machinebase: fully initialize devices registered by other devices

postinit_devices() may cause additional devices to be registered
(e.g. PCI hosts will register their cards). We were not calling
device_postinit on those devices, because the iterator over the
device map was set up at the start of the loop.

Keep looping until we've actually initialized all devices in the map.

machines/machinebase.cpp

@@ -24,6 +24,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 #include <machines/machinebase.h>
 
 #include <map>
+#include <set>
 #include <string>
 
 std::unique_ptr<MachineBase> gMachineObj = 0;
@@ -79,9 +80,18 @@ HWComponent* MachineBase::get_comp_by_type(HWCompType type) {
 
 int MachineBase::postinit_devices()
 {
-    for (auto it = this->device_map.begin(); it != this->device_map.end(); it++) {
-        if (it->second->device_postinit()) {
-            return -1;
+    // Allow additional devices to be registered by device_postinit, in which
+    // case we'll initialize them too.
+    std::set<std::string> initialized_devices;
+    while (initialized_devices.size() < this->device_map.size()) {
+        for (auto it = this->device_map.begin(); it != this->device_map.end(); it++) {
+            if (initialized_devices.find(it->first) == initialized_devices.end()) {
+                if (it->second->device_postinit()) {
+                    LOG_F(ERROR, "Could not initialize device %s", it->first.c_str());
+                    return -1;
+                }
+                initialized_devices.insert(it->first);
+            }
         }
     }