Merge remote branch 'markus/qerror' into staging

45 files changed, 1007 insertions, 533 deletions

diff --git a/Makefile.target b/Makefile.target
index ab3c438fad..56c6652315 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -172,6 +172,7 @@ endif #CONFIG_BSD_USER
 ifdef CONFIG_SOFTMMU
 
 obj-y = vl.o async.o monitor.o pci.o pci_host.o pcie_host.o machine.o gdbstub.o
+obj-y += qemu-error.o
 # virtio has to be here due to weird dependency between PCI and virtio-net.
 # need to fix this properly
 obj-y += virtio-blk.o virtio-balloon.o virtio-net.o virtio-pci.o virtio-serial-bus.o
diff --git a/audio/audio.c b/audio/audio.c
index 2a20e5be1b..dbf0b96f33 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -330,10 +330,10 @@ void AUD_vlog (const char *cap, const char *fmt, va_list ap)
 {
     if (conf.log_to_monitor) {
         if (cap) {
-            monitor_printf(cur_mon, "%s: ", cap);
+            monitor_printf(default_mon, "%s: ", cap);
         }
 
-        monitor_vprintf(cur_mon, fmt, ap);
+        monitor_vprintf(default_mon, fmt, ap);
     }
     else {
         if (cap) {
diff --git a/hw/pc.c b/hw/pc.c
index e50a48848d..2b3063df8d 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -230,40 +230,40 @@ static int boot_device2nibble(char boot_device)
     return 0;
 }
 
-/* copy/pasted from cmos_init, should be made a general function
- and used there as well */
-static int pc_boot_set(void *opaque, const char *boot_device)
+static int set_boot_dev(RTCState *s, const char *boot_device, int fd_bootchk)
 {
-    Monitor *mon = cur_mon;
 #define PC_MAX_BOOT_DEVICES 3
-    RTCState *s = (RTCState *)opaque;
     int nbds, bds[3] = { 0, };
     int i;
 
     nbds = strlen(boot_device);
     if (nbds > PC_MAX_BOOT_DEVICES) {
-        monitor_printf(mon, "Too many boot devices for PC\n");
+        error_report("Too many boot devices for PC");
         return(1);
     }
     for (i = 0; i < nbds; i++) {
         bds[i] = boot_device2nibble(boot_device[i]);
         if (bds[i] == 0) {
-            monitor_printf(mon, "Invalid boot device for PC: '%c'\n",
-                           boot_device[i]);
+            error_report("Invalid boot device for PC: '%c'",
+                         boot_device[i]);
             return(1);
         }
     }
     rtc_set_memory(s, 0x3d, (bds[1] << 4) | bds[0]);
-    rtc_set_memory(s, 0x38, (bds[2] << 4));
+    rtc_set_memory(s, 0x38, (bds[2] << 4) | (fd_bootchk ? 0x0 : 0x1));
     return(0);
 }
 
+static int pc_boot_set(void *opaque, const char *boot_device)
+{
+    return set_boot_dev(opaque, boot_device, 0);
+}
+
 /* hd_table must contain 4 block drivers */
 static void cmos_init(ram_addr_t ram_size, ram_addr_t above_4g_mem_size,
                       const char *boot_device, DriveInfo **hd_table)
 {
     RTCState *s = rtc_state;
-    int nbds, bds[3] = { 0, };
     int val;
     int fd0, fd1, nb;
     int i;
@@ -302,22 +302,9 @@ static void cmos_init(ram_addr_t ram_size, ram_addr_t above_4g_mem_size,
     rtc_set_memory(s, 0x5f, smp_cpus - 1);
 
     /* set boot devices, and disable floppy signature check if requested */
-#define PC_MAX_BOOT_DEVICES 3
-    nbds = strlen(boot_device);
-    if (nbds > PC_MAX_BOOT_DEVICES) {
-        fprintf(stderr, "Too many boot devices for PC\n");
+    if (set_boot_dev(s, boot_device, fd_bootchk)) {
         exit(1);
     }
-    for (i = 0; i < nbds; i++) {
-        bds[i] = boot_device2nibble(boot_device[i]);
-        if (bds[i] == 0) {
-            fprintf(stderr, "Invalid boot device for PC: '%c'\n",
-                    boot_device[i]);
-            exit(1);
-        }
-    }
-    rtc_set_memory(s, 0x3d, (bds[1] << 4) | bds[0]);
-    rtc_set_memory(s, 0x38, (bds[2] << 4) | (fd_bootchk ?  0x0 : 0x1));
 
     /* floppy type */
 
diff --git a/hw/pci-hotplug.c b/hw/pci-hotplug.c
index bd82c6aab7..eb3701bc89 100644
--- a/hw/pci-hotplug.c
+++ b/hw/pci-hotplug.c
@@ -54,7 +54,7 @@ static PCIDevice *qemu_pci_hot_add_nic(Monitor *mon,
         return NULL;
     }
 
-    opts = qemu_opts_parse(&qemu_net_opts, opts_str ? opts_str : "", NULL);
+    opts = qemu_opts_parse(&qemu_net_opts, opts_str ? opts_str : "", 0);
     if (!opts) {
         monitor_printf(mon, "parsing network options '%s' failed\n",
                        opts_str ? opts_str : "");
@@ -73,14 +73,15 @@ static PCIDevice *qemu_pci_hot_add_nic(Monitor *mon,
     return pci_nic_init(&nd_table[ret], "rtl8139", devaddr);
 }
 
-static int scsi_hot_add(DeviceState *adapter, DriveInfo *dinfo, int printinfo)
+static int scsi_hot_add(Monitor *mon, DeviceState *adapter,
+                        DriveInfo *dinfo, int printinfo)
 {
     SCSIBus *scsibus;
     SCSIDevice *scsidev;
 
     scsibus = DO_UPCAST(SCSIBus, qbus, QLIST_FIRST(&adapter->child_bus));
     if (!scsibus || strcmp(scsibus->qbus.info->name, "SCSI") != 0) {
-        qemu_error("Device is not a SCSI adapter\n");
+        error_report("Device is not a SCSI adapter");
         return -1;
     }
 
@@ -97,7 +98,8 @@ static int scsi_hot_add(DeviceState *adapter, DriveInfo *dinfo, int printinfo)
     dinfo->unit = scsidev->id;
 
     if (printinfo)
-        qemu_error("OK bus %d, unit %d\n", scsibus->busnr, scsidev->id);
+        monitor_printf(mon, "OK bus %d, unit %d\n",
+                       scsibus->busnr, scsidev->id);
     return 0;
 }
 
@@ -131,7 +133,7 @@ void drive_hot_add(Monitor *mon, const QDict *qdict)
             monitor_printf(mon, "no pci device with address %s\n", pci_addr);
             goto err;
         }
-        if (scsi_hot_add(&dev->qdev, dinfo, 1) != 0) {
+        if (scsi_hot_add(mon, &dev->qdev, dinfo, 1) != 0) {
             goto err;
         }
         break;
@@ -203,7 +205,7 @@ static PCIDevice *qemu_pci_hot_add_storage(Monitor *mon,
         if (qdev_init(&dev->qdev) < 0)
             dev = NULL;
         if (dev && dinfo) {
-            if (scsi_hot_add(&dev->qdev, dinfo, 0) != 0) {
+            if (scsi_hot_add(mon, &dev->qdev, dinfo, 0) != 0) {
                 qdev_unplug(&dev->qdev);
                 dev = NULL;
             }
diff --git a/hw/pci.c b/hw/pci.c
index eb2043e500..0dbca173e3 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -589,12 +589,12 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus,
             if (!bus->devices[devfn])
                 goto found;
         }
-        qemu_error("PCI: no devfn available for %s, all in use\n", name);
+        error_report("PCI: no devfn available for %s, all in use", name);
         return NULL;
     found: ;
     } else if (bus->devices[devfn]) {
-        qemu_error("PCI: devfn %d not available for %s, in use by %s\n", devfn,
-                 name, bus->devices[devfn]->name);
+        error_report("PCI: devfn %d not available for %s, in use by %s",
+                     devfn, name, bus->devices[devfn]->name);
         return NULL;
     }
     pci_dev->bus = bus;
@@ -1476,8 +1476,8 @@ PCIDevice *pci_nic_init(NICInfo *nd, const char *default_model,
 
     bus = pci_get_bus_devfn(&devfn, devaddr);
     if (!bus) {
-        qemu_error("Invalid PCI device address %s for device %s\n",
-                   devaddr, pci_nic_names[i]);
+        error_report("Invalid PCI device address %s for device %s",
+                     devaddr, pci_nic_names[i]);
         return NULL;
     }
 
@@ -1768,8 +1768,8 @@ static int pci_add_option_rom(PCIDevice *pdev)
 
     size = get_image_size(path);
     if (size < 0) {
-        qemu_error("%s: failed to find romfile \"%s\"\n", __FUNCTION__,
-                   pdev->romfile);
+        error_report("%s: failed to find romfile \"%s\"",
+                     __FUNCTION__, pdev->romfile);
         return -1;
     }
     if (size & (size - 1)) {
diff --git a/hw/qdev-properties.c b/hw/qdev-properties.c
index 24671aff9f..92d6793747 100644
--- a/hw/qdev-properties.c
+++ b/hw/qdev-properties.c
@@ -402,17 +402,11 @@ PropertyInfo qdev_prop_vlan = {
 
 /* --- pointer --- */
 
-static int print_ptr(DeviceState *dev, Property *prop, char *dest, size_t len)
-{
-    void **ptr = qdev_get_prop_ptr(dev, prop);
-    return snprintf(dest, len, "<%p>", *ptr);
-}
-
+/* Not a proper property, just for dirty hacks.  TODO Remove it!  */
 PropertyInfo qdev_prop_ptr = {
     .name  = "ptr",
     .type  = PROP_TYPE_PTR,
     .size  = sizeof(void*),
-    .print = print_ptr,
 };
 
 /* --- mac address --- */
@@ -547,31 +541,31 @@ int qdev_prop_parse(DeviceState *dev, const char *name, const char *value)
     int ret;
 
     prop = qdev_prop_find(dev, name);
-    if (!prop) {
-        fprintf(stderr, "property \"%s.%s\" not found\n",
-                dev->info->name, name);
-        return -1;
-    }
-    if (!prop->info->parse) {
-        fprintf(stderr, "property \"%s.%s\" has no parser\n",
-                dev->info->name, name);
+    /*
+     * TODO Properties without a parse method are just for dirty
+     * hacks.  qdev_prop_ptr is the only such PropertyInfo.  It's
+     * marked for removal.  The test !prop->info->parse should be
+     * removed along with it.
+     */
+    if (!prop || !prop->info->parse) {
+        qerror_report(QERR_PROPERTY_NOT_FOUND, dev->info->name, name);
         return -1;
     }
     ret = prop->info->parse(dev, prop, value);
     if (ret < 0) {
         switch (ret) {
         case -EEXIST:
-            fprintf(stderr, "property \"%s.%s\": \"%s\" is already in use\n",
-                    dev->info->name, name, value);
+            qerror_report(QERR_PROPERTY_VALUE_IN_USE,
+                          dev->info->name, name, value);
             break;
         default:
         case -EINVAL:
-            fprintf(stderr, "property \"%s.%s\": failed to parse \"%s\"\n",
-                    dev->info->name, name, value);
+            qerror_report(QERR_PROPERTY_VALUE_BAD,
+                          dev->info->name, name, value);
             break;
         case -ENOENT:
-            fprintf(stderr, "property \"%s.%s\": could not find \"%s\"\n",
-                    dev->info->name, name, value);
+            qerror_report(QERR_PROPERTY_VALUE_NOT_FOUND,
+                          dev->info->name, name, value);
             break;
         }
         return -1;
diff --git a/hw/qdev.c b/hw/qdev.c
index b634890068..17a46a7bb3 100644
--- a/hw/qdev.c
+++ b/hw/qdev.c
@@ -29,7 +29,6 @@
 #include "qdev.h"
 #include "sysemu.h"
 #include "monitor.h"
-#include "qerror.h"
 
 static int qdev_hotplug = 0;
 
@@ -78,13 +77,32 @@ static DeviceInfo *qdev_find_info(BusInfo *bus_info, const char *name)
     return NULL;
 }
 
+static DeviceState *qdev_create_from_info(BusState *bus, DeviceInfo *info)
+{
+    DeviceState *dev;
+
+    assert(bus->info == info->bus_info);
+    dev = qemu_mallocz(info->size);
+    dev->info = info;
+    dev->parent_bus = bus;
+    qdev_prop_set_defaults(dev, dev->info->props);
+    qdev_prop_set_defaults(dev, dev->parent_bus->info->props);
+    qdev_prop_set_globals(dev);
+    QLIST_INSERT_HEAD(&bus->children, dev, sibling);
+    if (qdev_hotplug) {
+        assert(bus->allow_hotplug);
+        dev->hotplugged = 1;
+    }
+    dev->state = DEV_STATE_CREATED;
+    return dev;
+}
+
 /* Create a new device.  This only initializes the device state structure
    and allows properties to be set.  qdev_init should be called to
    initialize the actual device emulation.  */
 DeviceState *qdev_create(BusState *bus, const char *name)
 {
     DeviceInfo *info;
-    DeviceState *dev;
 
     if (!bus) {
         if (!main_system_bus) {
@@ -98,42 +116,23 @@ DeviceState *qdev_create(BusState *bus, const char *name)
         hw_error("Unknown device '%s' for bus '%s'\n", name, bus->info->name);
     }
 
-    dev = qemu_mallocz(info->size);
-    dev->info = info;
-    dev->parent_bus = bus;
-    qdev_prop_set_defaults(dev, dev->info->props);
-    qdev_prop_set_defaults(dev, dev->parent_bus->info->props);
-    qdev_prop_set_globals(dev);
-    QLIST_INSERT_HEAD(&bus->children, dev, sibling);
-    if (qdev_hotplug) {
-        assert(bus->allow_hotplug);
-        dev->hotplugged = 1;
-    }
-    dev->state = DEV_STATE_CREATED;
-    return dev;
+    return qdev_create_from_info(bus, info);
 }
 
-static int qdev_print_devinfo(DeviceInfo *info, char *dest, int len)
+static void qdev_print_devinfo(DeviceInfo *info)
 {
-    int pos = 0;
-    int ret;
-
-    ret = snprintf(dest+pos, len-pos, "name \"%s\", bus %s",
-                   info->name, info->bus_info->name);
-    pos += MIN(len-pos,ret);
+    error_printf("name \"%s\", bus %s",
+                 info->name, info->bus_info->name);
     if (info->alias) {
-        ret = snprintf(dest+pos, len-pos, ", alias \"%s\"", info->alias);
-        pos += MIN(len-pos,ret);
+        error_printf(", alias \"%s\"", info->alias);
     }
     if (info->desc) {
-        ret = snprintf(dest+pos, len-pos, ", desc \"%s\"", info->desc);
-        pos += MIN(len-pos,ret);
+        error_printf(", desc \"%s\"", info->desc);
     }
     if (info->no_user) {
-        ret = snprintf(dest+pos, len-pos, ", no-user");
-        pos += MIN(len-pos,ret);
+        error_printf(", no-user");
     }
-    return pos;
+    error_printf("\n");
 }
 
 static int set_property(const char *name, const char *value, void *opaque)
@@ -146,8 +145,6 @@ static int set_property(const char *name, const char *value, void *opaque)
         return 0;
 
     if (qdev_prop_parse(dev, name, value) == -1) {
-        qemu_error("can't set property \"%s\" to \"%s\" for \"%s\"\n",
-                   name, value, dev->info->name);
         return -1;
     }
     return 0;
@@ -157,14 +154,15 @@ int qdev_device_help(QemuOpts *opts)
 {
     const char *driver;
     DeviceInfo *info;
-    char msg[256];
     Property *prop;
 
     driver = qemu_opt_get(opts, "driver");
     if (driver && !strcmp(driver, "?")) {
         for (info = device_info_list; info != NULL; info = info->next) {
-            qdev_print_devinfo(info, msg, sizeof(msg));
-            qemu_error("%s\n", msg);
+            if (info->no_user) {
+                continue;       /* not available, don't show */
+            }
+            qdev_print_devinfo(info);
         }
         return 1;
     }
@@ -179,7 +177,16 @@ int qdev_device_help(QemuOpts *opts)
     }
 
     for (prop = info->props; prop && prop->name; prop++) {
-        qemu_error("%s.%s=%s\n", info->name, prop->name, prop->info->name);
+        /*
+         * TODO Properties without a parser are just for dirty hacks.
+         * qdev_prop_ptr is the only such PropertyInfo.  It's marked
+         * for removal.  This conditional should be removed along with
+         * it.
+         */
+        if (!prop->info->parse) {
+            continue;           /* no way to set it, don't show */
+        }
+        error_printf("%s.%s=%s\n", info->name, prop->name, prop->info->name);
     }
     return 1;
 }
@@ -193,19 +200,15 @@ DeviceState *qdev_device_add(QemuOpts *opts)
 
     driver = qemu_opt_get(opts, "driver");
     if (!driver) {
-        qemu_error("-device: no driver specified\n");
+        qerror_report(QERR_MISSING_PARAMETER, "driver");
         return NULL;
     }
 
     /* find driver */
     info = qdev_find_info(NULL, driver);
-    if (!info) {
-        qemu_error_new(QERR_DEVICE_NOT_FOUND, driver);
-        return NULL;
-    }
-    if (info->no_user) {
-        qemu_error("device \"%s\" can't be added via command line\n",
-                   info->name);
+    if (!info || info->no_user) {
+        qerror_report(QERR_INVALID_PARAMETER, "driver");
+        error_printf_unless_qmp("Try with argument '?' for a list.\n");
         return NULL;
     }
 
@@ -213,22 +216,29 @@ DeviceState *qdev_device_add(QemuOpts *opts)
     path = qemu_opt_get(opts, "bus");
     if (path != NULL) {
         bus = qbus_find(path);
+        if (!bus) {
+            return NULL;
+        }
+        if (bus->info != info->bus_info) {
+            qerror_report(QERR_BAD_BUS_FOR_DEVICE,
+                           driver, bus->info->name);
+            return NULL;
+        }
     } else {
         bus = qbus_find_recursive(main_system_bus, NULL, info->bus_info);
-    }
-    if (!bus) {
-        qemu_error("Did not find %s bus for %s\n",
-                   path ? path : info->bus_info->name, info->name);
-        return NULL;
+        if (!bus) {
+            qerror_report(QERR_NO_BUS_FOR_DEVICE,
+                           info->name, info->bus_info->name);
+            return NULL;
+        }
     }
     if (qdev_hotplug && !bus->allow_hotplug) {
-        qemu_error("Bus %s does not support hotplugging\n",
-                   bus->name);
+        qerror_report(QERR_BUS_NO_HOTPLUG, bus->name);
         return NULL;
     }
 
     /* create device, set properties */
-    qdev = qdev_create(bus, driver);
+    qdev = qdev_create_from_info(bus, info);
     id = qemu_opts_id(opts);
     if (id) {
         qdev->id = id;
@@ -238,7 +248,7 @@ DeviceState *qdev_device_add(QemuOpts *opts)
         return NULL;
     }
     if (qdev_init(qdev) < 0) {
-        qemu_error("Error initializing device %s\n", driver);
+        qerror_report(QERR_DEVICE_INIT_FAILED, driver);
         return NULL;
     }
     qdev->opts = opts;
@@ -277,8 +287,8 @@ int qdev_init(DeviceState *dev)
 int qdev_unplug(DeviceState *dev)
 {
     if (!dev->parent_bus->allow_hotplug) {
-        qemu_error("Bus %s does not support hotplugging\n",
-                   dev->parent_bus->name);
+        error_report("Bus %s does not support hotplugging",
+                     dev->parent_bus->name);
         return -1;
     }
     assert(dev->info->unplug != NULL);
@@ -465,35 +475,33 @@ static DeviceState *qdev_find_recursive(BusState *bus, const char *id)
     return NULL;
 }
 
-static void qbus_list_bus(DeviceState *dev, char *dest, int len)
+static void qbus_list_bus(DeviceState *dev)
 {
     BusState *child;
     const char *sep = " ";
-    int pos = 0;
 
-    pos += snprintf(dest+pos, len-pos,"child busses at \"%s\":",
-                    dev->id ? dev->id : dev->info->name);
+    error_printf("child busses at \"%s\":",
+                 dev->id ? dev->id : dev->info->name);
     QLIST_FOREACH(child, &dev->child_bus, sibling) {
-        pos += snprintf(dest+pos, len-pos, "%s\"%s\"", sep, child->name);
+        error_printf("%s\"%s\"", sep, child->name);
         sep = ", ";
     }
+    error_printf("\n");
 }
 
-static void qbus_list_dev(BusState *bus, char *dest, int len)
+static void qbus_list_dev(BusState *bus)
 {
     DeviceState *dev;
     const char *sep = " ";
-    int pos = 0;
 
-    pos += snprintf(dest+pos, len-pos, "devices at \"%s\":",
-                    bus->name);
+    error_printf("devices at \"%s\":", bus->name);
     QLIST_FOREACH(dev, &bus->children, sibling) {
-        pos += snprintf(dest+pos, len-pos, "%s\"%s\"",
-                        sep, dev->info->name);
+        error_printf("%s\"%s\"", sep, dev->info->name);
         if (dev->id)
-            pos += snprintf(dest+pos, len-pos, "/\"%s\"", dev->id);
+            error_printf("/\"%s\"", dev->id);
         sep = ", ";
     }
+    error_printf("\n");
 }
 
 static BusState *qbus_find_bus(DeviceState *dev, char *elem)
@@ -540,7 +548,7 @@ static BusState *qbus_find(const char *path)
 {
     DeviceState *dev;
     BusState *bus;
-    char elem[128], msg[256];
+    char elem[128];
     int pos, len;
 
     /* find start element */
@@ -549,62 +557,75 @@ static BusState *qbus_find(const char *path)
         pos = 0;
     } else {
         if (sscanf(path, "%127[^/]%n", elem, &len) != 1) {
-            qemu_error("path parse error (\"%s\")\n", path);
-            return NULL;
+            assert(!path[0]);
+            elem[0] = len = 0;
         }
         bus = qbus_find_recursive(main_system_bus, elem, NULL);
         if (!bus) {
-            qemu_error("bus \"%s\" not found\n", elem);
+            qerror_report(QERR_BUS_NOT_FOUND, elem);
             return NULL;
         }
         pos = len;
     }
 
     for (;;) {
+        assert(path[pos] == '/' || !path[pos]);
+        while (path[pos] == '/') {
+            pos++;
+        }
         if (path[pos] == '\0') {
-            /* we are done */
             return bus;
         }
 
         /* find device */
-        if (sscanf(path+pos, "/%127[^/]%n", elem, &len) != 1) {
-            qemu_error("path parse error (\"%s\" pos %d)\n", path, pos);
-            return NULL;
+        if (sscanf(path+pos, "%127[^/]%n", elem, &len) != 1) {
+            assert(0);
+            elem[0] = len = 0;
         }
         pos += len;
         dev = qbus_find_dev(bus, elem);
         if (!dev) {
-            qbus_list_dev(bus, msg, sizeof(msg));
-            qemu_error("device \"%s\" not found\n%s\n", elem, msg);
+            qerror_report(QERR_DEVICE_NOT_FOUND, elem);
+            if (!monitor_cur_is_qmp()) {
+                qbus_list_dev(bus);
+            }
             return NULL;
         }
+
+        assert(path[pos] == '/' || !path[pos]);
+        while (path[pos] == '/') {
+            pos++;
+        }
         if (path[pos] == '\0') {
             /* last specified element is a device.  If it has exactly
              * one child bus accept it nevertheless */
             switch (dev->num_child_bus) {
             case 0:
-                qemu_error("device has no child bus (%s)\n", path);
+                qerror_report(QERR_DEVICE_NO_BUS, elem);
                 return NULL;
             case 1:
                 return QLIST_FIRST(&dev->child_bus);
             default:
-                qbus_list_bus(dev, msg, sizeof(msg));
-                qemu_error("device has multiple child busses (%s)\n%s\n",
-                           path, msg);
+                qerror_report(QERR_DEVICE_MULTIPLE_BUSSES, elem);
+                if (!monitor_cur_is_qmp()) {
+                    qbus_list_bus(dev);
+                }
                 return NULL;
             }
         }
 
         /* find bus */
-        if (sscanf(path+pos, "/%127[^/]%n", elem, &len) != 1) {
-            qemu_error("path parse error (\"%s\" pos %d)\n", path, pos);
-            return NULL;
+        if (sscanf(path+pos, "%127[^/]%n", elem, &len) != 1) {
+            assert(0);
+            elem[0] = len = 0;
         }
         pos += len;
         bus = qbus_find_bus(dev, elem);
         if (!bus) {
-            qbus_list_bus(dev, msg, sizeof(msg));
-            qemu_error("child bus \"%s\" not found\n%s\n", elem, msg);
+            qerror_report(QERR_BUS_NOT_FOUND, elem);
+            if (!monitor_cur_is_qmp()) {
+                qbus_list_bus(dev);
+            }
             return NULL;
         }
     }
@@ -684,6 +705,12 @@ static void qdev_print_props(Monitor *mon, DeviceState *dev, Property *props,
     if (!props)
         return;
     while (props->name) {
+        /*
+         * TODO Properties without a print method are just for dirty
+         * hacks.  qdev_prop_ptr is the only such PropertyInfo.  It's
+         * marked for removal.  The test props->info->print should be
+         * removed along with it.
+         */
         if (props->info->print) {
             props->info->print(dev, props, buf, sizeof(buf));
             qdev_printf("%s-prop: %s = %s\n", prefix, props->name, buf);
@@ -735,25 +762,42 @@ void do_info_qtree(Monitor *mon)
 void do_info_qdm(Monitor *mon)
 {
     DeviceInfo *info;
-    char msg[256];
 
     for (info = device_info_list; info != NULL; info = info->next) {
-        qdev_print_devinfo(info, msg, sizeof(msg));
-        monitor_printf(mon, "%s\n", msg);
+        qdev_print_devinfo(info);
     }
 }
 
-void do_device_add(Monitor *mon, const QDict *qdict)
+/**
+ * do_device_add(): Add a device
+ *
+ * Argument qdict contains
+ * - "driver": the name of the new device's driver
+ * - "bus": the device's parent bus (device tree path)
+ * - "id": the device's ID (must be unique)
+ * - device properties
+ *
+ * Example:
+ *
+ * { "driver": "usb-net", "id": "eth1", "netdev": "netdev1" }
+ */
+int do_device_add(Monitor *mon, const QDict *qdict, QObject **ret_data)
 {
     QemuOpts *opts;
 
-    opts = qemu_opts_parse(&qemu_device_opts,
-                           qdict_get_str(qdict, "config"), "driver");
-    if (opts) {
-        if (qdev_device_help(opts) || qdev_device_add(opts) == NULL) {
-            qemu_opts_del(opts);
-        }
+    opts = qemu_opts_from_qdict(&qemu_device_opts, qdict);
+    if (!opts) {
+        return -1;
+    }
+    if (!monitor_cur_is_qmp() && qdev_device_help(opts)) {
+        qemu_opts_del(opts);
+        return 0;
+    }
+    if (!qdev_device_add(opts)) {
+        qemu_opts_del(opts);
+        return -1;
     }
+    return 0;
 }
 
 void do_device_del(Monitor *mon, const QDict *qdict)
@@ -763,7 +807,7 @@ void do_device_del(Monitor *mon, const QDict *qdict)
 
     dev = qdev_find_recursive(main_system_bus, id);
     if (NULL == dev) {
-        qemu_error("Device '%s' not found\n", id);
+        error_report("Device '%s' not found", id);
         return;
     }
     qdev_unplug(dev);
diff --git a/hw/qdev.h b/hw/qdev.h
index adfcf795c3..9475705b7b 100644
--- a/hw/qdev.h
+++ b/hw/qdev.h
@@ -175,7 +175,7 @@ void qbus_free(BusState *bus);
 
 void do_info_qtree(Monitor *mon);
 void do_info_qdm(Monitor *mon);
-void do_device_add(Monitor *mon, const QDict *qdict);
+int do_device_add(Monitor *mon, const QDict *qdict, QObject **ret_data);
 void do_device_del(Monitor *mon, const QDict *qdict);
 
 /*** qdev-properties.c ***/
diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index a2f9cc1cc3..383240bc07 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -1,5 +1,5 @@
 #include "hw.h"
-#include "sysemu.h"
+#include "qemu-error.h"
 #include "scsi.h"
 #include "scsi-defs.h"
 #include "block.h"
@@ -41,7 +41,7 @@ static int scsi_qdev_init(DeviceState *qdev, DeviceInfo *base)
         }
     }
     if (dev->id >= bus->ndev) {
-        qemu_error("bad scsi device id: %d\n", dev->id);
+        error_report("bad scsi device id: %d", dev->id);
         goto err;
     }
 
diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
index 8f7ffc143d..da56d2bc1c 100644
--- a/hw/scsi-disk.c
+++ b/hw/scsi-disk.c
@@ -19,8 +19,6 @@
  * the host adapter emulator.
  */
 
-#include <qemu-common.h>
-#include <sysemu.h>
 //#define DEBUG_SCSI
 
 #ifdef DEBUG_SCSI
@@ -34,6 +32,7 @@ do { printf("scsi-disk: " fmt , ## __VA_ARGS__); } while (0)
 do { fprintf(stderr, "scsi-disk: " fmt , ## __VA_ARGS__); } while (0)
 
 #include "qemu-common.h"
+#include "qemu-error.h"
 #include "block.h"
 #include "scsi.h"
 #include "scsi-defs.h"
@@ -1026,13 +1025,13 @@ static int scsi_disk_initfn(SCSIDevice *dev)
     uint64_t nb_sectors;
 
     if (!s->qdev.conf.dinfo || !s->qdev.conf.dinfo->bdrv) {
-        qemu_error("scsi-disk: drive property not set\n");
+        error_report("scsi-disk: drive property not set");
         return -1;
     }
     s->bs = s->qdev.conf.dinfo->bdrv;
 
     if (bdrv_is_sg(s->bs)) {
-        qemu_error("scsi-disk: unwanted /dev/sg*\n");
+        error_report("scsi-disk: unwanted /dev/sg*");
         return -1;
     }
 
diff --git a/hw/scsi-generic.c b/hw/scsi-generic.c
index de778efa3b..c9aa853cc4 100644
--- a/hw/scsi-generic.c
+++ b/hw/scsi-generic.c
@@ -12,6 +12,7 @@
  */
 
 #include "qemu-common.h"
+#include "qemu-error.h"
 #include "block.h"
 #include "scsi.h"
 
@@ -463,27 +464,27 @@ static int scsi_generic_initfn(SCSIDevice *dev)
     struct sg_scsi_id scsiid;
 
     if (!s->qdev.conf.dinfo || !s->qdev.conf.dinfo->bdrv) {
-        qemu_error("scsi-generic: drive property not set\n");
+        error_report("scsi-generic: drive property not set");
         return -1;
     }
     s->bs = s->qdev.conf.dinfo->bdrv;
 
     /* check we are really using a /dev/sg* file */
     if (!bdrv_is_sg(s->bs)) {
-        qemu_error("scsi-generic: not /dev/sg*\n");
+        error_report("scsi-generic: not /dev/sg*");
         return -1;
     }
 
     /* check we are using a driver managing SG_IO (version 3 and after */
     if (bdrv_ioctl(s->bs, SG_GET_VERSION_NUM, &sg_version) < 0 ||
         sg_version < 30000) {
-        qemu_error("scsi-generic: scsi generic interface too old\n");
+        error_report("scsi-generic: scsi generic interface too old");
         return -1;
     }
 
     /* get LUN of the /dev/sg? */
     if (bdrv_ioctl(s->bs, SG_GET_SCSI_ID, &scsiid)) {
-        qemu_error("scsi-generic: SG_GET_SCSI_ID ioctl failed\n");
+        error_report("scsi-generic: SG_GET_SCSI_ID ioctl failed");
         return -1;
     }
 
diff --git a/hw/usb-bus.c b/hw/usb-bus.c
index 7c823147ab..e2d87f2d1f 100644
--- a/hw/usb-bus.c
+++ b/hw/usb-bus.c
@@ -291,14 +291,14 @@ USBDevice *usbdevice_create(const char *cmdline)
     if (info == NULL) {
 #if 0
         /* no error because some drivers are not converted (yet) */
-        qemu_error("usbdevice %s not found\n", driver);
+        error_report("usbdevice %s not found", driver);
 #endif
         return NULL;
     }
 
     if (!usb->usbdevice_init) {
         if (params) {
-            qemu_error("usbdevice %s accepts no params\n", driver);
+            error_report("usbdevice %s accepts no params", driver);
             return NULL;
         }
         return usb_create_simple(bus, usb->qdev.name);
diff --git a/hw/usb-msd.c b/hw/usb-msd.c
index 1a11bc557e..e90a47e0e1 100644
--- a/hw/usb-msd.c
+++ b/hw/usb-msd.c
@@ -524,7 +524,7 @@ static int usb_msd_initfn(USBDevice *dev)
     MSDState *s = DO_UPCAST(MSDState, dev, dev);
 
     if (!s->conf.dinfo || !s->conf.dinfo->bdrv) {
-        qemu_error("usb-msd: drive property not set\n");
+        error_report("usb-msd: drive property not set");
         return -1;
     }
 
@@ -535,7 +535,7 @@ static int usb_msd_initfn(USBDevice *dev)
     usb_msd_handle_reset(dev);
 
     if (bdrv_key_required(s->conf.dinfo->bdrv)) {
-        if (s->dev.qdev.hotplugged) {
+        if (cur_mon) {
             monitor_read_bdrv_key_start(cur_mon, s->conf.dinfo->bdrv,
                                         usb_msd_password_cb, s);
             s->dev.auto_attach = 0;
diff --git a/hw/usb-net.c b/hw/usb-net.c
index 6875f112fe..4c17435c84 100644
--- a/hw/usb-net.c
+++ b/hw/usb-net.c
@@ -1478,7 +1478,7 @@ static USBDevice *usb_net_init(const char *cmdline)
     QemuOpts *opts;
     int idx;
 
-    opts = qemu_opts_parse(&qemu_net_opts, cmdline, NULL);
+    opts = qemu_opts_parse(&qemu_net_opts, cmdline, 0);
     if (!opts) {
         return NULL;
     }
diff --git a/hw/usb-serial.c b/hw/usb-serial.c
index 1410b11b2b..69f0e44f11 100644
--- a/hw/usb-serial.c
+++ b/hw/usb-serial.c
@@ -9,6 +9,7 @@
  */
 
 #include "qemu-common.h"
+#include "qemu-error.h"
 #include "usb.h"
 #include "qemu-char.h"
 
@@ -564,26 +565,26 @@ static USBDevice *usb_serial_init(const char *filename)
         if (strstart(filename, "vendorid=", &p)) {
             vendorid = strtol(p, &e, 16);
             if (e == p || (*e && *e != ',' && *e != ':')) {
-                qemu_error("bogus vendor ID %s\n", p);
+                error_report("bogus vendor ID %s", p);
                 return NULL;
             }
             filename = e;
         } else if (strstart(filename, "productid=", &p)) {
             productid = strtol(p, &e, 16);
             if (e == p || (*e && *e != ',' && *e != ':')) {
-                qemu_error("bogus product ID %s\n", p);
+                error_report("bogus product ID %s", p);
                 return NULL;
             }
             filename = e;
         } else {
-            qemu_error("unrecognized serial USB option %s\n", filename);
+            error_report("unrecognized serial USB option %s", filename);
             return NULL;
         }
         while(*filename == ',')
             filename++;
     }
     if (!*filename) {
-        qemu_error("character device specification needed\n");
+        error_report("character device specification needed");
         return NULL;
     }
     filename++;
diff --git a/hw/virtio-net.c b/hw/virtio-net.c
index 5c0093e879..be33c68bbc 100644
--- a/hw/virtio-net.c
+++ b/hw/virtio-net.c
@@ -15,6 +15,7 @@
 #include "net.h"
 #include "net/checksum.h"
 #include "net/tap.h"
+#include "qemu-error.h"
 #include "qemu-timer.h"
 #include "virtio-net.h"
 
@@ -764,7 +765,7 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
 
     if (version_id >= 7) {
         if (qemu_get_be32(f) && !peer_has_vnet_hdr(n)) {
-            qemu_error("virtio-net: saved image requires vnet_hdr=on\n");
+            error_report("virtio-net: saved image requires vnet_hdr=on");
             return -1;
         }
 
@@ -793,7 +794,7 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
 
     if (version_id >= 11) {
         if (qemu_get_byte(f) && !peer_has_ufo(n)) {
-            qemu_error("virtio-net: saved image requires TUN_F_UFO support\n");
+            error_report("virtio-net: saved image requires TUN_F_UFO support");
             return -1;
         }
     }
diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index 799f664d8e..6eb19cdf8c 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -19,7 +19,7 @@
 #include "virtio-blk.h"
 #include "virtio-net.h"
 #include "pci.h"
-#include "sysemu.h"
+#include "qemu-error.h"
 #include "msix.h"
 #include "net.h"
 #include "block_int.h"
@@ -459,7 +459,7 @@ static int virtio_blk_init_pci(PCIDevice *pci_dev)
         proxy->class_code = PCI_CLASS_STORAGE_SCSI;
 
     if (!proxy->block.dinfo) {
-        qemu_error("virtio-blk-pci: drive property not set\n");
+        error_report("virtio-blk-pci: drive property not set");
         return -1;
     }
     vdev = virtio_blk_init(&pci_dev->qdev, &proxy->block);
diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c
index d0e021932c..17c1ec1d06 100644
--- a/hw/virtio-serial-bus.c
+++ b/hw/virtio-serial-bus.c
@@ -485,7 +485,7 @@ static int virtser_port_qdev_init(DeviceState *qdev, DeviceInfo *base)
     plugging_port0 = port->is_console && !find_port_by_id(port->vser, 0);
 
     if (port->vser->config.nr_ports == bus->max_nr_ports && !plugging_port0) {
-        qemu_error("virtio-serial-bus: Maximum device limit reached\n");
+        error_report("virtio-serial-bus: Maximum device limit reached");
         return -1;
     }
     dev->info = info;
diff --git a/monitor.c b/monitor.c
index 672ae474bb..f0ec84d52f 100644
--- a/monitor.c
+++ b/monitor.c
@@ -67,6 +67,11 @@
  * 'F'          filename
  * 'B'          block device name
  * 's'          string (accept optional quote)
+ * 'O'          option string of the form NAME=VALUE,...
+ *              parsed according to QemuOptsList given by its name
+ *              Example: 'device:O' uses qemu_device_opts.
+ *              Restriction: only lists with empty desc are supported
+ *              TODO lift the restriction
  * 'i'          32 bit integer
  * 'l'          target long (32 or 64 bit)
  * 'M'          just like 'l', except in user mode the value is
@@ -177,7 +182,8 @@ static QLIST_HEAD(mon_list, Monitor) mon_list;
 static const mon_cmd_t mon_cmds[];
 static const mon_cmd_t info_cmds[];
 
-Monitor *cur_mon = NULL;
+Monitor *cur_mon;
+Monitor *default_mon;
 
 static void monitor_command_cb(Monitor *mon, const char *cmdline,
                                void *opaque);
@@ -193,6 +199,12 @@ static inline int monitor_ctrl_mode(const Monitor *mon)
     return (mon->flags & MONITOR_USE_CONTROL);
 }
 
+/* Return non-zero iff we have a current monitor, and it is in QMP mode.  */
+int monitor_cur_is_qmp(void)
+{
+    return cur_mon && monitor_ctrl_mode(cur_mon);
+}
+
 static void monitor_read_command(Monitor *mon, int show_prompt)
 {
     if (!mon->rs)
@@ -207,7 +219,7 @@ static int monitor_read_password(Monitor *mon, ReadLineFunc *readline_func,
                                  void *opaque)
 {
     if (monitor_ctrl_mode(mon)) {
-        qemu_error_new(QERR_MISSING_PARAMETER, "password");
+        qerror_report(QERR_MISSING_PARAMETER, "password");
         return -EINVAL;
     } else if (mon->rs) {
         readline_start(mon->rs, "Password: ", 1, readline_func, opaque);
@@ -606,7 +618,7 @@ static int do_info(Monitor *mon, const QDict *qdict, QObject **ret_data)
 
     if (cmd->name == NULL) {
         if (monitor_ctrl_mode(mon)) {
-            qemu_error_new(QERR_COMMAND_NOT_FOUND, item);
+            qerror_report(QERR_COMMAND_NOT_FOUND, item);
             return -1;
         }
         goto help;
@@ -638,7 +650,7 @@ static int do_info(Monitor *mon, const QDict *qdict, QObject **ret_data)
     } else {
         if (monitor_ctrl_mode(mon)) {
             /* handler not converted yet */
-            qemu_error_new(QERR_COMMAND_NOT_FOUND, item);
+            qerror_report(QERR_COMMAND_NOT_FOUND, item);
             return -1;
         } else {
             cmd->mhandler.info(mon);
@@ -960,7 +972,7 @@ static int do_cpu_set(Monitor *mon, const QDict *qdict, QObject **ret_data)
 {
     int index = qdict_get_int(qdict, "index");
     if (mon_set_cpu(index) < 0) {
-        qemu_error_new(QERR_INVALID_PARAMETER, "index");
+        qerror_report(QERR_INVALID_PARAMETER, "index");
         return -1;
     }
     return 0;
@@ -1013,12 +1025,12 @@ static int eject_device(Monitor *mon, BlockDriverState *bs, int force)
     if (bdrv_is_inserted(bs)) {
         if (!force) {
             if (!bdrv_is_removable(bs)) {
-                qemu_error_new(QERR_DEVICE_NOT_REMOVABLE,
+                qerror_report(QERR_DEVICE_NOT_REMOVABLE,
                                bdrv_get_device_name(bs));
                 return -1;
             }
             if (bdrv_is_locked(bs)) {
-                qemu_error_new(QERR_DEVICE_LOCKED, bdrv_get_device_name(bs));
+                qerror_report(QERR_DEVICE_LOCKED, bdrv_get_device_name(bs));
                 return -1;
             }
         }
@@ -1035,7 +1047,7 @@ static int do_eject(Monitor *mon, const QDict *qdict, QObject **ret_data)
 
     bs = bdrv_find(filename);
     if (!bs) {
-        qemu_error_new(QERR_DEVICE_NOT_FOUND, filename);
+        qerror_report(QERR_DEVICE_NOT_FOUND, filename);
         return -1;
     }
     return eject_device(mon, bs, force);
@@ -1048,12 +1060,12 @@ static int do_block_set_passwd(Monitor *mon, const QDict *qdict,
 
     bs = bdrv_find(qdict_get_str(qdict, "device"));
     if (!bs) {
-        qemu_error_new(QERR_DEVICE_NOT_FOUND, qdict_get_str(qdict, "device"));
+        qerror_report(QERR_DEVICE_NOT_FOUND, qdict_get_str(qdict, "device"));
         return -1;
     }
 
     if (bdrv_set_key(bs, qdict_get_str(qdict, "password")) < 0) {
-        qemu_error_new(QERR_INVALID_PASSWORD);
+        qerror_report(QERR_INVALID_PASSWORD);
         return -1;
     }
 
@@ -1068,13 +1080,13 @@ static int do_change_block(Monitor *mon, const char *device,
 
     bs = bdrv_find(device);
     if (!bs) {
-        qemu_error_new(QERR_DEVICE_NOT_FOUND, device);
+        qerror_report(QERR_DEVICE_NOT_FOUND, device);
         return -1;
     }
     if (fmt) {
         drv = bdrv_find_whitelisted_format(fmt);
         if (!drv) {
-            qemu_error_new(QERR_INVALID_BLOCK_FORMAT, fmt);
+            qerror_report(QERR_INVALID_BLOCK_FORMAT, fmt);
             return -1;
         }
     }
@@ -1090,7 +1102,7 @@ static int do_change_block(Monitor *mon, const char *device,
 static int change_vnc_password(const char *password)
 {
     if (vnc_display_password(NULL, password) < 0) {
-        qemu_error_new(QERR_SET_PASSWD_FAILED);
+        qerror_report(QERR_SET_PASSWD_FAILED);
         return -1;
     }
 
@@ -1118,7 +1130,7 @@ static int do_change_vnc(Monitor *mon, const char *target, const char *arg)
         }
     } else {
         if (vnc_display_open(NULL, target) < 0) {
-            qemu_error_new(QERR_VNC_SERVER_FAILED, target);
+            qerror_report(QERR_VNC_SERVER_FAILED, target);
             return -1;
         }
     }
@@ -1490,7 +1502,7 @@ static int do_memory_save(Monitor *mon, const QDict *qdict, QObject **ret_data)
 
     f = fopen(filename, "wb");
     if (!f) {
-        qemu_error_new(QERR_OPEN_FILE_FAILED, filename);
+        qerror_report(QERR_OPEN_FILE_FAILED, filename);
         return -1;
     }
     while (size != 0) {
@@ -1526,7 +1538,7 @@ static int do_physical_memory_save(Monitor *mon, const QDict *qdict,
 
     f = fopen(filename, "wb");
     if (!f) {
-        qemu_error_new(QERR_OPEN_FILE_FAILED, filename);
+        qerror_report(QERR_OPEN_FILE_FAILED, filename);
         return -1;
     }
     while (size != 0) {
@@ -2300,13 +2312,13 @@ static int do_info_balloon(Monitor *mon, MonitorCompletion cb, void *opaque)
     int ret;
 
     if (kvm_enabled() && !kvm_has_sync_mmu()) {
-        qemu_error_new(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
+        qerror_report(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
         return -1;
     }
 
     ret = qemu_balloon_status(cb, opaque);
     if (!ret) {
-        qemu_error_new(QERR_DEVICE_NOT_ACTIVE, "balloon");
+        qerror_report(QERR_DEVICE_NOT_ACTIVE, "balloon");
         return -1;
     }
 
@@ -2322,13 +2334,13 @@ static int do_balloon(Monitor *mon, const QDict *params,
     int ret;
 
     if (kvm_enabled() && !kvm_has_sync_mmu()) {
-        qemu_error_new(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
+        qerror_report(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
         return -1;
     }
 
     ret = qemu_balloon(qdict_get_int(params, "value"), cb, opaque);
     if (ret == 0) {
-        qemu_error_new(QERR_DEVICE_NOT_ACTIVE, "balloon");
+        qerror_report(QERR_DEVICE_NOT_ACTIVE, "balloon");
         return -1;
     }
 
@@ -2469,21 +2481,21 @@ static int do_getfd(Monitor *mon, const QDict *qdict, QObject **ret_data)
 
     fd = qemu_chr_get_msgfd(mon->chr);
     if (fd == -1) {
-        qemu_error_new(QERR_FD_NOT_SUPPLIED);
+        qerror_report(QERR_FD_NOT_SUPPLIED);
         return -1;
     }
 
     if (qemu_isdigit(fdname[0])) {
-        qemu_error_new(QERR_INVALID_PARAMETER, "fdname");
+        qerror_report(QERR_INVALID_PARAMETER, "fdname");
         return -1;
     }
 
     fd = dup(fd);
     if (fd == -1) {
         if (errno == EMFILE)
-            qemu_error_new(QERR_TOO_MANY_FILES);
+            qerror_report(QERR_TOO_MANY_FILES);
         else
-            qemu_error_new(QERR_UNDEFINED_ERROR);
+            qerror_report(QERR_UNDEFINED_ERROR);
         return -1;
     }
 
@@ -2522,7 +2534,7 @@ static int do_closefd(Monitor *mon, const QDict *qdict, QObject **ret_data)
         return 0;
     }
 
-    qemu_error_new(QERR_FD_NOT_FOUND, fdname);
+    qerror_report(QERR_FD_NOT_FOUND, fdname);
     return -1;
 }
 
@@ -2533,7 +2545,7 @@ static void do_loadvm(Monitor *mon, const QDict *qdict)
 
     vm_stop(0);
 
-    if (load_vmstate(mon, name) >= 0 && saved_vm_running)
+    if (load_vmstate(name) >= 0 && saved_vm_running)
         vm_start();
 }
 
@@ -3638,6 +3650,31 @@ static const mon_cmd_t *monitor_parse_command(Monitor *mon,
                 qdict_put(qdict, key, qstring_from_str(buf));
             }
             break;
+        case 'O':
+            {
+                QemuOptsList *opts_list;
+                QemuOpts *opts;
+
+                opts_list = qemu_find_opts(key);
+                if (!opts_list || opts_list->desc->name) {
+                    goto bad_type;
+                }
+                while (qemu_isspace(*p)) {
+                    p++;
+                }
+                if (!*p)
+                    break;
+                if (get_str(buf, sizeof(buf), &p) < 0) {
+                    goto fail;
+                }
+                opts = qemu_opts_parse(opts_list, buf, 1);
+                if (!opts) {
+                    goto fail;
+                }
+                qemu_opts_to_qdict(opts, qdict);
+                qemu_opts_del(opts);
+            }
+            break;
         case '/':
             {
                 int count, format, size;
@@ -3857,11 +3894,16 @@ fail:
     return NULL;
 }
 
-static void monitor_print_error(Monitor *mon)
+void monitor_set_error(Monitor *mon, QError *qerror)
 {
-    qerror_print(mon->error);
-    QDECREF(mon->error);
-    mon->error = NULL;
+    /* report only the first error */
+    if (!mon->error) {
+        mon->error = qerror;
+    } else {
+        MON_DEBUG("Additional error report at %s:%d\n",
+                  qerror->file, qerror->linenr);
+        QDECREF(qerror);
+    }
 }
 
 static int is_async_return(const QObject *data)
@@ -3875,45 +3917,49 @@ static int is_async_return(const QObject *data)
 
 static void handler_audit(Monitor *mon, const mon_cmd_t *cmd, int ret)
 {
-    if (ret && !monitor_has_error(mon)) {
-        /*
-         * If it returns failure, it must have passed on error.
-         *
-         * Action: Report an internal error to the client if in QMP.
-         */
-        if (monitor_ctrl_mode(mon)) {
-            qemu_error_new(QERR_UNDEFINED_ERROR);
+    if (monitor_ctrl_mode(mon)) {
+        if (ret && !monitor_has_error(mon)) {
+            /*
+             * If it returns failure, it must have passed on error.
+             *
+             * Action: Report an internal error to the client if in QMP.
+             */
+            qerror_report(QERR_UNDEFINED_ERROR);
+            MON_DEBUG("command '%s' returned failure but did not pass an error\n",
+                      cmd->name);
         }
-        MON_DEBUG("command '%s' returned failure but did not pass an error\n",
-                  cmd->name);
-    }
 
 #ifdef CONFIG_DEBUG_MONITOR
-    if (!ret && monitor_has_error(mon)) {
-        /*
-         * If it returns success, it must not have passed an error.
-         *
-         * Action: Report the passed error to the client.
-         */
-        MON_DEBUG("command '%s' returned success but passed an error\n",
-                  cmd->name);
-    }
+        if (!ret && monitor_has_error(mon)) {
+            /*
+             * If it returns success, it must not have passed an error.
+             *
+             * Action: Report the passed error to the client.
+             */
+            MON_DEBUG("command '%s' returned success but passed an error\n",
+                      cmd->name);
+        }
 
-    if (mon_print_count_get(mon) > 0 && strcmp(cmd->name, "info") != 0) {
-        /*
-         * Handlers should not call Monitor print functions.
-         *
-         * Action: Ignore them in QMP.
-         *
-         * (XXX: we don't check any 'info' or 'query' command here
-         * because the user print function _is_ called by do_info(), hence
-         * we will trigger this check. This problem will go away when we
-         * make 'query' commands real and kill do_info())
-         */
-        MON_DEBUG("command '%s' called print functions %d time(s)\n",
-                  cmd->name, mon_print_count_get(mon));
-    }
+        if (mon_print_count_get(mon) > 0 && strcmp(cmd->name, "info") != 0) {
+            /*
+             * Handlers should not call Monitor print functions.
+             *
+             * Action: Ignore them in QMP.
+             *
+             * (XXX: we don't check any 'info' or 'query' command here
+             * because the user print function _is_ called by do_info(), hence
+             * we will trigger this check. This problem will go away when we
+             * make 'query' commands real and kill do_info())
+             */
+            MON_DEBUG("command '%s' called print functions %d time(s)\n",
+                      cmd->name, mon_print_count_get(mon));
+        }
 #endif
+    } else {
+        assert(!monitor_has_error(mon));
+        QDECREF(mon->error);
+        mon->error = NULL;
+    }
 }
 
 static void monitor_call_handler(Monitor *mon, const mon_cmd_t *cmd,
@@ -3958,8 +4004,6 @@ static void handle_user_command(Monitor *mon, const char *cmdline)
     if (!cmd)
         goto out;
 
-    qemu_errors_to_mon(mon);
-
     if (monitor_handler_is_async(cmd)) {
         user_async_cmd_handler(mon, cmd, qdict);
     } else if (monitor_handler_ported(cmd)) {
@@ -3968,11 +4012,6 @@ static void handle_user_command(Monitor *mon, const char *cmdline)
         cmd->mhandler.cmd(mon, qdict);
     }
 
-    if (monitor_has_error(mon))
-        monitor_print_error(mon);
-
-    qemu_errors_to_previous();
-
 out:
     QDECREF(qdict);
 }
@@ -4209,7 +4248,7 @@ typedef struct CmdArgs {
 static int check_opt(const CmdArgs *cmd_args, const char *name, QDict *args)
 {
     if (!cmd_args->optional) {
-        qemu_error_new(QERR_MISSING_PARAMETER, name);
+        qerror_report(QERR_MISSING_PARAMETER, name);
         return -1;
     }
 
@@ -4242,7 +4281,7 @@ static int check_arg(const CmdArgs *cmd_args, QDict *args)
         case 'B':
         case 's':
             if (qobject_type(value) != QTYPE_QSTRING) {
-                qemu_error_new(QERR_INVALID_PARAMETER_TYPE, name, "string");
+                qerror_report(QERR_INVALID_PARAMETER_TYPE, name, "string");
                 return -1;
             }
             break;
@@ -4253,11 +4292,11 @@ static int check_arg(const CmdArgs *cmd_args, QDict *args)
             for (i = 0; keys[i]; i++) {
                 QObject *obj = qdict_get(args, keys[i]);
                 if (!obj) {
-                    qemu_error_new(QERR_MISSING_PARAMETER, name);
+                    qerror_report(QERR_MISSING_PARAMETER, name);
                     return -1;
                 }
                 if (qobject_type(obj) != QTYPE_QINT) {
-                    qemu_error_new(QERR_INVALID_PARAMETER_TYPE, name, "int");
+                    qerror_report(QERR_INVALID_PARAMETER_TYPE, name, "int");
                     return -1;
                 }
             }
@@ -4267,21 +4306,21 @@ static int check_arg(const CmdArgs *cmd_args, QDict *args)
         case 'l':
         case 'M':
             if (qobject_type(value) != QTYPE_QINT) {
-                qemu_error_new(QERR_INVALID_PARAMETER_TYPE, name, "int");
+                qerror_report(QERR_INVALID_PARAMETER_TYPE, name, "int");
                 return -1;
             }
             break;
         case 'b':
         case 'T':
             if (qobject_type(value) != QTYPE_QINT && qobject_type(value) != QTYPE_QFLOAT) {
-                qemu_error_new(QERR_INVALID_PARAMETER_TYPE, name, "number");
+                qerror_report(QERR_INVALID_PARAMETER_TYPE, name, "number");
                 return -1;
             }
             break;
         case '-':
             if (qobject_type(value) != QTYPE_QINT &&
                 qobject_type(value) != QTYPE_QBOOL) {
-                qemu_error_new(QERR_INVALID_PARAMETER_TYPE, name, "bool");
+                qerror_report(QERR_INVALID_PARAMETER_TYPE, name, "bool");
                 return -1;
             }
             if (qobject_type(value) == QTYPE_QBOOL) {
@@ -4290,6 +4329,7 @@ static int check_arg(const CmdArgs *cmd_args, QDict *args)
                          qint_from_int(qbool_get_int(qobject_to_qbool(value))));
             }
             break;
+        case 'O':
         default:
             /* impossible */
             abort();
@@ -4304,6 +4344,12 @@ static void cmd_args_init(CmdArgs *cmd_args)
     cmd_args->type = cmd_args->flag = cmd_args->optional = 0;
 }
 
+static int check_opts(QemuOptsList *opts_list, QDict *args)
+{
+    assert(!opts_list->desc->name);
+    return 0;
+}
+
 /*
  * This is not trivial, we have to parse Monitor command's argument
  * type syntax to be able to check the arguments provided by clients.
@@ -4316,6 +4362,7 @@ static int monitor_check_qmp_args(const mon_cmd_t *cmd, QDict *args)
     int err;
     const char *p;
     CmdArgs cmd_args;
+    QemuOptsList *opts_list;
 
     if (cmd->args_type == NULL) {
         return (qdict_size(args) == 0 ? 0 : -1);
@@ -4323,6 +4370,7 @@ static int monitor_check_qmp_args(const mon_cmd_t *cmd, QDict *args)
 
     err = 0;
     cmd_args_init(&cmd_args);
+    opts_list = NULL;
 
     for (p = cmd->args_type;; p++) {
         if (*p == ':') {
@@ -4331,16 +4379,23 @@ static int monitor_check_qmp_args(const mon_cmd_t *cmd, QDict *args)
             if (cmd_args.type == '-') {
                 cmd_args.flag = *p++;
                 cmd_args.optional = 1;
+            } else if (cmd_args.type == 'O') {
+                opts_list = qemu_find_opts(qstring_get_str(cmd_args.name));
+                assert(opts_list);
             } else if (*p == '?') {
                 cmd_args.optional = 1;
                 p++;
             }
 
             assert(*p == ',' || *p == '\0');
-            err = check_arg(&cmd_args, args);
-
-            QDECREF(cmd_args.name);
-            cmd_args_init(&cmd_args);
+            if (opts_list) {
+                err = check_opts(opts_list, args);
+                opts_list = NULL;
+            } else {
+                err = check_arg(&cmd_args, args);
+                QDECREF(cmd_args.name);
+                cmd_args_init(&cmd_args);
+            }
 
             if (err < 0) {
                 break;
@@ -4374,15 +4429,14 @@ static void handle_qmp_command(JSONMessageParser *parser, QList *tokens)
     const char *cmd_name, *info_item;
 
     args = NULL;
-    qemu_errors_to_mon(mon);
 
     obj = json_parser_parse(tokens, NULL);
     if (!obj) {
         // FIXME: should be triggered in json_parser_parse()
-        qemu_error_new(QERR_JSON_PARSING);
+        qerror_report(QERR_JSON_PARSING);
         goto err_out;
     } else if (qobject_type(obj) != QTYPE_QDICT) {
-        qemu_error_new(QERR_QMP_BAD_INPUT_OBJECT, "object");
+        qerror_report(QERR_QMP_BAD_INPUT_OBJECT, "object");
         qobject_decref(obj);
         goto err_out;
     }
@@ -4394,17 +4448,17 @@ static void handle_qmp_command(JSONMessageParser *parser, QList *tokens)
 
     obj = qdict_get(input, "execute");
     if (!obj) {
-        qemu_error_new(QERR_QMP_BAD_INPUT_OBJECT, "execute");
+        qerror_report(QERR_QMP_BAD_INPUT_OBJECT, "execute");
         goto err_input;
     } else if (qobject_type(obj) != QTYPE_QSTRING) {
-        qemu_error_new(QERR_QMP_BAD_INPUT_OBJECT, "string");
+        qerror_report(QERR_QMP_BAD_INPUT_OBJECT, "string");
         goto err_input;
     }
 
     cmd_name = qstring_get_str(qobject_to_qstring(obj));
 
     if (invalid_qmp_mode(mon, cmd_name)) {
-        qemu_error_new(QERR_COMMAND_NOT_FOUND, cmd_name);
+        qerror_report(QERR_COMMAND_NOT_FOUND, cmd_name);
         goto err_input;
     }
 
@@ -4413,7 +4467,7 @@ static void handle_qmp_command(JSONMessageParser *parser, QList *tokens)
      * converted into 'query-' commands
      */
     if (compare_cmd(cmd_name, "info")) {
-        qemu_error_new(QERR_COMMAND_NOT_FOUND, cmd_name);
+        qerror_report(QERR_COMMAND_NOT_FOUND, cmd_name);
         goto err_input;
     } else if (strstart(cmd_name, "query-", &info_item)) {
         cmd = monitor_find_command("info");
@@ -4422,7 +4476,7 @@ static void handle_qmp_command(JSONMessageParser *parser, QList *tokens)
     } else {
         cmd = monitor_find_command(cmd_name);
         if (!cmd || !monitor_handler_ported(cmd)) {
-            qemu_error_new(QERR_COMMAND_NOT_FOUND, cmd_name);
+            qerror_report(QERR_COMMAND_NOT_FOUND, cmd_name);
             goto err_input;
         }
     }
@@ -4455,7 +4509,6 @@ err_out:
     monitor_protocol_emitter(mon, NULL);
 out:
     QDECREF(args);
-    qemu_errors_to_previous();
 }
 
 /**
@@ -4624,8 +4677,8 @@ void monitor_init(CharDriverState *chr, int flags)
     }
 
     QLIST_INSERT_HEAD(&mon_list, mon, entry);
-    if (!cur_mon || (flags & MONITOR_IS_DEFAULT))
-        cur_mon = mon;
+    if (!default_mon || (flags & MONITOR_IS_DEFAULT))
+        default_mon = mon;
 }
 
 static void bdrv_password_cb(Monitor *mon, const char *password, void *opaque)
@@ -4656,7 +4709,7 @@ int monitor_read_bdrv_key_start(Monitor *mon, BlockDriverState *bs,
     }
 
     if (monitor_ctrl_mode(mon)) {
-        qemu_error_new(QERR_DEVICE_ENCRYPTED, bdrv_get_device_name(bs));
+        qerror_report(QERR_DEVICE_ENCRYPTED, bdrv_get_device_name(bs));
         return -1;
     }
 
@@ -4673,99 +4726,3 @@ int monitor_read_bdrv_key_start(Monitor *mon, BlockDriverState *bs,
 
     return err;
 }
-
-typedef struct QemuErrorSink QemuErrorSink;
-struct QemuErrorSink {
-    enum {
-        ERR_SINK_FILE,
-        ERR_SINK_MONITOR,
-    } dest;
-    union {
-        FILE    *fp;
-        Monitor *mon;
-    };
-    QemuErrorSink *previous;
-};
-
-static QemuErrorSink *qemu_error_sink;
-
-void qemu_errors_to_file(FILE *fp)
-{
-    QemuErrorSink *sink;
-
-    sink = qemu_mallocz(sizeof(*sink));
-    sink->dest = ERR_SINK_FILE;
-    sink->fp = fp;
-    sink->previous = qemu_error_sink;
-    qemu_error_sink = sink;
-}
-
-void qemu_errors_to_mon(Monitor *mon)
-{
-    QemuErrorSink *sink;
-
-    sink = qemu_mallocz(sizeof(*sink));
-    sink->dest = ERR_SINK_MONITOR;
-    sink->mon = mon;
-    sink->previous = qemu_error_sink;
-    qemu_error_sink = sink;
-}
-
-void qemu_errors_to_previous(void)
-{
-    QemuErrorSink *sink;
-
-    assert(qemu_error_sink != NULL);
-    sink = qemu_error_sink;
-    qemu_error_sink = sink->previous;
-    qemu_free(sink);
-}
-
-void qemu_error(const char *fmt, ...)
-{
-    va_list args;
-
-    assert(qemu_error_sink != NULL);
-    switch (qemu_error_sink->dest) {
-    case ERR_SINK_FILE:
-        va_start(args, fmt);
-        vfprintf(qemu_error_sink->fp, fmt, args);
-        va_end(args);
-        break;
-    case ERR_SINK_MONITOR:
-        va_start(args, fmt);
-        monitor_vprintf(qemu_error_sink->mon, fmt, args);
-        va_end(args);
-        break;
-    }
-}
-
-void qemu_error_internal(const char *file, int linenr, const char *func,
-                         const char *fmt, ...)
-{
-    va_list va;
-    QError *qerror;
-
-    assert(qemu_error_sink != NULL);
-
-    va_start(va, fmt);
-    qerror = qerror_from_info(file, linenr, func, fmt, &va);
-    va_end(va);
-
-    switch (qemu_error_sink->dest) {
-    case ERR_SINK_FILE:
-        qerror_print(qerror);
-        QDECREF(qerror);
-        break;
-    case ERR_SINK_MONITOR:
-        /* report only the first error */
-        if (!qemu_error_sink->mon->error) {
-            qemu_error_sink->mon->error = qerror;
-        } else {
-            MON_DEBUG("Additional error report at %s:%d\n", qerror->file,
-                      qerror->linenr);
-            QDECREF(qerror);
-        }
-        break;
-    }
-}
diff --git a/monitor.h b/monitor.h
index e5f2d2ba70..bd4ae34d48 100644
--- a/monitor.h
+++ b/monitor.h
@@ -3,10 +3,13 @@
 
 #include "qemu-common.h"
 #include "qemu-char.h"
+#include "qemu-error.h"
+#include "qerror.h"
 #include "qdict.h"
 #include "block.h"
 
 extern Monitor *cur_mon;
+extern Monitor *default_mon;
 
 /* flags for monitor_init */
 #define MONITOR_IS_DEFAULT    0x01
@@ -28,6 +31,8 @@ typedef enum MonitorEvent {
     QEVENT_MAX,
 } MonitorEvent;
 
+int monitor_cur_is_qmp(void);
+
 void monitor_protocol_event(MonitorEvent event, QObject *data);
 void monitor_init(CharDriverState *chr, int flags);
 
@@ -48,4 +53,6 @@ void monitor_flush(Monitor *mon);
 
 typedef void (MonitorCompletion)(void *opaque, QObject *ret_data);
 
+void monitor_set_error(Monitor *mon, QError *qerror);
+
 #endif /* !MONITOR_H */
diff --git a/net.c b/net.c
index e47f727629..1092bdcaa5 100644
--- a/net.c
+++ b/net.c
@@ -733,7 +733,7 @@ int qemu_find_nic_model(NICInfo *nd, const char * const *models,
             return i;
     }
 
-    qemu_error("qemu: Unsupported NIC model: %s\n", nd->model);
+    error_report("qemu: Unsupported NIC model: %s", nd->model);
     return -1;
 }
 
@@ -744,7 +744,7 @@ int net_handle_fd_param(Monitor *mon, const char *param)
 
         fd = monitor_get_fd(mon, param);
         if (fd == -1) {
-            qemu_error("No file descriptor named %s found", param);
+            error_report("No file descriptor named %s found", param);
             return -1;
         }
 
@@ -765,7 +765,7 @@ static int net_init_nic(QemuOpts *opts,
 
     idx = nic_get_free_idx();
     if (idx == -1 || nb_nics >= MAX_NICS) {
-        qemu_error("Too Many NICs\n");
+        error_report("Too Many NICs");
         return -1;
     }
 
@@ -776,7 +776,7 @@ static int net_init_nic(QemuOpts *opts,
     if ((netdev = qemu_opt_get(opts, "netdev"))) {
         nd->netdev = qemu_find_netdev(netdev);
         if (!nd->netdev) {
-            qemu_error("netdev '%s' not found\n", netdev);
+            error_report("netdev '%s' not found", netdev);
             return -1;
         }
     } else {
@@ -802,7 +802,7 @@ static int net_init_nic(QemuOpts *opts,
 
     if (qemu_opt_get(opts, "macaddr") &&
         net_parse_macaddr(nd->macaddr, qemu_opt_get(opts, "macaddr")) < 0) {
-        qemu_error("invalid syntax for ethernet address\n");
+        error_report("invalid syntax for ethernet address");
         return -1;
     }
 
@@ -810,7 +810,7 @@ static int net_init_nic(QemuOpts *opts,
                                        DEV_NVECTORS_UNSPECIFIED);
     if (nd->nvectors != DEV_NVECTORS_UNSPECIFIED &&
         (nd->nvectors < 0 || nd->nvectors > 0x7ffffff)) {
-        qemu_error("invalid # of vectors: %d\n", nd->nvectors);
+        error_report("invalid # of vectors: %d", nd->nvectors);
         return -1;
     }
 
@@ -1060,12 +1060,12 @@ int net_client_init(Monitor *mon, QemuOpts *opts, int is_netdev)
 
     if (!is_netdev) {
         if (!type) {
-            qemu_error("No type specified for -net\n");
+            error_report("No type specified for -net");
             return -1;
         }
     } else {
         if (!type) {
-            qemu_error("No type specified for -netdev\n");
+            error_report("No type specified for -netdev");
             return -1;
         }
 
@@ -1077,21 +1077,21 @@ int net_client_init(Monitor *mon, QemuOpts *opts, int is_netdev)
             strcmp(type, "vde") != 0 &&
 #endif
             strcmp(type, "socket") != 0) {
-            qemu_error("The '%s' network backend type is not valid with -netdev\n",
-                       type);
+            error_report("The '%s' network backend type is not valid with -netdev",
+                         type);
             return -1;
         }
 
         if (qemu_opt_get(opts, "vlan")) {
-            qemu_error("The 'vlan' parameter is not valid with -netdev\n");
+            error_report("The 'vlan' parameter is not valid with -netdev");
             return -1;
         }
         if (qemu_opt_get(opts, "name")) {
-            qemu_error("The 'name' parameter is not valid with -netdev\n");
+            error_report("The 'name' parameter is not valid with -netdev");
             return -1;
         }
         if (!qemu_opts_id(opts)) {
-            qemu_error("The id= parameter is required with -netdev\n");
+            error_report("The id= parameter is required with -netdev");
             return -1;
         }
     }
@@ -1124,7 +1124,7 @@ int net_client_init(Monitor *mon, QemuOpts *opts, int is_netdev)
         }
     }
 
-    qemu_error("Invalid -net type '%s'\n", type);
+    error_report("Invalid -net type '%s'", type);
     return -1;
 }
 
@@ -1159,7 +1159,7 @@ void net_host_device_add(Monitor *mon, const QDict *qdict)
         return;
     }
 
-    opts = qemu_opts_parse(&qemu_net_opts, opts_str ? opts_str : "", NULL);
+    opts = qemu_opts_parse(&qemu_net_opts, opts_str ? opts_str : "", 0);
     if (!opts) {
         monitor_printf(mon, "parsing network options '%s' failed\n",
                        opts_str ? opts_str : "");
@@ -1364,7 +1364,7 @@ int net_client_parse(QemuOptsList *opts_list, const char *optarg)
     }
 #endif
 
-    if (!qemu_opts_parse(opts_list, optarg, "type")) {
+    if (!qemu_opts_parse(opts_list, optarg, 1)) {
         return -1;
     }
 
diff --git a/net/dump.c b/net/dump.c
index d50b4eeac4..6db7ecf959 100644
--- a/net/dump.c
+++ b/net/dump.c
@@ -25,6 +25,7 @@
 #include "dump.h"
 #include "qemu-common.h"
 #include "sysemu.h"
+#include "qemu-error.h"
 #include "qemu-log.h"
 
 typedef struct DumpState {
@@ -107,7 +108,7 @@ static int net_dump_init(VLANState *vlan, const char *device,
 
     fd = open(filename, O_CREAT | O_WRONLY | O_BINARY, 0644);
     if (fd < 0) {
-        qemu_error("-net dump: can't open %s\n", filename);
+        error_report("-net dump: can't open %s", filename);
         return -1;
     }
 
@@ -120,7 +121,7 @@ static int net_dump_init(VLANState *vlan, const char *device,
     hdr.linktype = 1;
 
     if (write(fd, &hdr, sizeof(hdr)) < sizeof(hdr)) {
-        qemu_error("-net dump write error: %s\n", strerror(errno));
+        error_report("-net dump write error: %s", strerror(errno));
         close(fd);
         return -1;
     }
diff --git a/net/slirp.c b/net/slirp.c
index 7f846ec6f9..b41c60a39b 100644
--- a/net/slirp.c
+++ b/net/slirp.c
@@ -413,14 +413,14 @@ static int slirp_hostfwd(SlirpState *s, const char *redir_str,
 
     if (slirp_add_hostfwd(s->slirp, is_udp, host_addr, host_port, guest_addr,
                           guest_port) < 0) {
-        qemu_error("could not set up host forwarding rule '%s'\n",
-                   redir_str);
+        error_report("could not set up host forwarding rule '%s'",
+                     redir_str);
         return -1;
     }
     return 0;
 
  fail_syntax:
-    qemu_error("invalid host forwarding rule '%s'\n", redir_str);
+    error_report("invalid host forwarding rule '%s'", redir_str);
     return -1;
 }
 
@@ -473,10 +473,10 @@ static void slirp_smb_cleanup(SlirpState *s)
         snprintf(cmd, sizeof(cmd), "rm -rf %s", s->smb_dir);
         ret = system(cmd);
         if (ret == -1 || !WIFEXITED(ret)) {
-            qemu_error("'%s' failed.\n", cmd);
+            error_report("'%s' failed.", cmd);
         } else if (WEXITSTATUS(ret)) {
-            qemu_error("'%s' failed. Error code: %d\n",
-                    cmd, WEXITSTATUS(ret));
+            error_report("'%s' failed. Error code: %d",
+                         cmd, WEXITSTATUS(ret));
         }
         s->smb_dir[0] = '\0';
     }
@@ -493,7 +493,7 @@ static int slirp_smb(SlirpState* s, const char *exported_dir,
     snprintf(s->smb_dir, sizeof(s->smb_dir), "/tmp/qemu-smb.%ld-%d",
              (long)getpid(), instance++);
     if (mkdir(s->smb_dir, 0700) < 0) {
-        qemu_error("could not create samba server dir '%s'\n", s->smb_dir);
+        error_report("could not create samba server dir '%s'", s->smb_dir);
         return -1;
     }
     snprintf(smb_conf, sizeof(smb_conf), "%s/%s", s->smb_dir, "smb.conf");
@@ -501,8 +501,8 @@ static int slirp_smb(SlirpState* s, const char *exported_dir,
     f = fopen(smb_conf, "w");
     if (!f) {
         slirp_smb_cleanup(s);
-        qemu_error("could not create samba server configuration file '%s'\n",
-                   smb_conf);
+        error_report("could not create samba server configuration file '%s'",
+                     smb_conf);
         return -1;
     }
     fprintf(f,
@@ -533,7 +533,7 @@ static int slirp_smb(SlirpState* s, const char *exported_dir,
 
     if (slirp_add_exec(s->slirp, 0, smb_cmdline, &vserver_addr, 139) < 0) {
         slirp_smb_cleanup(s);
-        qemu_error("conflicting/invalid smbserver address\n");
+        error_report("conflicting/invalid smbserver address");
         return -1;
     }
     return 0;
@@ -618,14 +618,14 @@ static int slirp_guestfwd(SlirpState *s, const char *config_str,
     snprintf(buf, sizeof(buf), "guestfwd.tcp:%d", port);
     fwd->hd = qemu_chr_open(buf, p, NULL);
     if (!fwd->hd) {
-        qemu_error("could not open guest forwarding device '%s'\n", buf);
+        error_report("could not open guest forwarding device '%s'", buf);
         qemu_free(fwd);
         return -1;
     }
 
     if (slirp_add_exec(s->slirp, 3, fwd->hd, &server, port) < 0) {
-        qemu_error("conflicting/invalid host:port in guest forwarding "
-                   "rule '%s'\n", config_str);
+        error_report("conflicting/invalid host:port in guest forwarding "
+                     "rule '%s'", config_str);
         qemu_free(fwd);
         return -1;
     }
@@ -638,7 +638,7 @@ static int slirp_guestfwd(SlirpState *s, const char *config_str,
     return 0;
 
  fail_syntax:
-    qemu_error("invalid guest forwarding rule '%s'\n", config_str);
+    error_report("invalid guest forwarding rule '%s'", config_str);
     return -1;
 }
 
diff --git a/net/socket.c b/net/socket.c
index 442a9c790c..1c4e153e3f 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -28,9 +28,9 @@
 #include "net.h"
 #include "qemu-char.h"
 #include "qemu-common.h"
+#include "qemu-error.h"
 #include "qemu-option.h"
 #include "qemu_socket.h"
-#include "sysemu.h"
 
 typedef struct NetSocketState {
     VLANClientState nc;
@@ -506,7 +506,7 @@ int net_init_socket(QemuOpts *opts,
         if (qemu_opt_get(opts, "listen") ||
             qemu_opt_get(opts, "connect") ||
             qemu_opt_get(opts, "mcast")) {
-            qemu_error("listen=, connect= and mcast= is invalid with fd=\n");
+            error_report("listen=, connect= and mcast= is invalid with fd=");
             return -1;
         }
 
@@ -525,7 +525,7 @@ int net_init_socket(QemuOpts *opts,
         if (qemu_opt_get(opts, "fd") ||
             qemu_opt_get(opts, "connect") ||
             qemu_opt_get(opts, "mcast")) {
-            qemu_error("fd=, connect= and mcast= is invalid with listen=\n");
+            error_report("fd=, connect= and mcast= is invalid with listen=");
             return -1;
         }
 
@@ -540,7 +540,7 @@ int net_init_socket(QemuOpts *opts,
         if (qemu_opt_get(opts, "fd") ||
             qemu_opt_get(opts, "listen") ||
             qemu_opt_get(opts, "mcast")) {
-            qemu_error("fd=, listen= and mcast= is invalid with connect=\n");
+            error_report("fd=, listen= and mcast= is invalid with connect=");
             return -1;
         }
 
@@ -555,7 +555,7 @@ int net_init_socket(QemuOpts *opts,
         if (qemu_opt_get(opts, "fd") ||
             qemu_opt_get(opts, "connect") ||
             qemu_opt_get(opts, "listen")) {
-            qemu_error("fd=, connect= and listen= is invalid with mcast=\n");
+            error_report("fd=, connect= and listen= is invalid with mcast=");
             return -1;
         }
 
@@ -565,7 +565,7 @@ int net_init_socket(QemuOpts *opts,
             return -1;
         }
     } else {
-        qemu_error("-socket requires fd=, listen=, connect= or mcast=\n");
+        error_report("-socket requires fd=, listen=, connect= or mcast=");
         return -1;
     }
 
diff --git a/net/tap-bsd.c b/net/tap-bsd.c
index 815997dc7b..e51d06848d 100644
--- a/net/tap-bsd.c
+++ b/net/tap-bsd.c
@@ -69,7 +69,8 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required
         }
     }
     if (fd < 0) {
-        qemu_error("warning: could not open %s (%s): no virtual network emulation\n", dname, strerror(errno));
+        error_report("warning: could not open %s (%s): no virtual network emulation",
+                   dname, strerror(errno));
         return -1;
     }
 #else
@@ -89,8 +90,8 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required
         *vnet_hdr = 0;
 
         if (vnet_hdr_required && !*vnet_hdr) {
-            qemu_error("vnet_hdr=1 requested, but no kernel "
-                       "support for IFF_VNET_HDR available");
+            error_report("vnet_hdr=1 requested, but no kernel "
+                         "support for IFF_VNET_HDR available");
             close(fd);
             return -1;
         }
diff --git a/net/tap-linux.c b/net/tap-linux.c
index 6af9e824d3..03b83012f8 100644
--- a/net/tap-linux.c
+++ b/net/tap-linux.c
@@ -31,6 +31,7 @@
 
 #include "sysemu.h"
 #include "qemu-common.h"
+#include "qemu-error.h"
 
 int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required)
 {
@@ -57,8 +58,8 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required
         }
 
         if (vnet_hdr_required && !*vnet_hdr) {
-            qemu_error("vnet_hdr=1 requested, but no kernel "
-                       "support for IFF_VNET_HDR available");
+            error_report("vnet_hdr=1 requested, but no kernel "
+                         "support for IFF_VNET_HDR available");
             close(fd);
             return -1;
         }
@@ -96,7 +97,7 @@ int tap_set_sndbuf(int fd, QemuOpts *opts)
     }
 
     if (ioctl(fd, TUNSETSNDBUF, &sndbuf) == -1 && qemu_opt_get(opts, "sndbuf")) {
-        qemu_error("TUNSETSNDBUF ioctl failed: %s\n", strerror(errno));
+        error_report("TUNSETSNDBUF ioctl failed: %s", strerror(errno));
         return -1;
     }
     return 0;
@@ -107,7 +108,7 @@ int tap_probe_vnet_hdr(int fd)
     struct ifreq ifr;
 
     if (ioctl(fd, TUNGETIFF, &ifr) != 0) {
-        qemu_error("TUNGETIFF ioctl() failed: %s\n", strerror(errno));
+        error_report("TUNGETIFF ioctl() failed: %s", strerror(errno));
         return 0;
     }
 
diff --git a/net/tap-solaris.c b/net/tap-solaris.c
index 0b428617bd..50d127ad3f 100644
--- a/net/tap-solaris.c
+++ b/net/tap-solaris.c
@@ -186,8 +186,8 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required
         *vnet_hdr = 0;
 
         if (vnet_hdr_required && !*vnet_hdr) {
-            qemu_error("vnet_hdr=1 requested, but no kernel "
-                       "support for IFF_VNET_HDR available");
+            error_report("vnet_hdr=1 requested, but no kernel "
+                         "support for IFF_VNET_HDR available");
             close(fd);
             return -1;
         }
diff --git a/net/tap-win32.c b/net/tap-win32.c
index 8370c803bf..a5c2ce9e32 100644
--- a/net/tap-win32.c
+++ b/net/tap-win32.c
@@ -706,7 +706,7 @@ int net_init_tap(QemuOpts *opts, Monitor *mon, const char *name, VLANState *vlan
     ifname = qemu_opt_get(opts, "ifname");
 
     if (!ifname) {
-        qemu_error("tap: no interface name\n");
+        error_report("tap: no interface name");
         return -1;
     }
 
diff --git a/net/tap.c b/net/tap.c
index 7a7320c1a2..672b0ee0b4 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -38,6 +38,7 @@
 #include "sysemu.h"
 #include "qemu-char.h"
 #include "qemu-common.h"
+#include "qemu-error.h"
 
 #include "net/tap-linux.h"
 
@@ -393,7 +394,7 @@ int net_init_tap(QemuOpts *opts, Monitor *mon, const char *name, VLANState *vlan
             qemu_opt_get(opts, "script") ||
             qemu_opt_get(opts, "downscript") ||
             qemu_opt_get(opts, "vnet_hdr")) {
-            qemu_error("ifname=, script=, downscript= and vnet_hdr= is invalid with fd=\n");
+            error_report("ifname=, script=, downscript= and vnet_hdr= is invalid with fd=");
             return -1;
         }
 
diff --git a/qemu-config.c b/qemu-config.c
index 246fae6f99..150157ca7c 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -1,4 +1,5 @@
 #include "qemu-common.h"
+#include "qemu-error.h"
 #include "qemu-option.h"
 #include "qemu-config.h"
 #include "sysemu.h"
@@ -85,6 +86,7 @@ QemuOptsList qemu_drive_opts = {
 
 QemuOptsList qemu_chardev_opts = {
     .name = "chardev",
+    .implied_opt_name = "backend",
     .head = QTAILQ_HEAD_INITIALIZER(qemu_chardev_opts.head),
     .desc = {
         {
@@ -151,6 +153,7 @@ QemuOptsList qemu_chardev_opts = {
 
 QemuOptsList qemu_device_opts = {
     .name = "device",
+    .implied_opt_name = "driver",
     .head = QTAILQ_HEAD_INITIALIZER(qemu_device_opts.head),
     .desc = {
         /*
@@ -164,6 +167,7 @@ QemuOptsList qemu_device_opts = {
 
 QemuOptsList qemu_netdev_opts = {
     .name = "netdev",
+    .implied_opt_name = "type",
     .head = QTAILQ_HEAD_INITIALIZER(qemu_netdev_opts.head),
     .desc = {
         /*
@@ -176,6 +180,7 @@ QemuOptsList qemu_netdev_opts = {
 
 QemuOptsList qemu_net_opts = {
     .name = "net",
+    .implied_opt_name = "type",
     .head = QTAILQ_HEAD_INITIALIZER(qemu_net_opts.head),
     .desc = {
         /*
@@ -226,6 +231,7 @@ QemuOptsList qemu_global_opts = {
 
 QemuOptsList qemu_mon_opts = {
     .name = "mon",
+    .implied_opt_name = "chardev",
     .head = QTAILQ_HEAD_INITIALIZER(qemu_mon_opts.head),
     .desc = {
         {
@@ -303,7 +309,7 @@ static QemuOptsList *lists[] = {
     NULL,
 };
 
-static QemuOptsList *find_list(const char *group)
+QemuOptsList *qemu_find_opts(const char *group)
 {
     int i;
 
@@ -312,7 +318,7 @@ static QemuOptsList *find_list(const char *group)
             break;
     }
     if (lists[i] == NULL) {
-        qemu_error("there is no option group \"%s\"\n", group);
+        error_report("there is no option group \"%s\"", group);
     }
     return lists[i];
 }
@@ -326,19 +332,19 @@ int qemu_set_option(const char *str)
 
     rc = sscanf(str, "%63[^.].%63[^.].%63[^=]%n", group, id, arg, &offset);
     if (rc < 3 || str[offset] != '=') {
-        qemu_error("can't parse: \"%s\"\n", str);
+        error_report("can't parse: \"%s\"", str);
         return -1;
     }
 
-    list = find_list(group);
+    list = qemu_find_opts(group);
     if (list == NULL) {
         return -1;
     }
 
     opts = qemu_opts_find(list, id);
     if (!opts) {
-        qemu_error("there is no %s \"%s\" defined\n",
-                   list->name, id);
+        error_report("there is no %s \"%s\" defined",
+                     list->name, id);
         return -1;
     }
 
@@ -356,7 +362,7 @@ int qemu_global_option(const char *str)
 
     rc = sscanf(str, "%63[^.].%63[^=]%n", driver, property, &offset);
     if (rc < 2 || str[offset] != '=') {
-        qemu_error("can't parse: \"%s\"\n", str);
+        error_report("can't parse: \"%s\"", str);
         return -1;
     }
 
@@ -424,13 +430,17 @@ void qemu_config_write(FILE *fp)
     }
 }
 
-int qemu_config_parse(FILE *fp)
+int qemu_config_parse(FILE *fp, const char *fname)
 {
     char line[1024], group[64], id[64], arg[64], value[1024];
+    Location loc;
     QemuOptsList *list = NULL;
     QemuOpts *opts = NULL;
+    int res = -1, lno = 0;
 
+    loc_push_none(&loc);
     while (fgets(line, sizeof(line), fp) != NULL) {
+        loc_set_file(fname, ++lno);
         if (line[0] == '\n') {
             /* skip empty lines */
             continue;
@@ -441,35 +451,41 @@ int qemu_config_parse(FILE *fp)
         }
         if (sscanf(line, "[%63s \"%63[^\"]\"]", group, id) == 2) {
             /* group with id */
-            list = find_list(group);
+            list = qemu_find_opts(group);
             if (list == NULL)
-                return -1;
+                goto out;
             opts = qemu_opts_create(list, id, 1);
             continue;
         }
         if (sscanf(line, "[%63[^]]]", group) == 1) {
             /* group without id */
-            list = find_list(group);
+            list = qemu_find_opts(group);
             if (list == NULL)
-                return -1;
+                goto out;
             opts = qemu_opts_create(list, NULL, 0);
             continue;
         }
         if (sscanf(line, " %63s = \"%1023[^\"]\"", arg, value) == 2) {
             /* arg = value */
             if (opts == NULL) {
-                fprintf(stderr, "no group defined\n");
-                return -1;
+                error_report("no group defined");
+                goto out;
             }
             if (qemu_opt_set(opts, arg, value) != 0) {
-                fprintf(stderr, "failed to set \"%s\" for %s\n",
-                        arg, group);
-                return -1;
+                error_report("failed to set \"%s\" for %s", arg, group);
+                goto out;
             }
             continue;
         }
-        fprintf(stderr, "parse error: %s\n", line);
-        return -1;
+        error_report("parse error");
+        goto out;
     }
-    return 0;
+    if (ferror(fp)) {
+        error_report("error reading file");
+        goto out;
+    }
+    res = 0;
+out:
+    loc_pop(&loc);
+    return res;
 }
diff --git a/qemu-config.h b/qemu-config.h
index b335c42926..f217c589f7 100644
--- a/qemu-config.h
+++ b/qemu-config.h
@@ -11,11 +11,12 @@ extern QemuOptsList qemu_global_opts;
 extern QemuOptsList qemu_mon_opts;
 extern QemuOptsList qemu_cpudef_opts;
 
+QemuOptsList *qemu_find_opts(const char *group);
 int qemu_set_option(const char *str);
 int qemu_global_option(const char *str);
 void qemu_add_globals(void);
 
 void qemu_config_write(FILE *fp);
-int qemu_config_parse(FILE *fp);
+int qemu_config_parse(FILE *fp, const char *fname);
 
 #endif /* QEMU_CONFIG_H */
diff --git a/qemu-error.c b/qemu-error.c
new file mode 100644
index 0000000000..5d5fe3742f
--- /dev/null
+++ b/qemu-error.c
@@ -0,0 +1,227 @@
+/*
+ * Error reporting
+ *
+ * Copyright (C) 2010 Red Hat Inc.
+ *
+ * Authors:
+ *  Markus Armbruster <armbru@redhat.com>,
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include <stdio.h>
+#include "monitor.h"
+#include "sysemu.h"
+
+/*
+ * Print to current monitor if we have one, else to stderr.
+ * TODO should return int, so callers can calculate width, but that
+ * requires surgery to monitor_vprintf().  Left for another day.
+ */
+void error_vprintf(const char *fmt, va_list ap)
+{
+    if (cur_mon) {
+        monitor_vprintf(cur_mon, fmt, ap);
+    } else {
+        vfprintf(stderr, fmt, ap);
+    }
+}
+
+/*
+ * Print to current monitor if we have one, else to stderr.
+ * TODO just like error_vprintf()
+ */
+void error_printf(const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start(ap, fmt);
+    error_vprintf(fmt, ap);
+    va_end(ap);
+}
+
+void error_printf_unless_qmp(const char *fmt, ...)
+{
+    va_list ap;
+
+    if (!monitor_cur_is_qmp()) {
+        va_start(ap, fmt);
+        error_vprintf(fmt, ap);
+        va_end(ap);
+    }
+}
+
+static Location std_loc = {
+    .kind = LOC_NONE
+};
+static Location *cur_loc = &std_loc;
+
+/*
+ * Push location saved in LOC onto the location stack, return it.
+ * The top of that stack is the current location.
+ * Needs a matching loc_pop().
+ */
+Location *loc_push_restore(Location *loc)
+{
+    assert(!loc->prev);
+    loc->prev = cur_loc;
+    cur_loc = loc;
+    return loc;
+}
+
+/*
+ * Initialize *LOC to "nowhere", push it onto the location stack.
+ * The top of that stack is the current location.
+ * Needs a matching loc_pop().
+ * Return LOC.
+ */
+Location *loc_push_none(Location *loc)
+{
+    loc->kind = LOC_NONE;
+    loc->prev = NULL;
+    return loc_push_restore(loc);
+}
+
+/*
+ * Pop the location stack.
+ * LOC must be the current location, i.e. the top of the stack.
+ */
+Location *loc_pop(Location *loc)
+{
+    assert(cur_loc == loc && loc->prev);
+    cur_loc = loc->prev;
+    loc->prev = NULL;
+    return loc;
+}
+
+/*
+ * Save the current location in LOC, return LOC.
+ */
+Location *loc_save(Location *loc)
+{
+    *loc = *cur_loc;
+    loc->prev = NULL;
+    return loc;
+}
+
+/*
+ * Change the current location to the one saved in LOC.
+ */
+void loc_restore(Location *loc)
+{
+    Location *prev = cur_loc->prev;
+    assert(!loc->prev);
+    *cur_loc = *loc;
+    cur_loc->prev = prev;
+}
+
+/*
+ * Change the current location to "nowhere in particular".
+ */
+void loc_set_none(void)
+{
+    cur_loc->kind = LOC_NONE;
+}
+
+/*
+ * Change the current location to argument ARGV[IDX..IDX+CNT-1].
+ */
+void loc_set_cmdline(char **argv, int idx, int cnt)
+{
+    cur_loc->kind = LOC_CMDLINE;
+    cur_loc->num = cnt;
+    cur_loc->ptr = argv + idx;
+}
+
+/*
+ * Change the current location to file FNAME, line LNO.
+ */
+void loc_set_file(const char *fname, int lno)
+{
+    assert (fname || cur_loc->kind == LOC_FILE);
+    cur_loc->kind = LOC_FILE;
+    cur_loc->num = lno;
+    if (fname) {
+        cur_loc->ptr = fname;
+    }
+}
+
+static const char *progname;
+
+/*
+ * Set the program name for error_print_loc().
+ */
+void error_set_progname(const char *argv0)
+{
+    const char *p = strrchr(argv0, '/');
+    progname = p ? p + 1 : argv0;
+}
+
+/*
+ * Print current location to current monitor if we have one, else to stderr.
+ */
+void error_print_loc(void)
+{
+    const char *sep = "";
+    int i;
+    const char *const *argp;
+
+    if (!cur_mon) {
+        fprintf(stderr, "%s:", progname);
+        sep = " ";
+    }
+    switch (cur_loc->kind) {
+    case LOC_CMDLINE:
+        argp = cur_loc->ptr;
+        for (i = 0; i < cur_loc->num; i++) {
+            error_printf("%s%s", sep, argp[i]);
+            sep = " ";
+        }
+        error_printf(": ");
+        break;
+    case LOC_FILE:
+        error_printf("%s:", (const char *)cur_loc->ptr);
+        if (cur_loc->num) {
+            error_printf("%d:", cur_loc->num);
+        }
+        error_printf(" ");
+        break;
+    default:
+        error_printf(sep);
+    }
+}
+
+/*
+ * Print an error message to current monitor if we have one, else to stderr.
+ * Prepend the current location and append a newline.
+ * It's wrong to call this in a QMP monitor.  Use qerror_report() there.
+ */
+void error_report(const char *fmt, ...)
+{
+    va_list ap;
+
+    error_print_loc();
+    va_start(ap, fmt);
+    error_vprintf(fmt, ap);
+    va_end(ap);
+    error_printf("\n");
+}
+
+void qerror_report_internal(const char *file, int linenr, const char *func,
+                            const char *fmt, ...)
+{
+    va_list va;
+    QError *qerror;
+
+    va_start(va, fmt);
+    qerror = qerror_from_info(file, linenr, func, fmt, &va);
+    va_end(va);
+
+    if (monitor_cur_is_qmp()) {
+        monitor_set_error(cur_mon, qerror);
+    } else {
+        qerror_print(qerror);
+        QDECREF(qerror);
+    }
+}
diff --git a/qemu-error.h b/qemu-error.h
new file mode 100644
index 0000000000..e63c6ab31d
--- /dev/null
+++ b/qemu-error.h
@@ -0,0 +1,47 @@
+/*
+ * Error reporting
+ *
+ * Copyright (C) 2010 Red Hat Inc.
+ *
+ * Authors:
+ *  Markus Armbruster <armbru@redhat.com>,
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef QEMU_ERROR_H
+#define QEMU_ERROR_H
+
+typedef struct Location {
+    /* all members are private to qemu-error.c */
+    enum { LOC_NONE, LOC_CMDLINE, LOC_FILE } kind;
+    int num;
+    const void *ptr;
+    struct Location *prev;
+} Location;
+
+Location *loc_push_restore(Location *loc);
+Location *loc_push_none(Location *loc);
+Location *loc_pop(Location *loc);
+Location *loc_save(Location *loc);
+void loc_restore(Location *loc);
+void loc_set_none(void);
+void loc_set_cmdline(char **argv, int idx, int cnt);
+void loc_set_file(const char *fname, int lno);
+
+void error_vprintf(const char *fmt, va_list ap);
+void error_printf(const char *fmt, ...) __attribute__ ((format(printf, 1, 2)));
+void error_printf_unless_qmp(const char *fmt, ...)
+    __attribute__ ((format(printf, 1, 2)));
+void error_print_loc(void);
+void error_set_progname(const char *argv0);
+void error_report(const char *fmt, ...) __attribute__ ((format(printf, 1, 2)));
+void qerror_report_internal(const char *file, int linenr, const char *func,
+                            const char *fmt, ...)
+    __attribute__ ((format(printf, 4, 5)));
+
+#define qerror_report(fmt, ...) \
+    qerror_report_internal(__FILE__, __LINE__, __func__, fmt, ## __VA_ARGS__)
+
+#endif
diff --git a/qemu-monitor.hx b/qemu-monitor.hx
index 7f9d261cd9..5308f364e7 100644
--- a/qemu-monitor.hx
+++ b/qemu-monitor.hx
@@ -570,10 +570,11 @@ ETEXI
 
     {
         .name       = "device_add",
-        .args_type  = "config:s",
-        .params     = "device",
+        .args_type  = "device:O",
+        .params     = "driver[,prop=value][,...]",
         .help       = "add device, like -device on the command line",
-        .mhandler.cmd = do_device_add,
+        .user_print = monitor_user_noop,
+        .mhandler.cmd_new = do_device_add,
     },
 
 STEXI
diff --git a/qemu-option.c b/qemu-option.c
index de40bffc7d..dc340b8dc7 100644
--- a/qemu-option.c
+++ b/qemu-option.c
@@ -27,6 +27,8 @@
 #include <string.h>
 
 #include "qemu-common.h"
+#include "qemu-error.h"
+#include "qemu-objects.h"
 #include "qemu-option.h"
 
 /*
@@ -483,6 +485,7 @@ struct QemuOpt {
 struct QemuOpts {
     char *id;
     QemuOptsList *list;
+    Location loc;
     QTAILQ_HEAD(QemuOptHead, QemuOpt) head;
     QTAILQ_ENTRY(QemuOpts) next;
 };
@@ -653,6 +656,7 @@ QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id, int fail_if_exist
         opts->id = qemu_strdup(id);
     }
     opts->list = list;
+    loc_save(&opts->loc);
     QTAILQ_INIT(&opts->head);
     QTAILQ_INSERT_TAIL(&list->head, opts, next);
     return opts;
@@ -749,12 +753,17 @@ int qemu_opts_do_parse(QemuOpts *opts, const char *params, const char *firstname
     return 0;
 }
 
-QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params, const char *firstname)
+QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params,
+                          int permit_abbrev)
 {
+    const char *firstname;
     char value[1024], *id = NULL;
     const char *p;
     QemuOpts *opts;
 
+    assert(!permit_abbrev || list->implied_opt_name);
+    firstname = permit_abbrev ? list->implied_opt_name : NULL;
+
     if (strncmp(params, "id=", 3) == 0) {
         get_opt_value(value, sizeof(value), params+3);
         id = qemu_strdup(value);
@@ -774,6 +783,84 @@ QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params, const char *fi
     return opts;
 }
 
+static void qemu_opts_from_qdict_1(const char *key, QObject *obj, void *opaque)
+{
+    char buf[32];
+    const char *value;
+    int n;
+
+    if (!strcmp(key, "id")) {
+        return;
+    }
+
+    switch (qobject_type(obj)) {
+    case QTYPE_QSTRING:
+        value = qstring_get_str(qobject_to_qstring(obj));
+        break;
+    case QTYPE_QINT:
+        n = snprintf(buf, sizeof(buf), "%" PRId64,
+                     qint_get_int(qobject_to_qint(obj)));
+        assert(n < sizeof(buf));
+        value = buf;
+        break;
+    case QTYPE_QFLOAT:
+        n = snprintf(buf, sizeof(buf), "%.17g",
+                     qfloat_get_double(qobject_to_qfloat(obj)));
+        assert(n < sizeof(buf));
+        value = buf;
+        break;
+    case QTYPE_QBOOL:
+        strcpy(buf, qbool_get_int(qobject_to_qbool(obj)) ? "on" : "off");
+        value = buf;
+        break;
+    default:
+        return;
+    }
+    qemu_opt_set(opaque, key, value);
+}
+
+/*
+ * Create QemuOpts from a QDict.
+ * Use value of key "id" as ID if it exists and is a QString.
+ * Only QStrings, QInts, QFloats and QBools are copied.  Entries with
+ * other types are silently ignored.
+ */
+QemuOpts *qemu_opts_from_qdict(QemuOptsList *list, const QDict *qdict)
+{
+    QemuOpts *opts;
+
+    opts = qemu_opts_create(list, qdict_get_try_str(qdict, "id"), 1);
+    if (opts == NULL)
+        return NULL;
+
+    qdict_iter(qdict, qemu_opts_from_qdict_1, opts);
+    return opts;
+}
+
+/*
+ * Convert from QemuOpts to QDict.
+ * The QDict values are of type QString.
+ * TODO We'll want to use types appropriate for opt->desc->type, but
+ * this is enough for now.
+ */
+QDict *qemu_opts_to_qdict(QemuOpts *opts, QDict *qdict)
+{
+    QemuOpt *opt;
+    QObject *val;
+
+    if (!qdict) {
+        qdict = qdict_new();
+    }
+    if (opts->id) {
+        qdict_put(qdict, "id", qstring_from_str(opts->id));
+    }
+    QTAILQ_FOREACH(opt, &opts->head, next) {
+        val = QOBJECT(qstring_from_str(opt->str));
+        qdict_put_obj(qdict, opt->name, val);
+    }
+    return qdict;
+}
+
 /* Validate parsed opts against descriptions where no
  * descriptions were provided in the QemuOptsList.
  */
@@ -810,13 +897,17 @@ int qemu_opts_validate(QemuOpts *opts, const QemuOptDesc *desc)
 int qemu_opts_foreach(QemuOptsList *list, qemu_opts_loopfunc func, void *opaque,
                       int abort_on_failure)
 {
+    Location loc;
     QemuOpts *opts;
     int rc = 0;
 
+    loc_push_none(&loc);
     QTAILQ_FOREACH(opts, &list->head, next) {
+        loc_restore(&opts->loc);
         rc |= func(opts, opaque);
         if (abort_on_failure  &&  rc != 0)
             break;
     }
+    loc_pop(&loc);
     return rc;
 }
diff --git a/qemu-option.h b/qemu-option.h
index f3f1de755d..58136f3032 100644
--- a/qemu-option.h
+++ b/qemu-option.h
@@ -28,6 +28,7 @@
 
 #include <stdint.h>
 #include "qemu-queue.h"
+#include "qdict.h"
 
 enum QEMUOptionParType {
     OPT_FLAG,
@@ -96,6 +97,7 @@ typedef struct QemuOptDesc {
 
 struct QemuOptsList {
     const char *name;
+    const char *implied_opt_name;
     QTAILQ_HEAD(, QemuOpts) head;
     QemuOptDesc desc[];
 };
@@ -117,7 +119,9 @@ const char *qemu_opts_id(QemuOpts *opts);
 void qemu_opts_del(QemuOpts *opts);
 int qemu_opts_validate(QemuOpts *opts, const QemuOptDesc *desc);
 int qemu_opts_do_parse(QemuOpts *opts, const char *params, const char *firstname);
-QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params, const char *firstname);
+QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params, int permit_abbrev);
+QemuOpts *qemu_opts_from_qdict(QemuOptsList *list, const QDict *qdict);
+QDict *qemu_opts_to_qdict(QemuOpts *opts, QDict *qdict);
 
 typedef int (*qemu_opts_loopfunc)(QemuOpts *opts, void *opaque);
 int qemu_opts_print(QemuOpts *opts, void *dummy);
diff --git a/qemu-tool.c b/qemu-tool.c
index 18b48af319..97ca949964 100644
--- a/qemu-tool.c
+++ b/qemu-tool.c
@@ -13,9 +13,9 @@
 
 #include "qemu-common.h"
 #include "monitor.h"
-#include "sysemu.h"
 #include "qemu-timer.h"
 #include "qemu-log.h"
+#include "qemu-error.h"
 
 #include <sys/time.h>
 
@@ -33,8 +33,6 @@ void qemu_service_io(void)
 {
 }
 
-Monitor *cur_mon;
-
 void monitor_printf(Monitor *mon, const char *fmt, ...)
 {
 }
@@ -106,7 +104,31 @@ int64_t qemu_get_clock(QEMUClock *clock)
     return (tv.tv_sec * 1000000000LL + (tv.tv_usec * 1000)) / 1000000;
 }
 
-void qemu_error(const char *fmt, ...)
+Location *loc_push_restore(Location *loc)
+{
+    return loc;
+}
+
+Location *loc_push_none(Location *loc)
+{
+    return loc;
+}
+
+Location *loc_pop(Location *loc)
+{
+    return loc;
+}
+
+Location *loc_save(Location *loc)
+{
+    return loc;
+}
+
+void loc_restore(Location *loc)
+{
+}
+
+void error_report(const char *fmt, ...)
 {
     va_list args;
 
diff --git a/qerror.c b/qerror.c
index 2f657f4f7b..26eb70472e 100644
--- a/qerror.c
+++ b/qerror.c
@@ -12,8 +12,8 @@
 #include "qjson.h"
 #include "qerror.h"
 #include "qstring.h"
-#include "sysemu.h"
 #include "qemu-common.h"
+#include "qemu-error.h"
 
 static void qerror_destroy_obj(QObject *obj);
 
@@ -41,48 +41,68 @@ static const QType qerror_type = {
  */
 static const QErrorStringTable qerror_table[] = {
     {
+        .error_fmt = QERR_BAD_BUS_FOR_DEVICE,
+        .desc      = "Device '%(device)' can't go on a %(bad_bus_type) bus",
+    },
+    {
+        .error_fmt = QERR_BUS_NOT_FOUND,
+        .desc      = "Bus '%(bus)' not found",
+    },
+    {
+        .error_fmt = QERR_BUS_NO_HOTPLUG,
+        .desc      = "Bus '%(bus)' does not support hotplugging",
+    },
+    {
         .error_fmt = QERR_COMMAND_NOT_FOUND,
         .desc      = "The command %(name) has not been found",
     },
     {
         .error_fmt = QERR_DEVICE_ENCRYPTED,
-        .desc      = "The %(device) is encrypted",
+        .desc      = "Device '%(device)' is encrypted",
+    },
+    {
+        .error_fmt = QERR_DEVICE_INIT_FAILED,
+        .desc      = "Device '%(device)' could not be initialized",
     },
     {
         .error_fmt = QERR_DEVICE_LOCKED,
-        .desc      = "Device %(device) is locked",
+        .desc      = "Device '%(device)' is locked",
+    },
+    {
+        .error_fmt = QERR_DEVICE_MULTIPLE_BUSSES,
+        .desc      = "Device '%(device)' has multiple child busses",
     },
     {
         .error_fmt = QERR_DEVICE_NOT_ACTIVE,
-        .desc      = "The %(device) device has not been activated by the guest",
+        .desc      = "Device '%(device)' has not been activated by the guest",
     },
     {
         .error_fmt = QERR_DEVICE_NOT_FOUND,
-        .desc      = "The %(device) device has not been found",
+        .desc      = "Device '%(device)' not found",
     },
     {
         .error_fmt = QERR_DEVICE_NOT_REMOVABLE,
-        .desc      = "Device %(device) is not removable",
+        .desc      = "Device '%(device)' is not removable",
+    },
+    {
+        .error_fmt = QERR_DEVICE_NO_BUS,
+        .desc      = "Device '%(device)' has no child bus",
     },
     {
         .error_fmt = QERR_FD_NOT_FOUND,
-        .desc      = "Failed to find file descriptor named %(name)",
+        .desc      = "File descriptor named '%(name)' not found",
     },
     {
         .error_fmt = QERR_FD_NOT_SUPPLIED,
         .desc      = "No file descriptor supplied via SCM_RIGHTS",
     },
     {
-        .error_fmt = QERR_OPEN_FILE_FAILED,
-        .desc      = "Could not open '%(filename)'",
-    },
-    {
         .error_fmt = QERR_INVALID_BLOCK_FORMAT,
-        .desc      = "Invalid block format %(name)",
+        .desc      = "Invalid block format '%(name)'",
     },
     {
         .error_fmt = QERR_INVALID_PARAMETER,
-        .desc      = "Invalid parameter %(name)",
+        .desc      = "Invalid parameter '%(name)'",
     },
     {
         .error_fmt = QERR_INVALID_PARAMETER_TYPE,
@@ -90,7 +110,7 @@ static const QErrorStringTable qerror_table[] = {
     },
     {
         .error_fmt = QERR_INVALID_PASSWORD,
-        .desc      = "The entered password is invalid",
+        .desc      = "Password incorrect",
     },
     {
         .error_fmt = QERR_JSON_PARSING,
@@ -102,7 +122,31 @@ static const QErrorStringTable qerror_table[] = {
     },
     {
         .error_fmt = QERR_MISSING_PARAMETER,
-        .desc      = "Parameter %(name) is missing",
+        .desc      = "Parameter '%(name)' is missing",
+    },
+    {
+        .error_fmt = QERR_NO_BUS_FOR_DEVICE,
+        .desc      = "No '%(bus)' bus found for device '%(device)'",
+    },
+    {
+        .error_fmt = QERR_OPEN_FILE_FAILED,
+        .desc      = "Could not open '%(filename)'",
+    },
+    {
+        .error_fmt = QERR_PROPERTY_NOT_FOUND,
+        .desc      = "Property '%(device).%(property)' not found",
+    },
+    {
+        .error_fmt = QERR_PROPERTY_VALUE_BAD,
+        .desc      = "Property '%(device).%(property)' doesn't take value '%(value)'",
+    },
+    {
+        .error_fmt = QERR_PROPERTY_VALUE_IN_USE,
+        .desc      = "Property '%(device).%(property)' can't take value '%(value)', it's in use",
+    },
+    {
+        .error_fmt = QERR_PROPERTY_VALUE_NOT_FOUND,
+        .desc      = "Property '%(device).%(property)' can't find value '%(value)'",
     },
     {
         .error_fmt = QERR_QMP_BAD_INPUT_OBJECT,
@@ -224,6 +268,7 @@ QError *qerror_from_info(const char *file, int linenr, const char *func,
     QError *qerr;
 
     qerr = qerror_new();
+    loc_save(&qerr->loc);
     qerr->linenr = linenr;
     qerr->file = file;
     qerr->func = func;
@@ -318,13 +363,15 @@ QString *qerror_human(const QError *qerror)
  * qerror_print(): Print QError data
  *
  * This function will print the member 'desc' of the specified QError object,
- * it uses qemu_error() for this, so that the output is routed to the right
+ * it uses error_report() for this, so that the output is routed to the right
  * place (ie. stderr or Monitor's device).
  */
-void qerror_print(const QError *qerror)
+void qerror_print(QError *qerror)
 {
     QString *qstring = qerror_human(qerror);
-    qemu_error("%s\n", qstring_get_str(qstring));
+    loc_push_restore(&qerror->loc);
+    error_report("%s", qstring_get_str(qstring));
+    loc_pop(&qerror->loc);
     QDECREF(qstring);
 }
 
diff --git a/qerror.h b/qerror.h
index ee59615bd2..88b297a96d 100644
--- a/qerror.h
+++ b/qerror.h
@@ -14,6 +14,7 @@
 
 #include "qdict.h"
 #include "qstring.h"
+#include "qemu-error.h"
 #include <stdarg.h>
 
 typedef struct QErrorStringTable {
@@ -24,6 +25,7 @@ typedef struct QErrorStringTable {
 typedef struct QError {
     QObject_HEAD;
     QDict *error;
+    Location loc;
     int linenr;
     const char *file;
     const char *func;
@@ -34,21 +36,36 @@ QError *qerror_new(void);
 QError *qerror_from_info(const char *file, int linenr, const char *func,
                          const char *fmt, va_list *va);
 QString *qerror_human(const QError *qerror);
-void qerror_print(const QError *qerror);
+void qerror_print(QError *qerror);
 QError *qobject_to_qerror(const QObject *obj);
 
 /*
  * QError class list
  */
+#define QERR_BAD_BUS_FOR_DEVICE \
+    "{ 'class': 'BadBusForDevice', 'data': { 'device': %s, 'bad_bus_type': %s } }"
+
+#define QERR_BUS_NOT_FOUND \
+    "{ 'class': 'BusNotFound', 'data': { 'bus': %s } }"
+
+#define QERR_BUS_NO_HOTPLUG \
+    "{ 'class': 'BusNoHotplug', 'data': { 'bus': %s } }"
+
 #define QERR_COMMAND_NOT_FOUND \
     "{ 'class': 'CommandNotFound', 'data': { 'name': %s } }"
 
 #define QERR_DEVICE_ENCRYPTED \
     "{ 'class': 'DeviceEncrypted', 'data': { 'device': %s } }"
 
-#define QERR_DEVICE_LOCKED                                      \
+#define QERR_DEVICE_INIT_FAILED \
+    "{ 'class': 'DeviceInitFailed', 'data': { 'device': %s } }"
+
+#define QERR_DEVICE_LOCKED \
     "{ 'class': 'DeviceLocked', 'data': { 'device': %s } }"
 
+#define QERR_DEVICE_MULTIPLE_BUSSES \
+    "{ 'class': 'DeviceMultipleBusses', 'data': { 'device': %s } }"
+
 #define QERR_DEVICE_NOT_ACTIVE \
     "{ 'class': 'DeviceNotActive', 'data': { 'device': %s } }"
 
@@ -58,15 +75,15 @@ QError *qobject_to_qerror(const QObject *obj);
 #define QERR_DEVICE_NOT_REMOVABLE \
     "{ 'class': 'DeviceNotRemovable', 'data': { 'device': %s } }"
 
+#define QERR_DEVICE_NO_BUS \
+    "{ 'class': 'DeviceNoBus', 'data': { 'device': %s } }"
+
 #define QERR_FD_NOT_FOUND \
     "{ 'class': 'FdNotFound', 'data': { 'name': %s } }"
 
 #define QERR_FD_NOT_SUPPLIED \
     "{ 'class': 'FdNotSupplied', 'data': {} }"
 
-#define QERR_OPEN_FILE_FAILED \
-    "{ 'class': 'OpenFileFailed', 'data': { 'filename': %s } }"
-
 #define QERR_INVALID_BLOCK_FORMAT \
     "{ 'class': 'InvalidBlockFormat', 'data': { 'name': %s } }"
 
@@ -88,18 +105,36 @@ QError *qobject_to_qerror(const QObject *obj);
 #define QERR_MISSING_PARAMETER \
     "{ 'class': 'MissingParameter', 'data': { 'name': %s } }"
 
+#define QERR_NO_BUS_FOR_DEVICE \
+    "{ 'class': 'NoBusForDevice', 'data': { 'device': %s, 'bus': %s } }"
+
+#define QERR_OPEN_FILE_FAILED \
+    "{ 'class': 'OpenFileFailed', 'data': { 'filename': %s } }"
+
+#define QERR_PROPERTY_NOT_FOUND \
+    "{ 'class': 'PropertyNotFound', 'data': { 'device': %s, 'property': %s } }"
+
+#define QERR_PROPERTY_VALUE_BAD \
+    "{ 'class': 'PropertyValueBad', 'data': { 'device': %s, 'property': %s, 'value': %s } }"
+
+#define QERR_PROPERTY_VALUE_IN_USE \
+    "{ 'class': 'PropertyValueInUse', 'data': { 'device': %s, 'property': %s, 'value': %s } }"
+
+#define QERR_PROPERTY_VALUE_NOT_FOUND \
+    "{ 'class': 'PropertyValueNotFound', 'data': { 'device': %s, 'property': %s, 'value': %s } }"
+
 #define QERR_QMP_BAD_INPUT_OBJECT \
     "{ 'class': 'QMPBadInputObject', 'data': { 'expected': %s } }"
 
 #define QERR_SET_PASSWD_FAILED \
     "{ 'class': 'SetPasswdFailed', 'data': {} }"
 
-#define QERR_UNDEFINED_ERROR \
-    "{ 'class': 'UndefinedError', 'data': {} }"
-
 #define QERR_TOO_MANY_FILES \
     "{ 'class': 'TooManyFiles', 'data': {} }"
 
+#define QERR_UNDEFINED_ERROR \
+    "{ 'class': 'UndefinedError', 'data': {} }"
+
 #define QERR_VNC_SERVER_FAILED \
     "{ 'class': 'VNCServerFailed', 'data': { 'target': %s } }"
 
diff --git a/savevm.c b/savevm.c
index 15477e9d82..086c92a704 100644
--- a/savevm.c
+++ b/savevm.c
@@ -1737,7 +1737,7 @@ void do_savevm(Monitor *mon, const QDict *qdict)
         vm_start();
 }
 
-int load_vmstate(Monitor *mon, const char *name)
+int load_vmstate(const char *name)
 {
     DriveInfo *dinfo;
     BlockDriverState *bs, *bs1;
@@ -1747,7 +1747,7 @@ int load_vmstate(Monitor *mon, const char *name)
 
     bs = get_bs_snapshots();
     if (!bs) {
-        monitor_printf(mon, "No block device supports snapshots\n");
+        error_report("No block device supports snapshots");
         return -EINVAL;
     }
 
@@ -1759,22 +1759,21 @@ int load_vmstate(Monitor *mon, const char *name)
         if (bdrv_has_snapshot(bs1)) {
             ret = bdrv_snapshot_goto(bs1, name);
             if (ret < 0) {
-                if (bs != bs1)
-                    monitor_printf(mon, "Warning: ");
                 switch(ret) {
                 case -ENOTSUP:
-                    monitor_printf(mon,
-                                   "Snapshots not supported on device '%s'\n",
-                                   bdrv_get_device_name(bs1));
+                    error_report("%sSnapshots not supported on device '%s'",
+                                 bs != bs1 ? "Warning: " : "",
+                                 bdrv_get_device_name(bs1));
                     break;
                 case -ENOENT:
-                    monitor_printf(mon, "Could not find snapshot '%s' on "
-                                   "device '%s'\n",
-                                   name, bdrv_get_device_name(bs1));
+                    error_report("%sCould not find snapshot '%s' on device '%s'",
+                                 bs != bs1 ? "Warning: " : "",
+                                 name, bdrv_get_device_name(bs1));
                     break;
                 default:
-                    monitor_printf(mon, "Error %d while activating snapshot on"
-                                   " '%s'\n", ret, bdrv_get_device_name(bs1));
+                    error_report("%sError %d while activating snapshot on '%s'",
+                                 bs != bs1 ? "Warning: " : "",
+                                 ret, bdrv_get_device_name(bs1));
                     break;
                 }
                 /* fatal on snapshot block device */
@@ -1792,13 +1791,13 @@ int load_vmstate(Monitor *mon, const char *name)
     /* restore the VM state */
     f = qemu_fopen_bdrv(bs, 0);
     if (!f) {
-        monitor_printf(mon, "Could not open VM state file\n");
+        error_report("Could not open VM state file");
         return -EINVAL;
     }
     ret = qemu_loadvm_state(f);
     qemu_fclose(f);
     if (ret < 0) {
-        monitor_printf(mon, "Error %d while loading VM state\n", ret);
+        error_report("Error %d while loading VM state", ret);
         return ret;
     }
     return 0;
diff --git a/slirp/misc.c b/slirp/misc.c
index dcb1dc117b..1aeb401082 100644
--- a/slirp/misc.c
+++ b/slirp/misc.c
@@ -260,7 +260,7 @@ void lprint(const char *format, ...)
     va_list args;
 
     va_start(args, format);
-    monitor_vprintf(cur_mon, format, args);
+    monitor_vprintf(default_mon, format, args);
     va_end(args);
 }
 
diff --git a/sysemu.h b/sysemu.h
index afa11b5519..8a9c630ebd 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -54,7 +54,7 @@ extern qemu_irq qemu_system_powerdown;
 void qemu_system_reset(void);
 
 void do_savevm(Monitor *mon, const QDict *qdict);
-int load_vmstate(Monitor *mon, const char *name);
+int load_vmstate(const char *name);
 void do_delvm(Monitor *mon, const QDict *qdict);
 void do_info_snapshots(Monitor *mon);
 
@@ -73,17 +73,6 @@ int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f);
 void qemu_savevm_state_cancel(Monitor *mon, QEMUFile *f);
 int qemu_loadvm_state(QEMUFile *f);
 
-void qemu_errors_to_file(FILE *fp);
-void qemu_errors_to_mon(Monitor *mon);
-void qemu_errors_to_previous(void);
-void qemu_error(const char *fmt, ...) __attribute__ ((format(printf, 1, 2)));
-void qemu_error_internal(const char *file, int linenr, const char *func,
-                         const char *fmt, ...)
-                         __attribute__ ((format(printf, 4, 5)));
-
-#define qemu_error_new(fmt, ...) \
-    qemu_error_internal(__FILE__, __LINE__, __func__, fmt, ## __VA_ARGS__)
-
 #ifdef _WIN32
 /* Polling handling */
 
diff --git a/usb-linux.c b/usb-linux.c
index a9c15c6d1d..d0d7cff496 100644
--- a/usb-linux.c
+++ b/usb-linux.c
@@ -1188,9 +1188,6 @@ static int usb_host_scan_dev(void *opaque, USBScanFunc *func)
  */
 static int usb_host_read_file(char *line, size_t line_size, const char *device_file, const char *device_name)
 {
-#if 0
-    Monitor *mon = cur_mon;
-#endif
     FILE *f;
     int ret = 0;
     char filename[PATH_MAX];
@@ -1201,11 +1198,6 @@ static int usb_host_read_file(char *line, size_t line_size, const char *device_f
     if (f) {
         ret = fgets(line, line_size, f) != NULL;
         fclose(f);
-#if 0
-    } else {
-        if (mon)
-            monitor_printf(mon, "husb: could not open %s\n", filename);
-#endif
     }
 
     return ret;
diff --git a/vl.c b/vl.c
index a3e43ad9a7..01dc1aa2d9 100644
--- a/vl.c
+++ b/vl.c
@@ -1813,7 +1813,7 @@ QemuOpts *drive_add(const char *file, const char *fmt, ...)
     vsnprintf(optstr, sizeof(optstr), fmt, ap);
     va_end(ap);
 
-    opts = qemu_opts_parse(&qemu_drive_opts, optstr, NULL);
+    opts = qemu_opts_parse(&qemu_drive_opts, optstr, 0);
     if (!opts) {
         fprintf(stderr, "%s: huh? duplicate? (%s)\n",
                 __FUNCTION__, optstr);
@@ -2539,7 +2539,7 @@ void do_usb_add(Monitor *mon, const QDict *qdict)
 {
     const char *devname = qdict_get_str(qdict, "devname");
     if (usb_device_add(devname, 1) < 0) {
-        qemu_error("could not add USB device '%s'\n", devname);
+        error_report("could not add USB device '%s'", devname);
     }
 }
 
@@ -2547,7 +2547,7 @@ void do_usb_del(Monitor *mon, const QDict *qdict)
 {
     const char *devname = qdict_get_str(qdict, "devname");
     if (usb_device_del(devname) < 0) {
-        qemu_error("could not delete USB device '%s'\n", devname);
+        error_report("could not delete USB device '%s'", devname);
     }
 }
 
@@ -4370,7 +4370,7 @@ static int balloon_parse(const char *arg)
     if (!strncmp(arg, "virtio", 6)) {
         if (arg[6] == ',') {
             /* have params -> parse them */
-            opts = qemu_opts_parse(&qemu_device_opts, arg+7, NULL);
+            opts = qemu_opts_parse(&qemu_device_opts, arg+7, 0);
             if (!opts)
                 return  -1;
         } else {
@@ -4796,6 +4796,7 @@ static const QEMUOption *lookup_opt(int argc, char **argv,
     char *r = argv[optind];
     const char *optarg;
 
+    loc_set_cmdline(argv, optind, 1);
     optind++;
     /* Treat --foo the same as -foo.  */
     if (r[1] == '-')
@@ -4803,8 +4804,7 @@ static const QEMUOption *lookup_opt(int argc, char **argv,
     popt = qemu_options;
     for(;;) {
         if (!popt->name) {
-            fprintf(stderr, "%s: invalid option -- '%s'\n",
-                    argv[0], r);
+            error_report("invalid option");
             exit(1);
         }
         if (!strcmp(popt->name, r + 1))
@@ -4813,11 +4813,11 @@ static const QEMUOption *lookup_opt(int argc, char **argv,
     }
     if (popt->flags & HAS_ARG) {
         if (optind >= argc) {
-            fprintf(stderr, "%s: option '%s' requires an argument\n",
-                    argv[0], r);
+            error_report("requires an argument");
             exit(1);
         }
         optarg = argv[optind++];
+        loc_set_cmdline(argv, optind - 2, 2);
     } else {
         optarg = NULL;
     }
@@ -4862,9 +4862,10 @@ int main(int argc, char **argv, char **envp)
     int show_vnc_port = 0;
     int defconfig = 1;
 
+    error_set_progname(argv[0]);
+
     init_clocks();
 
-    qemu_errors_to_file(stderr);
     qemu_cache_utils_init(envp);
 
     QLIST_INIT (&vm_change_state_head);
@@ -4940,18 +4941,22 @@ int main(int argc, char **argv, char **envp)
     }
 
     if (defconfig) {
+        const char *fname;
         FILE *fp;
-        fp = fopen(CONFIG_QEMU_CONFDIR "/qemu.conf", "r");
+
+        fname = CONFIG_QEMU_CONFDIR "/qemu.conf";
+        fp = fopen(fname, "r");
         if (fp) {
-            if (qemu_config_parse(fp) != 0) {
+            if (qemu_config_parse(fp, fname) != 0) {
                 exit(1);
             }
             fclose(fp);
         }
 
-        fp = fopen(CONFIG_QEMU_CONFDIR "/target-" TARGET_ARCH ".conf", "r");
+        fname = CONFIG_QEMU_CONFDIR "/target-" TARGET_ARCH ".conf";
+        fp = fopen(fname, "r");
         if (fp) {
-            if (qemu_config_parse(fp) != 0) {
+            if (qemu_config_parse(fp, fname) != 0) {
                 exit(1);
             }
             fclose(fp);
@@ -5360,7 +5365,7 @@ int main(int argc, char **argv, char **envp)
                 default_monitor = 0;
                 break;
             case QEMU_OPTION_mon:
-                opts = qemu_opts_parse(&qemu_mon_opts, optarg, "chardev");
+                opts = qemu_opts_parse(&qemu_mon_opts, optarg, 1);
                 if (!opts) {
                     fprintf(stderr, "parse error: %s\n", optarg);
                     exit(1);
@@ -5368,7 +5373,7 @@ int main(int argc, char **argv, char **envp)
                 default_monitor = 0;
                 break;
             case QEMU_OPTION_chardev:
-                opts = qemu_opts_parse(&qemu_chardev_opts, optarg, "backend");
+                opts = qemu_opts_parse(&qemu_chardev_opts, optarg, 1);
                 if (!opts) {
                     fprintf(stderr, "parse error: %s\n", optarg);
                     exit(1);
@@ -5471,7 +5476,7 @@ int main(int argc, char **argv, char **envp)
                 add_device_config(DEV_USB, optarg);
                 break;
             case QEMU_OPTION_device:
-                if (!qemu_opts_parse(&qemu_device_opts, optarg, "driver")) {
+                if (!qemu_opts_parse(&qemu_device_opts, optarg, 1)) {
                     exit(1);
                 }
                 break;
@@ -5580,7 +5585,7 @@ int main(int argc, char **argv, char **envp)
                 configure_rtc_date_offset(optarg, 1);
                 break;
             case QEMU_OPTION_rtc:
-                opts = qemu_opts_parse(&qemu_rtc_opts, optarg, NULL);
+                opts = qemu_opts_parse(&qemu_rtc_opts, optarg, 0);
                 if (!opts) {
                     fprintf(stderr, "parse error: %s\n", optarg);
                     exit(1);
@@ -5641,7 +5646,7 @@ int main(int argc, char **argv, char **envp)
                         fprintf(stderr, "open %s: %s\n", optarg, strerror(errno));
                         exit(1);
                     }
-                    if (qemu_config_parse(fp) != 0) {
+                    if (qemu_config_parse(fp, optarg) != 0) {
                         exit(1);
                     }
                     fclose(fp);
@@ -5666,6 +5671,7 @@ int main(int argc, char **argv, char **envp)
             }
         }
     }
+    loc_set_none();
 
     /* If no data_dir is specified then try to find it relative to the
        executable path.  */
@@ -6081,7 +6087,7 @@ int main(int argc, char **argv, char **envp)
 
     qemu_system_reset();
     if (loadvm) {
-        if (load_vmstate(cur_mon, loadvm) < 0) {
+        if (load_vmstate(loadvm) < 0) {
             autostart = 0;
         }
     }
diff --git a/vnc.c b/vnc.c
index 7ce73dca3d..f10a37f749 100644
--- a/vnc.c
+++ b/vnc.c
@@ -1046,11 +1046,10 @@ static void audio_capture(void *opaque, void *buf, int size)
 
 static void audio_add(VncState *vs)
 {
-    Monitor *mon = cur_mon;
     struct audio_capture_ops ops;
 
     if (vs->audio_cap) {
-        monitor_printf(mon, "audio already running\n");
+        monitor_printf(default_mon, "audio already running\n");
         return;
     }
 
@@ -1060,7 +1059,7 @@ static void audio_add(VncState *vs)
 
     vs->audio_cap = AUD_add_capture(&vs->as, &ops, vs);
     if (!vs->audio_cap) {
-        monitor_printf(mon, "Failed to add audio capture\n");
+        monitor_printf(default_mon, "Failed to add audio capture\n");
     }
 }