Re: [PATCH 2/2] arm/efi: Use dom0less configuration when using EFI boot

[Luca Fancellu <luca.fancellu@arm.com>]

> On 16 Sep 2021, at 07:50, Jan Beulich <jbeulich@suse.com> wrote:
> 
> On 16.09.2021 03:16, Stefano Stabellini wrote:
>> On Wed, 15 Sep 2021, Luca Fancellu wrote:
>>> +static void __init handle_dom0less_domain_node(EFI_FILE_HANDLE dir_handle,
>>> +                                               int domain_node,
>>> +                                               int addr_cells,
>>> +                                               int size_cells)
>>> +{
>>> +    /*
>>> +     * Check for nodes compatible with multiboot,{kernel,ramdisk,device-tree}
>>> +     * inside this node
>>> +     */
>>> +    for ( int module_node = fdt_first_subnode(fdt, domain_node);
>> 
>> int module_node;
>> 
>> for ( module_node = fdt_first_subnode(fdt, domain_node);
> 
> Not just here iirc from briefly looking over the patch as a whole
> yesterday: Use of plain "int" would better be limited to cases where
> values may also be negative. I don't suppose that's possible here as
> well as in a number of other cases.

Hi Jan,

fdt_first_subnode(…) can return -FDT_ERR_NOTFOUND.

> 
>>> @@ -1285,14 +1286,21 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
>>>             efi_bs->FreePool(name.w);
>>>         }
>>> 
>>> -        if ( !name.s )
>>> -            blexit(L"No Dom0 kernel image specified.");
>>> -
>>>         efi_arch_cfg_file_early(loaded_image, dir_handle, section.s);
>>> 
>>> -        option_str = split_string(name.s);
>>> +#ifdef CONFIG_ARM
>>> +        /* dom0less feature is supported only on ARM */
>>> +        dom0less_found = check_dom0less_efi_boot(dir_handle);
>>> +#endif
>> 
>> Rather than an #ifdef here you can simply implement
>> check_dom0less_efi_boot on x86 as a static inline returning always
>> false.
> 
> Indeed, and the properly named (efi_arch_...()).

Ok, I was unsure if a solution like that was going to be accepted, I will update the code then.

Cheers,
Luca

> 
> Jan
>