From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754831Ab0CDP0x (ORCPT ); Thu, 4 Mar 2010 10:26:53 -0500 Received: from mtaout02-winn.ispmail.ntl.com ([81.103.221.48]:41659 "EHLO mtaout02-winn.ispmail.ntl.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754500Ab0CDP0w (ORCPT ); Thu, 4 Mar 2010 10:26:52 -0500 From: Ian Campbell To: Bastian Blank Cc: Stefano Stabellini , "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" In-Reply-To: <20100303161428.GB26656@wavehammer.waldi.eu.org> References: <20100303121726.GA26656@wavehammer.waldi.eu.org> <20100303161428.GB26656@wavehammer.waldi.eu.org> Content-Type: text/plain; charset="UTF-8" Date: Thu, 04 Mar 2010 15:26:35 +0000 Message-ID: <1267716395.11737.33485.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 X-Mailer: Evolution 2.28.2 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 62.200.22.2 X-SA-Exim-Mail-From: ijc@hellion.org.uk Subject: Re: [Xen-devel] [PATCH 4 of 4] Linux pvops: xen pci platform device driver X-SA-Exim-Version: 4.2.1 (built Wed, 25 Jun 2008 17:14:11 +0000) X-SA-Exim-Scanned: Yes (on hopkins.hellion.org.uk) X-Cloudmark-Analysis: v=1.1 cv=1ggfb5FlKZQUfF3vzm9UBYZ2uTfLsbs/8dSljwg5+mE= c=1 sm=0 a=eg4TgaQpvW0A:10 a=cKYKwiJ3QjskgAzcbucA:9 a=ACHGwvuM-d64-r4cTDhonaqCQSoA:4 a=HpAAvcLHHh0Zw7uRqdWCyQ==:117 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2010-03-03 at 17:14 +0100, Bastian Blank wrote: > > > During the initialization of the xen pci device driver, we write to > a > > magic ioport that causes qemu to unplug some emulated devices, disc > and > > network in particular. > > This parameter is meant to present the user a choice about what > emulated > > devices to unplug. > > Somehow I don't think this belongs here. It looks like a workaround, > you can always ask qemu to not bind them at the beginning and the > guest system to not provide drivers. Qemu needs to start off providing the devices so that the BIOS and bootloader can do their thing. It's only once the final OS is up and running that we want to swap to the paravirt drivers and this interface provides a safe mechanism to ensure only one set of devices is active at a time. Ian. -- Ian Campbell Current Noise: Spiritual Beggars - Euphoria Usage: fortune -P [-f] -a [xsz] Q: file [rKe9] -v6[+] file1 ... From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Campbell Subject: Re: [PATCH 4 of 4] Linux pvops: xen pci platform device driver Date: Thu, 04 Mar 2010 15:26:35 +0000 Message-ID: <1267716395.11737.33485.camel@zakaz.uk.xensource.com> References: <20100303121726.GA26656@wavehammer.waldi.eu.org> <20100303161428.GB26656@wavehammer.waldi.eu.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20100303161428.GB26656@wavehammer.waldi.eu.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Bastian Blank Cc: "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" , Stefano Stabellini List-Id: xen-devel@lists.xenproject.org On Wed, 2010-03-03 at 17:14 +0100, Bastian Blank wrote: > > > During the initialization of the xen pci device driver, we write to > a > > magic ioport that causes qemu to unplug some emulated devices, disc > and > > network in particular. > > This parameter is meant to present the user a choice about what > emulated > > devices to unplug. > > Somehow I don't think this belongs here. It looks like a workaround, > you can always ask qemu to not bind them at the beginning and the > guest system to not provide drivers. Qemu needs to start off providing the devices so that the BIOS and bootloader can do their thing. It's only once the final OS is up and running that we want to swap to the paravirt drivers and this interface provides a safe mechanism to ensure only one set of devices is active at a time. Ian. -- Ian Campbell Current Noise: Spiritual Beggars - Euphoria Usage: fortune -P [-f] -a [xsz] Q: file [rKe9] -v6[+] file1 ...