From patchwork Mon Nov 1 14:03:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxim Levitsky X-Patchwork-Id: 12596477 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3180FC433EF for ; Mon, 1 Nov 2021 14:04:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A324610F7 for ; Mon, 1 Nov 2021 14:04:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232027AbhKAOHJ (ORCPT ); Mon, 1 Nov 2021 10:07:09 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:21059 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231874AbhKAOHI (ORCPT ); Mon, 1 Nov 2021 10:07:08 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1635775475; 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=gM7AO5OOtc3qIzzXj1XX3dC+Uumbk2mOegBA6a5u5zw=; b=CQ5u6CspOrvSzT3vpjl2bikx6WMHR8lapYK6tGSKMwAmEftvdxcV7naL09cD+n7g8I/L/S XvwPZQwZqAzXSEKphnQ+bNf2wdmcUX5Ep9cHqSCc7I1MdZTPbYv30+7bCulOHdYH51GjUo 8rAXbmF1bVSy0o1xxC3xKKTQVyDTELk= 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-403-xdvsj5LgPpmmI589lXHEHg-1; Mon, 01 Nov 2021 10:04:34 -0400 X-MC-Unique: xdvsj5LgPpmmI589lXHEHg-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 21FDD802682; Mon, 1 Nov 2021 14:04:32 +0000 (UTC) Received: from localhost.localdomain (unknown [10.40.194.243]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0FC6C100EB3D; Mon, 1 Nov 2021 14:04:05 +0000 (UTC) From: Maxim Levitsky To: kvm@vger.kernel.org Cc: Shuah Khan , linux-kselftest@vger.kernel.org (open list:KERNEL SELFTEST FRAMEWORK), Borislav Petkov , Paolo Bonzini , linux-kernel@vger.kernel.org (open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)), Joerg Roedel , "H. Peter Anvin" , Maxim Levitsky , Thomas Gleixner , Vitaly Kuznetsov , Bandan Das , Wanpeng Li , Jim Mattson , Sean Christopherson , Wei Huang , x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)), Ingo Molnar Subject: [PATCH v2 3/6] KVM: x86: nSVM: implement nested LBR virtualization Date: Mon, 1 Nov 2021 16:03:21 +0200 Message-Id: <20211101140324.197921-4-mlevitsk@redhat.com> In-Reply-To: <20211101140324.197921-1-mlevitsk@redhat.com> References: <20211101140324.197921-1-mlevitsk@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 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 | 8 ++++++++ arch/x86/kvm/svm/svm.h | 1 + 3 files changed, 28 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 9239631846d88..eca0f2f41bf30 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -518,8 +518,19 @@ 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) @@ -579,6 +590,9 @@ 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); @@ -841,7 +855,10 @@ 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 c08f8804d107f..0ae8fa9400902 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -884,6 +884,10 @@ 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; @@ -1016,6 +1020,9 @@ static __init void svm_set_cpu_caps(void) if (tsc_scaling) kvm_cpu_cap_set(X86_FEATURE_TSCRATEMSR); + 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); } @@ -4147,6 +4154,7 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) guest_cpuid_has(vcpu, X86_FEATURE_NRIPS); svm->tsc_scaling_enabled = tsc_scaling && guest_cpuid_has(vcpu, X86_FEATURE_TSCRATEMSR); + svm->lbrv_enabled = lbrv && guest_cpuid_has(vcpu, X86_FEATURE_LBRV); svm_recalc_instruction_intercepts(vcpu, svm); diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index ff84f84f697f7..c3d46fdf4b9ad 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -164,6 +164,7 @@ struct vcpu_svm { /* cached guest cpuid flags for faster access */ bool nrips_enabled : 1; bool tsc_scaling_enabled : 1; + bool lbrv_enabled : 1; u32 ldr_reg; u32 dfr_reg;