From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: Non-exiting rdpmc on KVM guests? Date: Wed, 22 Apr 2015 17:26:44 +0200 Message-ID: <20150422152644.GB3007@worktop.Skamania.guest> References: <20150421150514.GC3182@worktop.meeting.verilan.com> <55367BB6.3050103@redhat.com> <20150421205139.GA2898@worktop.Skamania.guest> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Paolo Bonzini , Andy Lutomirski , kvm list To: Andy Lutomirski Return-path: Received: from bombadil.infradead.org ([198.137.202.9]:60645 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965612AbbDVP0y (ORCPT ); Wed, 22 Apr 2015 11:26:54 -0400 Content-Disposition: inline In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On Tue, Apr 21, 2015 at 02:10:53PM -0700, Andy Lutomirski wrote: > One question is whether we care if we leak unrelated counters to the > guest. (We already leak them to unrelated user tasks, so this is > hopefully not a big deal. OTOH, the API is different for guests.) Good question indeed. I really do not know. > Another question is whether it's even worth trying to optimize this. I think I just ran into a bunch of people who think virt pmu stuff is important, but we'll have to see if they follow up with the effort of actually doing the work. My only concern is that they'll not make a mess of things ;-)