From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B2CF5C04AA7 for ; Mon, 13 May 2019 18:49:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 92D932070D for ; Mon, 13 May 2019 18:49:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728461AbfEMStc (ORCPT ); Mon, 13 May 2019 14:49:32 -0400 Received: from mga01.intel.com ([192.55.52.88]:12382 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728455AbfEMStc (ORCPT ); Mon, 13 May 2019 14:49:32 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 May 2019 11:49:31 -0700 X-ExtLoop1: 1 Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.36]) by fmsmga007.fm.intel.com with ESMTP; 13 May 2019 11:49:30 -0700 Date: Mon, 13 May 2019 11:49:30 -0700 From: Sean Christopherson To: Krish Sadhukhan Cc: kvm@vger.kernel.org, pbonzini@redhat.com, rkrcmar@redhat.com, jmattson@google.com Subject: Re: [PATCH 1/8][KVMnVMX]: Enable "load IA32_PERF_GLOBAL_CTRL" VM-exit control for nested guests Message-ID: <20190513184930.GF28561@linux.intel.com> References: <20190424231724.2014-1-krish.sadhukhan@oracle.com> <20190424231724.2014-2-krish.sadhukhan@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190424231724.2014-2-krish.sadhukhan@oracle.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, Apr 24, 2019 at 07:17:17PM -0400, Krish Sadhukhan wrote: > Signed-off-by: Krish Sadhukhan > Reviewed-by: Karl Heubaum > --- > arch/x86/kvm/vmx/nested.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > index 3170e291215d..42a4deb662c6 100644 > --- a/arch/x86/kvm/vmx/nested.c > +++ b/arch/x86/kvm/vmx/nested.c > @@ -5493,7 +5493,8 @@ void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps, > msrs->exit_ctls_high |= > VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR | > VM_EXIT_LOAD_IA32_EFER | VM_EXIT_SAVE_IA32_EFER | > - VM_EXIT_SAVE_VMX_PREEMPTION_TIMER | VM_EXIT_ACK_INTR_ON_EXIT; > + VM_EXIT_SAVE_VMX_PREEMPTION_TIMER | VM_EXIT_ACK_INTR_ON_EXIT | > + VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL; This exposes the control to L1 but doesn't implement the backing functionality. The backing functionality, consistency checks and exposure to L1 should be a single patch. The consistency checks could be added earlier, but I don't see much value in doing so given that the checks are (currently) a few lines. > > /* We support free control of debug control saving. */ > msrs->exit_ctls_low &= ~VM_EXIT_SAVE_DEBUG_CONTROLS; > -- > 2.17.2 >