trace: Add QAPI/QMP interfaces to query and control per-vCPU tracing state

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 119 insertions, 29 deletions

diff --git a/trace/qmp.c b/trace/qmp.c
index 8aa2660aac..11d2564e7b 100644
--- a/trace/qmp.c
+++ b/trace/qmp.c
@@ -1,7 +1,7 @@
 /*
  * QMP commands for tracing events.
  *
- * Copyright (C) 2014 Lluís Vilanova <vilanova@ac.upc.edu>
+ * Copyright (C) 2014-2016 Lluís Vilanova <vilanova@ac.upc.edu>
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
@@ -12,63 +12,153 @@
 #include "trace/control.h"
 
 
-TraceEventInfoList *qmp_trace_event_get_state(const char *name, Error **errp)
+static CPUState *get_cpu(bool has_vcpu, int vcpu, Error **errp)
 {
+    if (has_vcpu) {
+        CPUState *cpu = qemu_get_cpu(vcpu);
+        if (cpu == NULL) {
+            error_setg(errp, "invalid vCPU index %u", vcpu);
+        }
+        return cpu;
+    } else {
+        return NULL;
+    }
+}
+
+static bool check_events(bool has_vcpu, bool ignore_unavailable, bool is_pattern,
+                         const char *name, Error **errp)
+{
+    if (!is_pattern) {
+        TraceEvent *ev = trace_event_name(name);
+
+        /* error for non-existing event */
+        if (ev == NULL) {
+            error_setg(errp, "unknown event \"%s\"", name);
+            return false;
+        }
+
+        /* error for non-vcpu event */
+        if (has_vcpu && !trace_event_is_vcpu(ev)) {
+            error_setg(errp, "event \"%s\" is not vCPU-specific", name);
+            return false;
+        }
+
+        /* error for unavailable event */
+        if (!ignore_unavailable && !trace_event_get_state_static(ev)) {
+            error_setg(errp, "event \"%s\" is disabled", name);
+            return false;
+        }
+
+        return true;
+    } else {
+        /* error for unavailable events */
+        TraceEvent *ev = NULL;
+        while ((ev = trace_event_pattern(name, ev)) != NULL) {
+            if (!ignore_unavailable && !trace_event_get_state_static(ev)) {
+                error_setg(errp, "event \"%s\" is disabled", trace_event_get_name(ev));
+                return false;
+            }
+        }
+        return true;
+    }
+}
+
+TraceEventInfoList *qmp_trace_event_get_state(const char *name,
+                                              bool has_vcpu, int64_t vcpu,
+                                              Error **errp)
+{
+    Error *err = NULL;
     TraceEventInfoList *events = NULL;
-    bool found = false;
     TraceEvent *ev;
+    bool is_pattern = trace_event_is_pattern(name);
+    CPUState *cpu;
 
+    /* Check provided vcpu */
+    cpu = get_cpu(has_vcpu, vcpu, &err);
+    if (err) {
+        error_propagate(errp, err);
+        return NULL;
+    }
+
+    /* Check events */
+    if (!check_events(has_vcpu, true, is_pattern, name, errp)) {
+        return NULL;
+    }
+
+    /* Get states (all errors checked above) */
     ev = NULL;
     while ((ev = trace_event_pattern(name, ev)) != NULL) {
-        TraceEventInfoList *elem = g_new(TraceEventInfoList, 1);
+        TraceEventInfoList *elem;
+        bool is_vcpu = trace_event_is_vcpu(ev);
+        if (has_vcpu && !is_vcpu) {
+            continue;
+        }
+
+        elem = g_new(TraceEventInfoList, 1);
         elem->value = g_new(TraceEventInfo, 1);
+        elem->value->vcpu = is_vcpu;
         elem->value->name = g_strdup(trace_event_get_name(ev));
+
         if (!trace_event_get_state_static(ev)) {
             elem->value->state = TRACE_EVENT_STATE_UNAVAILABLE;
-        } else if (!trace_event_get_state_dynamic(ev)) {
-            elem->value->state = TRACE_EVENT_STATE_DISABLED;
         } else {
-            elem->value->state = TRACE_EVENT_STATE_ENABLED;
+            if (has_vcpu) {
+                if (is_vcpu) {
+                    if (trace_event_get_vcpu_state_dynamic(cpu, ev)) {
+                        elem->value->state = TRACE_EVENT_STATE_ENABLED;
+                    } else {
+                        elem->value->state = TRACE_EVENT_STATE_DISABLED;
+                    }
+                }
+                /* else: already skipped above */
+            } else {
+                if (trace_event_get_state_dynamic(ev)) {
+                    elem->value->state = TRACE_EVENT_STATE_ENABLED;
+                } else {
+                    elem->value->state = TRACE_EVENT_STATE_DISABLED;
+                }
+            }
         }
         elem->next = events;
         events = elem;
-        found = true;
-    }
-
-    if (!found && !trace_event_is_pattern(name)) {
-        error_setg(errp, "unknown event \"%s\"", name);
     }
 
     return events;
 }
 
 void qmp_trace_event_set_state(const char *name, bool enable,
-                               bool has_ignore_unavailable,
-                               bool ignore_unavailable, Error **errp)
+                               bool has_ignore_unavailable, bool ignore_unavailable,
+                               bool has_vcpu, int64_t vcpu,
+                               Error **errp)
 {
-    bool found = false;
+    Error *err = NULL;
     TraceEvent *ev;
+    bool is_pattern = trace_event_is_pattern(name);
+    CPUState *cpu;
 
-    /* Check all selected events are dynamic */
-    ev = NULL;
-    while ((ev = trace_event_pattern(name, ev)) != NULL) {
-        found = true;
-        if (!(has_ignore_unavailable && ignore_unavailable) &&
-            !trace_event_get_state_static(ev)) {
-            error_setg(errp, "cannot set dynamic tracing state for \"%s\"",
-                       trace_event_get_name(ev));
-            return;
-        }
+    /* Check provided vcpu */
+    cpu = get_cpu(has_vcpu, vcpu, &err);
+    if (err) {
+        error_propagate(errp, err);
+        return;
     }
-    if (!found && !trace_event_is_pattern(name)) {
-        error_setg(errp, "unknown event \"%s\"", name);
+
+    /* Check events */
+    if (!check_events(has_vcpu, has_ignore_unavailable && ignore_unavailable,
+                      is_pattern, name, errp)) {
         return;
     }
 
-    /* Apply changes */
+    /* Apply changes (all errors checked above) */
     ev = NULL;
     while ((ev = trace_event_pattern(name, ev)) != NULL) {
-        if (trace_event_get_state_static(ev)) {
+        if (!trace_event_get_state_static(ev) ||
+            (has_vcpu && !trace_event_is_vcpu(ev))) {
+            continue;
+        }
+        if (has_vcpu) {
+            trace_event_set_vcpu_state_dynamic(cpu, ev, enable);
+        } else {
             trace_event_set_state_dynamic(ev, enable);
         }
     }