From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Liu Subject: Re: [PATCH 3/3] tools: introduce parameter max_ranges. Date: Wed, 20 Jan 2016 10:17:47 +0000 Message-ID: <20160120101747.GM1691@citrix.com> References: <20160119115349.GV1691@citrix.com> <7a1e981ca15b491e878fb32287f5ea7a@AMSPEX02CL03.citrite.net> <20160119143725.GI1691@citrix.com> <968fc8fc8f824ee7903fe7c8cbb7b5c0@AMSPEX02CL03.citrite.net> <20160119150400.GK1691@citrix.com> <1453216725.29930.84.camel@citrix.com> <569F0008.1010201@linux.intel.com> <569F14EF.9040108@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <569F14EF.9040108@linux.intel.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: "Yu, Zhang" Cc: "Tian, Kevin" , "Keir (Xen.org)" , Ian Campbell , Andrew Cooper , "xen-devel@lists.xen.org" , Paul Durrant , Stefano Stabellini , "Lv, Zhiyuan" , "jbeulich@suse.com" , Wei Liu List-Id: xen-devel@lists.xenproject.org On Wed, Jan 20, 2016 at 01:02:39PM +0800, Yu, Zhang wrote: > > > On 1/20/2016 11:58 AM, Tian, Kevin wrote: > >>From: Yu, Zhang [mailto:yu.c.zhang@linux.intel.com] > >>Sent: Wednesday, January 20, 2016 11:33 AM > >>>As a feature this write-protection has nothing to be GPU virtualization specific. > >>>In the future the same mediated pass-through idea used in XenGT may be > >>>used on other I/O devices which need to shadow some structure w/ requirement > >>>to write-protect guest memory. So it's not good to tie this to either XenGT > >>>or GTT. > >>> > >>Thank you, Kevin. > >>Well, if this parameter is not supposed to be xengt specific, we do not > >>need to connect it with any xengt flag such as ."vgt=1" or "GVT-g=1". > >>Hence the user will have to configure the max_wp_ram_ranges himself, > >>right? > >> > > > >Not always. The option can be configured manually by the user, or > >automatically set in the code when "vgt=1" is recognized. > > OK. That sounds more reasonable. :) > To give a summary, I'll do the following changes in next version: > > 1> rename this new parameter to "max_wp_ram_ranges", then use this > parameter as the wp-ram rangeset limit, for the I/O rangeset, keep > MAX_NR_IO_RANGES as its limit; > 2> clear the documentation part; > 3> define a LIBXL_HAVE_XXX in libxl.h to indicate a new field in the > build info; > 4> We do not introduce the xengt flag by now, and will add code to > automatically set the "max_wp_ram_ranges" after this flag is accepted > in the future. > > Does anyone have more suggestions? :) > Ian posted an enquiry earlier: "Could we use something like one of those to cause the t/stack to just DTRT without the user having to micromanage the amount of pages which are allowed to have this property?" Is that possible? Wei. > B.R. > Yu > > > >Thanks > >Kevin > >