From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1ZVIJa-0006Ya-KD for mharc-grub-devel@gnu.org; Fri, 28 Aug 2015 07:59:26 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43555) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZVIJX-0006VK-RQ for grub-devel@gnu.org; Fri, 28 Aug 2015 07:59:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZVIJU-0003za-J5 for grub-devel@gnu.org; Fri, 28 Aug 2015 07:59:23 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:53362) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZVIJU-0003zS-FA for grub-devel@gnu.org; Fri, 28 Aug 2015 07:59:20 -0400 X-IronPort-AV: E=Sophos;i="5.17,424,1437436800"; d="scan'208";a="298913987" Message-ID: <55E04D15.8030601@citrix.com> Date: Fri, 28 Aug 2015 12:59:17 +0100 From: Andrew Cooper User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.8.0 MIME-Version: 1.0 To: Jan Beulich Subject: Re: [PATCH v2 22/23] x86: make Xen early boot code relocatable References: <1437402558-7313-1-git-send-email-daniel.kiper@oracle.com> <1437402558-7313-23-git-send-email-daniel.kiper@oracle.com> <55DF28E6020000780009D6E4@prv-mh.provo.novell.com> <20150827151054.GI10944@olila.local.net-space.pl> <55DF48FB020000780009D83F@prv-mh.provo.novell.com> <55DF5125.20708@citrix.com> <55E021C4020000780009DA95@prv-mh.provo.novell.com> In-Reply-To: <55E021C4020000780009DA95@prv-mh.provo.novell.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-DLP: MIA2 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 66.165.176.63 Cc: Juergen Gross , grub-devel@gnu.org, wei.liu2@citrix.com, ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com, phcoder@gmail.com, Daniel Kiper , roy.franz@linaro.org, ning.sun@intel.com, david.vrabel@citrix.com, xen-devel@lists.xenproject.org, qiaowei.ren@intel.com, keir@xen.org, richard.l.maliszewski@intel.com, gang.wei@intel.com, fu.wei@linaro.org X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list Reply-To: The development of GNU GRUB List-Id: The development of GNU GRUB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 Aug 2015 11:59:24 -0000 On 28/08/15 07:54, Jan Beulich wrote: > >> Therefore I am very much +1 get grub working. > Then you kind of misunderstood: I'm not against getting grub2 > working (i.e. patches prior to this one are fine in principle). What > I'm against is hacking around firmware+grub2 combinations not > suitable for Xen's purposes (where one could argue which of the > three is really at fault, and I'm far from convinced it's Xen). Irrespective of the EFI angle, there are other good reasons for making Xens boot code position-independent and able to be located elsewhere. The region of memory between 0x10000 and 0x10fffe is at increased risk of clobbering from buggy firmwares. I have submitted bugfixes to Xen before, and there are further investigations which didn't result in anything upstream. Moving the Xen text section out of this high risk region would make even legacy boot more reliable. Currently IMO it is a Xen bug that it strictly must be placed at the 1MB boundary to boot. ~Andrew