Re: CURRENT- and vmd(8): Panic upon bootup with recent HEAD

From: Warner Losh <imp_at_bsdimp.com>
Date: Sun, 04 Jul 2021 22:17:48 UTC
On Sun, Jul 4, 2021 at 3:13 PM Neel Chauhan <neel@neelc.org> wrote:

> Hi freebsd-current@ (CC'd ambrisko@ and imp@),
>
> Right now, with a laptop (HP Spectre x360 13t-aw200) which needs the
> vmd(8) driver for NVMe, I am getting kernel panics upon bootup with a
> recent kernel.
>
> Here's a screenshot of the panic:
> https://bz-attachments.freebsd.org/attachment.cgi?id=226185 (blurry
> since I took it on the plane)
>
> The bug is here:
> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=256915
>
> If I use an older kernel (which I'm doing for now), it works fine. If I
> use the memstick USB, it crashes with the same panic.
>
> I initially thought it was commit
> ddfc9c4c59e2ea4871100d8c076adffe3af8ff21, but even when I reverted to
> one before the said commit, it still panicked with the same error.
>
> I don't see any changes to vmd(8), so changes to some other PC subsystem
> (PCI/ACPI/x86/NVMe/etc.) after commit
> ab6d05336caaa10ae315f81534851e3764a8660c (current kernel commit) must
> have caused the error.
>

Have you used 'git bisect' yet? It looks like there's only about 244
commits between
last known working and the known broken commit of mine....

The panic is because we're trying to get the pci attributes of a non-pci
device and
an assertion is failing.

Warner