Re: [PATCH v4 08/13] x86/hyperlaunch: locate dom0 initrd with hyperlaunch

[dmkhn@xxxxxxxxx]

On Thu, Apr 17, 2025 at 01:48:30PM +0100, Alejandro Vallejo wrote:
> From: "Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx>
> 
> Look for a subnode of type `multiboot,ramdisk` within a domain node and
> parse via the fdt_read_multiboot_module() helper. After a successful
> helper call, the module index is returned and the module is guaranteed
> to be in the module list.
> 
> Fix unused typo in adjacent comment.
> 
> Signed-off-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Jason Andryuk <jason.andryuk@xxxxxxx>
> Signed-off-by: Alejandro Vallejo <agarciav@xxxxxxx>
> ---
> v4:
>   * s/XENLOG_ERR/XENLOG_WARNING/ on duplicate ramdisk.
>   * Removed stray ")" in printk
>   * s/else if/if/ (because of continue)
>   * Removed trailing continue
> ---
>  xen/arch/x86/setup.c            |  4 ++--
>  xen/common/domain-builder/fdt.c | 25 +++++++++++++++++++++++++
>  2 files changed, 27 insertions(+), 2 deletions(-)
> 
> diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
> index 4cae13163b..76ceb5221f 100644
> --- a/xen/arch/x86/setup.c
> +++ b/xen/arch/x86/setup.c
> @@ -2150,11 +2150,11 @@ void asmlinkage __init noreturn __start_xen(void)
>       * At this point all capabilities that consume boot modules should have
>       * claimed their boot modules. Find the first unclaimed boot module and
>       * claim it as the initrd ramdisk. Do a second search to see if there are
> -     * any remaining unclaimed boot modules, and report them as unusued 
> initrd
> +     * any remaining unclaimed boot modules, and report them as unused initrd
>       * candidates.
>       */
>      initrdidx = first_boot_module_index(bi, BOOTMOD_UNKNOWN);
> -    if ( initrdidx < MAX_NR_BOOTMODS )
> +    if ( !bi->hyperlaunch_enabled && initrdidx < MAX_NR_BOOTMODS )
>      {
>          bi->mods[initrdidx].type = BOOTMOD_RAMDISK;
>          bi->domains[0].module = &bi->mods[initrdidx];
> diff --git a/xen/common/domain-builder/fdt.c b/xen/common/domain-builder/fdt.c
> index 50fde2d007..c0f526a4ce 100644
> --- a/xen/common/domain-builder/fdt.c
> +++ b/xen/common/domain-builder/fdt.c
> @@ -216,6 +216,31 @@ static int __init process_domain_node(
>                  bd->kernel->fdt_cmdline = fdt_get_prop_offset(
>                      fdt, node, "bootargs", &bd->kernel->cmdline_pa);
>          }
> +        else if ( !fdt_node_check_compatible(fdt, node, "multiboot,ramdisk") 
> )
> +        {
> +            int idx;
> +
> +            if ( bd->module )
> +            {
> +                printk(XENLOG_WARNING
> +                       "Duplicate module for domain %s\n", name);
> +                continue;
> +            }
> +
> +            idx = fdt_read_multiboot_module(fdt, node, address_cells,
> +                                            size_cells, bi);
> +            if ( idx < 0 )
> +            {
> +                printk(XENLOG_ERR
> +                       "  failed processing module for domain %s\n",
> +                       name);
> +                return -EINVAL;

Propagate fdt_read_multiboot_module()'s error to the caller, i.e.:

                   return idx;

?

> +            }
> +
> +            printk(XENLOG_INFO "  module: multiboot-index=%d\n", idx);
> +            bi->mods[idx].type = BOOTMOD_RAMDISK;
> +            bd->module = &bi->mods[idx];
> +        }
>      }
> 
>      if ( !bd->kernel )
> --
> 2.43.0
> 
>