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=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 66638C2BA83 for ; Fri, 7 Feb 2020 18:16:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4786020726 for ; Fri, 7 Feb 2020 18:16:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727766AbgBGSQ4 (ORCPT ); Fri, 7 Feb 2020 13:16:56 -0500 Received: from mx01.bbu.dsd.mx.bitdefender.com ([91.199.104.161]:40732 "EHLO mx01.bbu.dsd.mx.bitdefender.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727698AbgBGSQy (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 6CF26305D35B; 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 56E5E3052072; 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 61/78] KVM: introspection: restore the state of CR3 interception on unhook Date: Fri, 7 Feb 2020 20:16:19 +0200 Message-Id: <20200207181636.1065-62-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 CR3-write 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 | 64 ++++++++++++++++++++++++++++++-- arch/x86/kvm/svm.c | 5 +++ arch/x86/kvm/vmx/vmx.c | 5 +++ 4 files changed, 75 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h index 4ac209cb4ebf..24f3f8fdee62 100644 --- a/arch/x86/include/asm/kvmi_host.h +++ b/arch/x86/include/asm/kvmi_host.h @@ -13,6 +13,7 @@ struct kvmi_monitor_interception { struct kvmi_interception { bool restore_interception; struct kvmi_monitor_interception breakpoint; + struct kvmi_monitor_interception cr3w; }; struct kvm_vcpu_arch_introspection { @@ -28,6 +29,7 @@ bool kvmi_monitor_bp_intercept(struct kvm_vcpu *vcpu, u32 dbg); bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr, unsigned long old_value, unsigned long *new_value); bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu); +bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu, bool enable); #else /* CONFIG_KVM_INTROSPECTION */ @@ -37,6 +39,8 @@ static inline bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr, unsigned long old_value, unsigned long *new_value) { return true; } 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; } #endif /* CONFIG_KVM_INTROSPECTION */ diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c index 9917295e9a56..a522d4b1fa09 100644 --- a/arch/x86/kvm/kvmi.c +++ b/arch/x86/kvm/kvmi.c @@ -258,6 +258,59 @@ static void kvmi_arch_disable_bp_intercept(struct kvm_vcpu *vcpu) vcpu->arch.kvmi->breakpoint.kvm_intercepted = false; } +static bool monitor_cr3w_fct_kvmi(struct kvm_vcpu *vcpu, bool enable) +{ + vcpu->arch.kvmi->cr3w.kvmi_intercepted = enable; + + if (enable) + vcpu->arch.kvmi->cr3w.kvm_intercepted = + kvm_x86_ops->cr3_write_intercepted(vcpu); + else if (vcpu->arch.kvmi->cr3w.kvm_intercepted) + return true; + + return false; +} + +static bool monitor_cr3w_fct_kvm(struct kvm_vcpu *vcpu, bool enable) +{ + if (!vcpu->arch.kvmi->cr3w.kvmi_intercepted) + return false; + + vcpu->arch.kvmi->cr3w.kvm_intercepted = enable; + + if (!enable) + return true; + + return false; +} + +/* + * Returns true if one side (kvm or kvmi) tries to disable the CR3 write + * interception while the other side is still tracking it. + */ +bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu, bool enable) +{ + struct kvmi_interception *arch_vcpui = READ_ONCE(vcpu->arch.kvmi); + + return (arch_vcpui && arch_vcpui->cr3w.monitor_fct(vcpu, enable)); +} +EXPORT_SYMBOL(kvmi_monitor_cr3w_intercept); + +static void kvmi_control_cr3w_intercept(struct kvm_vcpu *vcpu, bool enable) +{ + vcpu->arch.kvmi->cr3w.monitor_fct = monitor_cr3w_fct_kvmi; + kvm_x86_ops->control_cr3_intercept(vcpu, CR_TYPE_W, enable); + vcpu->arch.kvmi->cr3w.monitor_fct = monitor_cr3w_fct_kvm; +} + +static void kvmi_arch_disable_cr3w_intercept(struct kvm_vcpu *vcpu) +{ + kvmi_control_cr3w_intercept(vcpu, false); + + vcpu->arch.kvmi->cr3w.kvmi_intercepted = false; + vcpu->arch.kvmi->cr3w.kvm_intercepted = false; +} + int kvmi_arch_cmd_control_intercept(struct kvm_vcpu *vcpu, unsigned int event_id, bool enable) { @@ -302,6 +355,7 @@ bool kvmi_arch_restore_interception(struct kvm_vcpu *vcpu) return false; kvmi_arch_disable_bp_intercept(vcpu); + kvmi_arch_disable_cr3w_intercept(vcpu); return true; } @@ -315,8 +369,13 @@ bool kvmi_arch_vcpu_alloc(struct kvm_vcpu *vcpu) return false; arch_vcpui->breakpoint.monitor_fct = monitor_bp_fct_kvm; + arch_vcpui->cr3w.monitor_fct = monitor_cr3w_fct_kvm; - /* pair with kvmi_monitor_bp_intercept() */ + /* + * paired with: + * - kvmi_monitor_bp_intercept() + * - kvmi_monitor_cr3w_intercept() + */ smp_wmb(); WRITE_ONCE(vcpu->arch.kvmi, arch_vcpui); @@ -354,8 +413,7 @@ int kvmi_arch_cmd_vcpu_control_cr(struct kvm_vcpu *vcpu, case 0: break; case 3: - kvm_x86_ops->control_cr3_intercept(vcpu, CR_TYPE_W, - req->enable); + kvmi_control_cr3w_intercept(vcpu, req->enable); break; case 4: break; diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 37b018988d7d..909308711bb7 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -7326,6 +7326,11 @@ static void svm_control_cr3_intercept(struct kvm_vcpu *vcpu, int type, { struct vcpu_svm *svm = to_svm(vcpu); +#ifdef CONFIG_KVM_INTROSPECTION + if ((type & CR_TYPE_W) && kvmi_monitor_cr3w_intercept(vcpu, enable)) + type &= ~CR_TYPE_W; +#endif /* CONFIG_KVM_INTROSPECTION */ + if (type & CR_TYPE_R) enable ? set_cr_intercept(svm, INTERCEPT_CR3_READ) : clr_cr_intercept(svm, INTERCEPT_CR3_READ); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index d3d7908995b5..157dfc3f756a 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -2907,6 +2907,11 @@ static void vmx_control_cr3_intercept(struct kvm_vcpu *vcpu, int type, struct vcpu_vmx *vmx = to_vmx(vcpu); u32 cr3_exec_control = 0; +#ifdef CONFIG_KVM_INTROSPECTION + if ((type & CR_TYPE_W) && kvmi_monitor_cr3w_intercept(vcpu, enable)) + type &= ~CR_TYPE_W; +#endif /* CONFIG_KVM_INTROSPECTION */ + if (type & CR_TYPE_R) cr3_exec_control |= CPU_BASED_CR3_STORE_EXITING; if (type & CR_TYPE_W)