From: Mihai Donțu <mdontu@xxxxxxxxxxxxxxx>
This command enables/disables vCPU introspection events.
Signed-off-by: Mihai Donțu <mdontu@xxxxxxxxxxxxxxx>
Signed-off-by: Adalbert Lazăr <alazar@xxxxxxxxxxxxxxx>
---
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 --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,
};
