Comment 1 for bug 1081182

Further investigation, first the type will always work because it just returns a string with zero processing.

http://kernel.ubuntu.com/git?p=ubuntu/ubuntu-precise.git;a=blob;f=drivers/xen/sys-hypervisor.c;h=1e0fe01eb6705dee98acd115be1ab781cdabbc10;hb=ba6c2f688e255a1f52f2930ae9e6d62ede804289#l37

When comparing this to upstream, there seems to be a much newer way of getting that information (and if it fails, fallback). Maybe because it's a bit problematic when using the most recent release of Xen to use the older method?

https://github.com/torvalds/linux/commit/5c13f8067745efc15f6ad0158b58d57c44104c25

This commit added a new hypercall of getting it with a fallback to the original, I would speculate that if that's added, it'll work in all scenarios.