From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH v11 3/9] tools: provide interface for generic MSR access Date: Mon, 23 Jun 2014 09:29:18 -0400 Message-ID: <20140623132918.GC9153@laptop.dumpdata.com> References: <20140620173420.GK19876@laptop.dumpdata.com> <53A7EFA6020000780001C4AE@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <53A7EFA6020000780001C4AE@mail.emea.novell.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: Jan Beulich Cc: keir@xen.org, Ian.Campbell@citrix.com, stefano.stabellini@eu.citrix.com, George.Dunlap@eu.citrix.com, andrew.cooper3@citrix.com, Ian.Jackson@eu.citrix.com, xen-devel@lists.xen.org, Dongxiao Xu , dgdegra@tycho.nsa.gov List-Id: xen-devel@lists.xenproject.org On Mon, Jun 23, 2014 at 08:13:10AM +0100, Jan Beulich wrote: > >>> On 20.06.14 at 19:34, wrote: > > On Fri, Jun 20, 2014 at 10:31:44PM +0800, Dongxiao Xu wrote: > >> Xen added a new sysctl hypercall for generic MSR access, and this is the > >> tool side change to wrapper the hypercall into xc APIs. > > > > I really like the idea that Jan surfaced. That is use an > > cpu bitmap for the operation (see xc_tbuf.c as an example) > > and my recent postings http://osdir.com/ml/general/2014-06/msg24386.html. > > > > That way you can define exactly which CPUs you want to do it > > at and you can do one nice hypercall that will do it all at > > once for you. > > CPU bitmap? Me? I don't think I ever suggested anything like that, > not the least because it would become problematic where to store > the data (would need to be either [potentially very] sparse arrays, > or need a complicated [or at least ugly] mechanism for each CPU to > find its slot). I am sorry for the assumption. In that case lets drop that idea. > > Jan >