From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jan Beulich" Subject: Re: (v2) Design proposal for RMRR fix Date: Wed, 14 Jan 2015 15:07:43 +0000 Message-ID: <54B6944F0200007800054F4E@mail.emea.novell.com> References: <54B3A71002000078000538E1@mail.emea.novell.com> <54B3AB380200007800053917@mail.emea.novell.com> <54B3AE8802000078000539B7@mail.emea.novell.com> <54B515E6020000780005444A@mail.emea.novell.com> <54B54D48020000780005473E@mail.emea.novell.com> <54B540AA.1010905@eu.citrix.com> <1421237878.19103.244.camel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1421237878.19103.244.camel@citrix.com> Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell , Kevin Tian Cc: "wei.liu2@citrix.com" , "stefano.stabellini@eu.citrix.com" , George Dunlap , "tim@xen.org" , "ian.jackson@eu.citrix.com" , "xen-devel@lists.xen.org" , Yang Z Zhang , Tiejun Chen List-Id: xen-devel@lists.xenproject.org >>> On 14.01.15 at 13:17, wrote: > On Wed, 2015-01-14 at 08:06 +0000, Tian, Kevin wrote: >> - RMRRs conflicting with guest BIOS in <1MB area, as an example of >> hard conflicts > > OOI what is the (estimated) probability of such an RMRR existing which > doesn't already conflict with the real host BIOS? Surely the host BIOS will know to place the RMRRs outside its BIOS image. > Host BIOSes are generally large compared to the guest BIOS, but with the > amount of decompression and relocation etc they do I don't know how much > of them generally remains in the <1MB region. Recall the example: (host) RMRR naming E0000-EFFFF, which overlaps with the init-time guest BIOS image, but doesn't overlap with its resident part (as long as that doesn't exceed 64k in size). Jan