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=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 A2C20C433E1 for ; Mon, 13 Jul 2020 22:38:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7E0FD20890 for ; Mon, 13 Jul 2020 22:38:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726517AbgGMWiQ (ORCPT ); Mon, 13 Jul 2020 18:38:16 -0400 Received: from mga04.intel.com ([192.55.52.120]:5700 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726345AbgGMWiP (ORCPT ); Mon, 13 Jul 2020 18:38:15 -0400 IronPort-SDR: 44qvSvFyo2lKePg1IkSrTkh6K5bjZHrKtX7eDSAFhv+QIGKhPskQLOqp/pk2qRQvcBcJAFSORs gJ6Evsj2karQ== X-IronPort-AV: E=McAfee;i="6000,8403,9681"; a="146224462" X-IronPort-AV: E=Sophos;i="5.75,349,1589266800"; d="scan'208";a="146224462" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jul 2020 15:38:15 -0700 IronPort-SDR: IpyIMX0t1rB8a1TTalxn/v1J7mpdLo6d6Z5VYqRXv0StGB90ulFvBo7C0zNAGwuavejuV4PmA3 OlO8yrVixS9w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,349,1589266800"; d="scan'208";a="429551992" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.152]) by orsmga004.jf.intel.com with ESMTP; 13 Jul 2020 15:38:14 -0700 Date: Mon, 13 Jul 2020 15:38:14 -0700 From: Sean Christopherson To: Vitaly Kuznetsov Cc: kvm@vger.kernel.org, Paolo Bonzini , Wanpeng Li , Jim Mattson , Junaid Shahid , linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 5/9] KVM: nSVM: introduce nested_svm_load_cr3()/nested_npt_enabled() Message-ID: <20200713223814.GG29725@linux.intel.com> References: <20200710141157.1640173-1-vkuznets@redhat.com> <20200710141157.1640173-6-vkuznets@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200710141157.1640173-6-vkuznets@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 10, 2020 at 04:11:53PM +0200, Vitaly Kuznetsov wrote: > As a preparatory change for implementing nested specifig PGD switch for s/specifig/specific > nSVM (following nVMX' nested_vmx_load_cr3()) instead of relying on nVMX's > kvm_set_cr3() introduce nested_svm_load_cr3(). The changelog isn't all that helpful to understanding the actual change. All this is doing is wrapping kvm_set_cr3(), but that's not at all obvious from reading the above. E.g. Add nested_svm_load_cr3() as a pass-through to kvm_set_cr3() as a preparatory change for implementing nested specific PGD switch for nSVM, (following nVMx's nested_vmx_load_cr3()). > No functional change intended. > > Signed-off-by: Vitaly Kuznetsov > --- > arch/x86/kvm/svm/nested.c | 21 +++++++++++++++++++-- > 1 file changed, 19 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c > index 5e6c988a4e6b..180929f3dbef 100644 > --- a/arch/x86/kvm/svm/nested.c > +++ b/arch/x86/kvm/svm/nested.c > @@ -311,6 +311,21 @@ static void nested_vmcb_save_pending_event(struct vcpu_svm *svm, > nested_vmcb->control.exit_int_info = exit_int_info; > } > > +static inline bool nested_npt_enabled(struct vcpu_svm *svm) > +{ > + return svm->nested.ctl.nested_ctl & SVM_NESTED_CTL_NP_ENABLE; > +} > + > +/* > + * Load guest's cr3 at nested entry. @nested_npt is true if we are > + * emulating VM-Entry into a guest with NPT enabled. > + */ > +static int nested_svm_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3, > + bool nested_npt) IMO the addition of nested_npt_enabled() should be a separate patch, and the additoin of @nested_npt should be in patch 7. Hypothetically speaking, if nested_npt_enabled() is inaccurate at the call site in nested_prepare_vmcb_save(), then this patch is technically wrong even though it doesn't introduce a bug. Given that the call site of nested_svm_load_cr3() is moved in patch 7, I don't see any value in adding the placeholder parameter early. > +{ > + return kvm_set_cr3(vcpu, cr3); > +} > + > static void nested_prepare_vmcb_save(struct vcpu_svm *svm, struct vmcb *nested_vmcb) > { > /* Load the nested guest state */ > @@ -324,7 +339,8 @@ static void nested_prepare_vmcb_save(struct vcpu_svm *svm, struct vmcb *nested_v > svm_set_efer(&svm->vcpu, nested_vmcb->save.efer); > svm_set_cr0(&svm->vcpu, nested_vmcb->save.cr0); > svm_set_cr4(&svm->vcpu, nested_vmcb->save.cr4); > - (void)kvm_set_cr3(&svm->vcpu, nested_vmcb->save.cr3); > + (void)nested_svm_load_cr3(&svm->vcpu, nested_vmcb->save.cr3, > + nested_npt_enabled(svm)); > > svm->vmcb->save.cr2 = svm->vcpu.arch.cr2 = nested_vmcb->save.cr2; > kvm_rax_write(&svm->vcpu, nested_vmcb->save.rax); > @@ -343,7 +359,8 @@ static void nested_prepare_vmcb_save(struct vcpu_svm *svm, struct vmcb *nested_v > static void nested_prepare_vmcb_control(struct vcpu_svm *svm) > { > const u32 mask = V_INTR_MASKING_MASK | V_GIF_ENABLE_MASK | V_GIF_MASK; > - if (svm->nested.ctl.nested_ctl & SVM_NESTED_CTL_NP_ENABLE) > + > + if (nested_npt_enabled(svm)) > nested_svm_init_mmu_context(&svm->vcpu); > > /* Guest paging mode is active - reset mmu */ > -- > 2.25.4 >