Re: [PATCH v10 10/15] fw_cfg: add "modify" functions for all types

["Marc-André Lureau" <marcandre.lureau@gmail.com>]

On Wed, Oct 16, 2019 at 12:22 PM Sergio Lopez <slp@redhat.com> wrote:
>
> This allows to alter the contents of an already added item.
>
> Signed-off-by: Sergio Lopez <slp@redhat.com>
> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

Used to fix kernel command line in following patch "hw/i386: Introduce
the microvm machine type", except fw_cfg_modify_i64().


Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>


> ---
>  include/hw/nvram/fw_cfg.h | 42 +++++++++++++++++++++++++++++++++++++++
>  hw/nvram/fw_cfg.c         | 29 +++++++++++++++++++++++++++
>  2 files changed, 71 insertions(+)
>
> diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h
> index 80e435d303..b5291eefad 100644
> --- a/include/hw/nvram/fw_cfg.h
> +++ b/include/hw/nvram/fw_cfg.h
> @@ -98,6 +98,20 @@ void fw_cfg_add_bytes(FWCfgState *s, uint16_t key, void *data, size_t len);
>   */
>  void fw_cfg_add_string(FWCfgState *s, uint16_t key, const char *value);
>
> +/**
> + * fw_cfg_modify_string:
> + * @s: fw_cfg device being modified
> + * @key: selector key value for new fw_cfg item
> + * @value: NUL-terminated ascii string
> + *
> + * Replace the fw_cfg item available by selecting the given key. The new
> + * data will consist of a dynamically allocated copy of the provided string,
> + * including its NUL terminator. The data being replaced, assumed to have
> + * been dynamically allocated during an earlier call to either
> + * fw_cfg_add_string() or fw_cfg_modify_string(), is freed before returning.
> + */
> +void fw_cfg_modify_string(FWCfgState *s, uint16_t key, const char *value);
> +
>  /**
>   * fw_cfg_add_i16:
>   * @s: fw_cfg device being modified
> @@ -136,6 +150,20 @@ void fw_cfg_modify_i16(FWCfgState *s, uint16_t key, uint16_t value);
>   */
>  void fw_cfg_add_i32(FWCfgState *s, uint16_t key, uint32_t value);
>
> +/**
> + * fw_cfg_modify_i32:
> + * @s: fw_cfg device being modified
> + * @key: selector key value for new fw_cfg item
> + * @value: 32-bit integer
> + *
> + * Replace the fw_cfg item available by selecting the given key. The new
> + * data will consist of a dynamically allocated copy of the given 32-bit
> + * value, converted to little-endian representation. The data being replaced,
> + * assumed to have been dynamically allocated during an earlier call to
> + * either fw_cfg_add_i32() or fw_cfg_modify_i32(), is freed before returning.
> + */
> +void fw_cfg_modify_i32(FWCfgState *s, uint16_t key, uint32_t value);
> +
>  /**
>   * fw_cfg_add_i64:
>   * @s: fw_cfg device being modified
> @@ -148,6 +176,20 @@ void fw_cfg_add_i32(FWCfgState *s, uint16_t key, uint32_t value);
>   */
>  void fw_cfg_add_i64(FWCfgState *s, uint16_t key, uint64_t value);
>
> +/**
> + * fw_cfg_modify_i64:
> + * @s: fw_cfg device being modified
> + * @key: selector key value for new fw_cfg item
> + * @value: 64-bit integer
> + *
> + * Replace the fw_cfg item available by selecting the given key. The new
> + * data will consist of a dynamically allocated copy of the given 64-bit
> + * value, converted to little-endian representation. The data being replaced,
> + * assumed to have been dynamically allocated during an earlier call to
> + * either fw_cfg_add_i64() or fw_cfg_modify_i64(), is freed before returning.
> + */
> +void fw_cfg_modify_i64(FWCfgState *s, uint16_t key, uint64_t value);
> +
>  /**
>   * fw_cfg_add_file:
>   * @s: fw_cfg device being modified
> diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
> index 7dc3ac378e..aef1727250 100644
> --- a/hw/nvram/fw_cfg.c
> +++ b/hw/nvram/fw_cfg.c
> @@ -690,6 +690,15 @@ void fw_cfg_add_string(FWCfgState *s, uint16_t key, const char *value)
>      fw_cfg_add_bytes(s, key, g_memdup(value, sz), sz);
>  }
>
> +void fw_cfg_modify_string(FWCfgState *s, uint16_t key, const char *value)
> +{
> +    size_t sz = strlen(value) + 1;
> +    char *old;
> +
> +    old = fw_cfg_modify_bytes_read(s, key, g_memdup(value, sz), sz);
> +    g_free(old);
> +}
> +
>  void fw_cfg_add_i16(FWCfgState *s, uint16_t key, uint16_t value)
>  {
>      uint16_t *copy;
> @@ -720,6 +729,16 @@ void fw_cfg_add_i32(FWCfgState *s, uint16_t key, uint32_t value)
>      fw_cfg_add_bytes(s, key, copy, sizeof(value));
>  }
>
> +void fw_cfg_modify_i32(FWCfgState *s, uint16_t key, uint32_t value)
> +{
> +    uint32_t *copy, *old;
> +
> +    copy = g_malloc(sizeof(value));
> +    *copy = cpu_to_le32(value);
> +    old = fw_cfg_modify_bytes_read(s, key, copy, sizeof(value));
> +    g_free(old);
> +}
> +
>  void fw_cfg_add_i64(FWCfgState *s, uint16_t key, uint64_t value)
>  {
>      uint64_t *copy;
> @@ -730,6 +749,16 @@ void fw_cfg_add_i64(FWCfgState *s, uint16_t key, uint64_t value)
>      fw_cfg_add_bytes(s, key, copy, sizeof(value));
>  }
>
> +void fw_cfg_modify_i64(FWCfgState *s, uint16_t key, uint64_t value)
> +{
> +    uint64_t *copy, *old;
> +
> +    copy = g_malloc(sizeof(value));
> +    *copy = cpu_to_le64(value);
> +    old = fw_cfg_modify_bytes_read(s, key, copy, sizeof(value));
> +    g_free(old);
> +}
> +
>  void fw_cfg_set_order_override(FWCfgState *s, int order)
>  {
>      assert(s->fw_cfg_order_override == 0);
> --
> 2.21.0
>
>


--
Marc-André Lureau