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=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 DC765C433F5 for ; Sun, 12 Sep 2021 10:36:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B6D4C61209 for ; Sun, 12 Sep 2021 10:36:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234965AbhILKhh (ORCPT ); Sun, 12 Sep 2021 06:37:37 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:40812 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229597AbhILKhg (ORCPT ); Sun, 12 Sep 2021 06:37:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631442982; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SJrlF3qoDx/aav2O69lvlRtO6fUeYfbdtCxqNNdYeAU=; b=Jssr3vQ0tKCD78w8Fou+CZgtCAOom78XCqgzPi6CTT/A1go3jyuUuuXy/ry0x0SQ7pChXc /i50ULPAdxDylezyicsTlntLq3bbLiwss+zKD/zk55Fmi4I2Cj9g+HLOCU5r/r1BATYH/X pnjbkeGMB7dJcXowMILjmY71g4f1SW4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-247-EGGFgw44MBKK-GYQVldqYw-1; Sun, 12 Sep 2021 06:36:00 -0400 X-MC-Unique: EGGFgw44MBKK-GYQVldqYw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 34F7E1808300; Sun, 12 Sep 2021 10:35:59 +0000 (UTC) Received: from starship (unknown [10.35.206.50]) by smtp.corp.redhat.com (Postfix) with ESMTP id A338A60C04; Sun, 12 Sep 2021 10:35:54 +0000 (UTC) Message-ID: <5fb5397289ba9ad44c9c959a5ecc4a1cfce72f00.camel@redhat.com> Subject: Re: [PATCH v2 3/3] KVM: nSVM: call KVM_REQ_GET_NESTED_STATE_PAGES on exit from SMM mode From: Maxim Levitsky To: Sean Christopherson Cc: kvm@vger.kernel.org, Joerg Roedel , Thomas Gleixner , Jim Mattson , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , "open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , Wanpeng Li , Paolo Bonzini , Borislav Petkov , "H. Peter Anvin" , Ingo Molnar , Vitaly Kuznetsov Date: Sun, 12 Sep 2021 13:35:53 +0300 In-Reply-To: References: <20210823114618.1184209-1-mlevitsk@redhat.com> <20210823114618.1184209-4-mlevitsk@redhat.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-2.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2021-09-09 at 00:59 +0000, Sean Christopherson wrote: > On Mon, Aug 23, 2021, Maxim Levitsky wrote: > > This allows nested SVM code to be more similar to nested VMX code. > > > > Signed-off-by: Maxim Levitsky > > --- > > arch/x86/kvm/svm/nested.c | 9 ++++++--- > > arch/x86/kvm/svm/svm.c | 8 +++++++- > > arch/x86/kvm/svm/svm.h | 3 ++- > > 3 files changed, 15 insertions(+), 5 deletions(-) > > > > diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c > > index 5e13357da21e..678fd21f6077 100644 > > --- a/arch/x86/kvm/svm/nested.c > > +++ b/arch/x86/kvm/svm/nested.c > > @@ -572,7 +572,7 @@ static void nested_svm_copy_common_state(struct vmcb *from_vmcb, struct vmcb *to > > } > > > > int enter_svm_guest_mode(struct kvm_vcpu *vcpu, u64 vmcb12_gpa, > > - struct vmcb *vmcb12) > > + struct vmcb *vmcb12, bool from_entry) > > from_vmrun would be a better name. VMX uses the slightly absstract from_vmentry > because of the VMLAUNCH vs. VMRESUME silliness. If we want to explicitly follow > VMX then from_vmentry would be more appropriate, but I don't see any reason not > to be more precise. OK. > > > { > > struct vcpu_svm *svm = to_svm(vcpu); > > int ret; > > @@ -602,13 +602,16 @@ int enter_svm_guest_mode(struct kvm_vcpu *vcpu, u64 vmcb12_gpa, > > nested_vmcb02_prepare_save(svm, vmcb12); > > > > ret = nested_svm_load_cr3(&svm->vcpu, vmcb12->save.cr3, > > - nested_npt_enabled(svm), true); > > + nested_npt_enabled(svm), from_entry); > > if (ret) > > return ret; > > > > if (!npt_enabled) > > vcpu->arch.mmu->inject_page_fault = svm_inject_page_fault_nested; > > > > + if (!from_entry) > > + kvm_make_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu); > > + > > svm_set_gif(svm, true); > > > > return 0; > > @@ -674,7 +677,7 @@ int nested_svm_vmrun(struct kvm_vcpu *vcpu) > > > > svm->nested.nested_run_pending = 1; > > > > - if (enter_svm_guest_mode(vcpu, vmcb12_gpa, vmcb12)) > > + if (enter_svm_guest_mode(vcpu, vmcb12_gpa, vmcb12, true)) > > goto out_exit_err; > > > > if (nested_svm_vmrun_msrpm(svm)) > > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c > > index ea7a4dacd42f..76ee15af8c48 100644 > > --- a/arch/x86/kvm/svm/svm.c > > +++ b/arch/x86/kvm/svm/svm.c > > @@ -4354,6 +4354,12 @@ static int svm_leave_smm(struct kvm_vcpu *vcpu, const char *smstate) > > if (svm_allocate_nested(svm)) > > return 1; > > > > + /* Exit from the SMM to the non root mode also uses > > + * the KVM_REQ_GET_NESTED_STATE_PAGES request, > > + * but in this case the pdptrs must be always reloaded > > + */ > > + vcpu->arch.pdptrs_from_userspace = false; > > Hmm, I think this belongs in the previous patch. And I would probably go so far > as to say it belongs in emulator_leave_smm(), i.e. pdptrs_from_userspace should > be cleared on RSM regardless of what mode is being resumed. I actually don't think that this belongs to a previous patch, since this issue didn't exist on SVM, since it didn't call the KVM_REQ_GET_NESTED_STATE_PAGES. However I do agree with you that it makes sense to move this hack to the common x86 code. I had put it to kvm_smm_changed, and will soon send a new version. > > > + > > /* > > * Restore L1 host state from L1 HSAVE area as VMCB01 was > > * used during SMM (see svm_enter_smm()) > > @@ -4368,7 +4374,7 @@ static int svm_leave_smm(struct kvm_vcpu *vcpu, const char *smstate) > > > > vmcb12 = map.hva; > > nested_load_control_from_vmcb12(svm, &vmcb12->control); > > - ret = enter_svm_guest_mode(vcpu, vmcb12_gpa, vmcb12); > > + ret = enter_svm_guest_mode(vcpu, vmcb12_gpa, vmcb12, false); > > > > kvm_vcpu_unmap(vcpu, &map, true); > > kvm_vcpu_unmap(vcpu, &map_save, true); > > diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h > > index 524d943f3efc..51ffa46ab257 100644 > > --- a/arch/x86/kvm/svm/svm.h > > +++ b/arch/x86/kvm/svm/svm.h > > @@ -459,7 +459,8 @@ static inline bool nested_exit_on_nmi(struct vcpu_svm *svm) > > return vmcb_is_intercept(&svm->nested.ctl, INTERCEPT_NMI); > > } > > > > -int enter_svm_guest_mode(struct kvm_vcpu *vcpu, u64 vmcb_gpa, struct vmcb *vmcb12); > > +int enter_svm_guest_mode(struct kvm_vcpu *vcpu, > > + u64 vmcb_gpa, struct vmcb *vmcb12, bool from_entry); > > Alignment is funky, it can/should match the definition, e.g. Oops, forgot to check the prototype - these things you write once and forget about them, as long as it compiles :-) > > int enter_svm_guest_mode(struct kvm_vcpu *vcpu, u64 vmcb12_gpa, > struct vmcb *vmcb12, bool from_entry); > > > void svm_leave_nested(struct vcpu_svm *svm); > > void svm_free_nested(struct vcpu_svm *svm); > > int svm_allocate_nested(struct vcpu_svm *svm); > > -- > > 2.26.3 > > Thanks for the review! Best regards, Maxim Levitsky