From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: iommu=0 leading to panic when system defaults to using x2apic Date: Fri, 10 Dec 2010 10:06:53 +0000 Message-ID: References: <4D01FD050200007800027296@vpn.id2.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4D01FD050200007800027296@vpn.id2.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Jan Beulich , "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org Are you looking at xen-4.0? I think you should look at latest xen-unstable and we can backpoprt patches if that is more satisfactory. I did a big cleanup patch yesterday which makes the code smaller and clearer than it was, yet I don't understand the dependencies between x2apic-enabled-by-bios and the need for interrupt remapping, and all that stuff. -- Keir On 10/12/2010 09:12, "Jan Beulich" wrote: > Why wouldn't iommu=0 imply not using the x2apic, if use of the > iommu indeed is a prerequisite (which by itself seems questionable > as long as APIC IDs aren't wider than 8 bits)? > > Looking further at enable_bsp_x2apic(), I also wonder whether > the pre-enabled case, when specifying iommu=0 and x2apic=0, > can actually work if iommu=0 is a prerequisite (intremap_enabled() > would return 1 in that case afaics, so the early check doesn't help). > > Thanks, Jan > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel