qemu: json: Fix daemon crash on handling domain shutdown event

commit a8eba5036 added further checking of the guest shutdown cause, but
this enhancement is available since qemu 2.10, causing a crash because
of a NULL pointer dereference on older qemus.

Thread 1 "libvirtd" received signal SIGSEGV, Segmentation fault.
0x00007ffff72441af in virJSONValueObjectGet (object=0x0,
                                             key=0x7fffd5ef11bf "guest")
    at util/virjson.c:769
769	    if (object->type != VIR_JSON_TYPE_OBJECT)
(gdb) bt
0  in virJSONValueObjectGet
1  in virJSONValueObjectGetBoolean
2  in qemuMonitorJSONHandleShutdown
3  in qemuMonitorJSONIOProcessEvent
4  in qemuMonitorJSONIOProcessLine
5  in qemuMonitorJSONIOProcess
6  in qemuMonitorIOProcess

Signed-off-by: Erik Skultety <eskultet@redhat.com>

src/conf/capabilities.c

@@ -1643,5 +1643,6 @@ virCapabilitiesInitCaches(virCapsPtr caps)
     VIR_FREE(path);
     VIR_DIR_CLOSE(dirp);
     virCapsHostCacheBankFree(bank);
+    virBitmapFree(cpus);
     return ret;
 }

src/node_device/node_device_udev.c

@@ -1764,6 +1764,13 @@ static int nodeStateInitialize(bool privileged,
 
     udev_monitor_enable_receiving(priv->udev_monitor);
 
+    /* mimic udevd's behaviour and override the systems rmem_max limit in case
+     * there's a significant number of device 'add' events
+     */
+    if (geteuid() == 0)
+        udev_monitor_set_receive_buffer_size(priv->udev_monitor,
+                                             128 * 1024 * 1024);
+
     /* We register the monitor with the event callback so we are
      * notified by udev of device changes before we enumerate existing
      * devices because libvirt will simply recreate the device if we

src/qemu/qemu_monitor_json.c

@@ -528,7 +528,7 @@ static void qemuMonitorJSONHandleShutdown(qemuMonitorPtr mon, virJSONValuePtr da
     bool guest = false;
     virTristateBool guest_initiated = VIR_TRISTATE_BOOL_ABSENT;
 
-    if (virJSONValueObjectGetBoolean(data, "guest", &guest) == 0)
+    if (data && virJSONValueObjectGetBoolean(data, "guest", &guest) == 0)
         guest_initiated = guest ? VIR_TRISTATE_BOOL_YES : VIR_TRISTATE_BOOL_NO;
 
     qemuMonitorEmitShutdown(mon, guest_initiated);

src/util/virhostcpu.c

@@ -1093,7 +1093,7 @@ virHostCPUGetMap(unsigned char **cpumap,
     if (online)
         *online = virBitmapCountBits(cpus);
 
-    ret = virBitmapSize(cpus);
+    ret = virHostCPUGetCount();
 
  cleanup:
     if (ret < 0 && cpumap)