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Bridging the Gap between Software and Hardware Techniques for I/O Virtualization
Santos, Jose Renato; Turner, Yoshio; Janakiraman, G.; Pratt, Ian
Keyword(s): Virtualization, Networking, Operating System, I/O, Performance Analysis, Xen
Abstract: The paravirtualized I/O driver domain model, used in Xen, provides several advantages including device driver isolation in a safe execution environment, support for guest VM transparent services including live migration, and hardware independence for guests. However, these advantages currently come at the cost of high CPU overhead which can lead to low throughput for high bandwidth links such as 10 gigabit Ethernet. Direct I/O has been proposed as the solution to this performance problem but at the cost of removing the benefits of the driver domain model. In this paper we show how to significantly narrow the performance gap by significantly improving the performance of the driver domain model. In particular, we reduce execution costs for conventional NICs by 56% on the receive path, and we achieve close to direct I/O performance for network devices supporting multiple hardware receive queues. These results make the Xen driver domain model an attractive solution for I/O virtualization for a wider range of scenarios.
Additional Publication Information: To be published and presented at 2008 Usenix Annual Technical Conference, June 22-27, 2008, Boston, Massachusetts.
External Posting Date: June 21, 2008 [Fulltext]. Approved for External Publication
Internal Posting Date: June 21, 2008 [Fulltext]
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