Re: [PATCH v5 5/8] xl/libxl: add a blkdev_start parameter

[Ian Campbell <Ian.Campbell@citrix.com>]

On Fri, 2012-05-04 at 12:13 +0100, Stefano Stabellini wrote:
> Introduce a blkdev_start in xl.conf and a corresponding string in
> libxl_domain_build_info.
> 
> Add a blkdev_start parameter to libxl__device_disk_local_attach: it is
> going to be used in a following patch.
> 
> blkdev_start specifies the first block device to be used for temporary
> block device allocations by the toolstack.
> 
> Changes in v5:
> - change the type of the blkdev_start parameter to
> libxl__device_disk_local_attach to const char *.
> 
> Changes in v4:
> - pass blkdev_start in libxl_domain_build_info.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  tools/examples/xl.conf         |    3 +++
>  tools/libxl/libxl_bootloader.c |    3 ++-
>  tools/libxl/libxl_create.c     |    3 +++
>  tools/libxl/libxl_internal.c   |    3 ++-
>  tools/libxl/libxl_internal.h   |    3 ++-
>  tools/libxl/libxl_types.idl    |    1 +
>  tools/libxl/xl.c               |    3 +++
>  tools/libxl/xl.h               |    1 +
>  tools/libxl/xl_cmdimpl.c       |    2 ++
>  9 files changed, 19 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/examples/xl.conf b/tools/examples/xl.conf
> index 56d3b3b..ebf057c 100644
> --- a/tools/examples/xl.conf
> +++ b/tools/examples/xl.conf
> @@ -12,3 +12,6 @@
>  
>  # default output format used by "xl list -l"
>  #output_format="json"
> +
> +# first block device to be used for temporary VM disk mounts
> +#blkdev_start="xvda"

Need a patch to docs/man/xl.conf.pod.5 as well. If you add that then:
Acked-by: Ian Campbell <ian.campbell@citrix.com>


I suppose this is necessarily Linux specific and we'll need a patch from
the BSD folks?

> diff --git a/tools/libxl/libxl_bootloader.c b/tools/libxl/libxl_bootloader.c
> index 83cac78..123b06e 100644
> --- a/tools/libxl/libxl_bootloader.c
> +++ b/tools/libxl/libxl_bootloader.c
> @@ -387,7 +387,8 @@ int libxl_run_bootloader(libxl_ctx *ctx,
>          goto out_close;
>      }
>  
> -    diskpath = libxl__device_disk_local_attach(gc, disk, &tmpdisk);
> +    diskpath = libxl__device_disk_local_attach(gc, disk, &tmpdisk,
> +            info->blkdev_start);
>      if (!diskpath) {
>          rc = ERROR_FAIL;
>          goto out_close;
> diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
> index 7ab2f72..f2fcdf0 100644
> --- a/tools/libxl/libxl_create.c
> +++ b/tools/libxl/libxl_create.c
> @@ -107,6 +107,9 @@ int libxl__domain_build_info_setdefault(libxl__gc *gc,
>          }
>      }
>  
> +    if (b_info->blkdev_start == NULL)
> +        b_info->blkdev_start = strdup("xvda");
> +
>      if (b_info->type == LIBXL_DOMAIN_TYPE_HVM) {
>          if (!b_info->u.hvm.bios)
>              switch (b_info->device_model_version) {
> diff --git a/tools/libxl/libxl_internal.c b/tools/libxl/libxl_internal.c
> index 1bf5d73..bd5ebb3 100644
> --- a/tools/libxl/libxl_internal.c
> +++ b/tools/libxl/libxl_internal.c
> @@ -482,7 +482,8 @@ out:
>  
>  char * libxl__device_disk_local_attach(libxl__gc *gc,
>          const libxl_device_disk *in_disk,
> -        libxl_device_disk **new_disk)
> +        libxl_device_disk **new_disk,
> +        const char *blkdev_start)
>  {
>      libxl_ctx *ctx = gc->owner;
>      char *dev = NULL;
> diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
> index 096c96d..0074ec4 100644
> --- a/tools/libxl/libxl_internal.h
> +++ b/tools/libxl/libxl_internal.h
> @@ -1015,7 +1015,8 @@ _hidden int libxl__device_disk_add(libxl__gc *gc, uint32_t domid,
>   */
>  _hidden char * libxl__device_disk_local_attach(libxl__gc *gc,
>          const libxl_device_disk *in_disk,
> -        libxl_device_disk **new_disk);
> +        libxl_device_disk **new_disk,
> +        const char *blkdev_start);
>  _hidden int libxl__device_disk_local_detach(libxl__gc *gc,
>          libxl_device_disk *disk);
>  
> diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
> index 68599cb..7131696 100644
> --- a/tools/libxl/libxl_types.idl
> +++ b/tools/libxl/libxl_types.idl
> @@ -253,6 +253,7 @@ libxl_domain_build_info = Struct("domain_build_info",[
>      ("localtime",       libxl_defbool),
>      ("disable_migrate", libxl_defbool),
>      ("cpuid",           libxl_cpuid_policy_list),
> +    ("blkdev_start",    string),
>      
>      ("device_model_version", libxl_device_model_version),
>      ("device_model_stubdomain", libxl_defbool),
> diff --git a/tools/libxl/xl.c b/tools/libxl/xl.c
> index a6ffd25..4596c4f 100644
> --- a/tools/libxl/xl.c
> +++ b/tools/libxl/xl.c
> @@ -35,6 +35,7 @@
>  xentoollog_logger_stdiostream *logger;
>  int dryrun_only;
>  int autoballoon = 1;
> +char *blkdev_start;
>  char *lockfile;
>  char *default_vifscript = NULL;
>  char *default_bridge = NULL;
> @@ -91,6 +92,8 @@ static void parse_global_config(const char *configfile,
>              fprintf(stderr, "invalid default output format \"%s\"\n", buf);
>          }
>      }
> +    if (!xlu_cfg_get_string (config, "blkdev_start", &buf, 0))
> +        blkdev_start = strdup(buf);
>      xlu_cfg_destroy(config);
>  }
>  
> diff --git a/tools/libxl/xl.h b/tools/libxl/xl.h
> index f0d0ec8..3fbe14d 100644
> --- a/tools/libxl/xl.h
> +++ b/tools/libxl/xl.h
> @@ -112,6 +112,7 @@ extern int dryrun_only;
>  extern char *lockfile;
>  extern char *default_vifscript;
>  extern char *default_bridge;
> +extern char *blkdev_start;
>  
>  enum output_format {
>      OUTPUT_FORMAT_JSON,
> diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
> index 28f5cab..7338562 100644
> --- a/tools/libxl/xl_cmdimpl.c
> +++ b/tools/libxl/xl_cmdimpl.c
> @@ -595,6 +595,8 @@ static void parse_config_data(const char *configfile_filename_report,
>      }
>  
>      libxl_domain_build_info_init_type(b_info, c_info->type);
> +    if (blkdev_start)
> +        b_info->blkdev_start = strdup(blkdev_start);
>  
>      /* the following is the actual config parsing with overriding values in the structures */
>      if (!xlu_cfg_get_long (config, "cpu_weight", &l, 0))