From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937249AbdIZQvj (ORCPT ); Tue, 26 Sep 2017 12:51:39 -0400 Received: from mga05.intel.com ([192.55.52.43]:45487 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935892AbdIZQvi (ORCPT ); Tue, 26 Sep 2017 12:51:38 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.42,441,1500966000"; d="scan'208";a="1223982615" Date: Tue, 26 Sep 2017 09:51:37 -0700 From: Andi Kleen To: Wei Wang Cc: virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, mst@redhat.com, rkrcmar@redhat.com, mingo@redhat.com Subject: Re: [PATCH v1 0/4] Enable LBR for the guest Message-ID: <20170926165137.GR4311@tassilo.jf.intel.com> References: <1506314696-4632-1-git-send-email-wei.w.wang@intel.com> <20170925145908.GN4311@tassilo.jf.intel.com> <59CA1417.7070602@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <59CA1417.7070602@intel.com> User-Agent: Mutt/1.8.3 (2017-05-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On the other side, it seems that the (guest) kernel driver also works > without > the above being supported, should we change it to report error and stop > using the PMU features when the check of the above two fails (at > intel_pmu_init())? You could add the extra check for the LBR code yes, although it already checks if the LBR MSRs work, so in practice it's likely already covered. -Andi