Correct, I'm running the installer as a PVHVM domain (this is how XenServer supports Jessie onwards).
I tried running the xen netboot image, but although it booted it then complained about a display issue, and didn't seem to bring up the disk, so it doesn't look like that is PVHVM compatible. Would be good if the Xen drivers could be included in the 686 kernel, or if there was a Xen PVHVM compatible installer we could use (although a separate kernel may cause complications for CD installs). John
