On Fri, 13 Oct 2023, Julien Grall wrote: > Hi George, > > On 13/10/2023 17:06, George Dunlap wrote: > > On Fri, Oct 13, 2023 at 4:56 PM Julien Grall <jul...@xen.org> wrote: > > > > The initial patch that > > > > introduced it didn't mention wanting to include dom0 specifically; on > > > > the contrary it said: > > > > > > > > "The extra notification is harmless for domains that don't require it." > > > > > > ... even if this is what the commit message says, we can't tell whether > > > someone would start to rely on it. I definitely see use-cases for it. > > > > > > But I agree that the chance they are actualy used is slim as we didn't > > > document it. > > > > If a dom0 kernel started relying on the behavior, it would be a bug, > > since it would be incompatible with releases before 4.16. So I think > > the only risk here would be if some bit of a system's userspace > > tooling relied on it; but I can't really see how that would come to > > be. > > > > If someone reports a bug, we can always add the reporting back, when > > we're not under time pressure. > > > > > Your reasoning makes sense. I don't fully agree with it, but at the end > > > of the day we need to have a solution for dom0less guests... So if the > > > others agree with you, then I will disagree and commit. > > > > > > That said, I think the commit message should explain why removing dom0 > > > notification is ok. > > > > Yes, absolutely. > > > > Do you or Stefano want to pick it up? I think you'd be able to test > > it more thoroughly. I can build-test it and send it to gitlab-CI, but > > anything more will take a lot more setup. > > I just asked you a similar question on Matrix. :) Stefano was able to > reproduce the issue. So it would probably be best for him to pick up at least > the testing part. > > Stefano, do you have some cycle to send the patch as well? If not, I can do > it.
I have done the work and the patch works: https://marc.info/?l=xen-devel&m=169723822001933 However, you should know that I tried to reproduce the original race condition without the patch, but I couldn't.
