Re: [PATCH v1 5/7] xen-bus: Set offline if backend's state is XenbusStateClosed

[David Woodhouse <dwmw2@xxxxxxxxxxxxx>]

(When sending a series, if you Cc someone on one message please could you Cc them on the whole thread for context? Thanks.)

> Both state (XenbusStateClosed) and online (0) are expected by
> toolstack/xl devd to completely destroy the device. But "offline"
> is never being set by the backend resulting in timeout during
> domain destruction, garbage in Xestore and still running Qemu
> instance.

I would dearly love to see a clear state diagram showing all the possible state transitions during device creation, fe/be reconnecting, and hot plug/unplug. Does anything like that exist? Any test cases for the common and the less common transitions, and even the illegal ones which need to be handled gracefully?

Fantasy aside, can you please confirm that this patch series was tested with hotplug (device_add in the monitor) *and* unplug in QEMU, both under real Xen and ideally also emulated Xen in KVM?

Thanks.