There’s been talk about Microsoft’s Windows Server 2012 R2’s Hyper-V having better support for Linux guests via the integration services code.
However, it doesn’t mean your existing kernels will magically support Dynamic Memory, VSS Snapshots, Hyper-V’s new Frame Buffer Driver and in staging Keyboard Driver.
Hint: You’ll either need to backport the newer code into your production kernel in order to take advantage of the new features that Microsoft’s already committed in the mainline Linux kernel code.
In my own experiments, adding hv_snapshot.c to a EL6-based kernel allows the guest to be backed up via VSS online. Also, the patch that fixes a bug where the KVP code automatically negotiated the highest version available compiles cleanly in the EL6-based kernel. The userspace daemon from the mainline tree also cleanly builds too without too much code modification. Clone this git repository here if you want to build a rpm for that userspace daemon: https://github.com/v10networks/hv_kvp_daemon.git
Obviously with Ubuntu 12.04 kernels, those patches can be much more cleanly applied as the Hyper-V integration code is more up-to-date than what the Prominent North American Enterprise Linux Vendor has integrated to their kernels.
tl;dr: If you want to take advantage of the new guest capabilities that Microsoft has offered in their latest talks, you’ll need to either backport or take the plunge with a mainline kernel with those changes.
Don’t be the fool that’s going to post on TechNet forums complaining about that “XYZ feature that you guys have promised doesn’t work.” Duh, because the code hasn’t been complied in!