From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Chen, Tiejun" Subject: Re: [RFC][PATCH 4/5] tools:firmware:hvmloader: reserve RMRR mappings in e820 Date: Tue, 12 Aug 2014 18:56:33 +0800 Message-ID: <53E9F2E1.8050507@intel.com> References: <1407409371-31728-1-git-send-email-tiejun.chen@intel.com> <1407409371-31728-5-git-send-email-tiejun.chen@intel.com> <53E88482020000780002AFB9@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <53E88482020000780002AFB9@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 , Kevin Tian Cc: Yang Z Zhang , "xen-devel@lists.xen.org" , "ian.jackson@eu.citrix.com" , "ian.campbell@citrix.com" , "stefano.stabellini@eu.citrix.com" List-Id: xen-devel@lists.xenproject.org On 2014/8/11 14:53, Jan Beulich wrote: >>>> On 08.08.14 at 23:47, wrote: >>> From: Chen, Tiejun >>> Sent: Thursday, August 07, 2014 4:03 AM >>> >>> We need to reserve all RMRR mappings in e820 to avoid any >>> potential guest memory conflict. >> >> strictly speaking besides reserving in e820, you should also poke later >> MMIO BAR allocations to avoid confliction too. Currently it's relative >> to low_mem_pgend, which is likely to be different from host layout >> so it's still possible to see a virtual MMIO bar base conflicting to the >> RMRR ranges which are supposed to be sparse. > > Correct. And what's worse: Possible collisions between RMRRs and > the BIOS we place into the VM need to be taken care of, which may > turn out rather tricky. Looks BIOS itself ranges is covered with a e820 entry, so I think the codes to sort all entries can check this thing as well. Thanks Tiejun > > Jan > > >