Re: [PATCH v2 8/8] xen/arm: Add support for SMMUv3 driver

[Julien Grall <julien@xxxxxxx>]

On 09/12/2020 07:55, Bertrand Marquis wrote:
> Hi,
Hi,

> I also agree with the issue on the spinlock but we have no equivalent of 
> something
> looking like a mutex for now in Xen so this would require some major redesign 
> and
> will take us far from the linux driver.
I agree that keeping the Xen implementation close to the Linux one is 
important. However, I view this has a the secondary goal. The primary 
goal is to have a safe and secure driver.
If it means introducing a new set of lock or diverging from Linux, then 
so it be.
> I would suggest to add a comment before this part of the code with a “TODO” so 
> that
> it is clear inside the code.
> We could also add some comment in Kconfig to mention this possible “faulty” 
> behaviour.
I think it would be enough to write in the Kconfig that the driver is 
"experimental and should not be used in production".
Ideally, I would like a list of known issues for the driver (could be in 
the cover letter or/and at the top of the source file) so we can track 
what's missing to get it supported.
Cheers,

--
Julien Grall