2026-08-14T06:07:18Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:7150 2024-03-06T10:39:52Z ddc:004 open_access

VCDC: The Virtualized Complicated Device Controller Jiang, Zhe Audsley, Neil Many-core System I/O Virtualization Real-time I/O Hardware Manager I/O virtualization enables time and space multiplexing of I/O devices, by mapping multiple logical I/O devices upon a smaller number of physical devices. However, due to the existence of additional virtualization layers, requesting an I/O from a guest virtual machine requires complicated sequences of operations. This leads to I/O performance losses, and makes precise timing of I/O operations unpredictable. This paper proposes a hardware I/O virtualization system, termed the Virtualized Complicated Device Controller (VCDC). This I/O system allows user applications to access and operate I/O devices directly from guest VMs, and bypasses the guest OS, the Virtual Machine Monitor (VMM) and low layer I/O drivers. We show that the VCDC efficiently reduces the software overhead and enhances the I/O performance and timing predictability. Furthermore, VCDC also exhibits good scalability that can handle I/O requests from variable number of CPUs in a system. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Zhe Jiang and Neil Audsley 2017 Is Part Of LIPIcs, Volume 76, 29th Euromicro Conference on Real-Time Systems (ECRTS 2017) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.ECRTS.2017.5 urn:nbn:de:0030-drops-71501 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ECRTS.2017.5 eng https://creativecommons.org/licenses/by/3.0/legalcode