From owner-freebsd-xen@freebsd.org Fri Feb 26 13:08:57 2016 Return-Path: Delivered-To: freebsd-xen@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 828E6AB5BBB for ; Fri, 26 Feb 2016 13:08:57 +0000 (UTC) (envelope-from prvs=8571d395d=roger.pau@citrix.com) Received: from SMTP02.CITRIX.COM (smtp02.citrix.com [66.165.176.63]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "mail.citrix.com", Issuer "Verizon Public SureServer CA G14-SHA2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 3772CA76 for ; Fri, 26 Feb 2016 13:08:56 +0000 (UTC) (envelope-from prvs=8571d395d=roger.pau@citrix.com) X-IronPort-AV: E=Sophos;i="5.22,498,1449532800"; d="scan'208";a="341357539" Subject: Re: Porting the block-iscsi hotplug script To: =?UTF-8?Q?Gustau_P=c3=a9rez?= , "freebsd-xen@freebsd.org >> FreeBSD XEN" References: <553DEB97.5000300@entel.upc.edu> <5540A053.4080409@entel.upc.edu> <5540F3FC.80606@citrix.com> <5541FC8A.8080009@citrix.com> <5542365D.10403@entel.upc.edu> <55423ECD.6000404@citrix.com> <5556F21D.2050005@entel.upc.edu> <555EEFBA.5080902@citrix.com> <555EF542.3090002@citrix.com> <555F9B3F.1000600@entel.upc.edu> <55602512.1090702@citrix.com> <56C6FA2F.8040900@gmail.com> <56CAC8CB.8030107@gmail.com> <56CADEDA.4050007@citrix.com> <56CB0057.1060509@gmail.com> <56CB041E.1020009@citrix.com> <56CB2D90.5080809@gmail.com> <56CB34BA.6060809@citrix.com> <56CC24BD.6050609@gmail.com> <56CC32E5.5010101@citrix.com> <56CC7637.3080408@gmail.com> <56CF5668.6090605@citrix.com> <56D0091F.80408@gmail.com> <56D02863.7040100@citrix.com> <56D03D95.9090509@gmail.com> From: =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= Message-ID: <56D04E5F.8070901@citrix.com> Date: Fri, 26 Feb 2016 14:08:47 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <56D03D95.9090509@gmail.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-DLP: MIA2 X-BeenThere: freebsd-xen@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Discussion of the freebsd port to xen - implementation and usage List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Feb 2016 13:08:57 -0000 El 26/2/16 a les 12:57, Gustau Pérez ha escrit: > > > El 26/02/16 a les 11:26, Roger Pau Monné ha escrit: >> Hello, >> >> I've rebased everything on top of Xen 4.5, so it can be applied to the >> xen-tools and xen-kernel packages without issues, I've uploaded all the >> patches to: >> >> https://people.freebsd.org/~royger/hotplug/ > > So in my case, I'd need those patches and the patches at [1] (or the > machine would panic at the ata stage during the boot), wouldn't I? I > don't know if I'll be able to deal with that today or this weekend, if > not monday I'll test and let you know. Not any more, I've just updated the Xen ports and added the patches in [1]: https://svnweb.freebsd.org/ports?view=revision&revision=409604 >> As you can see, each folder contains the patches that should be applied >> to each component. With this I've been able to use the simple block >> hotplug script that's included in the series. >> >> There's a limitation with block hotplug scripts, that is not specific to >> FreeBSD (the same applies to Linux for example). You cannot use block >> hotplug scripts with HVM guests. This is because HVM guests require a >> QEMU instance, and in order to provide a virtual disk to QEMU it must be >> a file or block device present on the system. Then when using block >> hotplug scripts the block device can only be made available using what >> we call a local attach (attaching the virtual disk to Dom0), and libxl >> doesn't do that yet. Of course patches are very welcome to remove this >> limitation ;). The code to perform local attaching to Dom0 is already in >> libxl, it's just not used for this case. >> >> Roger. > > In fact this is the scenario I'm most interested in :) I'll first > take a took a the current situation with PV guests and build that > hotplug script and then I think I'd like to deal with the support for > HVM guests. It shouldn't be too hard, as I said the code is already there. The only issue I foresee is that you will have to find somewhere to store the information about the disk you have locally-attached, so you can remove it when the guest is destroyed. Roger.