[Pkg-xen-devel] Request for patch to fix boot loop issue in Xen 4.17.6

[Andrew Cooper]

On 18/05/2025 12:24 pm, Maximilian Engelhardt wrote:
> On Montag, 12. Mai 2025 10:54:50 CEST Jan Beulich wrote:
>> On 03.05.2025 16:02, Ngamia Djabiri Julie wrote:
>>> Dear Xen developers,
>>>
>>> I would like to ask if the following fix can also be included in Xen
>>> 4.17.6 (and eventually in the Xen versions after 4.17.6 that don't have
>>> the fix) :
>>>
>>> https://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=dd05d265b8abda4cc
>>> 7206b29cd71b77fb46658bf
>>>
>>> This bug causes a boot loop in nested virtualization environments (for
>>> instance nested environments that use VMware Workstation), making Xen
>>> unable to start. It was introduced in version 4.17.3 and the fix has
>>> already be included in 4.19(.2) and 4.20(.0) and woud be planned to be
>>> included in Xen 4.18.6 in the coming weeks.
>>>
>>> Even though Xen 4.17 is in security-only support, this is an issue that
>>> blocks testing and usage for users and projects such as Alpine Linux.
>> I fear I don't view this severe enough an issue to break the security-only
>> status of that branch. People concerned ought to simply update to a branch
>> where the bug was fixed. Or the distro could include a backport.
> The Debian Xen team now got a request to include this fix in Xen 4.17 in 
> Debian stable:
>
> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1105222
>
> We understand that Xen 4.17 is in upstream security-only support and thus this 
> patch will not land there.
>
> Debian can take the patch if it's confirmed by upstream Xen to be fine for Xen 
> 4.17 and low risk. We had problems in the past with incomplete backports of 
> patches that turned out to cause regressions, so we try to avoid backporting 
> patches without upstream Xen confirmation.

Yes, it is safe.

https://github.com/xenserver/xen.pg/blob/XS-8.4/patches/backport-dd05d265b8ab.patch
is the backport I did for XenServer's Xen 4.17.  I don't recall there
being any conflicts or problems.

~Andrew