From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Campbell Subject: Re: [v5][PATCH 10/16] tools: introduce some new parameters to set rdm policy Date: Wed, 8 Jul 2015 09:32:22 +0100 Message-ID: <1436344342.25646.275.camel@citrix.com> References: <1436249837-14747-1-git-send-email-tiejun.chen@intel.com> <1436249837-14747-11-git-send-email-tiejun.chen@intel.com> <20150707102150.GQ1134@zion.uk.xensource.com> <559C74B3.7090909@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <559C74B3.7090909@intel.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: "Chen, Tiejun" Cc: Ian Jackson , Stefano Stabellini , Wei Liu , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On Wed, 2015-07-08 at 08:54 +0800, Chen, Tiejun wrote: > >> +"none" is the default value and it means we don't check any reserved regions > >> +and then all rdm policies would be ignored. Guest just works as before and > >> +the conflict of RDM and guest address space wouldn't be handled, and then > >> +this may result in the associated device not being able to work or even crash > >> +the VM. So if you're assigning this kind of device, this option is not > >> +recommended unless you can make sure any conflict doesn't exist. > >> + > > > > One issue didn't come to conclusion during last round of review. Ian was > > asking what's the difference with type=none vs not specifying rdm option > > at all. > > > > You need to either convince Ian or remove "type=none" in *xl* level. > > I.e. don't touch the libxl IDL. It still needs a none type. > > I'll update this next revision. And also rephrase this doc to address > your comments below. FTR I think I indicated yesterday that I was satisfied with your explanation for why type=none exists as an option even at the xl level, namely that it allows us to change the default in the future. Ian.