From mboxrd@z Thu Jan 1 00:00:00 1970 From: Derek Murray Subject: Re: Re: Next steps with pv_ops for Xen Date: Wed, 05 Dec 2007 17:17:23 +0000 Message-ID: <4756DD23.7070502@cl.cam.ac.uk> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: "xen-devel@lists.xensource.com" , Eduardo Habkost , Juan Quintela , "Stephen C. Tweedie" , Jan Beulich , Glauber de Oliveira Costa , Chris Wright , "virtualization@lists.osdl.org" , Gerd Hoffmann List-Id: virtualization@lists.linuxfoundation.org Keir Fraser wrote: > > Actually I'm not so sure now. Presumably you add VM_PFNMAP to make > vm_normal_page() return NULL? But actually I would expect pte_pfn() to > return max_mapnr because the mapped page is not a local page. And that > should cause vm_normal_page() to return NULL always, regardless of whether > you assert VM_PFNMAP. Is gntdev being used to grant-and-map local pages in > the test that causes the crash? That's right (gntdev is being used to map (but not grant) a local page). The test case creates a virtual block device in Dom0, and attempts to map its ring buffer in a user-space daemon in Dom0. Therefore pte_pfn succeeds. Regards, Derek.