Re: [PATCH 0/4] arm64: Make kexec_file_load honor iomem reservations

[Catalin Marinas]

On Wed, May 26, 2021 at 08:05:27PM +0100, Marc Zyngier wrote:
> This series is a complete departure from the approach I initially sent
> almost a month ago[1]. Instead of trying to teach EFI, ACPI and other
> subsystem to use memblock, I've decided to stick with the iomem
> resource tree and use that exclusively for arm64.
> 
> This means that my current approach is (despite what I initially
> replied to both Dave and Catalin) to provide an arm64-specific
> implementation of arch_kexec_locate_mem_hole() which walks the
> resource tree and excludes ranges of RAM that have been registered for
> any odd purpose. This is exactly what the userspace implementation
> does, and I don't really see a good reason to diverge from it.
> 
> Again, this allows my Synquacer board to reliably use kexec_file_load
> with as little as 256M, something that would always fail before as it
> would overwrite most of the reserved tables.
> 
> Obviously, this is now at least 5.14 material. Given how broken
> kexec_file_load is for non-crash kernels on arm64 at the moment,
> should we at least disable it in 5.13 and all previous stable kernels?

I think it makes sense to disable it in the current and earlier kernels.

For this series:

Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>