Oracle has released Oracle VM Server for SPARC 3.2 packages for Solaris 10 control domains. The package can be downloaded from http://www.oracle.com/technetwork/server-storage/vm/downloads/index.html#OVMSPARC
Not all of the performance and functional enhancements of Oracle VM Server for SPARC 3.2 are available when used with Solaris 10. Oracle recommends that customers use Solaris 11, especially for the control domain, service and I/O domains. Note that future Oracle VM Server for SPARC releases will no longer support the
running of the Oracle Solaris 10 OS in control domains. You can continue
to run the Oracle Solaris 10 OS in guest domains, root domains, and I/O
domains when using future releases. Solaris 10 guest domains can be used with Solaris 11 control domains, allowing interoperability while moving to Solaris 11. For additional details, please see the Release Notes.