trace: dynamically allocate trace_dstate in CPUState

The CPUState struct has a bitmap tracking which VCPU
events are currently active. This is indexed based on
the event ID values, and sized according the maximum
TraceEventVCPUID enum value.

When we start dynamically assigning IDs at runtime,
we can't statically declare a bitmap without making
an assumption about the max event count. This problem
can be solved by dynamically allocating the per-CPU
dstate bitmap.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-15-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index 22b54d6d9375556f344bd2bc3b0962d34d381cef..6d481a1dc05bb0ee0c32a3c2f0847a7e7136f441 100644 (file)
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -27,7 +27,6 @@
 #include "qemu/bitmap.h"
 #include "qemu/queue.h"
 #include "qemu/thread.h"
-#include "trace/generated-events.h"
 
 typedef int (*WriteCoreDumpFunction)(const void *buf, size_t size,
                                      void *opaque);
@@ -345,8 +344,12 @@ struct CPUState {
     struct KVMState *kvm_state;
     struct kvm_run *kvm_run;
 
-    /* Used for events with 'vcpu' and *without* the 'disabled' properties */
-    DECLARE_BITMAP(trace_dstate, TRACE_VCPU_EVENT_COUNT);
+    /*
+     * Used for events with 'vcpu' and *without* the 'disabled' properties.
+     * Dynamically allocated based on bitmap requried to hold up to
+     * trace_get_vcpu_event_count() entries.
+     */
+    unsigned long *trace_dstate;
 
     /* TODO Move common fields from CPUArchState here. */
     int cpu_index; /* used by alpha TCG */

diff --git a/qom/cpu.c b/qom/cpu.c
index e765bc0caf2c4f89c3cd8f6663ed017346e38323..c40f774a0caa87cd8b057fa63598972ba3917774 100644 (file)
--- a/qom/cpu.c
+++ b/qom/cpu.c
@@ -360,12 +360,15 @@ static void cpu_common_initfn(Object *obj)
     qemu_mutex_init(&cpu->work_mutex);
     QTAILQ_INIT(&cpu->breakpoints);
     QTAILQ_INIT(&cpu->watchpoints);
-    bitmap_zero(cpu->trace_dstate, TRACE_VCPU_EVENT_COUNT);
+
+    cpu->trace_dstate = bitmap_new(trace_get_vcpu_event_count());
 }
 
 static void cpu_common_finalize(Object *obj)
 {
-    cpu_exec_exit(CPU(obj));
+    CPUState *cpu = CPU(obj);
+    cpu_exec_exit(cpu);
+    g_free(cpu->trace_dstate);
 }
 
 static int64_t cpu_common_get_arch_id(CPUState *cpu)

diff --git a/trace/control.c b/trace/control.c
index a2313273d8808ef413116be4ab270adf8ab7528d..5f10e2d96e8023626a53c9d99cd68264c30d9092 100644 (file)
--- a/trace/control.c
+++ b/trace/control.c
@@ -290,3 +290,8 @@ char *trace_opt_parse(const char *optarg)
 
     return trace_file;
 }
+
+uint32_t trace_get_vcpu_event_count(void)
+{
+    return TRACE_VCPU_EVENT_COUNT;
+}

diff --git a/trace/control.h b/trace/control.h
index 3f30a0c2b77cde76fd60867b9faa7e831923d6d2..69635bfb8b92193cf87f85f61ef024ee81884db7 100644 (file)
--- a/trace/control.h
+++ b/trace/control.h
@@ -232,6 +232,13 @@ extern QemuOptsList qemu_trace_opts;
  */
 char *trace_opt_parse(const char *optarg);
 
+/**
+ * trace_get_vcpu_event_count:
+ *
+ * Return the number of known vcpu-specific events
+ */
+uint32_t trace_get_vcpu_event_count(void);
+
 
 #include "trace/control-internal.h"