Re: [PATCH 6/7] x86/kexec: Pass boot params directly to new kernel

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 09/06/2026 4:45 pm, Kevin Lampis wrote:
> diff --git a/xen/arch/x86/machine_kexec.c b/xen/arch/x86/machine_kexec.c
> index f921eec5aa..2edc1bd0af 100644
> --- a/xen/arch/x86/machine_kexec.c
> +++ b/xen/arch/x86/machine_kexec.c
> @@ -198,7 +198,8 @@ void machine_kexec(struct kexec_image *image)
>  
>      kexec_reloc(page_to_maddr(image->control_code_page),
>                  page_to_maddr(image->aux_page),
> -                image->head, image->entry_maddr, reloc_flags);
> +                image->head, image->entry_maddr, reloc_flags,
> +                image->boot_params);

With this in context, the field really ought to be named entry_arg.

Linux boot_params is just one possible option (even if it is the only
option right now).

>  }
>  
>  int machine_kexec_get(xen_kexec_range_t *range)
> diff --git a/xen/arch/x86/x86_64/kexec_reloc.S 
> b/xen/arch/x86/x86_64/kexec_reloc.S
> index b52d31a654..6a2c839b83 100644
> --- a/xen/arch/x86/x86_64/kexec_reloc.S
> +++ b/xen/arch/x86/x86_64/kexec_reloc.S
> @@ -33,6 +33,7 @@ FUNC(kexec_reloc, PAGE_SIZE)
>          /* %rdx - indirection page maddr */
>          /* %rcx - entry maddr (%rbp) */
>          /* %r8 - flags */
> +        /* %r9 - boot params */
>  
>          movq    %rcx, %rbp
>  
> @@ -71,6 +72,8 @@ FUNC(kexec_reloc, PAGE_SIZE)
>          movq    %rdx, %rdi
>          call    relocate_pages
>  
> +        movq %r9, %rsi /* boot params */
> +

The surrounding code has not been cleaned up to Xen style yet.  This
should be:

        mov     %r9, %rsi /* entry_arg */

~Andrew