Also look for dmi information in /sys/class

older kernels such as 2.6.26 have it there.

src/node_device/node_device_udev.c

@@ -1407,7 +1407,12 @@ static int udevSetupSystemDev(void)
     device = udev_device_new_from_syspath(udev, DMI_DEVPATH);
     if (device == NULL) {
         VIR_ERROR("Failed to get udev device for syspath '%s'\n", DMI_DEVPATH);
-        goto out;
+
+        device = udev_device_new_from_syspath(udev, DMI_DEVPATH_FALLBACK);
+        if (device == NULL) {
+            VIR_ERROR("Failed to get udev device for syspath '%s'\n", DMI_DEVPATH_FALLBACK);
+            goto out;
+        }
     }
 
     data = &def->caps->data;

src/node_device/node_device_udev.h

@@ -26,6 +26,7 @@
 #define SYSFS_DATA_SIZE 4096
 #define DRV_STATE_UDEV_MONITOR(ds) ((struct udev_monitor *)((ds)->privateData))
 #define DMI_DEVPATH "/sys/devices/virtual/dmi/id"
+#define DMI_DEVPATH_FALLBACK "/sys/class/dmi/id"
 #define PROPERTY_FOUND 0
 #define PROPERTY_MISSING 1
 #define PROPERTY_ERROR -1