I got the panic again last night. This was running a 3.11 kernel for the host, but of course the 1st and 2nd level guests were still running 3.10 as 3.11 is still in -proposed. So, although it's possible to get a test run with (3.11, 3.10, 3.10) I really need to try running with (3.11, 3.11, 3.11) to see if this provides a reliable solution.
I got the panic again last night. This was running a 3.11 kernel for the host, but of course the 1st and 2nd level guests were still running 3.10 as 3.11 is still in -proposed. So, although it's possible to get a test run with (3.11, 3.10, 3.10) I really need to try running with (3.11, 3.11, 3.11) to see if this provides a reliable solution.