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From: "Adalbert Lazăr" <alazar@bitdefender.com>
To: kvm@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Nicușor Cîțu" <ncitu@bitdefender.com>,
	"Adalbert Lazăr" <alazar@bitdefender.com>
Subject: [PATCH v9 61/84] KVM: introspection: add cleanup support for vCPUs
Date: Wed, 22 Jul 2020 00:08:59 +0300
Message-ID: <20200721210922.7646-62-alazar@bitdefender.com> (raw)
In-Reply-To: <20200721210922.7646-1-alazar@bitdefender.com>

From: Nicușor Cîțu <ncitu@bitdefender.com>

On unhook the introspection channel is closed. This will signal the
receiving thread to call kvmi_put() and exit. There might be vCPU threads
handling introspection commands or waiting for event replies. These will
also call kvmi_put() and re-enter in guest. Once the reference counter
reaches zero, the structures keeping the introspection data will be freed.

In order to restore the interception of CRs, MSRs, BP, descriptor-table
registers, from all vCPUs (some of which might run from userspace),
we keep the needed information in another structure (kvmi_interception)
which will be used and freed by each of them before re-entering in guest.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h   |  3 ++
 arch/x86/include/asm/kvmi_host.h  |  4 +++
 arch/x86/kvm/kvmi.c               | 49 +++++++++++++++++++++++++++++++
 virt/kvm/introspection/kvmi.c     | 32 ++++++++++++++++++--
 virt/kvm/introspection/kvmi_int.h |  5 ++++
 5 files changed, 90 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8a119fb7c623..acfcebce51dd 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -840,6 +840,9 @@ struct kvm_vcpu_arch {
 
 	/* #PF translated error code from EPT/NPT exit reason */
 	u64 error_code;
+
+	/* Control the interception for KVM Introspection */
+	struct kvmi_interception *kvmi;
 };
 
 struct kvm_lpage_info {
diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h
index 05ade3a16b24..6d274f173fb5 100644
--- a/arch/x86/include/asm/kvmi_host.h
+++ b/arch/x86/include/asm/kvmi_host.h
@@ -4,6 +4,10 @@
 
 #include <asm/kvmi.h>
 
+struct kvmi_interception {
+	bool restore_interception;
+};
+
 struct kvm_vcpu_arch_introspection {
 };
 
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index f13272350bc9..ca2ce7498cfe 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -290,3 +290,52 @@ void kvmi_arch_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, u8 insn_len)
 		kvmi_handle_common_event_actions(vcpu->kvm, action);
 	}
 }
+
+static void kvmi_arch_restore_interception(struct kvm_vcpu *vcpu)
+{
+}
+
+bool kvmi_arch_clean_up_interception(struct kvm_vcpu *vcpu)
+{
+	struct kvmi_interception *arch_vcpui = vcpu->arch.kvmi;
+
+	if (!arch_vcpui)
+		return false;
+
+	if (!arch_vcpui->restore_interception)
+		return false;
+
+	kvmi_arch_restore_interception(vcpu);
+
+	return true;
+}
+
+bool kvmi_arch_vcpu_alloc_interception(struct kvm_vcpu *vcpu)
+{
+	struct kvmi_interception *arch_vcpui;
+
+	arch_vcpui = kzalloc(sizeof(*arch_vcpui), GFP_KERNEL);
+	if (!arch_vcpui)
+		return false;
+
+	return true;
+}
+
+void kvmi_arch_vcpu_free_interception(struct kvm_vcpu *vcpu)
+{
+	kfree(vcpu->arch.kvmi);
+	WRITE_ONCE(vcpu->arch.kvmi, NULL);
+}
+
+bool kvmi_arch_vcpu_introspected(struct kvm_vcpu *vcpu)
+{
+	return !!READ_ONCE(vcpu->arch.kvmi);
+}
+
+void kvmi_arch_request_interception_cleanup(struct kvm_vcpu *vcpu)
+{
+	struct kvmi_interception *arch_vcpui = READ_ONCE(vcpu->arch.kvmi);
+
+	if (arch_vcpui)
+		arch_vcpui->restore_interception = true;
+}
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index a5264696c630..083dd8be9252 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -197,7 +197,7 @@ static bool alloc_vcpui(struct kvm_vcpu *vcpu)
 
 	vcpu->kvmi = vcpui;
 
-	return true;
+	return kvmi_arch_vcpu_alloc_interception(vcpu);
 }
 
 static int create_vcpui(struct kvm_vcpu *vcpu)
@@ -231,6 +231,9 @@ static void free_vcpui(struct kvm_vcpu *vcpu)
 
 	kfree(vcpui);
 	vcpu->kvmi = NULL;
+
+	kvmi_arch_request_interception_cleanup(vcpu);
+	kvmi_make_request(vcpu, false);
 }
 
 static void free_kvmi(struct kvm *kvm)
@@ -253,6 +256,7 @@ void kvmi_vcpu_uninit(struct kvm_vcpu *vcpu)
 {
 	mutex_lock(&vcpu->kvm->kvmi_lock);
 	free_vcpui(vcpu);
+	kvmi_arch_vcpu_free_interception(vcpu);
 	mutex_unlock(&vcpu->kvm->kvmi_lock);
 }
 
@@ -404,6 +408,21 @@ static int kvmi_recv_thread(void *arg)
 	return 0;
 }
 
+static bool ready_to_hook(struct kvm *kvm)
+{
+	struct kvm_vcpu *vcpu;
+	int i;
+
+	if (kvm->kvmi)
+		return false;
+
+	kvm_for_each_vcpu(i, vcpu, kvm)
+		if (kvmi_arch_vcpu_introspected(vcpu))
+			return false;
+
+	return true;
+}
+
 int kvmi_hook(struct kvm *kvm, const struct kvm_introspection_hook *hook)
 {
 	struct kvm_introspection *kvmi;
@@ -411,7 +430,7 @@ int kvmi_hook(struct kvm *kvm, const struct kvm_introspection_hook *hook)
 
 	mutex_lock(&kvm->kvmi_lock);
 
-	if (kvm->kvmi) {
+	if (!ready_to_hook(kvm)) {
 		err = -EEXIST;
 		goto out;
 	}
@@ -836,7 +855,7 @@ void kvmi_handle_requests(struct kvm_vcpu *vcpu)
 
 	kvmi = kvmi_get(vcpu->kvm);
 	if (!kvmi)
-		return;
+		goto out;
 
 	for (;;) {
 		kvmi_run_jobs(vcpu);
@@ -848,6 +867,13 @@ void kvmi_handle_requests(struct kvm_vcpu *vcpu)
 	}
 
 	kvmi_put(vcpu->kvm);
+
+out:
+	if (kvmi_arch_clean_up_interception(vcpu)) {
+		mutex_lock(&vcpu->kvm->kvmi_lock);
+		kvmi_arch_vcpu_free_interception(vcpu);
+		mutex_unlock(&vcpu->kvm->kvmi_lock);
+	}
 }
 
 int kvmi_cmd_vcpu_pause(struct kvm_vcpu *vcpu, bool wait)
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 810dde913ad6..05bfde7d7f1a 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -65,6 +65,11 @@ int kvmi_cmd_vcpu_set_registers(struct kvm_vcpu *vcpu,
 				const struct kvm_regs *regs);
 
 /* arch */
+bool kvmi_arch_vcpu_alloc_interception(struct kvm_vcpu *vcpu);
+void kvmi_arch_vcpu_free_interception(struct kvm_vcpu *vcpu);
+bool kvmi_arch_vcpu_introspected(struct kvm_vcpu *vcpu);
+void kvmi_arch_request_interception_cleanup(struct kvm_vcpu *vcpu);
+bool kvmi_arch_clean_up_interception(struct kvm_vcpu *vcpu);
 int kvmi_arch_cmd_vcpu_get_info(struct kvm_vcpu *vcpu,
 				struct kvmi_vcpu_get_info_reply *rpl);
 void kvmi_arch_setup_event(struct kvm_vcpu *vcpu, struct kvmi_event *ev);

  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 ` Adalbert Lazăr [this message]
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 ` [PATCH v9 74/84] KVM: introspection: restore the state of descriptor-table register interception on unhook Adalbert Lazăr
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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