From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH v5 p2 16/19] tools/libxl: arm: Use an higher value for the GIC phandle Date: Thu, 9 Apr 2015 18:02:18 +0100 Message-ID: <5526B09A.5050605@citrix.com> References: <1428592185-18581-1-git-send-email-julien.grall@citrix.com> <1428592185-18581-17-git-send-email-julien.grall@citrix.com> <21798.42495.633318.607315@mariner.uk.xensource.com> <5526A9ED.2000803@gmail.com> <21798.44594.785262.371575@mariner.uk.xensource.com> <5526B013.9080906@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1YgFqr-0001AI-UN for xen-devel@lists.xenproject.org; Thu, 09 Apr 2015 17:02:50 +0000 In-Reply-To: <5526B013.9080906@citrix.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: Ian Jackson Cc: Wei Liu , ian.campbell@citrix.com, Julien Grall , tim@xen.org, stefano.stabellini@citrix.com, xen-devel@lists.xenproject.org List-Id: xen-devel@lists.xenproject.org On 09/04/15 18:00, Julien Grall wrote: > On 09/04/15 17:52, Ian Jackson wrote: >> Julien Grall writes ("Re: [Xen-devel] [PATCH v5 p2 16/19] tools/libxl: arm: Use an higher value for the GIC phandle"): >>> On 09/04/15 17:17, Ian Jackson wrote: >>> I only expect people using the partial device tree in very specific use >>> case. Generic use case is not even possible with the current status of >>> non-PCI (i.e device tree) passthrough. So people control their environment. >>> >>> As I said later in patch, supporting dynamic allocation will require >>> some rework in the device tree creation for the guest. >>> >>> So I was suggesting this solution as temporary in order to not block the >>> DT passthrough. >> >> What would happen if our assumption about the DT compiler were >> violated ? > > The phandle would be present in 2 different nodes of the DT. FYI, that > may also happen if a user use 2 times the same phandle in the partial DT. > > The guest may retrieve the wrong node and warn/crash depending on the > implementation. > > Although, it won't impact neither Xen nor the toolstack. (To be more complete) Because Xen and the toolstack doesn't made any usage of the phandle. The toolstack only generates the device tree and copy necessary node from the partial DT. -- Julien Grall