Re: [Qemu-devel] [PATCH v11 04/34] fw_cfg: add fw_cfg_machine_reset function

[Paolo Bonzini <pbonzini@redhat.com>]

Il 07/10/2014 10:00, arei.gonglei@huawei.com ha scritto:
> From: Gonglei <arei.gonglei@huawei.com>
> 
> We must assure that the changed bootindex can take effect
> when guest is rebooted. So we introduce fw_cfg_machine_reset(),
> which change the fw_cfg file's bootindex data using the new
> global fw_boot_order list.
> 
> Signed-off-by: Chenliang <chenliang88@huawei.com>
> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
> Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  hw/nvram/fw_cfg.c         | 55 ++++++++++++++++++++++++++++++++++++++++++++---
>  include/hw/nvram/fw_cfg.h |  2 ++
>  2 files changed, 54 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
> index b71d251..e7ed27e 100644
> --- a/hw/nvram/fw_cfg.c
> +++ b/hw/nvram/fw_cfg.c
> @@ -402,6 +402,26 @@ static void fw_cfg_add_bytes_read_callback(FWCfgState *s, uint16_t key,
>      s->entries[arch][key].callback_opaque = callback_opaque;
>  }
>  
> +static void *fw_cfg_modify_bytes_read(FWCfgState *s, uint16_t key,
> +                                              void *data, size_t len)
> +{
> +    void *ptr;
> +    int arch = !!(key & FW_CFG_ARCH_LOCAL);
> +
> +    key &= FW_CFG_ENTRY_MASK;
> +
> +    assert(key < FW_CFG_MAX_ENTRY && len < UINT32_MAX);
> +
> +    /* return the old data to the function caller, avoid memory leak */
> +    ptr = s->entries[arch][key].data;
> +    s->entries[arch][key].data = data;
> +    s->entries[arch][key].len = len;
> +    s->entries[arch][key].callback_opaque = NULL;
> +    s->entries[arch][key].callback = NULL;
> +
> +    return ptr;
> +}
> +
>  void fw_cfg_add_bytes(FWCfgState *s, uint16_t key, void *data, size_t len)
>  {
>      fw_cfg_add_bytes_read_callback(s, key, NULL, NULL, data, len);
> @@ -499,13 +519,42 @@ void fw_cfg_add_file(FWCfgState *s,  const char *filename,
>      fw_cfg_add_file_callback(s, filename, NULL, NULL, data, len);
>  }
>  
> -static void fw_cfg_machine_ready(struct Notifier *n, void *data)
> +void *fw_cfg_modify_file(FWCfgState *s, const char *filename,
> +                        void *data, size_t len)
> +{
> +    int i, index;
> +
> +    assert(s->files);
> +
> +    index = be32_to_cpu(s->files->count);
> +    assert(index < FW_CFG_FILE_SLOTS);
> +
> +    for (i = 0; i < index; i++) {
> +        if (strcmp(filename, s->files->f[i].name) == 0) {
> +            return fw_cfg_modify_bytes_read(s, FW_CFG_FILE_FIRST + i,
> +                                     data, len);
> +        }
> +    }
> +    /* add new one */
> +    fw_cfg_add_file_callback(s, filename, NULL, NULL, data, len);
> +    return NULL;
> +}
> +
> +static void fw_cfg_machine_reset(void *opaque)
>  {
> +    void *ptr;
>      size_t len;
> -    FWCfgState *s = container_of(n, FWCfgState, machine_ready);
> +    FWCfgState *s = opaque;
>      char *bootindex = get_boot_devices_list(&len, false);
>  
> -    fw_cfg_add_file(s, "bootorder", (uint8_t*)bootindex, len);
> +    ptr = fw_cfg_modify_file(s, "bootorder", (uint8_t *)bootindex, len);
> +    g_free(ptr);
> +}
> +
> +static void fw_cfg_machine_ready(struct Notifier *n, void *data)
> +{
> +    FWCfgState *s = container_of(n, FWCfgState, machine_ready);
> +    qemu_register_reset(fw_cfg_machine_reset, s);
>  }
>  
>  FWCfgState *fw_cfg_init(uint32_t ctl_port, uint32_t data_port,
> diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h
> index 72b1549..56e1ed7 100644
> --- a/include/hw/nvram/fw_cfg.h
> +++ b/include/hw/nvram/fw_cfg.h
> @@ -76,6 +76,8 @@ void fw_cfg_add_file(FWCfgState *s, const char *filename, void *data,
>  void fw_cfg_add_file_callback(FWCfgState *s, const char *filename,
>                                FWCfgReadCallback callback, void *callback_opaque,
>                                void *data, size_t len);
> +void *fw_cfg_modify_file(FWCfgState *s, const char *filename, void *data,
> +                         size_t len);
>  FWCfgState *fw_cfg_init(uint32_t ctl_port, uint32_t data_port,
>                          hwaddr crl_addr, hwaddr data_addr);
>  
> 

Acked-by: Paolo Bonzini <pbonzini@redhat.com>