Hi Roger,
On 25/01/2022 16:09, Roger Pau Monné wrote:
On Tue, Jan 25, 2022 at 03:32:16PM +0000, Julien Grall wrote:
Hi,
On 24/01/2022 16:02, Roger Pau Monne wrote:
By writing an empty "hotplug-status" xenstore node in the backend path
libxl can force Linux netback to wait for hotplug script execution
before proceeding to the 'connected' state.
I was actually chasing the same issue today :).
This is required so that netback doesn't skip state 2 (InitWait) and
Technically netback never skip state 2 (otherwise it would always be
reproducible). Instead, libxl may not be able to observe state 2 because
receive a watch is asynchronous and doesn't contain the value of the node.
So the backend may have moved to Connected before the state is read.
Right, might be more accurate to say it skips waiting for hotplug
script execution, and thus jumps from state 2 into 4.
I would add the jump happens when the frontend decides to connect.
Note I think
it's also possible that by the time we setup the watch in libxl the
state has already been set to 4.
Correct.
Cheers,
--
Julien Grall
