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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C41CC4332F for ; Wed, 21 Dec 2022 08:38:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234005AbiLUIiB (ORCPT ); Wed, 21 Dec 2022 03:38:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57404 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229436AbiLUIh7 (ORCPT ); Wed, 21 Dec 2022 03:37:59 -0500 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B06981900A for ; Wed, 21 Dec 2022 00:37:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1671611878; x=1703147878; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=059t+y3jjueqih2iKv0vuhvacm6KzcVU3zoCRngc5NU=; b=D1jRx9Ke2F4Vgq4hFrbKGXq2Icf6YRN340GwaqgQYhOqHuu0KiYqUrUs 65kbFwdxOVh+Z2v/XZGGONx5slAGJyikwSFzHyi2qQ1gqKNafkKQNj/3h pPCGe/5mzQ0l93f3AEJN5tkoCdnPGOw6w0iPnqapNXqzkEgxlWqqJTDk4 1aXgOpFL/9GFSdhZCJVShKxIoVNK2mvfcpo/cdbISJtU3+JkOS7y4LEfx cGyjMpHOUeUYGmzDRKBywmRoibD7eutajaU2cdVneexHBqys5wiWf2Asc pWfStgVGsKW9IPMjtG44oY2r67KkhmFLECgjf2FLzGyBjyBXk+323Qgbu Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10567"; a="317454658" X-IronPort-AV: E=Sophos;i="5.96,262,1665471600"; d="scan'208";a="317454658" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Dec 2022 00:37:58 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10567"; a="651340120" X-IronPort-AV: E=Sophos;i="5.96,262,1665471600"; d="scan'208";a="651340120" Received: from xruan5-mobl.ccr.corp.intel.com (HELO localhost) ([10.255.29.248]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Dec 2022 00:37:53 -0800 Date: Wed, 21 Dec 2022 16:37:52 +0800 From: Yu Zhang To: Robert Hoo Cc: pbonzini@redhat.com, seanjc@google.com, kirill.shutemov@linux.intel.com, kvm@vger.kernel.org, Jingqi Liu Subject: Re: [PATCH v3 6/9] KVM: x86: Untag LAM bits when applicable Message-ID: <20221221083752.gv4iuopad2ghy5vg@linux.intel.com> References: <20221209044557.1496580-1-robert.hu@linux.intel.com> <20221209044557.1496580-7-robert.hu@linux.intel.com> <20221221081439.b4da6avrgvydjo3r@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221221081439.b4da6avrgvydjo3r@linux.intel.com> User-Agent: NeoMutt/20171215 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, Dec 21, 2022 at 04:14:39PM +0800, Yu Zhang wrote: > > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > > index 9985dbb63e7b..16ddd3fcd3cb 100644 > > --- a/arch/x86/kvm/vmx/vmx.c > > +++ b/arch/x86/kvm/vmx/vmx.c > > @@ -2134,6 +2134,9 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > > (!msr_info->host_initiated && > > !guest_cpuid_has(vcpu, X86_FEATURE_MPX))) > > return 1; > > + > > + data = kvm_untagged_addr(data, vcpu); > > Do we really need to take pains to trigger the kvm_untagged_addr() > unconditionally? I mean, LAM may not be enabled by the guest or even > not exposed to the guest at all. > Ouch... I just realized, that unlike the paging mode, LAM can be enabled per-thread, instead of per-VM... B.R. Yu