[PATCH] xen-netback: Check for hotplug-status existence before watching

2021-04-13 Thread Michael Brown
rios such as reloading the xen-netfront module within a domU, or booting a domU via iPXE. There is unfortunately no way for the domU to work around this dom0 bug. Fix by explicitly checking for existence of the "hotplug-status" node, thereby creating the behaviour that was previously assumed

Re: xen-netback hotplug-status regression bug

2021-04-13 Thread Michael Brown
On 13/04/2021 11:55, Paul Durrant wrote: Ok, so it sound like this was probably my misunderstanding of xenstore semantics in the first place (although I'm sure I remember watch registration failing for non-existent nodes at some point in the past... that may have been with a non-upstream versio

Re: xen-netback hotplug-status regression bug

2021-04-13 Thread Michael Brown
On 13/04/2021 08:12, Paul Durrant wrote: If the frontend subsequently disconnects and reconnects (e.g. transitions through Closed->Initialising->Connected) then: - Nothing recreates "hotplug-status" - When the frontend re-enters Connected state, connect() sets up a watch on "hotplug-status" a

xen-netback hotplug-status regression bug

2021-04-10 Thread Michael Brown
Commit https://github.com/torvalds/linux/commit/1f25657 ("xen-netback: remove 'hotplug-status' once it has served its purpose") seems to have introduced a regression that prevents a vif frontend from transitioning more than once into Connected state. As far as I can tell: - The defined vif sc