Re: Hang booting Dom0: nvme timeout, completion polled

[Tom Li <tomli@xxxxxxxx>]

On Wed, Mar 15, 2023 at 07:22:49PM +0000, Jan Kellermann wrote:
> The host is hanging on:
> nvme nvme0: I/O 0 QID 0 timeout, completion polled
> nvme nvme1: I/O 8 QID 0 timeout, completion polled
> 
> Can anyone give hints for solving this problem?
> 
> Best regards and thank you in advance,
> Jan Kellermann

I've experienced the same problem on a X399 motherboard with Ryzen 5000
(Zen 3). Apparently, malfunctional IOMMU is currently is a systematic
issue on AMD Ryzen with Xen - it really should be reported as an upstream
bug, if nobody has done it yet - I was able to solve it by disabling SMT
(hyperthreading) in BIOS [1].

If SMT is still needed, another suggested solution by QubesOS users [2]
(which uses the Xen hypervisor) is booting Dom0 with the following
Linux kernel parameters:

    dom0_max_vcpus=1 dom0_vcpus_pin

This allocates one CPU to Dom0 exclusively [3] - although I haven't tested
it personally.

Cheers,
Tom Li

[1] https://github.com/QubesOS/qubes-issues/issues/8136

[2] https://forum.qubes-os.org/t/gpd-win-max-2-unable-to-boot-installer/14466/14

[3] https://wiki.xenproject.org/wiki/Xen_FAQ_Dom0