Re: [regression]Boot Hang on Kernel 6.1.83+ with Dell PowerEdge R770 and Intel Xeon 6710E

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Oct 14, 2024 at 11:39:57AM +0200, Jinpu Wang wrote:
> Hi Greg,
> 
> 
> On Fri, Oct 11, 2024 at 7:22 AM Jinpu Wang <jinpu.wang@ionos.com> wrote:
> >
> > Hi Baolu, Liang
> >
> > Thanks for the reply.
> >
> > On Thu, Oct 10, 2024 at 4:01 PM Baolu Lu <baolu.lu@linux.intel.com> wrote:
> > >
> > > On 2024/10/10 21:25, Liang, Kan wrote:
> > > > On 2024-10-10 6:10 a.m., Jinpu Wang wrote:
> > > >> Hi Greg,
> > > >>
> > > >>
> > > >> On Thu, Oct 10, 2024 at 11:31 AM Greg KH<gregkh@linuxfoundation.org> wrote:
> > > >>> On Thu, Oct 10, 2024 at 11:13:42AM +0200, Jinpu Wang wrote:
> > > >>>> Hi Greg,
> > > >>>>
> > > >>>> On Thu, Oct 10, 2024 at 11:07 AM Greg KH<gregkh@linuxfoundation.org> wrote:
> > > >>>>> On Thu, Oct 10, 2024 at 09:31:37AM +0200, Jinpu Wang wrote:
> > > >>>>>> Hello all,
> > > >>>>>>
> > > >>>>>> We are experiencing a boot hang issue when booting kernel version
> > > >>>>>> 6.1.83+ on a Dell Inc. PowerEdge R770 equipped with an Intel Xeon
> > > >>>>>> 6710E processor. After extensive testing and use of `git bisect`, we
> > > >>>>>> have traced the issue to commit:
> > > >>>>>>
> > > >>>>>> `586e19c88a0c ("iommu/vt-d: Retrieve IOMMU perfmon capability information")`
> > > >>>>>>
> > > >>>>>> This commit appears to be part of a larger patchset, which can be found here:
> > > >>>>>> [Patchset on lore.kernel.org](https://lore.kernel.org/
> > > >>>>>> lkml/7c4b3e4e-1c5d-04f1-1891-84f686c94736@linux.intel.com/T/)
> > > >>>>>>
> > > >>>>>> We attempted to boot with the `intel_iommu=off` option, but the system
> > > >>>>>> hangs in the same manner. However, the system boots successfully after
> > > >>>>>> disabling `CONFIG_INTEL_IOMMU_PERF_EVENTS`.
> > > >>>>> Is there any error messages?  Does the latest 6.6.y tree work properly?
> > > >>>>> If so, why not just use that, no new hardware should be using older
> > > >>>>> kernel trees anyway 🙂
> > > >>>> No error, just hang, I've removed "quiet" and added "debug".
> > > >>>> Yes, the latest 6.6.y tree works for this, but there are other
> > > >>>> problems/dependency we have to solve.
> > > >>> Ok, that implies that we need to add some other patch to 6.1.y, OR we
> > > >>> can revert it from 6.1.y.  Let me know what you think is the better
> > > >>> thing to do.
> > > >>>
> > > >> I think better to revert both:
> > > >> 8c91a4bfc7f8 ("iommu: Fix compilation without CONFIG_IOMMU_INTEL")
> > > > I'm not sure about this one. May need baolu's comments.
> > >
> > > I can't find this commit in the mainline kernel. I guess it fixes a
> > > compilation issue in the stable tree? If so, it depends on whether the
> > > issue is still there.
> > >
> > > Thanks,
> > > baolu
> >
> > Both commits are hash from stable tree for linux-6.1.y branch.
> > I tried only revert  586e19c88a0c ("iommu/vt-d: Retrieve IOMMU perfmon
> > capability information")
> >
> > There is a minor conflict in the Makefile, but it's easy to fix. I
> > attached the patch below,
> > Greg please consider including it.
> >
> > Thx!
> I'm attaching the revert here again, maybe you missed the email,
> please consider to include it in 6.1.y.

I did miss that, sorry, now queued up!

greg k-h