Subject: Re: [PATCH v6 04/25] iommu/arm-smmu-v3: Move TLB range invalidation into common code

From: Jason Gunthorpe <[email-masked]>
Date: Tue, 5 May 2026 13:17:09 -0300

On Mon, May 04, 2026 at 12:15:17PM +0000, Mostafa Saleh wrote:

> I am not sure if it’s worth it, the hypervisor is much simpler, there
> is a single page table, it’s locked (also identity mapped), it’s
> updated on VM boot/teardown only, we don’t even use iotlb_gather at
> the moment, although possible but I wanted to keep this series as
> simple as I can then we can add more features later.
> So this patch is the least intrusive change, as whatever the main SMMUv3
> driver does, the range tlb invalidation logic is the same.
> But I am happy to experiment with that when posted.

Okay, then maybe just always push a full invalidation?

I didn't like seeing the range invalidation lifted out, especially how
ugly that will turn into after my next series. So, don't use range or
use the proper full gather flow seem like the right two options.

I'm not so interested in minimal change, but maximum forward
maintainability. It is much easier to manage if you double compile
more of the driver exactly the same, and call functions in a fairly
normal way vs make special cases and special functions..

Jason