From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH RFC 5/5] pvh: dom0 boot option to specify iommu rw ranges Date: Tue, 17 Feb 2015 14:14:20 +0000 Message-ID: <54E34CBC.7060904@citrix.com> References: <20150213185247.GA12753@elena.ufimtseva> <54DE7623.1000106@citrix.com> <20150213232154.GB13156@elena.ufimtseva> <54E343D4020000780006095C@mail.emea.novell.com> <54E342DA.4090600@citrix.com> <54E352BB02000078000609AE@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <54E352BB02000078000609AE@mail.emea.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich Cc: Elena Ufimtseva , kevin.tian@intel.com, tim@xen.org, xen-devel@lists.xen.org, yang.z.zhang@intel.com, boris.ostrovsky@oracle.com, roger.pau@citrix.com List-Id: xen-devel@lists.xenproject.org On 17/02/15 13:39, Jan Beulich wrote: >>>> On 17.02.15 at 14:32, wrote: >> On 17/02/15 12:36, Jan Beulich wrote: >>>>>> On 14.02.15 at 00:21, wrote: >>>> On Fri, Feb 13, 2015 at 10:09:39PM +0000, Andrew Cooper wrote: >>>>> If I understand the problem correctly, I believe that the correct >>>>> solution would be to add a dmar_rmrr[ command line parameter along the >>>>> same lines as ivrs_hpet[ and ivrs_ioapic[ which allows the user to >>>>> inject corrections to the ACPI tables via the command line. >>>> Yes, if we agree to classify those magic locations as being not reported >>>> by ACPI machinery. >>> One fundamental problem for someone to use this proposed option >>> in practice is - how does(s)he learn which region(s) to specify? >> Trial and improvement, or find a manual for the affected system. > If such an address range would appear in a manual, it would > almost certainly also appear in the ACPI tables In an ideal world. > (unless by manual you mean errata documentation). Also a valid source of information. ~Andrew