For the last few weeks I've been working on getting Xen running on 64-bit ARM (AArch64), using the Fast Models. This morning I finally solved the last bug (a pretty dumb one as it turns out) and booted domain 0 to a prompt! A screenshot is worth 1,000 words, although you'll just have to trust me that this is running under Xen :-):

Xen on ARM64 Prompt

At the moment I'm using the same 32-bit dom0 kernel as we run on the 32-bit port of Xen, obviously we eventually want to support both 32- and 64-bit guests. In fact we went to a fair bit of trouble with the 32-bit port to try and ensure that the hypercall ABI would be the same for both and avoid the need for a compatibility layer (Stefano's talk from XenSummit in the summer has some details on that).

Combined with Debian bug #599161 finally being tracked down and fixed upstream all in all this is shaping up to be a pretty good week!