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From: "Adalbert Lazăr" <alazar@bitdefender.com>
To: kvm@vger.kernel.org
Cc: "Adalbert Lazăr" <alazar@bitdefender.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Nicușor Cîțu" <ncitu@bitdefender.com>,
	virtualization@lists.linux-foundation.org
Subject: [PATCH v9 74/84] KVM: introspection: restore the state of descriptor-table register interception on unhook
Date: Wed, 22 Jul 2020 00:09:12 +0300
Message-ID: <20200721210922.7646-75-alazar@bitdefender.com> (raw)
In-Reply-To: <20200721210922.7646-1-alazar@bitdefender.com>

From: Nicușor Cîțu <ncitu@bitdefender.com>

This commit also ensures that the introspection tool and the userspace
do not disable each other the descriptor-table access VM-exit.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvmi_host.h |  4 +++
 arch/x86/kvm/kvmi.c              | 45 ++++++++++++++++++++++++++++++++
 arch/x86/kvm/svm/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 09ebed80a8cc..0ed1879fd250 100644
--- a/arch/x86/include/asm/kvmi_host.h
+++ b/arch/x86/include/asm/kvmi_host.h
@@ -17,6 +17,7 @@ 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 {
@@ -35,6 +36,7 @@ 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, u8 xcr,
 		       u64 old_value, u64 new_value);
+bool kvmi_monitor_desc_intercept(struct kvm_vcpu *vcpu, bool enable);
 bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor, bool write);
 
 #else /* CONFIG_KVM_INTROSPECTION */
@@ -50,6 +52,8 @@ 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, u8 xcr,
 					u64 old_value, u64 new_value) { }
+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,
 					 bool write) { return true; }
 
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 3ae43a4c8764..dfe1b887b4f3 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -361,12 +361,52 @@ 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.desc_ctrl_supported())
 		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;
 }
@@ -374,6 +414,9 @@ 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,
@@ -445,11 +488,13 @@ bool kvmi_arch_vcpu_alloc_interception(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/svm.c b/arch/x86/kvm/svm/svm.c
index a0b91007e484..20f6905b45aa 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1555,6 +1555,9 @@ 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 74bdcd4966ca..8d396a2d2309 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3162,6 +3162,9 @@ 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
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  parent reply index

Thread overview: 88+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-21 21:07 [PATCH v9 00/84] VM introspection Adalbert Lazăr
2020-07-21 21:07 ` [PATCH v9 01/84] signal: export kill_pid_info() Adalbert Lazăr
2020-07-22  6:36   ` Christoph Hellwig
2020-07-21 21:08 ` [PATCH v9 02/84] KVM: UAPI: add error codes used by the VM introspection code Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 03/84] KVM: add kvm_vcpu_kick_and_wait() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 04/84] KVM: add kvm_get_max_gfn() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 05/84] KVM: doc: fix the hypercall numbering Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 06/84] KVM: x86: add kvm_arch_vcpu_get_regs() and kvm_arch_vcpu_get_sregs() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 07/84] KVM: x86: add kvm_arch_vcpu_set_regs() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 08/84] KVM: x86: avoid injecting #PF when emulate the VMCALL instruction Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 09/84] KVM: x86: add .bp_intercepted() to struct kvm_x86_ops Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 10/84] KVM: x86: add .control_cr3_intercept() " Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 11/84] KVM: x86: add .cr3_write_intercepted() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 12/84] KVM: x86: add .desc_ctrl_supported() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 13/84] KVM: svm: add support for descriptor-table exits Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 14/84] KVM: x86: add .control_desc_intercept() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 15/84] KVM: x86: add .desc_intercepted() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 16/84] KVM: x86: export .msr_write_intercepted() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 17/84] KVM: x86: use MSR_TYPE_R, MSR_TYPE_W and MSR_TYPE_RW with AMD Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 18/84] KVM: svm: pass struct kvm_vcpu to set_msr_interception() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 19/84] KVM: vmx: pass struct kvm_vcpu to the intercept msr related functions Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 20/84] KVM: x86: add .control_msr_intercept() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 21/84] KVM: x86: vmx: use a symbolic constant when checking the exit qualifications Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 22/84] KVM: x86: save the error code during EPT/NPF exits handling Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 23/84] KVM: x86: add .fault_gla() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 24/84] KVM: x86: add .spt_fault() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 25/84] KVM: x86: add .gpt_translation_fault() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 26/84] KVM: x86: add .control_singlestep() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 27/84] KVM: x86: export kvm_arch_vcpu_set_guest_debug() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 28/84] KVM: x86: extend kvm_mmu_gva_to_gpa_system() with the 'access' parameter Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 29/84] KVM: x86: export kvm_inject_pending_exception() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 30/84] KVM: x86: export kvm_vcpu_ioctl_x86_get_xsave() Adalbert Lazăr
2020-07-22  1:31   ` kernel test robot
2020-07-21 21:08 ` [PATCH v9 31/84] KVM: x86: export kvm_vcpu_ioctl_x86_set_xsave() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 32/84] KVM: x86: page track: provide all callbacks with the guest virtual address Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 33/84] KVM: x86: page track: add track_create_slot() callback Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 34/84] KVM: x86: page_track: add support for preread, prewrite and preexec Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 35/84] KVM: x86: wire in the preread/prewrite/preexec page trackers Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 36/84] KVM: x86: disable gpa_available optimization for fetch and page-walk SPT violations Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 37/84] KVM: introduce VM introspection Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 38/84] KVM: introspection: add hook/unhook ioctls Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 39/84] KVM: introspection: add permission access ioctls Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 40/84] KVM: introspection: add the read/dispatch message function Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 41/84] KVM: introspection: add KVMI_GET_VERSION Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 42/84] KVM: introspection: add KVMI_VM_CHECK_COMMAND and KVMI_VM_CHECK_EVENT Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 43/84] KVM: introspection: add KVMI_VM_GET_INFO Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 44/84] KVM: introspection: add KVMI_EVENT_UNHOOK Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 45/84] KVM: introspection: add KVMI_VM_CONTROL_EVENTS Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 46/84] KVM: introspection: add KVMI_VM_READ_PHYSICAL/KVMI_VM_WRITE_PHYSICAL Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 47/84] KVM: introspection: add vCPU related data Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 48/84] KVM: introspection: add a jobs list to every introspected vCPU Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 49/84] KVM: introspection: handle vCPU introspection requests Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 50/84] KVM: introspection: handle vCPU commands Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 51/84] KVM: introspection: add KVMI_VCPU_GET_INFO Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 52/84] KVM: introspection: add KVMI_VCPU_PAUSE Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 53/84] KVM: introspection: add KVMI_EVENT_PAUSE_VCPU Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 54/84] KVM: introspection: add the crash action handling on the event reply Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 55/84] KVM: introspection: add KVMI_VCPU_CONTROL_EVENTS Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 56/84] KVM: introspection: add KVMI_VCPU_GET_REGISTERS Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 57/84] KVM: introspection: add KVMI_VCPU_SET_REGISTERS Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 58/84] KVM: introspection: add KVMI_VCPU_GET_CPUID Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 59/84] KVM: introspection: add KVMI_EVENT_HYPERCALL Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 60/84] KVM: introspection: add KVMI_EVENT_BREAKPOINT Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 61/84] KVM: introspection: add cleanup support for vCPUs Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 62/84] KVM: introspection: restore the state of #BP interception on unhook Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 63/84] KVM: introspection: add KVMI_VM_CONTROL_CLEANUP Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 64/84] KVM: introspection: add KVMI_VCPU_CONTROL_CR and KVMI_EVENT_CR Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 65/84] KVM: introspection: restore the state of CR3 interception on unhook Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 66/84] KVM: introspection: add KVMI_VCPU_INJECT_EXCEPTION + KVMI_EVENT_TRAP Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 67/84] KVM: introspection: add KVMI_VM_GET_MAX_GFN Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 68/84] KVM: introspection: add KVMI_EVENT_XSETBV Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 69/84] KVM: introspection: add KVMI_VCPU_GET_XCR Adalbert Lazăr
2020-07-22  8:25   ` kernel test robot
2020-07-21 21:09 ` [PATCH v9 70/84] KVM: introspection: add KVMI_VCPU_GET_XSAVE Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 71/84] KVM: introspection: add KVMI_VCPU_SET_XSAVE Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 72/84] KVM: introspection: add KVMI_VCPU_GET_MTRR_TYPE Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 73/84] KVM: introspection: add KVMI_EVENT_DESCRIPTOR Adalbert Lazăr
2020-07-21 21:09 ` Adalbert Lazăr [this message]
2020-07-21 21:09 ` [PATCH v9 75/84] KVM: introspection: add KVMI_VCPU_CONTROL_MSR and KVMI_EVENT_MSR Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 76/84] KVM: introspection: restore the state of MSR interception on unhook Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 77/84] KVM: introspection: add KVMI_VM_SET_PAGE_ACCESS Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 78/84] KVM: introspection: add KVMI_EVENT_PF Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 79/84] KVM: introspection: extend KVMI_GET_VERSION with struct kvmi_features Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 80/84] KVM: introspection: add KVMI_VCPU_CONTROL_SINGLESTEP Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 81/84] KVM: introspection: add KVMI_EVENT_SINGLESTEP Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 82/84] KVM: introspection: add KVMI_VCPU_TRANSLATE_GVA Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 83/84] KVM: introspection: emulate a guest page table walk on SPT violations due to A/D bit updates Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 84/84] KVM: x86: call the page tracking code on emulation failure Adalbert Lazăr

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