Re: [PATCH v2 13/13] SUPPORT.md: write down restriction of 32-bit tool stacks

[Julien Grall <julien@xxxxxxx>]

Hi Jan,

On 05/07/2021 16:18, Jan Beulich wrote:
> Let's try to avoid giving the impression that 32-bit tool stacks are as
> capable as 64-bit ones.
Would you be able to provide a few examples of the known issues in the 
commit message? This would be helpful for anyone to understand why we 
decided to drop the support.
At least on Arm, we tried to design the hypercall ABI in such a way that 
it should be possible to use a 32-bit toolstack.
That said, I am not aware of anyone using the 32-bit ABI on 64-bit Arm 
hypervisor. So dropping the support should be fine.
Cheers,

> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> ---
> v2: Wording adjustments as per review discussion.
>
> --- a/SUPPORT.md
> +++ b/SUPPORT.md
> @@ -131,6 +131,12 @@ ARM only has one guest type at the momen
>   
>   ## Toolstack
>   
> +While 32-bit builds of the tool stack are generally supported, restrictions
> +apply in particular when running on top of a 64-bit hypervisor.  For example,
> +very large guests aren't expected to be manageable in this case.  This includes
> +guests giving the appearance of being large, by altering their own memory
> +layouts.
> +
>   ### xl
>   
>       Status: Supported
--
Julien Grall