Virtual Machine Communication Facility

The IBM Virtual Machine Communication Facility (VMCF) is a feature of the VM/370 operating system introduced in Release 3 in 1976. It "provides a method of communication and data transfer between virtual machines operating under the same VM/370 system."

VMCF uses paravirtualization through the diagnose instruction VMCF SEND function to send data, in blocks of up to 2048 bytes, from one virtual machine to another. The receiving virtual machine accesses the data thru the diagnose RECEIVE function. It provides a simpler interface and greater performance than the prior use of virtual channel-to-channel adapters for the same purpose.

VMCF was superseded by the Inter User Communication Vehicle (IUCV), introduced in 1980 with VM/SP.

References

• Jensen, R. M. (1979). "A formal approach for communication between logically isolated virtual machines". IBM Systems Journal. 18 (1). Institute of Electrical and Electronics Engineers: 71–92. doi:10.1147/sj.181.0071. ISSN 0018-8670. Retrieved 29 March 2025.

• "Proceedings". The Second International Conference on Computers and Applications, Beijing (Peking), People's Republic of China, June 23–27, 1987. Institute of Electrical and Electronics Engineers: 360. June 1987. ISBN 978-0-8186-8780-8. Retrieved 29 March 2025.

External links

• Date, Shashank Prabhakar (1986). "A multi-tasking hierarchical file system for VM/CMS using virtual machine communication". University of Houston. Retrieved March 30, 2025.
• Faconti, G; Santoro, N. "APL106 VSAPL Virtual Machine Communication Facility Auxiliary Processor" (PDF). Consiglio Nazionale della Ricerche. Retrieved Mar 30, 2025.
• Jensen, R.M. (March 1979). "A formal approach for communication between logically isolated virtual machines". IBM Systems Journal. 18 (1): 71–92. doi:10.1147/sj.181.0071. Retrieved March 30, 2025.