From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH v2] ARM: DT: Add binding for GIC virtualization extentions (VGIC) Date: Thu, 10 May 2012 12:11:06 +0100 Message-ID: <4FABA24A.9040209@arm.com> References: <1336586277-28454-1-git-send-email-marc.zyngier@arm.com> <201205092047.06852.arnd@arndb.de> <201205101053.09954.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <201205101053.09954.arnd-r2nGTMty4D4@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: Arnd Bergmann Cc: "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , "david.vrabel-Sxgqhf6Nn4DQT0dZR+AlfA@public.gmane.org" , "rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: devicetree@vger.kernel.org On 10/05/12 11:53, Arnd Bergmann wrote: > On Wednesday 09 May 2012, Marc Zyngier wrote: >>> >>> Sounds good. I don't have a strong preference whether that should be a >>> property like you suggest or a separate "compatible" value, maybe Rob or >>> Grant can comment on what they prefer. >> >> At the moment, the compatible string should be pretty explicit, as it is >> not possible to build an A7 or A15 based SoC without the virtualization >> extensions. > > Ok, makes sense. Then again, if you run an A15 guests on an A15 host, > the virtual GIC would not have those extensions, right? Indeed, they would be inaccessible (the hypervisor should not map them into the guest address space). I'd expect the guest kernel not to try to use them anyway, as it wouldn't be able to use the HYP mode. But again, this is implementation specific. M. -- Jazz is not dead. It just smells funny...