diff mbox series

[RFC,v6,29/92] kvm: introspection: add KVMI_CONTROL_EVENTS

Message ID 20190809160047.8319-30-alazar@bitdefender.com
State New, archived
Headers show
Series VM introspection | expand

Commit Message

Adalbert Lazăr Aug. 9, 2019, 3:59 p.m. UTC
From: Mihai Donțu <mdontu@bitdefender.com>

This command enables/disables vCPU introspection events.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virtual/kvm/kvmi.rst | 53 ++++++++++++++++++++++++++++++
 include/uapi/linux/kvmi.h          |  7 ++++
 virt/kvm/kvmi.c                    | 13 ++++++++
 virt/kvm/kvmi_int.h                |  6 +++-
 virt/kvm/kvmi_msg.c                | 24 ++++++++++++++
 5 files changed, 102 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/Documentation/virtual/kvm/kvmi.rst b/Documentation/virtual/kvm/kvmi.rst
index 71897338e85a..957641802cac 100644
--- a/Documentation/virtual/kvm/kvmi.rst
+++ b/Documentation/virtual/kvm/kvmi.rst
@@ -456,6 +456,59 @@  Returns the TSC frequency (in HZ) for the specified vCPU if available
 * -KVM_EINVAL - padding is not zero
 * -KVM_EAGAIN - the selected vCPU can't be introspected yet
 
+8. KVMI_CONTROL_EVENTS
+----------------------
+
+:Architectures: all
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_control_events {
+		__u16 event_id;
+		__u8 enable;
+		__u8 padding1;
+		__u32 padding2;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code
+
+Enables/disables vCPU introspection events. This command can be used with
+the following events::
+
+	KVMI_EVENT_CR
+	KVMI_EVENT_MSR
+	KVMI_EVENT_XSETBV
+	KVMI_EVENT_BREAKPOINT
+	KVMI_EVENT_HYPERCALL
+	KVMI_EVENT_PF
+	KVMI_EVENT_TRAP
+	KVMI_EVENT_DESCRIPTOR
+	KVMI_EVENT_SINGLESTEP
+
+When an event is enabled, the introspection tool is notified and it
+must reply with: continue, retry, crash, etc. (see **Events** below).
+
+The *KVMI_EVENT_PAUSE_VCPU* event is always allowed,
+because it is triggered by the *KVMI_PAUSE_VCPU* command.
+The *KVMI_EVENT_CREATE_VCPU* and *KVMI_EVENT_UNHOOK* events are controlled
+by the *KVMI_CONTROL_VM_EVENTS* command.
+
+:Errors:
+
+* -KVM_EINVAL - the selected vCPU is invalid
+* -KVM_EINVAL - the event ID is invalid
+* -KVM_EINVAL - padding is not zero
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+* -KVM_EPERM - the access is restricted by the host
+* -KVM_EOPNOTSUPP - one the events can't be intercepted in the current setup
+
 Events
 ======
 
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index c56e676ddb2b..934c0610140a 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -120,6 +120,13 @@  struct kvmi_get_vcpu_info_reply {
 	__u64 tsc_speed;
 };
 
+struct kvmi_control_events {
+	__u16 event_id;
+	__u8 enable;
+	__u8 padding1;
+	__u32 padding2;
+};
+
 struct kvmi_control_vm_events {
 	__u16 event_id;
 	__u8 enable;
diff --git a/virt/kvm/kvmi.c b/virt/kvm/kvmi.c
index 5cbc82b284f4..14963474617e 100644
--- a/virt/kvm/kvmi.c
+++ b/virt/kvm/kvmi.c
@@ -969,6 +969,19 @@  void kvmi_handle_requests(struct kvm_vcpu *vcpu)
 	kvmi_put(vcpu->kvm);
 }
 
+int kvmi_cmd_control_events(struct kvm_vcpu *vcpu, unsigned int event_id,
+			    bool enable)
+{
+	struct kvmi_vcpu *ivcpu = IVCPU(vcpu);
+
+	if (enable)
+		set_bit(event_id, ivcpu->ev_mask);
+	else
+		clear_bit(event_id, ivcpu->ev_mask);
+
+	return 0;
+}
+
 int kvmi_cmd_control_vm_events(struct kvmi *ikvm, unsigned int event_id,
 			       bool enable)
 {
diff --git a/virt/kvm/kvmi_int.h b/virt/kvm/kvmi_int.h
index d798908d0f70..c0044cae8089 100644
--- a/virt/kvm/kvmi_int.h
+++ b/virt/kvm/kvmi_int.h
@@ -95,6 +95,8 @@  struct kvmi_vcpu {
 	bool reply_waiting;
 	struct kvmi_vcpu_reply reply;
 
+	DECLARE_BITMAP(ev_mask, KVMI_NUM_EVENTS);
+
 	struct list_head job_list;
 	spinlock_t job_lock;
 
@@ -131,7 +133,7 @@  struct kvmi_mem_access {
 
 static inline bool is_event_enabled(struct kvm_vcpu *vcpu, int event)
 {
-	return false; /* TODO */
+	return test_bit(event, IVCPU(vcpu)->ev_mask);
 }
 
 /* kvmi_msg.c */
@@ -146,6 +148,8 @@  int kvmi_msg_send_unhook(struct kvmi *ikvm);
 void *kvmi_msg_alloc(void);
 void *kvmi_msg_alloc_check(size_t size);
 void kvmi_msg_free(void *addr);
+int kvmi_cmd_control_events(struct kvm_vcpu *vcpu, unsigned int event_id,
+			    bool enable);
 int kvmi_cmd_control_vm_events(struct kvmi *ikvm, unsigned int event_id,
 			       bool enable);
 int kvmi_run_jobs_and_wait(struct kvm_vcpu *vcpu);
diff --git a/virt/kvm/kvmi_msg.c b/virt/kvm/kvmi_msg.c
index 3372d8c7e74f..a3c67af8674e 100644
--- a/virt/kvm/kvmi_msg.c
+++ b/virt/kvm/kvmi_msg.c
@@ -24,6 +24,7 @@  static const char *const msg_IDs[] = {
 	[KVMI_CHECK_COMMAND]         = "KVMI_CHECK_COMMAND",
 	[KVMI_CHECK_EVENT]           = "KVMI_CHECK_EVENT",
 	[KVMI_CONTROL_CMD_RESPONSE]  = "KVMI_CONTROL_CMD_RESPONSE",
+	[KVMI_CONTROL_EVENTS]        = "KVMI_CONTROL_EVENTS",
 	[KVMI_CONTROL_VM_EVENTS]     = "KVMI_CONTROL_VM_EVENTS",
 	[KVMI_EVENT]                 = "KVMI_EVENT",
 	[KVMI_EVENT_REPLY]           = "KVMI_EVENT_REPLY",
@@ -403,6 +404,28 @@  static int handle_get_vcpu_info(struct kvm_vcpu *vcpu,
 	return reply_cb(vcpu, msg, 0, &rpl, sizeof(rpl));
 }
 
+static int handle_control_events(struct kvm_vcpu *vcpu,
+				 const struct kvmi_msg_hdr *msg,
+				 const void *_req,
+				 vcpu_reply_fct reply_cb)
+{
+	unsigned long known_events = KVMI_KNOWN_VCPU_EVENTS;
+	const struct kvmi_control_events *req = _req;
+	struct kvmi *ikvm = IKVM(vcpu->kvm);
+	int ec;
+
+	if (req->padding1 || req->padding2)
+		ec = -KVM_EINVAL;
+	else if (!test_bit(req->event_id, &known_events))
+		ec = -KVM_EINVAL;
+	else if (!is_event_allowed(ikvm, req->event_id))
+		ec = -KVM_EPERM;
+	else
+		ec = kvmi_cmd_control_events(vcpu, req->event_id, req->enable);
+
+	return reply_cb(vcpu, msg, ec, NULL, 0);
+}
+
 /*
  * These commands are executed on the vCPU thread. The receiving thread
  * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd'
@@ -412,6 +435,7 @@  static int handle_get_vcpu_info(struct kvm_vcpu *vcpu,
 static int(*const msg_vcpu[])(struct kvm_vcpu *,
 			      const struct kvmi_msg_hdr *, const void *,
 			      vcpu_reply_fct) = {
+	[KVMI_CONTROL_EVENTS]   = handle_control_events,
 	[KVMI_EVENT_REPLY]      = handle_event_reply,
 	[KVMI_GET_VCPU_INFO]    = handle_get_vcpu_info,
 };