From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tim Deegan Subject: Re: [PATCH 3/8] xen/arm: Implement p2m_type_t as an enum Date: Thu, 5 Dec 2013 17:07:37 +0100 Message-ID: <20131205160737.GA2093@deinos.phlegethon.org> References: <1386258131-755-1-git-send-email-julien.grall@linaro.org> <1386258131-755-4-git-send-email-julien.grall@linaro.org> <1386258750.20047.84.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1VobSl-0006Dm-UM for xen-devel@lists.xenproject.org; Thu, 05 Dec 2013 16:07:40 +0000 Content-Disposition: inline In-Reply-To: <1386258750.20047.84.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: xen-devel@lists.xenproject.org, Julien Grall , stefano.stabellini@citrix.com, patches@linaro.org List-Id: xen-devel@lists.xenproject.org At 15:52 +0000 on 05 Dec (1386255150), Ian Campbell wrote: > On Thu, 2013-12-05 at 15:42 +0000, Julien Grall wrote: > > Until now, Xen doesn't know the type of the page (ram, foreign page, mmio,...). > > Introduce p2m_type_t with basic types: > > - p2m_invalid: Nothing is mapped here > > Do we really need this? Is it not equivalent to not setting the present > bit? I see x86 has the same type though -- Tim can you explain why. There are other not-present types on x86: PoD, paged-out, emulated-MMIO. Tim.