Rebooting the Root Domain With PCIe Endpoints Configured in Oracle VM Server for SPARC 3.2 Administration Guide does not indicate that a resilient I/O domain can continue to operate even when the root domain that is the owner of the PCIe bus becomes unavailable.
If the I/O domain is resilient, it can continue to operate even if the root domain that is the owner of the PCIe bus becomes unavailable. See I/O Domain Resiliency in Oracle VM Server for SPARC 3.2 Administration Guide .