[fedora-virt] mouse stopped working in F16 guests (on F16 host, using VNC/cirrus)

[Chuck Anderson]

I had a couple original F16 guests (un-updated) that I had originally
installed under a F13 host months ago.  I installed a new copy (not
upgraded) of F16 on the host and imported the guests with their
original storage.  This all worked fine until I did "yum update" on
the F16 guests (these guests are used for off-net testing, so they
were never updated until today--500+ entries in the update
transaction).  Now the mouse pointers don't show up in the guests in
virt-manager, and "xev" on the guests shows no mouse activity at all.

I'm using cirrus for the video hardware and VNC for the remote display
protocol.  I've tried rebooting host & guests with no improvement.

How can I troubleshoot/fix this?

Thanks.