From owner-soc-status@FreeBSD.ORG Fri Apr 12 07:22:05 2013 Return-Path: Delivered-To: soc-status@FreeBSD.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id EEBA04FC; Fri, 12 Apr 2013 07:22:05 +0000 (UTC) (envelope-from theraven@FreeBSD.org) Received: from theravensnest.org (theraven.freebsd.your.org [216.14.102.27]) by mx1.freebsd.org (Postfix) with ESMTP id C525113A5; Fri, 12 Apr 2013 07:22:02 +0000 (UTC) Received: from [192.168.0.2] (cpc10-cmbg15-2-0-cust123.5-4.cable.virginmedia.com [86.30.246.124]) (authenticated bits=0) by theravensnest.org (8.14.5/8.14.5) with ESMTP id r3C7LsY6074798 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NO); Fri, 12 Apr 2013 07:22:00 GMT (envelope-from theraven@FreeBSD.org) Content-Type: text/plain; charset=windows-1252 Mime-Version: 1.0 (Mac OS X Mail 6.2 \(1499\)) Subject: =?utf-8?Q?Re=3A_Mentor_of_the_Project_=22PCI_frontend_XEN_PV_dri?= =?utf-8?Q?ver=22=EF=BC=9F?= From: David Chisnall In-Reply-To: <920A79FE-8C56-4D26-8611-3CD48602FC3B@freebsd.org> Date: Fri, 12 Apr 2013 08:21:51 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: <5BDCBCBB-E65D-472E-B990-F1382A4BADF0@FreeBSD.org> References: <920A79FE-8C56-4D26-8611-3CD48602FC3B@freebsd.org> To: "Justin T. Gibbs" X-Mailer: Apple Mail (2.1499) Cc: soc-status X-BeenThere: soc-status@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Summer of Code Status Reports and Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Apr 2013 07:22:06 -0000 On 12 Apr 2013, at 05:13, "Justin T. Gibbs" wrote: > This particular project was proposed for last year's GSoC when both = attilio@FreeBSD.org and I were actively working on full Xen PV support = for FreeBSD. That project still continues, but at a slower pace due to = changing needs at our respective employers. Given the lack of maturity = of our Xen PV port, I think this would be a difficult project to attempt = at this time. >=20 > If you are interested in Xen and have access to x86 hardware with HVM = capabilities, writing a SCSI or USB PV frontend for FreeBSD is a better = project to select. FreeBSD's Xen HVM support is very robust and, unlike = the PCI frontend driver, these drivers can be developed using an HVM = guest. The resulting drivers should work equally well in full PV mode = (with perhaps a few minor tweaks) when it is better supported. >=20 > I will update the wiki sometime tomorrow with more information on Xen = projects that are appropriate for this year's GSoC. Do we support PHV mode in Xen yet? If not, then this might be a good = GSoC project. Most of the effort - it uses the PV boot mechanism, but = then the HVM pmap and PV drivers (including event channels, no APIC = emulation). Unlike the PV mode, it won't require us to maintain two = i386 pmap implementations for the increasingly rare case of trying to = run FreeBSD VMs on CPUs without virtualisation support, and it doesn't = have the QEMU overhead in dom0 that HVM does (even when you're using = fully PV devices, you still need it to boot), and which causes hosting = providers to charge more for HVM. David