Re: [Xen-devel] [PATCH 1/7] libxl, Introduce dm-version xenstore key.

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Fri, 2011-10-07 at 13:10 +0100, Anthony PERARD wrote:
> The key is /local/domain/$domid/dm-version.

I've been wondering if we should introduce /libxl/$domid/ as a place for
keeping tooltack internal droppings like this. The danger with putting
stuff in /local/domain is that domains come to rely on them.

> This come with libxl__device_model_version_running helper function.
> 
> Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
> ---
>  tools/libxl/libxl_create.c   |    5 +++++
>  tools/libxl/libxl_internal.c |   19 +++++++++++++++++++
>  tools/libxl/libxl_internal.h |    5 +++++
>  3 files changed, 29 insertions(+), 0 deletions(-)
> 
> diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
> index e1e3258..3f33d90 100644
> --- a/tools/libxl/libxl_create.c
> +++ b/tools/libxl/libxl_create.c
> @@ -175,6 +175,11 @@ int libxl__domain_build(libxl__gc *gc,
>  
>      gettimeofday(&start_time, NULL);
>  
> +    localents = libxl__calloc(gc, 3, sizeof (char *));
> +    i = 0;
> +    localents[i++] = "dm-version";
> +    localents[i++] = libxl__strdup(gc, 
> libxl_device_model_version_to_string(dm_info->device_model_version));
> +

You don't seem to use this anywhere?

>      switch (info->type) {
>      case LIBXL_DOMAIN_TYPE_HVM:
>          ret = libxl__build_hvm(gc, domid, info, dm_info, state);
> diff --git a/tools/libxl/libxl_internal.c b/tools/libxl/libxl_internal.c
> index 3b8a41f..e535c0c 100644
> --- a/tools/libxl/libxl_internal.c
> +++ b/tools/libxl/libxl_internal.c
> @@ -318,3 +318,22 @@ int libxl__fd_set_cloexec(int fd)
>      }
>      return fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
>  }
> +
> +libxl_device_model_version libxl__device_model_version_running(libxl__gc *gc,
> +                                                               uint32_t 
> domid)
> +{
> +    char *path = NULL;
> +    char *dm_version = NULL;
> +    libxl_device_model_version value;
> +
> +    path = libxl__sprintf(gc, "/local/domain/%d/dm-version", domid);
> +    dm_version = libxl__xs_read(gc, XBT_NULL, path);
> +    if (!dm_version) {

This would be a bug, since it would imply an inconsistent version of
libxl was used to create the domain? (not sure what our policy around
this actually is / should be).

> +        return LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL;
> +    }
> +
> +    if (libxl_device_model_version_from_string(dm_version, &value) < 0) {
> +        return LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL;
> +    }
> +    return value;
> +}
> diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
> index 935c899..4dd0f91 100644
> --- a/tools/libxl/libxl_internal.h
> +++ b/tools/libxl/libxl_internal.h
> @@ -554,4 +554,9 @@ _hidden void libxl__json_object_free(libxl__gc *gc, 
> libxl__json_object *obj);
>  
>  _hidden libxl__json_object *libxl__json_parse(libxl__gc *gc, const char *s);
>  
> +  /* Based on /local/domain/$domid/dm-version xenstore key
> +   * default is qemu xen traditional */
> +_hidden libxl_device_model_version
> +libxl__device_model_version_running(libxl__gc *gc, uint32_t domid);
> +
>  #endif



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