Re: [PATCH] swiotlb-xen: fix DMA_ATTR_NO_KERNEL_MAPPING on arm

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 28 Apr 2022, Boris Ostrovsky wrote:
> On 4/28/22 5:49 PM, Stefano Stabellini wrote:
> > On Thu, 28 Apr 2022, Christoph Hellwig wrote:
> > > On Tue, Apr 26, 2022 at 04:07:45PM -0700, Stefano Stabellini wrote:
> > > > > Reported-by: Rahul Singh <Rahul.Singh@xxxxxxx>
> > > > > Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> > > > Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
> > > Do you want to take this through the Xen tree or should I pick it up?
> > > Either way I'd love to see some testing on x86 as well.
> > I agree on the x86 testing. Juergen, Boris?
> > 
> > I'd say to take this patch via the Xen tree but Juergen has just sent a
> > Xen pull request to Linux last Saturday. Juergen do you plan to send
> > another one? Do you have something else lined up? If not, it might be
> > better to let Christoph pick it up.
> 
> 
> We don't have anything pending.
> 
> 
> I can test it but at best tomorrow so not sure we can get this into rc5. Do
> you consider this an urgent fix or can we wait until 5.19? Because it's a bit
> too much IMO for rc6.

On one hand, Linux doesn't boot on a platform without this fix. On the
other hand, I totally see that this patch could introduce regressions on
x86 so I think it is fair that we are careful with it.

>From my point of view, it might be better to wait for 5.19 and mark it
as backport.