<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"> <title></title> </head> <body text="#000000" bgcolor="#ffffff"> <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"> <title></title> Dear Dennis, <blockquote cite="mid:4B36043B.6020800@conversis.de" type="cite">Why should I care? Don't get me wrong the idea sound interesting but I don't really see why it is so vitally important to put the HV right into the BIOS. The problem is that you loose support for a lot of hardware that cannot be booted with coreboot. </blockquote> Our engineering solution comes from a real world problem : faulty firmware (BIOS or UEFI) implementations prevent efficient I/O Virtualization. To quote David Woodhouse, lead Intel embedded software developer for the Linux Kernel and principal maintainer of the file drivers/pci/intel-iommu.c [0] ( Intel's I/O Virtualization, to provide high performance inside the virtual machines ) [1] : "Well done, Dell and HP -- although I didn't think it was possible, you have _further_ lowered my already-unprintable opinion of closed source BIOSes and BIOS engineers" <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: 'Times New Roman'; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; font-size: medium;"> "We _really_ need open source firmware. Or at _least_ firmware written by competent engineers -- but I think we've all fairly much given up on that happening by now?" Many commits of the file intel-iommu.c are related to BIOS bugs [2] [3] [4] [5] [6] [7]. And it is evident that Intel will not be able to test each firmware version on each IOMMU capable Hardware. By ensuring a full use of hardware capabilities inside Virtual Machines, through a custom Virtualization Firmware, it lowers the TCO (Total Cost of Ownership), thus requiring less frequent hardware upgrades that can be substantial saves on a large scale volume or a critical requirement for budget aware customers. <blockquote cite="mid:4B36043B.6020800@conversis.de" type="cite">Earlier this year we had to come up with a virtualization solution to host 80 VMs quickly and our first shot was VMWare ESX but that failed because ESX refused to work with the commodity hardware we were using. So we went with RHEL Xen instead which works beautifully on pretty much any system precisely because it isn't so closely wedded to any particular hardware. I think using a regular BIOS that boots a minimal Kernel/Initrd from a flash chip gives you pretty much the same benefits of a tiny footprint but actually works with pretty much every machine out there. </blockquote> We would greatly appreciate to invite you to a further reading of this Phoronix article entitled : "KVM Virtualization Performance With Linux 2.6.31" [8] : "The disk benchmarks took a large hit when running Ubuntu 9.10 "Karmic Koala" within a virtual machine using KVM, but that is to no surprise considering the setup." "Benchmarking Apache with the Kernel-based Virtual Machine took a huge performance hit," Our engineering target is to achieve 1:1 parity in terms of performance between real-hardware and a virtual machine. Each product has specific needs that is why we are very pleased that you were satisfied by your Virtualization Solution, to quote : "So we went with RHEL Xen instead which works beautifully", however it will not be the case for performance and budget aware customers. Best Regards, Guillaume FORTAINE [0] <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://git.infradead.org/iommu-2.6.git/blob/e0fc7e0b4b5e69616f10a894ab9afff3c64be74e:/drivers/pci/intel-iommu.c">http://git.infradead.org/iommu-2.6.git/blob/e0fc7e0b4b5e69616f10a894ab9afff3c64be74e:/drivers/pci/intel-iommu.c</a> [1] <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://patchwork.kernel.org/patch/42841/">http://patchwork.kernel.org/patch/42841/</a> [2] <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://git.infradead.org/iommu-2.6.git/commit/e0fc7e0b4b5e69616f10a894ab9afff3c64be74e">http://git.infradead.org/iommu-2.6.git/commit/e0fc7e0b4b5e69616f10a894ab9afff3c64be74e</a> [3] <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://git.infradead.org/iommu-2.6.git/commit/2ff729f5445cc47d1910386c36e53fc6b1c5e47a">http://git.infradead.org/iommu-2.6.git/commit/2ff729f5445cc47d1910386c36e53fc6b1c5e47a</a> [4] <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://git.infradead.org/iommu-2.6.git/commit/6ecbf01c7ce4c0f4c3bdfa0e64ac6258328fda6c">http://git.infradead.org/iommu-2.6.git/commit/6ecbf01c7ce4c0f4c3bdfa0e64ac6258328fda6c</a> [5] <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://git.infradead.org/iommu-2.6.git/commit/5854d9c8d18359b1fc2f23c0ef2d51dd53281bd6">http://git.infradead.org/iommu-2.6.git/commit/5854d9c8d18359b1fc2f23c0ef2d51dd53281bd6</a> [6] <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://git.infradead.org/iommu-2.6.git/commit/86cf898e1d0fca245173980e3897580db38569a8">http://git.infradead.org/iommu-2.6.git/commit/86cf898e1d0fca245173980e3897580db38569a8</a> [7] <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://git.infradead.org/iommu-2.6.git/commit/0815565adfe3f4c369110c57d8ffe83caefeed68">http://git.infradead.org/iommu-2.6.git/commit/0815565adfe3f4c369110c57d8ffe83caefeed68</a> [8] <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.phoronix.com/scan.php?page=article&item=linux_2631_kvm&num=6">http://www.phoronix.com/scan.php?page=article&item=linux_2631_kvm&num=6</a> </body> </html>