From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [PATCH] rdma: don't make pages writeable if not requiested Date: Thu, 21 Mar 2013 11:57:32 -0600 Message-ID: <20130321175732.GA3263@obsidianresearch.com> References: <20130321070357.GD28328@redhat.com> <20130321085107.GE28328@redhat.com> <20130321093946.GG28328@redhat.com> <20130321171115.GA653@obsidianresearch.com> <20130321171525.GE2994@redhat.com> <20130321172150.GA3118@obsidianresearch.com> <20130321174237.GA4060@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20130321174237.GA4060-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Michael S. Tsirkin" Cc: Roland Dreier , "Michael R. Hines" , Sean Hefty , Hal Rosenstock , Yishai Hadas , Christoph Lameter , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , LKML , qemu-devel-qX2TKyscuCcdnm+yROfE0A@public.gmane.org List-Id: linux-rdma@vger.kernel.org On Thu, Mar 21, 2013 at 07:42:37PM +0200, Michael S. Tsirkin wrote: > It doesn't actually, and our app would sometimes write to these pages. > It simply does not care which version does the remote get in this case > since we track writes and resend later. Heh, somehow I thought you might say that :) A new flag seems like the only way then - maybe: IBV_ACCESS_NON_COHERENT - The adaptor and the CPU do not share a coherent view of registered memory. Memory writes from the CPU after ibv_reg_mr completes may not be reflected in the memory viewed by the adaptor. Can only be combined with read only access permissions. Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751963Ab3CUR5p (ORCPT ); Thu, 21 Mar 2013 13:57:45 -0400 Received: from quartz.orcorp.ca ([184.70.90.242]:56181 "EHLO quartz.orcorp.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751362Ab3CUR5n (ORCPT ); Thu, 21 Mar 2013 13:57:43 -0400 Date: Thu, 21 Mar 2013 11:57:32 -0600 From: Jason Gunthorpe To: "Michael S. Tsirkin" Cc: Roland Dreier , "Michael R. Hines" , Sean Hefty , Hal Rosenstock , Yishai Hadas , Christoph Lameter , "linux-rdma@vger.kernel.org" , LKML , qemu-devel@nongnu.org Subject: Re: [PATCH] rdma: don't make pages writeable if not requiested Message-ID: <20130321175732.GA3263@obsidianresearch.com> References: <20130321070357.GD28328@redhat.com> <20130321085107.GE28328@redhat.com> <20130321093946.GG28328@redhat.com> <20130321171115.GA653@obsidianresearch.com> <20130321171525.GE2994@redhat.com> <20130321172150.GA3118@obsidianresearch.com> <20130321174237.GA4060@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130321174237.GA4060@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Broken-Reverse-DNS: no host name found for IP address 10.0.0.162 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 21, 2013 at 07:42:37PM +0200, Michael S. Tsirkin wrote: > It doesn't actually, and our app would sometimes write to these pages. > It simply does not care which version does the remote get in this case > since we track writes and resend later. Heh, somehow I thought you might say that :) A new flag seems like the only way then - maybe: IBV_ACCESS_NON_COHERENT - The adaptor and the CPU do not share a coherent view of registered memory. Memory writes from the CPU after ibv_reg_mr completes may not be reflected in the memory viewed by the adaptor. Can only be combined with read only access permissions. Jason From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:51466) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UIjkK-0005ka-Bo for qemu-devel@nongnu.org; Thu, 21 Mar 2013 13:57:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UIjkH-0007Az-Gy for qemu-devel@nongnu.org; Thu, 21 Mar 2013 13:57:48 -0400 Received: from quartz.orcorp.ca ([184.70.90.242]:52786) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UIjkH-0007As-8b for qemu-devel@nongnu.org; Thu, 21 Mar 2013 13:57:45 -0400 Date: Thu, 21 Mar 2013 11:57:32 -0600 From: Jason Gunthorpe Message-ID: <20130321175732.GA3263@obsidianresearch.com> References: <20130321070357.GD28328@redhat.com> <20130321085107.GE28328@redhat.com> <20130321093946.GG28328@redhat.com> <20130321171115.GA653@obsidianresearch.com> <20130321171525.GE2994@redhat.com> <20130321172150.GA3118@obsidianresearch.com> <20130321174237.GA4060@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130321174237.GA4060@redhat.com> Subject: Re: [Qemu-devel] [PATCH] rdma: don't make pages writeable if not requiested List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Roland Dreier , qemu-devel@nongnu.org, "linux-rdma@vger.kernel.org" , Yishai Hadas , LKML , "Michael R. Hines" , Hal Rosenstock , Sean Hefty , Christoph Lameter On Thu, Mar 21, 2013 at 07:42:37PM +0200, Michael S. Tsirkin wrote: > It doesn't actually, and our app would sometimes write to these pages. > It simply does not care which version does the remote get in this case > since we track writes and resend later. Heh, somehow I thought you might say that :) A new flag seems like the only way then - maybe: IBV_ACCESS_NON_COHERENT - The adaptor and the CPU do not share a coherent view of registered memory. Memory writes from the CPU after ibv_reg_mr completes may not be reflected in the memory viewed by the adaptor. Can only be combined with read only access permissions. Jason