From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751603AbeECMNJ (ORCPT ); Thu, 3 May 2018 08:13:09 -0400 Received: from mga03.intel.com ([134.134.136.65]:48675 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750930AbeECMNI (ORCPT ); Thu, 3 May 2018 08:13:08 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,358,1520924400"; d="scan'208";a="225491764" Date: Thu, 3 May 2018 15:13:01 +0300 From: Alexander Shishkin To: "Kang, Luwei" Cc: Alexander Shishkin , "kvm@vger.kernel.org" , "tglx@linutronix.de" , "mingo@redhat.com" , "hpa@zytor.com" , "x86@kernel.org" , "pbonzini@redhat.com" , "rkrcmar@redhat.com" , "linux-kernel@vger.kernel.org" , "joro@8bytes.org" , "peterz@infradead.org" , "chao.p.peng@linux.intel.com" Subject: Re: [PATCH v7 05/13] perf/x86/intel/pt: Introduce a new function to get capability of Intel PT Message-ID: <20180503121301.nlbm4cotbv26tc7l@um.fi.intel.com> References: <1525349323-9938-1-git-send-email-luwei.kang@intel.com> <1525349323-9938-6-git-send-email-luwei.kang@intel.com> <20180503105032.h73n5lcrwkdbahgm@um.fi.intel.com> <82D7661F83C1A047AF7DC287873BF1E167F6DDCE@SHSMSX101.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <82D7661F83C1A047AF7DC287873BF1E167F6DDCE@SHSMSX101.ccr.corp.intel.com> User-Agent: NeoMutt/20171215 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 03, 2018 at 11:04:52AM +0000, Kang, Luwei wrote: > > > New function __pt_cap_get() will be invoked in KVM to check if a > > > specific capability is availiable in KVM guest. > > > Another function pt_cap_get() can only check the hardware capabilities > > > but this may different with KVM guest because some features may not be > > > exposed to guest. > > > > Do we really need both in KVM? > > Yes, KVM need get host capability to estimate if can expose this feature > to guest Can you elaborate on this, what information do we need besides MSR_IA32_VMX_MISC[14]? Thanks, -- Alex