Re: Problems starting Xen domU after latest stable update

From: Jürgen Groß
Date: Fri Jan 29 2021 - 00:27:15 EST


On 29.01.21 01:51, Marek Marczykowski-Górecki wrote:
On Thu, Jan 28, 2021 at 07:03:00PM -0500, Boris Ostrovsky wrote:

On 1/28/21 6:52 PM, Michael D Labriola wrote:
Hey, everyone. I've run into problems starting up my Xen domUs as of
the latest batch of stable updates. Whenever I try to create one, I
get a bunch of block device errors like this:

libxl: error: libxl_device.c:1105:device_backend_callback: Domain 4:unable to add device with path /local/domain/0/backend/vbd/4/51712
libxl: error: libxl_device.c:1105:device_backend_callback: Domain 4:unable to add device with path /local/domain/0/backend/vbd/4/51728
libxl: error: libxl_device.c:1105:device_backend_callback: Domain 4:unable to add device with path /local/domain/0/backend/vbd/4/51744
libxl: error: libxl_device.c:1105:device_backend_callback: Domain 4:unable to add device with path /local/domain/0/backend/vbd/4/51760
libxl: error: libxl_device.c:1105:device_backend_callback: Domain 4:unable to add device with path /local/domain/0/backend/vbd/4/51776
libxl: error: libxl_create.c:1452:domcreate_launch_dm: Domain 4:unable to add disk devices
libxl: error: libxl_device.c:1105:device_backend_callback: Domain 4:unable to remove device with path /local/domain/0/backend/vbd/4/51712
libxl: error: libxl_device.c:1105:device_backend_callback: Domain 4:unable to remove device with path /local/domain/0/backend/vbd/4/51728
libxl: error: libxl_device.c:1105:device_backend_callback: Domain 4:unable to remove device with path /local/domain/0/backend/vbd/4/51744
libxl: error: libxl_device.c:1105:device_backend_callback: Domain 4:unable to remove device with path /local/domain/0/backend/vbd/4/51760
libxl: error: libxl_device.c:1105:device_backend_callback: Domain 4:unable to remove device with path /local/domain/0/backend/vbd/4/51776
libxl: error: libxl_domain.c:1290:devices_destroy_cb: Domain 4:libxl__devices_destroy failed
libxl: error: libxl_domain.c:1177:libxl__destroy_domid: Domain 4:Non-existant domain
libxl: error: libxl_domain.c:1131:domain_destroy_callback: Domain 4:Unable to destroy guest
libxl: error: libxl_domain.c:1058:domain_destroy_cb: Domain 4:Destruction of domain failed

I'm using Xen 4.13.1 on the box I've been testing with.

I bisected down to this commit, and reverting it does indeed fix my
problem. Well, this commit upstream and it's cherry-picked variants
on linux-5.4.y and linux-5.10.y.


You most likely need 5f46400f7a6a4fad635d5a79e2aa5a04a30ffea1. It hit Linus tree a few hours ago.

I can confirm this fixes the same issue for me (too?), thanks!
Shouldn't this patch have Cc: stable?

No, I don't think so.

The issue being fixed by the patch has been introduced only in 5.11
and the fixing patch references the buggy patch via a Fixes: tag.

If the buggy patch has been put into stable this Fixes: tag should
result in the fix being put into the same stable branches as well.


Juergen

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