Re: [PATCH v1 2/4] xen: arm: make VMAP only support in MMU system

[Julien Grall <julien@xxxxxxx>]

Hi,

On 02/08/2024 13:14, Ayan Kumar Halder wrote:
> From: Penny Zheng <penny.zheng@xxxxxxx>
>
> VMAP is widely used in ALTERNATIVE feature, CPUERRATA feature, etc to
> remap a range of memory with new memory attributes. Since this is
> highly dependent on virtual address translation, we choose to fold VMAP
> in MMU system.
>
> In this patch, we introduce a new Kconfig CONFIG_HAS_VMAP, and make it
> only support in MMU system on ARM architecture. And we make features
> like ALTERNATIVE, CPUERRATA, etc, now depend on VMAP.
While I agree that alternative should depend on VMAP (for now), I feel 
this is incorrect for CPUERRATA. Very likely, you will need to deal with 
them on the MPU.
Before making any suggestion, would you be able to clarify how you 
envision to deal with errata? Will they be selected at built time or 
boot time?
Cheers,

--
Julien Grall