This event is sent by the vCPU thread as a response to the
KVMI_VM_PAUSE_VCPU command, but it has a lower priority, being sent
after any other introspection event and when no other introspection
command is queued.
The number of KVMI_VCPU_EVENT_PAUSE will match the number of successful
KVMI_VM_PAUSE_VCPU commands.
Signed-off-by: Adalbert Lazăr <ala...@bitdefender.com>
---
Documentation/virt/kvm/kvmi.rst | 26 ++++++++
include/uapi/linux/kvmi.h | 2 +
.../testing/selftests/kvm/x86_64/kvmi_test.c | 65 ++++++++++++++++++-
virt/kvm/introspection/kvmi.c | 26 +++++++-
virt/kvm/introspection/kvmi_int.h | 1 +
virt/kvm/introspection/kvmi_msg.c | 18 +++++
6 files changed, 136 insertions(+), 2 deletions(-)
diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 5e99baf7e2f3..c86c83566c3d 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -596,3 +596,29 @@ the guest (see **Unhooking**) and the introspection has
been enabled for
this event (see **KVMI_VM_CONTROL_EVENTS**). The introspection tool has
a chance to unhook and close the introspection socket (signaling that
the operation can proceed).
+
+2. KVMI_VCPU_EVENT_PAUSE
+------------------------
+
+:Architectures: all
+:Versions: >= 1
+:Actions: CONTINUE, CRASH
+:Parameters:
+
+::
+
+ struct kvmi_event_hdr;
+ struct kvmi_vcpu_event;
+
+:Returns:
+
+::
+
+ struct kvmi_vcpu_hdr;
+ struct kvmi_vcpu_event_reply;
+
+This event is sent in response to a *KVMI_VCPU_PAUSE* command and
+cannot be controlled with *KVMI_VCPU_CONTROL_EVENTS*.
+Because it has a low priority, it will be sent after any other vCPU
+introspection event and when no other vCPU introspection command is
+queued.
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 6a57efb5664d..757d4b84f473 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -50,6 +50,8 @@ enum {
};
enum {
+ KVMI_VCPU_EVENT_PAUSE = KVMI_VCPU_EVENT_ID(0),
+
KVMI_NEXT_VCPU_EVENT
};
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 52765ca3f9c8..4c9dc6560ad9 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -34,6 +34,17 @@ static vm_paddr_t test_gpa;
static int page_size;
+struct vcpu_event {
+ struct kvmi_event_hdr hdr;
+ struct kvmi_vcpu_event common;
+};
+
+struct vcpu_reply {
+ struct kvmi_msg_hdr hdr;
+ struct kvmi_vcpu_hdr vcpu_hdr;
+ struct kvmi_vcpu_event_reply reply;
+};
+
struct vcpu_worker_data {
struct kvm_vm *vm;
int vcpu_id;
@@ -690,14 +701,66 @@ static void pause_vcpu(void)
cmd_vcpu_pause(1, 0);
}
+static void reply_to_event(struct kvmi_msg_hdr *ev_hdr, struct vcpu_event *ev,
+ __u8 action, struct vcpu_reply *rpl, size_t rpl_size)
+{
+ ssize_t r;
+
+ rpl->hdr.id = ev_hdr->id;
+ rpl->hdr.seq = ev_hdr->seq;
+ rpl->hdr.size = rpl_size - sizeof(rpl->hdr);
+
+ rpl->vcpu_hdr.vcpu = ev->common.vcpu;
+
+ rpl->reply.action = action;
+ rpl->reply.event = ev->hdr.event;
+
+ r = send(Userspace_socket, rpl, rpl_size, 0);
+ TEST_ASSERT(r == rpl_size,
+ "send() failed, sending %zd, result %zd, errno %d (%s)\n",
+ rpl_size, r, errno, strerror(errno));
+}
+
+static void receive_vcpu_event(struct kvmi_msg_hdr *msg_hdr,
+ struct vcpu_event *ev,
+ size_t ev_size, u16 ev_id)
+{
+ receive_event(msg_hdr, KVMI_VCPU_EVENT,
+ &ev->hdr, ev_id, ev_size);
+}
+
+static void discard_pause_event(struct kvm_vm *vm)
+{
+ struct vcpu_worker_data data = {.vm = vm, .vcpu_id = VCPU_ID};
+ struct vcpu_reply rpl = {};
+ struct kvmi_msg_hdr hdr;
+ pthread_t vcpu_thread;
+ struct vcpu_event ev;
+
+ vcpu_thread = start_vcpu_worker(&data);
+
+ receive_vcpu_event(&hdr, &ev, sizeof(ev), KVMI_VCPU_EVENT_PAUSE);
+
+ reply_to_event(&hdr, &ev, KVMI_EVENT_ACTION_CONTINUE,
+ &rpl, sizeof(rpl));
+
+ wait_vcpu_worker(vcpu_thread);
+}
+
static void test_pause(struct kvm_vm *vm)
{
- __u8 wait = 1, wait_inval = 2;
+ __u8 no_wait = 0, wait = 1, wait_inval = 2;
pause_vcpu();
+ discard_pause_event(vm);
cmd_vcpu_pause(wait, 0);
+ discard_pause_event(vm);
cmd_vcpu_pause(wait_inval, -KVM_EINVAL);
+
+ disallow_event(vm, KVMI_VCPU_EVENT_PAUSE);
+ cmd_vcpu_pause(no_wait, -KVM_EPERM);
+ allow_event(vm, KVMI_VCPU_EVENT_PAUSE);
}
static void test_introspection(struct kvm_vm *vm)
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 771e6b545698..3d26a7319fb7 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -103,6 +103,7 @@ static void kvmi_init_known_events(void)
bitmap_zero(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
kvmi_arch_init_vcpu_events_mask(Kvmi_known_vcpu_events);
+ set_bit(KVMI_VCPU_EVENT_PAUSE, Kvmi_known_vcpu_events);
bitmap_or(Kvmi_known_events, Kvmi_known_vm_events,
Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
@@ -740,12 +741,35 @@ void kvmi_run_jobs(struct kvm_vcpu *vcpu)
}
}
+static void kvmi_handle_unsupported_event_action(struct kvm *kvm)
+{
+ kvmi_sock_shutdown(KVMI(kvm));
+}
+
+void kvmi_handle_common_event_actions(struct kvm_vcpu *vcpu, u32 action)
+{
+ struct kvm *kvm = vcpu->kvm;
+
+ switch (action) {
+ default:
+ kvmi_handle_unsupported_event_action(kvm);
+ }
+}
+
static void kvmi_vcpu_pause_event(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+ u32 action;
atomic_dec(&vcpui->pause_requests);
- /* to be implemented */
+
+ action = kvmi_msg_send_vcpu_pause(vcpu);
+ switch (action) {
+ case KVMI_EVENT_ACTION_CONTINUE:
+ break;
+ default:
+ kvmi_handle_common_event_actions(vcpu, action);
+ }
}
void kvmi_handle_requests(struct kvm_vcpu *vcpu)
diff --git a/virt/kvm/introspection/kvmi_int.h
b/virt/kvm/introspection/kvmi_int.h
index 65d8c1c37796..0876740dfa24 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -38,6 +38,7 @@ int kvmi_send_vcpu_event(struct kvm_vcpu *vcpu, u32 ev_id,
int kvmi_msg_vcpu_reply(const struct kvmi_vcpu_msg_job *job,
const struct kvmi_msg_hdr *msg, int err,
const void *rpl, size_t rpl_size);
+u32 kvmi_msg_send_vcpu_pause(struct kvm_vcpu *vcpu);
/* kvmi.c */
void *kvmi_msg_alloc(void);
diff --git a/virt/kvm/introspection/kvmi_msg.c
b/virt/kvm/introspection/kvmi_msg.c
index 467c88185be1..71a28e26d382 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -258,6 +258,11 @@ static int handle_vm_pause_vcpu(struct kvm_introspection
*kvmi,
goto reply;
}
+ if (!kvmi_is_event_allowed(kvmi, KVMI_VCPU_EVENT_PAUSE)) {
+ err = -KVM_EPERM;
+ goto reply;
+ }
+
vcpu = kvmi_get_vcpu(kvmi, req->vcpu);
if (!vcpu)
err = -KVM_EINVAL;
@@ -697,3 +702,16 @@ int kvmi_send_vcpu_event(struct kvm_vcpu *vcpu, u32 ev_id,
return err;
}
+
+u32 kvmi_msg_send_vcpu_pause(struct kvm_vcpu *vcpu)
+{
+ u32 action;
+ int err;
+
+ err = kvmi_send_vcpu_event(vcpu, KVMI_VCPU_EVENT_PAUSE, NULL, 0,
+ NULL, 0, &action);
+ if (err)
+ return KVMI_EVENT_ACTION_CONTINUE;
+
+ return action;
+}
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