The static SR-IOV features are supported by the Oracle VM Server for SPARC 3.0 software and firmware. See PCIe SR-IOV Hardware and Software Requirements in Oracle VM Server for SPARC 3.0 Release Notes .
You can use the ldm set-io or ldm add-io command to set the iov property to on. You can also use the ldm add-domain or ldm set-domain command to set the rc-add-policy property to iov. See the ldm(1M) man page.
Rebooting the root domain affects SR-IOV, so carefully plan your direct I/O configuration changes to maximize the SR-IOV related changes to the root domain and to minimize root domain reboots.