Comment 61 for bug 681083

Tentiatively I would say no (makes not sense). The story there is that for 2.6.35 the code was at a point where save/restore seems to work. Upstream changed after that to use functionality introduced into the generic interrupt handling code. But that had the problem of not reactivating interrupts early enough. This has now been fixed in a backport to 2.6.32, but 2.6.35 dropped off being really being cared upstream. So there it will make sense to revert (or not apply the change) but for .32 not so much.

Beside, you say XS 6.0 works. So there seems to be a dependency at least to the host code. I am not that familiar with various XS versions. Maybe you could check what Xen version the guest reports in dmesg (for 5.6 and 6.0)?