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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 8ED76C2BA83 for ; Fri, 7 Feb 2020 18:17:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6CB1120726 for ; Fri, 7 Feb 2020 18:17:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727842AbgBGSQ5 (ORCPT ); Fri, 7 Feb 2020 13:16:57 -0500 Received: from mx01.bbu.dsd.mx.bitdefender.com ([91.199.104.161]:40642 "EHLO mx01.bbu.dsd.mx.bitdefender.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727681AbgBGSQy (ORCPT ); Fri, 7 Feb 2020 13:16:54 -0500 Received: from smtp.bitdefender.com (smtp01.buh.bitdefender.com [10.17.80.75]) by mx01.bbu.dsd.mx.bitdefender.com (Postfix) with ESMTPS id B89ED305D362; Fri, 7 Feb 2020 20:16:41 +0200 (EET) Received: from host.bbu.bitdefender.biz (unknown [195.210.4.22]) by smtp.bitdefender.com (Postfix) with ESMTPSA id AA951305207A; Fri, 7 Feb 2020 20:16:41 +0200 (EET) From: =?UTF-8?q?Adalbert=20Laz=C4=83r?= To: kvm@vger.kernel.org Cc: virtualization@lists.linux-foundation.org, Paolo Bonzini , Sean Christopherson , =?UTF-8?q?Nicu=C8=99or=20C=C3=AE=C8=9Bu?= , =?UTF-8?q?Adalbert=20Laz=C4=83r?= Subject: [RFC PATCH v7 68/78] KVM: introspection: restore the state of descriptor interception on unhook Date: Fri, 7 Feb 2020 20:16:26 +0200 Message-Id: <20200207181636.1065-69-alazar@bitdefender.com> In-Reply-To: <20200207181636.1065-1-alazar@bitdefender.com> References: <20200207181636.1065-1-alazar@bitdefender.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Nicușor Cîțu This commit also ensures that the introspection tool and the userspace do not disable each other the descriptor access VM-exit. Signed-off-by: Nicușor Cîțu Signed-off-by: Adalbert Lazăr --- arch/x86/include/asm/kvmi_host.h | 4 +++ arch/x86/kvm/kvmi.c | 45 ++++++++++++++++++++++++++++++++ arch/x86/kvm/svm.c | 3 +++ arch/x86/kvm/vmx/vmx.c | 3 +++ 4 files changed, 55 insertions(+) diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h index 8f9e6bd2953a..10b251856c0e 100644 --- a/arch/x86/include/asm/kvmi_host.h +++ b/arch/x86/include/asm/kvmi_host.h @@ -14,6 +14,7 @@ struct kvmi_interception { bool restore_interception; struct kvmi_monitor_interception breakpoint; struct kvmi_monitor_interception cr3w; + struct kvmi_monitor_interception descriptor; }; struct kvm_vcpu_arch_introspection { @@ -31,6 +32,7 @@ bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr, bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu); bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu, bool enable); void kvmi_xsetbv_event(struct kvm_vcpu *vcpu); +bool kvmi_monitor_desc_intercept(struct kvm_vcpu *vcpu, bool enable); bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor, u8 write); #else /* CONFIG_KVM_INTROSPECTION */ @@ -44,6 +46,8 @@ static inline bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu) { return false; } static inline bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu, bool enable) { return false; } static inline void kvmi_xsetbv_event(struct kvm_vcpu *vcpu) { } +static inline bool kvmi_monitor_desc_intercept(struct kvm_vcpu *vcpu, + bool enable) { return false; } static inline bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor, u8 write) { return true; } diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c index ed9b45060e2a..048f0e1f9f79 100644 --- a/arch/x86/kvm/kvmi.c +++ b/arch/x86/kvm/kvmi.c @@ -311,12 +311,52 @@ static void kvmi_arch_disable_cr3w_intercept(struct kvm_vcpu *vcpu) vcpu->arch.kvmi->cr3w.kvm_intercepted = false; } +/* + * Returns true if one side (kvm or kvmi) tries to disable the descriptor + * interception while the other side is still tracking it. + */ +bool kvmi_monitor_desc_intercept(struct kvm_vcpu *vcpu, bool enable) +{ + struct kvmi_interception *arch_vcpui = READ_ONCE(vcpu->arch.kvmi); + + return (arch_vcpui && arch_vcpui->descriptor.monitor_fct(vcpu, enable)); +} +EXPORT_SYMBOL(kvmi_monitor_desc_intercept); + +static bool monitor_desc_fct_kvmi(struct kvm_vcpu *vcpu, bool enable) +{ + vcpu->arch.kvmi->descriptor.kvmi_intercepted = enable; + + if (enable) + vcpu->arch.kvmi->descriptor.kvm_intercepted = + kvm_x86_ops->desc_intercepted(vcpu); + else if (vcpu->arch.kvmi->descriptor.kvm_intercepted) + return true; + + return false; +} + +static bool monitor_desc_fct_kvm(struct kvm_vcpu *vcpu, bool enable) +{ + if (!vcpu->arch.kvmi->descriptor.kvmi_intercepted) + return false; + + vcpu->arch.kvmi->descriptor.kvm_intercepted = enable; + + if (!enable) + return true; + + return false; +} + static int kvmi_control_desc_intercept(struct kvm_vcpu *vcpu, bool enable) { if (!kvm_x86_ops->umip_emulated()) return -KVM_EOPNOTSUPP; + vcpu->arch.kvmi->descriptor.monitor_fct = monitor_desc_fct_kvmi; kvm_x86_ops->control_desc_intercept(vcpu, enable); + vcpu->arch.kvmi->descriptor.monitor_fct = monitor_desc_fct_kvm; return 0; } @@ -324,6 +364,9 @@ static int kvmi_control_desc_intercept(struct kvm_vcpu *vcpu, bool enable) static void kvmi_arch_disable_desc_intercept(struct kvm_vcpu *vcpu) { kvmi_control_desc_intercept(vcpu, false); + + vcpu->arch.kvmi->descriptor.kvmi_intercepted = false; + vcpu->arch.kvmi->descriptor.kvm_intercepted = false; } int kvmi_arch_cmd_control_intercept(struct kvm_vcpu *vcpu, @@ -389,11 +432,13 @@ bool kvmi_arch_vcpu_alloc(struct kvm_vcpu *vcpu) arch_vcpui->breakpoint.monitor_fct = monitor_bp_fct_kvm; arch_vcpui->cr3w.monitor_fct = monitor_cr3w_fct_kvm; + arch_vcpui->descriptor.monitor_fct = monitor_desc_fct_kvm; /* * paired with: * - kvmi_monitor_bp_intercept() * - kvmi_monitor_cr3w_intercept() + * - kvmi_monitor_desc_intercept() */ smp_wmb(); WRITE_ONCE(vcpu->arch.kvmi, arch_vcpui); diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 988eb6937515..7cd48ef25f59 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -7388,6 +7388,9 @@ static void svm_control_desc_intercept(struct kvm_vcpu *vcpu, bool enable) { struct vcpu_svm *svm = to_svm(vcpu); + if (kvmi_monitor_desc_intercept(vcpu, enable)) + return; + if (enable) { set_intercept(svm, INTERCEPT_STORE_IDTR); set_intercept(svm, INTERCEPT_STORE_GDTR); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 68986f600f98..e423dbbf3cf5 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -3008,6 +3008,9 @@ static void vmx_control_desc_intercept(struct kvm_vcpu *vcpu, bool enable) { struct vcpu_vmx *vmx = to_vmx(vcpu); + if (kvmi_monitor_desc_intercept(vcpu, enable)) + return; + if (enable) secondary_exec_controls_setbit(vmx, SECONDARY_EXEC_DESC); else