From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: [PATCH] Included reserved memory regions in dom0 iommu mappings Date: Thu, 26 Feb 2009 16:11:43 +0000 Message-ID: References: <831D55AF5A11D64C9B4B43F59EEBF72023114BBA8F@FTLPMAILBOX02.citrite.net> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <831D55AF5A11D64C9B4B43F59EEBF72023114BBA8F@FTLPMAILBOX02.citrite.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Ross Philipson , "Cui, Dexuan" , "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org Yes, blacklist rather than whitelist, below 4G. Sounds good. -- Keir On 26/02/2009 15:38, "Ross Philipson" wrote: > There are some regions that I think would really need to be excluded that are > related to TXT and tboot too though. The current tboot code puts these in the > e820 as unusable as apposed to reserved. What if we mapped in all 4GB with the > exception of unusable ranges and where xen is? > > Thanks > Ross > > -----Original Message----- > From: Keir Fraser > Sent: Thursday, February 26, 2009 10:30 AM > To: Cui, Dexuan; Ross Philipson; xen-devel@lists.xensource.com > Subject: Re: [Xen-devel] [PATCH] Included reserved memory regions in dom0 > iommu mappings > > I'm not keen on Ross's patch anyway. I think if you have such a broken > system, the cmdline option should simply identity-map everything below 4GB, > unconditionally. Easy. > > -- Keir > > On 26/02/2009 09:20, "Cui, Dexuan" wrote: > >> The patch is useful when BIOS doesn’t report RMRR correctly; however the >> patch >> may not help in some situations. >> E.g., to work around a buggy BIOS, we may have to map such an E820 entry >> (XEN) 00000000cff0b000 - 00000000d0000000 (reserved). >> But if we use a xen parameter "mem=512m", or, if the host only has 512m >> memory, the variable 'max_page" is 512m/PAGE_SIZE, so even with the patch, >> the >> E820 entry would not be mapped, and Xen would still hang. >> >> -- Dexuan >> >> ________________________________________ >> From: xen-devel-bounces@lists.xensource.com >> [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of Ross Philipson >> Sent: 2009年2月24日 4:01 >> To: xen-devel@lists.xensource.com >> Subject: [Xen-devel] [PATCH] Included reserved memory regions in dom0 iommu >> mappings >> >> This adds a boolean boot parameter to xen to allow reserved memory >> regions to be added to the iommu mappings for dom0. The parameter >> is "iommu_include_reserved" and is off by default. A warning is >> also traced when incorrect RMRR to system memory map values are >> detected. This is being added to address some incorrect BIOS's that >> do not report correctly the requied reserved memory ranges in >> the RMRRs. When this occurs it currently can cause early boot hangs >> and crashes. >> >> Signed-off-by: Ross Philipson >> >> Based on changeset 19238 >> >> Thanks >> Ross >> >> >> Ross Philipson >> Senior Software Engineer >> Citrix Systems, Inc >> 14 Crosby Drive >> Bedford, MA 01730 >> 781-301-7949 >> ross.philipson@citrix.com >> > >