On 9/29/2021 7:26 PM, Chuck Zmudzinski wrote:
Ordinarily, as I understand the process, a bug in the stable version is first fixed in the unstable release and then the fix is migrated (backported) to the stable release. But it appears to me a fix in the unstable release will not be forthcoming soon, or it might be a different bug (see #991967, affecting the unstable release, sid, for more details).
Another way to look at this unusual situation: At the present time the Xen packages targeting the unstable version are identical to the Xen packages targeting the stable version. In other words, either the stable version is not really stable or the unstable version is actually stable. I argue it is the former and somewhere along the line the process for migrating a stable version of Xen into bullseye broke. I have identified when the process broke. It was when patches from unstable upstream Xen 4.16 were migrated to bullseye even though the upstream version of Xen for both stable and unstable was stable upstream Xen 4.14. In other words, the current Debian version of Xen targeting the stable distribution is actually an unstable version of Debian Xen that is a mixture of mostly stable Xen 4.14 and nine unstable patches from upstream Xen 4.16. This is causing instabilities and bugs such as #994899 and #991967 on amd64 and also likely i386. This upload to stable fixes this by removing the instabilities on amd64 and i386 without removing the good work done by the Debian Xen Team improving support for arm devices. So it is a win-win to accept this upload to stable. Going forward, work on Debian's unstable version of Xen can continue with investigating and fixing #991967 and eventually updating to a newer upstream version, which will probably be at least Xen 4.16 which in my tests already show that #994899 is fixed upstream in Xen 4.16, as discussed here: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=994899#5 To quote (with corrections and clarifications) from the aforementioned message: I also tested the current unstable (master) branch from Xen upstream, which is xen-c76cfad, which (upstream) calls Xen-4.16-unstable. I tested the current bullseye kernel (5.10.46-4) as a dom0 on that upstream Xen-4.16 hypervisor and did not see the bug, so this most definitely is NOT an upstream bug. So far all practical purposes, #994899 *is* fixed upstream in upstream's unstable version Xen 4.16. So we should be free to patch it in stable now. Chuck