Re: [PATCH v4 1/4] x86/HVM: update the start info structure layout

["Jan Beulich" <JBeulich@suse.com>]

>>> On 16.02.16 at 18:37, <roger.pau@citrix.com> wrote:
> --- a/xen/include/public/xen.h
> +++ b/xen/include/public/xen.h
> @@ -787,25 +787,46 @@ typedef struct start_info start_info_t;
>  /*
>   * Start of day structure passed to PVH guests in %ebx.
>   *
> - * NOTE: nothing will be loaded at physical address 0, so
> - * a 0 value in any of the address fields should be treated
> - * as not present.
> + * NOTE: nothing will be loaded at physical address 0, so a 0 value in any
> + * of the address fields should be treated as not present.
> + *
> + *  0 +----------------+
> + *    | magic          | Contains the magic value HVM_START_MAGIC_VALUE
> + *    |                | ("xEn3" with the 0x80 bit of the "E" set).
> + *  4 +----------------+
> + *    | version        | Version of this structure. Current version is 0. New
> + *    |                | versions are guaranteed to be backwards-compatible.
> + *  8 +----------------+
> + *    | flags          | SIF_xxx flags.
> + * 12 +----------------+
> + *    | cmdline_paddr  | Physical address of the command line,
> + *    |                | a zero-terminated ASCII string.
> + * 16 +----------------+
> + *    | nr_modules     | Number of modules passed to the kernel.
> + * 20 +----------------+
> + *    | modlist_paddr  | Physical address of an array of modules
> + *    |                | (layout of the structure below).
> + * 24 +----------------+
> + *    | rsdp_paddr     | Physical address of the RSDP ACPI data structure.
> + * 28 +----------------+
> + *
> + * The layout of each entry in the module structure is the following:
> + *
> + *  0 +----------------+
> + *    | paddr          | Physical address of the module.
> + *  8 +----------------+
> + *    | size           | Size of the module in bytes.
> + * 16 +----------------+
> + *    | cmdline_paddr  | Physical address of the command line,
> + *    |                | a zero-terminated ASCII string.
> + * 24 +----------------+
> + *    | reserved       |
> + * 32 +----------------+
> + *
> + * The address and size of the modules is a 64bit unsigned integer. However
> + * Xen will always try to place all modules below the 4GiB boundary.
>   */
> -struct hvm_start_info {
>  #define HVM_START_MAGIC_VALUE 0x336ec578
> -    uint32_t magic;             /* Contains the magic value 0x336ec578       */

I would have wanted to take the opportunity and prefix this
constant with XEN_, but I see that the tools already use it. May
I please ask for a follow-up patch to correct this name space
issue?

Jan