From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH] VT-d: improve RMRR validity checking Date: Tue, 9 Mar 2010 17:22:29 -0500 Message-ID: <20100309222229.GA700@phenom.dumpdata.com> References: <4B59098B.6000108@intel.com> <4B590FA4.4000008@jp.fujitsu.com> <4B59132B.40607@intel.com> <4B59188C.50901@jp.fujitsu.com> <4B59660F.4000909@intel.com> <7162ab21003091339i4adb8669safd5e074607386a2@mail.gmail.com> <20100309213026.GA12602@phenom.dumpdata.com> <7162ab21003091357v32b3c58qae708301fdf2764a@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <7162ab21003091357v32b3c58qae708301fdf2764a@mail.gmail.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: Alex Williamson Cc: "xen-devel@lists.xensource.com" , Noboru Iwamatsu , Weidong Han , "Cihula, Joseph" , "Kay, Allen M" , "linux@eikelenboom.it" , "keir.fraser@eu.citrix.com" List-Id: xen-devel@lists.xenproject.org On Tue, Mar 09, 2010 at 02:57:00PM -0700, Alex Williamson wrote: > On Tue, Mar 9, 2010 at 2:30 PM, Konrad Rzeszutek Wilk > wrote: > > On Tue, Mar 09, 2010 at 02:39:10PM -0700, Alex Williamson wrote: > >> > >> I have a system with what I consider to be a valid DRHD that's getti= ng > >> tripped up on this patch. =A0The problem is that the DRHD includes a= n > >> IOAPIC scope, where the IOAPIC is not materialized on the PCI bus. =A0= I > >> think Xen is being overzealous in it's validity checking and that th= is > >> is a valid configuration. =A0What do others think? =A0Are IOAPICs a > > > > How does upstream Linux handle this? >=20 > Last I checked, it works just fine, doesn't care that the IOAPIC isn't > materialized. This is from drivers/pci/intr_remapping.c (2.6.34-rc0): 795 if (ir_supported && ir_ioapic_num !=3D nr_ioapics) { 796 printk(KERN_WARNING 797 "Not all IO-APIC's listed under remapping hardware\n"); 798 return -1; 799 } 800=20 ir_ioapic_num is figured out from the count of DRHD's. So I think Linux would actually turn off VT-d.