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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 A6FF1ECE58D for ; Wed, 9 Oct 2019 06:44:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7EC4320B7C for ; Wed, 9 Oct 2019 06:44:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726349AbfJIGoz (ORCPT ); Wed, 9 Oct 2019 02:44:55 -0400 Received: from mga01.intel.com ([192.55.52.88]:37246 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725914AbfJIGoy (ORCPT ); Wed, 9 Oct 2019 02:44:54 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Oct 2019 23:44:53 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.67,273,1566889200"; d="scan'208";a="368658906" Received: from unknown (HELO localhost) ([10.239.159.128]) by orsmga005.jf.intel.com with ESMTP; 08 Oct 2019 23:44:51 -0700 Date: Wed, 9 Oct 2019 14:46:48 +0800 From: Yang Weijiang To: Jim Mattson Cc: Yang Weijiang , kvm list , LKML , Paolo Bonzini , Sean Christopherson , "Michael S. Tsirkin" , Radim =?utf-8?B?S3LEjW3DocWZ?= Subject: Re: [PATCH v7 6/7] KVM: x86: Load Guest fpu state when accessing MSRs managed by XSAVES Message-ID: <20191009064648.GD27851@local-michael-cet-test> References: <20190927021927.23057-1-weijiang.yang@intel.com> <20190927021927.23057-7-weijiang.yang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.3 (2019-02-01) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, Oct 02, 2019 at 12:56:30PM -0700, Jim Mattson wrote: > On Thu, Sep 26, 2019 at 7:17 PM Yang Weijiang wrote: > > > > From: Sean Christopherson > > > /* > > * Read or write a bunch of msrs. All parameters are kernel addresses. > > * > > @@ -3009,11 +3017,23 @@ static int __msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs *msrs, > > int (*do_msr)(struct kvm_vcpu *vcpu, > > unsigned index, u64 *data)) > > { > > + bool fpu_loaded = false; > > int i; > > + const u64 cet_bits = XFEATURE_MASK_CET_USER | XFEATURE_MASK_CET_KERNEL; > > + bool cet_xss = kvm_x86_ops->xsaves_supported() && > > + (kvm_supported_xss() & cet_bits); > > It seems like I've seen a lot of checks like this. Can this be > simplified (throughout this series) by sinking the > kvm_x86_ops->xsaves_supported() check into kvm_supported_xss()? That > is, shouldn't kvm_supported_xss() return 0 if > kvm_x86_ops->xsaves_supported() is false? > OK, let me add this check, thank you! > > - for (i = 0; i < msrs->nmsrs; ++i) > > + for (i = 0; i < msrs->nmsrs; ++i) { > > + if (!fpu_loaded && cet_xss && > > + is_xsaves_msr(entries[i].index)) { > > + kvm_load_guest_fpu(vcpu); > > + fpu_loaded = true; > > + } > > if (do_msr(vcpu, entries[i].index, &entries[i].data)) > > break; > > + } > > + if (fpu_loaded) > > + kvm_put_guest_fpu(vcpu); > > > > return i; > > } > > -- > > 2.17.2 > >