From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756738Ab2CVNZc (ORCPT ); Thu, 22 Mar 2012 09:25:32 -0400 Received: from rcsinet15.oracle.com ([148.87.113.117]:40654 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751096Ab2CVNZ3 (ORCPT ); Thu, 22 Mar 2012 09:25:29 -0400 Date: Thu, 22 Mar 2012 09:21:02 -0400 From: Konrad Rzeszutek Wilk To: Ian Campbell Cc: Stefano Stabellini , "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" Subject: Re: [Xen-devel] [PATCH] xen/xenbus: Add quirk to deal with misconfigured backends. Message-ID: <20120322132102.GA22545@phenom.dumpdata.com> References: <1332385189-29029-1-git-send-email-konrad.wilk@oracle.com> <1332413546.8817.64.camel@zakaz.uk.xensource.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1332413546.8817.64.camel@zakaz.uk.xensource.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: acsinet22.oracle.com [141.146.126.238] X-CT-RefId: str=0001.0A090208.4F6B2841.00E1,ss=1,re=0.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 22, 2012 at 10:52:26AM +0000, Ian Campbell wrote: > On Thu, 2012-03-22 at 10:44 +0000, Stefano Stabellini wrote: > > On Thu, 22 Mar 2012, Konrad Rzeszutek Wilk wrote: > > > A rather annoying and common case is when booting a PVonHVM guest > > > and exposing the PV KBD and PV VFB - as both of those do not > > > make any sense. The HVM guest is using the VGA driver and the emulated > > > keyboard for this. So we provide a very basic quirk framework > > > (can be expanded in the future) to not wait for 6 minutes for those devices > > > to initialize - they never wont. > > > > > > To trigger this, put this in your guest config: > > > > > > vfb = [ 'vnc=1, vnclisten=0.0.0.0 ,vncunused=1'] > > > > > > instead of this: > > > vnc=1 > > > vnclisten="0.0.0.0" > > > > While I do understand the issue you are trying to solve, it actually > > makes sense to have PV KBD (and PV VFB maybe in the future) in a PVonHVM > > guest. In particular PV KVB is already enabled in upstream QEMU for > > PVonHVM guests because it allows users to have a keyboard and mouse How about looking for a particular Xen version? The patch could check for anything less than 4.2 (does 4.2 use that version of QEMU that has this implemented?). I can't find any way to get the QEMU version from within the guest - DMI reports: DMI: Xen HVM domU, BIOS 4.1-120322 03/22/2012 > > without USB emulation, that requires lots of wakes up in QEMU. > > > > Maybe we could just reduce the timeout in general for all the PV > > devices? After all, why are we waiting 6 minutes? I could understand 6 > > seconds, but 6 minutes seem really too much. > > This was increased based on empirical evidence, way back (circa > 150:09c88868e344 in linux-2.6.18-xen.hg) > > It really can happen when starting lots of guests on a heavily loaded > dom0 that you timeout when connecting devices, at which point the guest > fails to boot if it happened to contain the root filesystem. > > Maybe a halfway house would be to wait a the longer time for more > critical devices (like disks and nics)? > > Ian. > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel