Re: [Xen-devel] Xen >4.10 bricks onboard NIC of Dell Optiplex 7060

[Jan Beulich <jbeulich@xxxxxxxx>]

On 27.10.2019 17:09,  Bell, Oren  wrote:
> I've encountered an issue where installing Xen >4.10 on a Dell Optiplex will 
> break the onboard NIC. This issue persists if the computer is booted without 
> Xen, after OS reinstall, and even if removing the SSD and HDD completely to 
> boot from a LiveUSB. The only way to fix the issue is to install Windows 10 
> on the machine. This appears to "fix" the firmware of the NIC. After 
> reinstalling Ubuntu, the NIC continues to work (until Xen is installed again).
> 
> This bug was confirmed with both Xen 4.10 and 4.12 installed on Ubuntu 18.04.
> 
> If this is a known issue, is there some "in-work patch" I can be pointed to?

This is a rather strange problem you're facing - Xen itself doesn't
do anything to NICs. Therefore I'm afraid some more experimenting
may be needed to somehow narrow where things go wrong. In particular
I'd be curious to understand whether it's indeed Xen that breaks
things, or whether e.g. other software misbehaves if run on top of
Xen. As a first step, could you boot
- Xen without a Dom0 kernel,
- Xen with a Dom0 kernel, but without a driver for the NIC,
- Xen with a Dom0 kernel and with a driver for the NIC, but without
  actually configuring/using the NIC?
Could you further check whether Xen using the presumably present
IOMMU matters? (Providing maximum verbosity hypervisor and kernel
logs would of course also help, in particular e.g. to know whether
there is an IOMMU in the system, and also to see whether any
anomalies get logged.)

Jan

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel