FreeBSD PVHVM call for testing

[Roger Pau Monné]

Hello,

I've pushed a new branch, pvhvm_v14 that contains support for live
migration. While there I've also rebased the changes on top of current
HEAD, so now it contains the recent fixes to blkfront and netfront.

http://xenbits.xen.org/gitweb/?p=people/royger/freebsd.git;a=shortlog;h=refs/heads/pvhvm_v14

Some notes on this branch, I've mainly tested it with Xen 4.3 (unstable)
because previous Xen versions have problems with the PV clock used in
PVHVM when migrating. In order to be able to migrate a PVHVM guest you
will need to add tsc_mode="native_paravirt" to your config file or apply
the following patch to Xen:

http://marc.info/?l=xen-devel&m=137036010517331

I would say that migration across the 4.x series will work without
problems (because they all have support for vector callback injection),
but migrating from 4.x to 3.x will certainly not work. On the other
hand, migrating a guest started on 3.4 to 4.0 should work, although I
have not tested it.

Also, if the migration process fails for some reason, resuming the
original guest on the sender side will leave the VM without working nics
and disks, this is a problem with netfront and blkfront not being able
to resume after suspension if the guest was not actually migrated.

Roger.