From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [RFC PATCH v2 3/3] tools, libxl: handle the iomem parameter with the memory_mapping hcall Date: Fri, 14 Mar 2014 12:00:21 +0000 Message-ID: <5322EF55.2050409@linaro.org> References: <1394439953-5723-1-git-send-email-avanzini.arianna@gmail.com> <1394439953-5723-4-git-send-email-avanzini.arianna@gmail.com> <1394724477.25873.105.camel@kazak.uk.xensource.com> <5321D005.8020203@linaro.org> <1394728598.4159.47.camel@Solace> <5321E111.2000103@linaro.org> <1394731935.16364.36.camel@kazak.uk.xensource.com> <1394735851.4159.82.camel@Solace> <1394790366.16364.64.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1394790366.16364.64.camel@kazak.uk.xensource.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 Campbell Cc: paolo.valente@unimore.it, Keir Fraser , stefano.stabellini@eu.citrix.com, Ian.Jackson@eu.citrix.com, Dario Faggioli , Tim Deegan , xen-devel@lists.xen.org, julien.grall@citrix.com, etrudeau@broadcom.com, Jan Beulich , Arianna Avanzini , viktor.kleinik@globallogic.com List-Id: xen-devel@lists.xenproject.org Hi Ian, On 03/14/2014 09:46 AM, Ian Campbell wrote: >> In Arianna's case, it think it would be more than fine to implement it >> that way, and call it from within the OS, isn't this the case, Arianna? > > It's certainly an option, and it would make a lot of the toolstack side > issues moot but I'm not at all sure it is the right answer. In > particular although it might be easy to bodge a mapping into many OSes I > can imagine getting such a think into something generic like Linux might > be more tricky -- in which case perhaps the toolstack should be taking > care of it, and that does have a certain appeal from the simplicity of > the guest interface side of things. The generic way for Linux (and other oses) is to use device tree passthrough. I still think the "iomem" is a hackish way to passthrough the hardware to guest. People who will use this solution are aware of there kernel should map itself the region. >> Also, just trying to recap, for Arianna's sake, moving the >> implementation of the DOMCTL in common code (and implementing the >> missing bits to make it works properly, of course) is still something we >> want, right? > > *If* we go the route of having the kernel make the mapping then there is > no need, is there? How the kernel will map the region? Regards, -- Julien Grall