From patchwork Tue Sep 14 15:48:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxim Levitsky X-Patchwork-Id: 12494027 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=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 95762C433F5 for ; Tue, 14 Sep 2021 15:50:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D7BC61252 for ; Tue, 14 Sep 2021 15:50:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235486AbhINPvo (ORCPT ); Tue, 14 Sep 2021 11:51:44 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:23127 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235505AbhINPvV (ORCPT ); Tue, 14 Sep 2021 11:51:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631634603; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=i57uulpf45Axgq/0Xg7VZTg9GdN6y//kXUWT8wj5cmc=; b=fJl0nUb5esWUZJBuAVv7lspqPK628zu/VTM8gyRjMlr+JKbnvIhhix0v5XIq5dXWJyRoEa H2hZegCkuhHZEHULYcqdgmVZvM2z87yYhRXMI23uKGJFikPLnAlxRz8bILDMw4DuA+qNkW DOkhB7yHj42q7pMN4olJ9XiO5xRWV4U= 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-29-MuID-62JN4qcBb3K7inOUw-1; Tue, 14 Sep 2021 11:50:02 -0400 X-MC-Unique: MuID-62JN4qcBb3K7inOUw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 49F621084683; Tue, 14 Sep 2021 15:50:00 +0000 (UTC) Received: from localhost.localdomain (unknown [10.35.206.50]) by smtp.corp.redhat.com (Postfix) with ESMTP id 80FB95C1BB; Tue, 14 Sep 2021 15:49:52 +0000 (UTC) From: Maxim Levitsky To: kvm@vger.kernel.org Cc: Vitaly Kuznetsov , Paolo Bonzini , Borislav Petkov , Bandan Das , linux-kernel@vger.kernel.org (open list), Joerg Roedel , Ingo Molnar , Wei Huang , Sean Christopherson , linux-kselftest@vger.kernel.org (open list:KERNEL SELFTEST FRAMEWORK), Maxim Levitsky , "H. Peter Anvin" , Jim Mattson , Thomas Gleixner , x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)), Shuah Khan , Wanpeng Li Subject: [PATCH 10/14] KVM: x86: nSVM: implement nested LBR virtualization Date: Tue, 14 Sep 2021 18:48:21 +0300 Message-Id: <20210914154825.104886-11-mlevitsk@redhat.com> In-Reply-To: <20210914154825.104886-1-mlevitsk@redhat.com> References: <20210914154825.104886-1-mlevitsk@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org This was tested with kvm-unit-test that was developed for this purpose. Signed-off-by: Maxim Levitsky --- arch/x86/kvm/svm/nested.c | 21 +++++++++++++++++++-- arch/x86/kvm/svm/svm.c | 9 +++++++++ arch/x86/kvm/svm/svm.h | 1 + 3 files changed, 29 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index c6f09b591696..aadbff9b6514 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -503,8 +503,19 @@ static void nested_vmcb02_prepare_save(struct vcpu_svm *svm, struct vmcb *vmcb12 vmcb_mark_dirty(svm->vmcb, VMCB_DR); } - if (unlikely(svm->vmcb01.ptr->control.virt_ext & LBR_CTL_ENABLE_MASK)) + if (unlikely(svm->lbrv_enabled && (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK))) { + svm_copy_lbrs(vmcb12, svm->vmcb); + /* + * TODO: to avoid TOC/TOU race, + * make sure that we only pick LBR enable bit from + * the guest. + */ + svm->vmcb->save.dbgctl &= LBR_CTL_ENABLE_MASK; + svm_update_lbrv(&svm->vcpu); + + } else if (unlikely(svm->vmcb01.ptr->control.virt_ext & LBR_CTL_ENABLE_MASK)) { svm_copy_lbrs(svm->vmcb01.ptr, svm->vmcb); + } } static void nested_vmcb02_prepare_control(struct vcpu_svm *svm) @@ -555,6 +566,9 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm) svm->vmcb->control.virt_ext = svm->vmcb01.ptr->control.virt_ext & LBR_CTL_ENABLE_MASK; + if (svm->lbrv_enabled) + svm->vmcb->control.virt_ext |= + (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK); nested_svm_transition_tlb_flush(vcpu); @@ -814,7 +828,10 @@ int nested_svm_vmexit(struct vcpu_svm *svm) svm_switch_vmcb(svm, &svm->vmcb01); - if (unlikely(svm->vmcb->control.virt_ext & LBR_CTL_ENABLE_MASK)) { + if (unlikely(svm->lbrv_enabled && (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK))) { + svm_copy_lbrs(svm->nested.vmcb02.ptr, vmcb12); + svm_update_lbrv(vcpu); + } else if (unlikely(svm->vmcb->control.virt_ext & LBR_CTL_ENABLE_MASK)) { svm_copy_lbrs(svm->nested.vmcb02.ptr, svm->vmcb); svm_update_lbrv(vcpu); } diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 981cc9765b95..66f99e8d804c 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -877,6 +877,10 @@ void svm_update_lbrv(struct kvm_vcpu *vcpu) bool current_enable_lbrv = !!(svm->vmcb->control.virt_ext & LBR_CTL_ENABLE_MASK); + if (unlikely(is_guest_mode(vcpu) && svm->lbrv_enabled)) + if (unlikely(svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK)) + enable_lbrv = true; + if (enable_lbrv == current_enable_lbrv) return; @@ -1006,6 +1010,9 @@ static __init void svm_set_cpu_caps(void) if (npt_enabled) kvm_cpu_cap_set(X86_FEATURE_NPT); + if (lbrv) + kvm_cpu_cap_set(X86_FEATURE_LBRV); + /* Nested VM can receive #VMEXIT instead of triggering #GP */ kvm_cpu_cap_set(X86_FEATURE_SVME_ADDR_CHK); } @@ -4081,6 +4088,8 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) svm->nrips_enabled = kvm_cpu_cap_has(X86_FEATURE_NRIPS) && guest_cpuid_has(vcpu, X86_FEATURE_NRIPS); + svm->lbrv_enabled = lbrv && guest_cpuid_has(vcpu, X86_FEATURE_LBRV); + svm_recalc_instruction_intercepts(vcpu, svm); /* For sev guests, the memory encryption bit is not reserved in CR3. */ diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 0c351e9c4d6d..c9a81e18707d 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -161,6 +161,7 @@ struct vcpu_svm { /* cached guest cpuid flags for faster access */ bool nrips_enabled : 1; + bool lbrv_enabled : 1; u32 ldr_reg; u32 dfr_reg;