Re: kernel NULL pointer dereference in quirk_clear_strap_no_soft_reset_dev2_f0 -> amd_smn_read

[Marek Marczykowski-Górecki]

On Fri, Jan 30, 2026 at 12:01:06PM -0500, Yazen Ghannam wrote:
> On Tue, Jan 13, 2026 at 02:01:34AM +0100, Marek Marczykowski-Górecki wrote:
> > Hi,
> > 
> > I've got a report that kernel 6.17.9 crashes when running a Xen HVM domU
> > with AMD Raphael/Granite Ridge USB controller passed through.
> > It worked correctly in 6.12.59. Between those versions, I don't see any
> > relevant change to quirk_clear_strap_no_soft_reset_dev2_f0() function,
> > but the AMD node driver did got some changes, so my guess is one of them
> > is to blame. I know the good-bad range is huge, but there aren't that
> > many changes to the AMD node driver in this range.
> > 
> > It's running on Qubes OS 4.3, which uses Xen 4.19, and does PCI
> > passthrough of USB controllers to a dedicated VM (HVM).
> > 
> 
> Hi Marek,
> 
> Can you please test with the following patch?
> adbf61cc47cb ("x86/acpi/boot: Correct acpi_is_processor_usable() check again")
> 
> This is in the TIP maintainers repo and linux-next.

FWIW I asked[1] a week ago the original reporter to test this, but
unfortunately no feedback so far.

[1] https://forum.qubes-os.org/t/yet-another-usb-keyboard-thread/38355/20

-- 
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab

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