From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: [PATCH 0 of 3] Update paging/sharing/access interfaces v2 Date: Fri, 10 Feb 2012 12:04:23 -0800 Message-ID: References: <20120210194517.GA23684@aepfle.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120210194517.GA23684@aepfle.de> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Olaf Hering , Andres Lagar-Cavilla Cc: andres@gridcentric.ca, xen-devel@lists.xensource.com, Tim Deegan , ian.campbell@citrix.com, adin@gridcentric.ca List-Id: xen-devel@lists.xenproject.org On 10/02/2012 11:45, "Olaf Hering" wrote: >> Actually, this hiatus allows me to float a perhaps cleaner way to map the >> ring: the known problem is that the pager may die abruptly, and Xen is >> still posting events to a page now belonging to some other dom0 process. >> This is dealt with in the qemu-dm case by stuffing the ring in an unused >> pfn (presumably somewhere in the mmio hole?) >> >> Would that work? Is there a policy for parceling out these "magic pfn's"? > > I was just thinking about this issue. The bug is that the ring lives in > dom0, the page should belong to domU and should be destroyed along with > it. And ring users in dom0 should request (and maybe initially allocate > and setup) a certain gfn belonging to domU. Yes indeed. The gpfn could be allocated by the domain builder, or by hvmloader (which might be too late!). -- Keir