cpu_write_elf32_note;