I have done a preliminary paravirtualization of Linux/ia64. There's still much work to be done, but I've checked in the preliminary work at:

bk://xen-ia64.bkbits.net/xenlinux-ia64-2.6.11.bk

Do a bk pull on this... when this is complete (warning: takes a long time!), you will need to do a "bk -r co" because the tree isn't checked out by default like the xen tree is. Once this is done, you can peruse the changes by searching for CONFIG_XEN (plus one change in arch/ia64/Kconfig). To build it (on an HP rx2600), do:

cd xenlinux-ia64-2.6.11.bk cp arch/ia64/configs/xen_zx1_defconfig .config yes "" | make ARCH=ia64 make ARCH=ia64

You will then need to privify the resulting vmlinux (using the privify tool provided and described in xen/arch/ia64/tools/privify in xeno-unstable.bk or xeno-unstable-ia64.bk

Note that there are a couple hard-to-reproduce bugs, both probably present but not exposed by a unparavirtualized Linux. First, I have seen periodic "freezes" when multiple interrupt sources are active. Second, after many pids are used (and the ia64 rid space wraps around), I sometimes see a crash.

Oh, and there are some required fixes that are checked in to bk://xen-ia64.bkbits.net/xeno-unstable-ia64.bk tree but may not yet be in the main xeno-unstable tree.

Caveat user, but the current code might be of interest to some.

Dan