Re: [6.1.y] Regression from b1e6e80a1b42 ("xen/swiotlb: add alignment check for dma buffers") when booting with Xen and mpt3sas_cm0 _scsih_probe failures

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Feb 28, 2025 at 01:50:12PM +0530, Harshvardhan Jha wrote:
> 
> On 15/02/25 8:25 PM, Greg KH wrote:
> > On Sat, Feb 15, 2025 at 02:39:46PM +0100, Jürgen Groß wrote:
> >> On 15.02.25 13:34, Greg KH wrote:
> >>> On Sat, Feb 15, 2025 at 12:47:57PM +0100, Jürgen Groß wrote:
> >>>> On 12.02.25 16:12, Harshit Mogalapalli wrote:
> >>>>> Hi Salvatore,
> >>>>>
> >>>>> On 12/02/25 00:56, Salvatore Bonaccorso wrote:
> >>>>>> Hi Harshit,
> >>>>>>
> >>>>>> On Sun, Feb 09, 2025 at 01:45:38AM +0530, Harshit Mogalapalli wrote:
> >>>>>>> Hi Salvatore,
> >>>>>>>
> >>>>>>> On 08/02/25 21:26, Salvatore Bonaccorso wrote:
> >>>>>>>> Hi Juergen, hi all,
> >>>>>>>>
> >>>>>>>> Radoslav Bodó reported in Debian an issue after updating our kernel
> >>>>>>>> from 6.1.112 to 6.1.115. His report in full is at:
> >>>>>>>>
> >>>>>>>> https://bugs.debian.org/1088159
> >>>>>>>>
> >>>>>>> Note:
> >>>>>>> We have seen this on 5.4.y kernel: More details here:
> >>>>>>> https://lore.kernel.org/all/9dd91f6e-1c66-4961-994e-dbda87d69dad@oracle.com/
> >>>>>> Thanks for the pointer, so looking at that thread I suspect the three
> >>>>>> referenced bugs in Debian are in the end all releated. We have one as
> >>>>>> well relating to the megasas_sas driver, this one for the mpt3sas
> >>>>>> driver and one for the i40e driver).
> >>>>>>
> >>>>>> AFAICS, there is not yet a patch which has landed upstream which I can
> >>>>>> redirect to a affected user to test?
> >>>>>>
> >>>>> Konrad pointed me at this thread: https://lore.kernel.org/
> >>>>> all/20250211120432.29493-1-jgross@suse.com/
> >>>>>
> >>>>> This has some fixes, but not landed upstream yet.
> >>>> Patches are upstream now. In case you still experience any problems, please
> >>>> speak up.
> >>> What specific commits should be backported here?
> >> Those are:
> >>
> >> e93ec87286bd1fd30b7389e7a387cfb259f297e3
> >> 85fcb57c983f423180ba6ec5d0034242da05cc54
> > Ugh, neither of them were marked for stable inclusion, why not?  Anyway,
> > I'll go queue them up after this round of kernels is released hopefully
> > tomorrow, but next time, please follow the stable kernel rules if you
> > know you want a patch included in a tree.
> 
> 
> Hi,
> 
> I see these patches in 6.12 now and upon manually checking these patches
> cleanly apply till 6.6 kernel so I guess they will be eventually back
> ported till there?

They are already in the following released kernels:
	6.1.129 6.6.79 6.12.16 6.13.4 6.14-rc3

and the first one is in the stable queues for 5.15, 5.10, and 5.4.  The
second one is not because as you mention:

> 6.1 and older kernels have conflicts while cherry
> picking these commits which makes it harder to verify them as the test
> machine I have runs on a much older kernel(5.4) unfortunately. If it
> could be at least be brought back till 5.15, testing this would become
> much easier.

The commit does not apply cleanly there.  If you need/want it there,
please provide a working and tested backport.

thanks,

greg k-h