From: Nicușor Cîțu <ncitu@xxxxxxxxxxxxxxx>
This event is sent when the current instruction has been single stepped
as a result of a KVMI_EVENT_PF event to which the introspection tool
set the singlestep field and responded with CONTINUE.
Signed-off-by: Nicușor Cîțu <ncitu@xxxxxxxxxxxxxxx>
Signed-off-by: Adalbert Lazăr <alazar@xxxxxxxxxxxxxxx>
---
Documentation/virtual/kvm/kvmi.rst | 25 +++++++++++++++++++
virt/kvm/kvmi.c | 40 ++++++++++++++++++++++++++++++
2 files changed, 65 insertions(+)
diff --git a/Documentation/virtual/kvm/kvmi.rst b/Documentation/virtual/kvm/kvmi.rst
index 8721a470de87..572abab1f6ef 100644
--- a/Documentation/virtual/kvm/kvmi.rst
+++ b/Documentation/virtual/kvm/kvmi.rst
@@ -1574,3 +1574,28 @@ introspection has been enabled for this event (see **KVMI_CONTROL_EVENTS**).
KVMI_DESC_TR
``write`` is 1 if the descriptor was written, 0 otherwise.
+
+12. KVMI_EVENT_SINGLESTEP
+-------------------------
+
+:Architectures: x86
+:Versions: >= 1
+:Actions: CONTINUE, CRASH
+:Parameters:
+
+::
+
+ struct kvmi_event;
+
+:Returns:
+
+::
+
+ struct kvmi_vcpu_hdr;
+ struct kvmi_event_reply;
+
+This event is sent when the current instruction has been executed
+(as a result of a *KVMI_EVENT_PF* event to which the introspection
+tool set the ``singlestep`` field and responded with *CONTINUE*)
+and the introspection has been enabled for this event
+(see **KVMI_CONTROL_EVENTS**).
diff --git a/virt/kvm/kvmi.c b/virt/kvm/kvmi.c
index a3a5af9080a9..3dfedf3ae739 100644
--- a/virt/kvm/kvmi.c
+++ b/virt/kvm/kvmi.c
@@ -1182,6 +1182,44 @@ void kvmi_trap_event(struct kvm_vcpu *vcpu)
kvmi_put(vcpu->kvm);
}
+static u32 kvmi_send_singlestep(struct kvm_vcpu *vcpu)
+{
+ int err, action;
+
+ err = kvmi_send_event(vcpu, KVMI_EVENT_SINGLESTEP, NULL, 0,
+ NULL, 0, &action);
+ if (err)
+ return KVMI_EVENT_ACTION_CONTINUE;
+
+ return action;
+}
+
+static void __kvmi_singlestep_event(struct kvm_vcpu *vcpu)
+{
+ u32 action;
+
+ action = kvmi_send_singlestep(vcpu);
+ switch (action) {
+ case KVMI_EVENT_ACTION_CONTINUE:
+ break;
+ default:
+ kvmi_handle_common_event_actions(vcpu, action, "SINGLESTEP");
+ }
+}
+
+static void kvmi_singlestep_event(struct kvm_vcpu *vcpu)
+{
+ struct kvmi_vcpu *ivcpu = IVCPU(vcpu);
+
+ if (!ivcpu->ss_requested)
+ return;
+
+ if (is_event_enabled(vcpu, KVMI_EVENT_SINGLESTEP))
+ __kvmi_singlestep_event(vcpu);
+
+ ivcpu->ss_requested = false;
+}
+
static bool __kvmi_create_vcpu_event(struct kvm_vcpu *vcpu)
{
u32 action;
@@ -1616,6 +1654,8 @@ void kvmi_stop_ss(struct kvm_vcpu *vcpu)
ivcpu->ss_owner = false;
+ kvmi_singlestep_event(vcpu);
+
out:
kvmi_put(kvm);
}
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