Re: [SeaBIOS] [PATCH v5 4/5] QEMU fw_cfg: Add functions for accessing files by key

[Igor Mammedov]

On Fri, 17 Feb 2017 22:21:58 -0800
[e-mail] wrote:
> From: Ben Warren <[e-mail]>
>
> When resuming from S3, only fw_cfg file keys are known.
> maybe something like this:

When resuming from S3 due to memory constrains fw_cfg files API
isn't available, so add simple API to get file 'key' and
write to file by using saved at boot time 'key'.

+ with Laszlo's suggestions on code consolidation

Reviewed-by: Igor Mammedov <[e-mail]>
> Signed-off-by: Ben Warren <[e-mail]>
> ---
>  src/fw/paravirt.c | 23 +++++++++++++++++++++++
>  src/fw/paravirt.h |  2 ++
>  2 files changed, 25 insertions(+)
>
> diff --git a/src/fw/paravirt.c b/src/fw/paravirt.c
> index 4618647..e513dd5 100644
> --- a/src/fw/paravirt.c
> +++ b/src/fw/paravirt.c
> @@ -352,6 +352,17 @@ qemu_cfg_write_file(void *src, struct romfile_s *file, u32 offset, u32 len)
>      return len;
>  }
>
> +// Bare-bones function for writing a file knowing only its unique
> +// identifying key (select)
> +int
> +qemu_cfg_write_file_simple(void *src, u16 key, u32 offset, u32 len)
> +{
> +    qemu_cfg_select(key);
> +    qemu_cfg_skip(offset);
> +    qemu_cfg_write(src, len);
> +    return len;
> +}
> +
>  static void
>  qemu_romfile_add(char *name, int select, int skip, int size)
>  {
> @@ -370,6 +381,18 @@ qemu_romfile_add(char *name, int select, int skip, int size)
>  }
>
> u16
> +qemu_get_romfile_key(struct romfile_s *file)
> +{
> +    struct qemu_romfile_s *qfile;
> +    qfile = container_of(file, struct qemu_romfile_s, file);
> +    if (!qfile) {
> +        warn_internalerror();
> +        return 0;
> +    }
> +    return qfile->select;
> +}
> +
> +u16
>  qemu_get_present_cpus_count(void)
>  {
>      u16 smp_count = 0;
> diff --git a/src/fw/paravirt.h b/src/fw/paravirt.h
> index fb220d8..16f3d9a 100644
> --- a/src/fw/paravirt.h
> +++ b/src/fw/paravirt.h
> @@ -56,5 +56,7 @@ void qemu_cfg_init(void);
>
> u16 qemu_get_present_cpus_count(void);
>  int qemu_cfg_write_file(void *src, struct romfile_s *file, u32 offset, u32 len);
> +int qemu_cfg_write_file_simple(void *src, u16 key, u32 offset, u32 len);
> +u16 qemu_get_romfile_key(struct romfile_s *file);
>
> #endif