LWN.net Logo

High-performance I/O in Virtual Machines

High-performance I/O in Virtual Machines

Posted Aug 13, 2009 4:43 UTC (Thu) by jgg (guest, #55211)
In reply to: High-performance I/O in Virtual Machines by abacus
Parent article: AlacrityVM

The new IB HCAs when combined with the snazzy PCI express virtualization stuff let the guest safely talk directly to the hardware and this whole issue becomes fairly moot. I've heard some of the FCoE chips will be able to do the same thing too. Any serious deployment with shared storage will want to go that way.


(Log in to post comments)

High-performance I/O in Virtual Machines

Posted Aug 13, 2009 13:38 UTC (Thu) by mcmanus (subscriber, #4569) [Link]

"the snazzy PCI express virtualization stuff let the guest safely talk directly to the hardware"

SR-IOV et al is really cool, but it still leaves open the problems of hairpin routing, firewall enforcement, etc where the alacrity approach really helps. There is talk of hardware answers to that too, but its further down the pipe. This kind of hardware is going to be substantially more expensive in the short term as well, so having more efficient answers in software is a plus for the ecosystem overall.

Also interesting, not long after this article was published there was a patch made available to virtio (for pure kvm) that reduces the trips through userspace for that code too: https://lists.linux-foundation.org/pipermail/virtualizati...

Copyright © 2013, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds