Re: [PATCH 2/2] make ioremap_wc() x86 only (for the time being)

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

On 2/19/26 4:53 PM, Jan Beulich wrote:
> Its use in domain building is questionable: Already at the point both uses
> were introduced, ioremap_cache() existed. I can't see why kernel and
> initrd would need mapping WC, when at the same time other similar mappings
> (in common/device-tree/) are done WB.
>
> With those uses replaced, neither Arm nor RISC-V have a need for the
> function anymore.
It is okay for RISC-V, but for Arm, IIRC, likely it was done because 
guest might start with cache disabled and PAGE_HYPERVISOR_WC on Arm uses 
"Normal Non-cacheable" what could lead to that guest won't see some part 
of kernel and/or initrd as it could be in a cache and won't be flushed 
to RAM.
But probably I misremembered something and 
clean_and_invalidate_dcache_va_range() or something similar should be 
called before guest is laucned.
For RISC-V part,
 Reviewed-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>

Thanks.

~ Oleksii