From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751403AbeEDKp4 (ORCPT ); Fri, 4 May 2018 06:45:56 -0400 Received: from merlin.infradead.org ([205.233.59.134]:54718 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750820AbeEDKpy (ORCPT ); Fri, 4 May 2018 06:45:54 -0400 Date: Fri, 4 May 2018 12:45:39 +0200 From: Peter Zijlstra To: Alexander Shishkin Cc: Paolo Bonzini , Luwei Kang , kvm@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, rkrcmar@redhat.com, linux-kernel@vger.kernel.org, joro@8bytes.org, chao.p.peng@linux.intel.com Subject: Re: [PATCH v7 06/13] KVM: x86: Add Intel Processor Trace virtualization mode Message-ID: <20180504104539.GM12217@hirez.programming.kicks-ass.net> References: <1525349323-9938-1-git-send-email-luwei.kang@intel.com> <1525349323-9938-7-git-send-email-luwei.kang@intel.com> <20180503113223.x2ykby6wglppgdwf@um.fi.intel.com> <47494e95-edcb-e8b5-0a32-004e9470dbdf@redhat.com> <20180503120215.dev7ti43zk7yoovn@um.fi.intel.com> <221c297b-1270-371b-70a3-4cff4bed7a7e@redhat.com> <20180503124847.tcrizs2sxy3j6mu2@um.fi.intel.com> <26505f7a-9e6b-efb9-e5f9-8aae3756be49@redhat.com> <20180503133823.tqbraql3b7ltuo6a@um.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180503133823.tqbraql3b7ltuo6a@um.fi.intel.com> User-Agent: Mutt/1.9.5 (2018-04-13) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 03, 2018 at 04:38:23PM +0300, Alexander Shishkin wrote: > On Thu, May 03, 2018 at 02:50:12PM +0200, Paolo Bonzini wrote: > > And you still need the module parameter to decide > > whether the host is _allowed_ to cause incomplete traces in the guest. > > Or rather a parameter to decide who wins in case both host and guest want > to trace the guest. That's arguably better than having different versions of > PT in the guest depending on a module parameter setting. Yes, that sounds like a much better approach.