A data processing system that includes a mode/reserve bit utilized to dynamically
change a processor's operating mode between a virtual addressing mode and a real
addressing mode. Each address block includes a reserve bit that indicates whether
real or virtual addressing is desired, and the reserve bit is assigned a value
by the software application executing on the processor. The value of the reserve
bit is dynamically set and signals the processor which operating mode is required
for the particular address block. The selection of virtual or real addressing mode
is determined by the particular application that is being executed by the processor.
When the particular application process seeks increased performance rather than
protection, the virtual operating mode is selected, allowing the application process
to send the effective addresses directly to the OS and hypervisor. This is accomplished
by setting the reserve bit to the value for virtual addressing mode. When data
protection is desired, the reserve bit is set to the value for real addressing
mode, and the data address is sent to the (memory cloner's) TLB, where it is translated
into a real address. The invention thus balances performance versus data protection.
