From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754852Ab1KGPrE (ORCPT ); Mon, 7 Nov 2011 10:47:04 -0500 Received: from merlin.infradead.org ([205.233.59.134]:46159 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751509Ab1KGPrD convert rfc822-to-8bit (ORCPT ); Mon, 7 Nov 2011 10:47:03 -0500 Subject: Re: [PATCHv2 7/9] KVM: Expose the architectural performance monitoring CPUID leaf From: Peter Zijlstra To: Gleb Natapov Cc: kvm@vger.kernel.org, avi@redhat.com, mtosatti@redhat.com, linux-kernel@vger.kernel.org, mingo@elte.hu, acme@ghostprotocols.net Date: Mon, 07 Nov 2011 16:45:57 +0100 In-Reply-To: <20111107154132.GH8670@redhat.com> References: <1320323618-10375-1-git-send-email-gleb@redhat.com> <1320323618-10375-8-git-send-email-gleb@redhat.com> <1320674987.18053.39.camel@twins> <20111107154132.GH8670@redhat.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Mailer: Evolution 3.0.3- Message-ID: <1320680757.17809.2.camel@twins> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2011-11-07 at 17:41 +0200, Gleb Natapov wrote: > > > + entry->eax = min(cap.version, 2) > > > + | (cap.num_counters_gp << 8) > > > + | (cap.bit_width_gp << 16) > > > + | (cap.events_mask_len << 24); > Do you mean by doing cpuid here directly instead of checking perf > capability? No I meant something like: union cpuid10_eax eax; eax.version = min(cap.version, 2); eax.bit_width = cap.bit_width; eax.num_counters = cap.num_counters; eax.mask_length = cap.mask_length; entry->eax = eax.full;