Merge remote-tracking branch 'remotes/kwolf/tags/for-upstream' into staging

qdev: Add JSON -device

- Add a JSON mode to the -device command line option
- net/vhost-{user,vdpa}: Fix device compatibility check
- Minor iotests fixes

# gpg: Signature made Fri 15 Oct 2021 07:41:22 AM PDT
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]

* remotes/kwolf/tags/for-upstream:
  vl: Enable JSON syntax for -device
  qdev: Base object creation on QDict rather than QemuOpts
  virtio-net: Avoid QemuOpts in failover_find_primary_device()
  virtio-net: Store failover primary opts pointer locally
  qdev: Add Error parameter to hide_device() callbacks
  qemu-option: Allow deleting opts during qemu_opts_foreach()
  softmmu/qdev-monitor: add error handling in qdev_set_id
  qdev: Make DeviceState.id independent of QemuOpts
  qdev: Avoid using string visitor for properties
  iotests/051: Fix typo
  iotests/245: Fix type for iothread property
  qom: Reduce use of error_propagate()
  net/vhost-vdpa: Fix device compatibility check
  net/vhost-user: Fix device compatibility check
  net: Introduce NetClientInfo.check_peer_type()

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

23 files changed, 280 insertions, 178 deletions

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 7170aaacd5..4160d49688 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -1459,7 +1459,7 @@ static void create_platform_bus(VirtMachineState *vms)
     MemoryRegion *sysmem = get_system_memory();
 
     dev = qdev_new(TYPE_PLATFORM_BUS_DEVICE);
-    dev->id = TYPE_PLATFORM_BUS_DEVICE;
+    dev->id = g_strdup(TYPE_PLATFORM_BUS_DEVICE);
     qdev_prop_set_uint32(dev, "num_irqs", PLATFORM_BUS_NUM_IRQS);
     qdev_prop_set_uint32(dev, "mmio_size", vms->memmap[VIRT_PLATFORM_BUS].size);
     sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
diff --git a/hw/core/qdev-properties-system.c b/hw/core/qdev-properties-system.c
index e71f5d64d1..a91f60567a 100644
--- a/hw/core/qdev-properties-system.c
+++ b/hw/core/qdev-properties-system.c
@@ -431,6 +431,12 @@ static void set_netdev(Object *obj, Visitor *v, const char *name,
             goto out;
         }
 
+        if (peers[i]->info->check_peer_type) {
+            if (!peers[i]->info->check_peer_type(peers[i], obj->class, errp)) {
+                goto out;
+            }
+        }
+
         ncs[i] = peers[i];
         ncs[i]->queue_index = i;
     }
diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index cefc5eaa0a..7f06403752 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -28,6 +28,7 @@
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "qapi/qapi-events-qdev.h"
+#include "qapi/qmp/qdict.h"
 #include "qapi/qmp/qerror.h"
 #include "qapi/visitor.h"
 #include "qemu/error-report.h"
@@ -211,14 +212,17 @@ void device_listener_unregister(DeviceListener *listener)
     QTAILQ_REMOVE(&device_listeners, listener, link);
 }
 
-bool qdev_should_hide_device(QemuOpts *opts)
+bool qdev_should_hide_device(const QDict *opts, bool from_json, Error **errp)
 {
+    ERRP_GUARD();
     DeviceListener *listener;
 
     QTAILQ_FOREACH(listener, &device_listeners, link) {
         if (listener->hide_device) {
-            if (listener->hide_device(listener, opts)) {
+            if (listener->hide_device(listener, opts, from_json, errp)) {
                 return true;
+            } else if (*errp) {
+                return false;
             }
         }
     }
@@ -955,7 +959,8 @@ static void device_finalize(Object *obj)
         dev->canonical_path = NULL;
     }
 
-    qemu_opts_del(dev->opts);
+    qobject_unref(dev->opts);
+    g_free(dev->id);
 }
 
 static void device_class_base_init(ObjectClass *class, void *data)
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index f205331dcf..09e173a558 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -796,23 +796,28 @@ static inline uint64_t virtio_net_supported_guest_offloads(VirtIONet *n)
 
 typedef struct {
     VirtIONet *n;
-    char *id;
-} FailoverId;
+    DeviceState *dev;
+} FailoverDevice;
 
 /**
- * Set the id of the failover primary device
+ * Set the failover primary device
  *
  * @opaque: FailoverId to setup
  * @opts: opts for device we are handling
  * @errp: returns an error if this function fails
  */
-static int failover_set_primary(void *opaque, QemuOpts *opts, Error **errp)
+static int failover_set_primary(DeviceState *dev, void *opaque)
 {
-    FailoverId *fid = opaque;
-    const char *standby_id = qemu_opt_get(opts, "failover_pair_id");
+    FailoverDevice *fdev = opaque;
+    PCIDevice *pci_dev = (PCIDevice *)
+        object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE);
 
-    if (g_strcmp0(standby_id, fid->n->netclient_name) == 0) {
-        fid->id = g_strdup(opts->id);
+    if (!pci_dev) {
+        return 0;
+    }
+
+    if (!g_strcmp0(pci_dev->failover_pair_id, fdev->n->netclient_name)) {
+        fdev->dev = dev;
         return 1;
     }
 
@@ -820,25 +825,6 @@ static int failover_set_primary(void *opaque, QemuOpts *opts, Error **errp)
 }
 
 /**
- * Find the primary device id for this failover virtio-net
- *
- * @n: VirtIONet device
- * @errp: returns an error if this function fails
- */
-static char *failover_find_primary_device_id(VirtIONet *n)
-{
-    Error *err = NULL;
-    FailoverId fid;
-
-    fid.n = n;
-    if (!qemu_opts_foreach(qemu_find_opts("device"),
-                           failover_set_primary, &fid, &err)) {
-        return NULL;
-    }
-    return fid.id;
-}
-
-/**
  * Find the primary device for this failover virtio-net
  *
  * @n: VirtIONet device
@@ -846,39 +832,38 @@ static char *failover_find_primary_device_id(VirtIONet *n)
  */
 static DeviceState *failover_find_primary_device(VirtIONet *n)
 {
-    char *id = failover_find_primary_device_id(n);
-
-    if (!id) {
-        return NULL;
-    }
+    FailoverDevice fdev = {
+        .n = n,
+    };
 
-    return qdev_find_recursive(sysbus_get_default(), id);
+    qbus_walk_children(sysbus_get_default(), failover_set_primary, NULL,
+                       NULL, NULL, &fdev);
+    return fdev.dev;
 }
 
 static void failover_add_primary(VirtIONet *n, Error **errp)
 {
     Error *err = NULL;
-    QemuOpts *opts;
-    char *id;
     DeviceState *dev = failover_find_primary_device(n);
 
     if (dev) {
         return;
     }
 
-    id = failover_find_primary_device_id(n);
-    if (!id) {
+    if (!n->primary_opts) {
         error_setg(errp, "Primary device not found");
         error_append_hint(errp, "Virtio-net failover will not work. Make "
                           "sure primary device has parameter"
                           " failover_pair_id=%s\n", n->netclient_name);
         return;
     }
-    opts = qemu_opts_find(qemu_find_opts("device"), id);
-    g_assert(opts); /* cannot be NULL because id was found using opts list */
-    dev = qdev_device_add(opts, &err);
+
+    dev = qdev_device_add_from_qdict(n->primary_opts,
+                                     n->primary_opts_from_json,
+                                     &err);
     if (err) {
-        qemu_opts_del(opts);
+        qobject_unref(n->primary_opts);
+        n->primary_opts = NULL;
     } else {
         object_unref(OBJECT(dev));
     }
@@ -3304,7 +3289,9 @@ static void virtio_net_migration_state_notifier(Notifier *notifier, void *data)
 }
 
 static bool failover_hide_primary_device(DeviceListener *listener,
-                                         QemuOpts *device_opts)
+                                         const QDict *device_opts,
+                                         bool from_json,
+                                         Error **errp)
 {
     VirtIONet *n = container_of(listener, VirtIONet, primary_listener);
     const char *standby_id;
@@ -3312,11 +3299,20 @@ static bool failover_hide_primary_device(DeviceListener *listener,
     if (!device_opts) {
         return false;
     }
-    standby_id = qemu_opt_get(device_opts, "failover_pair_id");
+    standby_id = qdict_get_try_str(device_opts, "failover_pair_id");
     if (g_strcmp0(standby_id, n->netclient_name) != 0) {
         return false;
     }
 
+    if (n->primary_opts) {
+        error_setg(errp, "Cannot attach more than one primary device to '%s'",
+                   n->netclient_name);
+        return false;
+    }
+
+    n->primary_opts = qdict_clone_shallow(device_opts);
+    n->primary_opts_from_json = from_json;
+
     /* failover_primary_hidden is set during feature negotiation */
     return qatomic_read(&n->failover_primary_hidden);
 }
@@ -3506,8 +3502,11 @@ static void virtio_net_device_unrealize(DeviceState *dev)
     g_free(n->vlans);
 
     if (n->failover) {
+        qobject_unref(n->primary_opts);
         device_listener_unregister(&n->primary_listener);
         remove_migration_state_change_notifier(&n->migration_state);
+    } else {
+        assert(n->primary_opts == NULL);
     }
 
     max_queues = n->multiqueue ? n->max_queues : 1;
diff --git a/hw/pci-bridge/pci_expander_bridge.c b/hw/pci-bridge/pci_expander_bridge.c
index 7112dc3062..10e6e7c2ab 100644
--- a/hw/pci-bridge/pci_expander_bridge.c
+++ b/hw/pci-bridge/pci_expander_bridge.c
@@ -245,7 +245,7 @@ static void pxb_dev_realize_common(PCIDevice *dev, bool pcie, Error **errp)
     } else {
         bus = pci_root_bus_new(ds, "pxb-internal", NULL, NULL, 0, TYPE_PXB_BUS);
         bds = qdev_new("pci-bridge");
-        bds->id = dev_name;
+        bds->id = g_strdup(dev_name);
         qdev_prop_set_uint8(bds, PCI_BRIDGE_DEV_PROP_CHASSIS_NR, pxb->bus_nr);
         qdev_prop_set_bit(bds, PCI_BRIDGE_DEV_PROP_SHPC, false);
     }
diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c
index 95451414dd..960e7efcd3 100644
--- a/hw/ppc/e500.c
+++ b/hw/ppc/e500.c
@@ -1006,7 +1006,7 @@ void ppce500_init(MachineState *machine)
     /* Platform Bus Device */
     if (pmc->has_platform_bus) {
         dev = qdev_new(TYPE_PLATFORM_BUS_DEVICE);
-        dev->id = TYPE_PLATFORM_BUS_DEVICE;
+        dev->id = g_strdup(TYPE_PLATFORM_BUS_DEVICE);
         qdev_prop_set_uint32(dev, "num_irqs", pmc->platform_bus_num_irqs);
         qdev_prop_set_uint32(dev, "mmio_size", pmc->platform_bus_size);
         sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 4feaa1cb68..5cdf1d4298 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -29,10 +29,10 @@
 #include "hw/qdev-properties.h"
 #include "hw/qdev-properties-system.h"
 #include "migration/vmstate.h"
+#include "qapi/qmp/qdict.h"
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
 #include "qemu/module.h"
-#include "qemu/option.h"
 #include "qemu/range.h"
 #include "qemu/units.h"
 #include "sysemu/kvm.h"
@@ -941,7 +941,7 @@ static void vfio_pci_size_rom(VFIOPCIDevice *vdev)
     }
 
     if (vfio_opt_rom_in_denylist(vdev)) {
-        if (dev->opts && qemu_opt_get(dev->opts, "rombar")) {
+        if (dev->opts && qdict_haskey(dev->opts, "rombar")) {
             warn_report("Device at %s is known to cause system instability"
                         " issues during option rom execution",
                         vdev->vbasedev.name);
diff --git a/hw/xen/xen-legacy-backend.c b/hw/xen/xen-legacy-backend.c
index be3cf4a195..085fd31ef7 100644
--- a/hw/xen/xen-legacy-backend.c
+++ b/hw/xen/xen-legacy-backend.c
@@ -276,7 +276,8 @@ static struct XenLegacyDevice *xen_be_get_xendev(const char *type, int dom,
     xendev = g_malloc0(ops->size);
     object_initialize(&xendev->qdev, ops->size, TYPE_XENBACKEND);
     OBJECT(xendev)->free = g_free;
-    qdev_set_id(DEVICE(xendev), g_strdup_printf("xen-%s-%d", type, dev));
+    qdev_set_id(DEVICE(xendev), g_strdup_printf("xen-%s-%d", type, dev),
+                &error_fatal);
     qdev_realize(DEVICE(xendev), xen_sysbus, &error_fatal);
     object_unref(OBJECT(xendev));
 
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index 4ff19c714b..1bad07002d 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -176,11 +176,11 @@ struct DeviceState {
     Object parent_obj;
     /*< public >*/
 
-    const char *id;
+    char *id;
     char *canonical_path;
     bool realized;
     bool pending_deleted_event;
-    QemuOpts *opts;
+    QDict *opts;
     int hotplugged;
     bool allow_unplug_during_migration;
     BusState *parent_bus;
@@ -201,8 +201,12 @@ struct DeviceListener {
      * informs qdev if a device should be visible or hidden.  We can
      * hide a failover device depending for example on the device
      * opts.
+     *
+     * On errors, it returns false and errp is set. Device creation
+     * should fail in this case.
      */
-    bool (*hide_device)(DeviceListener *listener, QemuOpts *device_opts);
+    bool (*hide_device)(DeviceListener *listener, const QDict *device_opts,
+                        bool from_json, Error **errp);
     QTAILQ_ENTRY(DeviceListener) link;
 };
 
@@ -831,13 +835,15 @@ void device_listener_unregister(DeviceListener *listener);
 
 /**
  * @qdev_should_hide_device:
- * @opts: QemuOpts as passed on cmdline.
+ * @opts: options QDict
+ * @from_json: true if @opts entries are typed, false for all strings
+ * @errp: pointer to error object
  *
  * Check if a device should be added.
  * When a device is added via qdev_device_add() this will be called,
  * and return if the device should be added now or not.
  */
-bool qdev_should_hide_device(QemuOpts *opts);
+bool qdev_should_hide_device(const QDict *opts, bool from_json, Error **errp);
 
 typedef enum MachineInitPhase {
     /* current_machine is NULL.  */
diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h
index 824a69c23f..74a10ebe85 100644
--- a/include/hw/virtio/virtio-net.h
+++ b/include/hw/virtio/virtio-net.h
@@ -209,6 +209,8 @@ struct VirtIONet {
     bool failover_primary_hidden;
     bool failover;
     DeviceListener primary_listener;
+    QDict *primary_opts;
+    bool primary_opts_from_json;
     Notifier migration_state;
     VirtioNetRssData rss_data;
     struct NetRxPkt *rx_pkt;
diff --git a/include/monitor/qdev.h b/include/monitor/qdev.h
index eaa947d73a..1d57bf6577 100644
--- a/include/monitor/qdev.h
+++ b/include/monitor/qdev.h
@@ -9,6 +9,31 @@ void qmp_device_add(QDict *qdict, QObject **ret_data, Error **errp);
 
 int qdev_device_help(QemuOpts *opts);
 DeviceState *qdev_device_add(QemuOpts *opts, Error **errp);
-void qdev_set_id(DeviceState *dev, const char *id);
+DeviceState *qdev_device_add_from_qdict(const QDict *opts,
+                                        bool from_json, Error **errp);
+
+/**
+ * qdev_set_id: parent the device and set its id if provided.
+ * @dev: device to handle
+ * @id: id to be given to the device, or NULL.
+ *
+ * Returns: the id of the device in case of success; otherwise NULL.
+ *
+ * @dev must be unrealized, unparented and must not have an id.
+ *
+ * If @id is non-NULL, this function tries to setup @dev qom path as
+ * "/peripheral/id". If @id is already taken, it fails. If it succeeds,
+ * the id field of @dev is set to @id (@dev now owns the given @id
+ * parameter).
+ *
+ * If @id is NULL, this function generates a unique name and setups @dev
+ * qom path as "/peripheral-anon/name". This name is not set as the id
+ * of @dev.
+ *
+ * Upon success, it returns the id/name (generated or provided). The
+ * returned string is owned by the corresponding child property and must
+ * not be freed by the caller.
+ */
+const char *qdev_set_id(DeviceState *dev, char *id, Error **errp);
 
 #endif
diff --git a/include/net/net.h b/include/net/net.h
index 5d1508081f..986288eb07 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -62,6 +62,7 @@ typedef struct SocketReadState SocketReadState;
 typedef void (SocketReadStateFinalize)(SocketReadState *rs);
 typedef void (NetAnnounce)(NetClientState *);
 typedef bool (SetSteeringEBPF)(NetClientState *, int);
+typedef bool (NetCheckPeerType)(NetClientState *, ObjectClass *, Error **);
 
 typedef struct NetClientInfo {
     NetClientDriver type;
@@ -84,6 +85,7 @@ typedef struct NetClientInfo {
     SetVnetBE *set_vnet_be;
     NetAnnounce *announce;
     SetSteeringEBPF *set_steering_ebpf;
+    NetCheckPeerType *check_peer_type;
 } NetClientInfo;
 
 struct NetClientState {
diff --git a/net/vhost-user.c b/net/vhost-user.c
index 4a939124d2..b1a0247b59 100644
--- a/net/vhost-user.c
+++ b/net/vhost-user.c
@@ -198,6 +198,19 @@ static bool vhost_user_has_ufo(NetClientState *nc)
     return true;
 }
 
+static bool vhost_user_check_peer_type(NetClientState *nc, ObjectClass *oc,
+                                       Error **errp)
+{
+    const char *driver = object_class_get_name(oc);
+
+    if (!g_str_has_prefix(driver, "virtio-net-")) {
+        error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
+        return false;
+    }
+
+    return true;
+}
+
 static NetClientInfo net_vhost_user_info = {
         .type = NET_CLIENT_DRIVER_VHOST_USER,
         .size = sizeof(NetVhostUserState),
@@ -207,6 +220,7 @@ static NetClientInfo net_vhost_user_info = {
         .has_ufo = vhost_user_has_ufo,
         .set_vnet_be = vhost_user_set_vnet_endianness,
         .set_vnet_le = vhost_user_set_vnet_endianness,
+        .check_peer_type = vhost_user_check_peer_type,
 };
 
 static gboolean net_vhost_user_watch(void *do_not_use, GIOCondition cond,
@@ -397,27 +411,6 @@ static Chardev *net_vhost_claim_chardev(
     return chr;
 }
 
-static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp)
-{
-    const char *name = opaque;
-    const char *driver, *netdev;
-
-    driver = qemu_opt_get(opts, "driver");
-    netdev = qemu_opt_get(opts, "netdev");
-
-    if (!driver || !netdev) {
-        return 0;
-    }
-
-    if (strcmp(netdev, name) == 0 &&
-        !g_str_has_prefix(driver, "virtio-net-")) {
-        error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
-        return -1;
-    }
-
-    return 0;
-}
-
 int net_init_vhost_user(const Netdev *netdev, const char *name,
                         NetClientState *peer, Error **errp)
 {
@@ -433,12 +426,6 @@ int net_init_vhost_user(const Netdev *netdev, const char *name,
         return -1;
     }
 
-    /* verify net frontend */
-    if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net,
-                          (char *)name, errp)) {
-        return -1;
-    }
-
     queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1;
     if (queues < 1 || queues > MAX_QUEUE_NUM) {
         error_setg(errp,
diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 912686457c..6dc68d8677 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -147,12 +147,26 @@ static bool vhost_vdpa_has_ufo(NetClientState *nc)
 
 }
 
+static bool vhost_vdpa_check_peer_type(NetClientState *nc, ObjectClass *oc,
+                                       Error **errp)
+{
+    const char *driver = object_class_get_name(oc);
+
+    if (!g_str_has_prefix(driver, "virtio-net-")) {
+        error_setg(errp, "vhost-vdpa requires frontend driver virtio-net-*");
+        return false;
+    }
+
+    return true;
+}
+
 static NetClientInfo net_vhost_vdpa_info = {
         .type = NET_CLIENT_DRIVER_VHOST_VDPA,
         .size = sizeof(VhostVDPAState),
         .cleanup = vhost_vdpa_cleanup,
         .has_vnet_hdr = vhost_vdpa_has_vnet_hdr,
         .has_ufo = vhost_vdpa_has_ufo,
+        .check_peer_type = vhost_vdpa_check_peer_type,
 };
 
 static int net_vhost_vdpa_init(NetClientState *peer, const char *device,
@@ -179,24 +193,6 @@ static int net_vhost_vdpa_init(NetClientState *peer, const char *device,
     return ret;
 }
 
-static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp)
-{
-    const char *name = opaque;
-    const char *driver, *netdev;
-
-    driver = qemu_opt_get(opts, "driver");
-    netdev = qemu_opt_get(opts, "netdev");
-    if (!driver || !netdev) {
-        return 0;
-    }
-    if (strcmp(netdev, name) == 0 &&
-        !g_str_has_prefix(driver, "virtio-net-")) {
-        error_setg(errp, "vhost-vdpa requires frontend driver virtio-net-*");
-        return -1;
-    }
-    return 0;
-}
-
 int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
                         NetClientState *peer, Error **errp)
 {
@@ -204,10 +200,5 @@ int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
 
     assert(netdev->type == NET_CLIENT_DRIVER_VHOST_VDPA);
     opts = &netdev->u.vhost_vdpa;
-    /* verify net frontend */
-    if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net,
-                          (char *)name, errp)) {
-        return -1;
-    }
     return net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name, opts->vhostdev);
 }
diff --git a/qapi/qdev.json b/qapi/qdev.json
index d75e68908b..69656b14df 100644
--- a/qapi/qdev.json
+++ b/qapi/qdev.json
@@ -32,17 +32,23 @@
 ##
 # @device_add:
 #
+# Add a device.
+#
 # @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
 #
-# Additional arguments depend on the type.
-#
-# Add a device.
+# Features:
+# @json-cli: If present, the "-device" command line option supports JSON
+#            syntax with a structure identical to the arguments of this
+#            command.
 #
 # Notes:
+#
+# Additional arguments depend on the type.
+#
 # 1. For detailed information about this command, please refer to the
 #    'docs/qdev-device-use.txt' file.
 #
@@ -67,7 +73,8 @@
 ##
 { 'command': 'device_add',
   'data': {'driver': 'str', '*bus': 'str', '*id': 'str'},
-  'gen': false } # so we can get the additional arguments
+  'gen': false, # so we can get the additional arguments
+  'features': ['json-cli'] }
 
 ##
 # @device_del:
diff --git a/qom/object.c b/qom/object.c
index e86cb05b84..6be710bc40 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -1389,7 +1389,7 @@ bool object_property_get(Object *obj, const char *name, Visitor *v,
 bool object_property_set(Object *obj, const char *name, Visitor *v,
                          Error **errp)
 {
-    Error *err = NULL;
+    ERRP_GUARD();
     ObjectProperty *prop = object_property_find_err(obj, name, errp);
 
     if (prop == NULL) {
@@ -1400,9 +1400,8 @@ bool object_property_set(Object *obj, const char *name, Visitor *v,
         error_setg(errp, QERR_PERMISSION_DENIED);
         return false;
     }
-    prop->set(obj, v, name, prop->opaque, &err);
-    error_propagate(errp, err);
-    return !err;
+    prop->set(obj, v, name, prop->opaque, errp);
+    return !*errp;
 }
 
 bool object_property_set_str(Object *obj, const char *name,
diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c
index ad9b56b59a..3b61c195c5 100644
--- a/qom/object_interfaces.c
+++ b/qom/object_interfaces.c
@@ -46,25 +46,18 @@ static void object_set_properties_from_qdict(Object *obj, const QDict *qdict,
                                              Visitor *v, Error **errp)
 {
     const QDictEntry *e;
-    Error *local_err = NULL;
 
-    if (!visit_start_struct(v, NULL, NULL, 0, &local_err)) {
-        goto out;
+    if (!visit_start_struct(v, NULL, NULL, 0, errp)) {
+        return;
     }
     for (e = qdict_first(qdict); e; e = qdict_next(qdict, e)) {
-        if (!object_property_set(obj, e->key, v, &local_err)) {
-            break;
+        if (!object_property_set(obj, e->key, v, errp)) {
+            goto out;
         }
     }
-    if (!local_err) {
-        visit_check_struct(v, &local_err);
-    }
-    visit_end_struct(v, NULL);
-
+    visit_check_struct(v, errp);
 out:
-    if (local_err) {
-        error_propagate(errp, local_err);
-    }
+    visit_end_struct(v, NULL);
 }
 
 void object_set_properties_from_keyval(Object *obj, const QDict *qdict,
diff --git a/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c
index 3df99ce9fc..89c473cb22 100644
--- a/softmmu/qdev-monitor.c
+++ b/softmmu/qdev-monitor.c
@@ -28,6 +28,8 @@
 #include "qapi/qmp/dispatch.h"
 #include "qapi/qmp/qdict.h"
 #include "qapi/qmp/qerror.h"
+#include "qapi/qmp/qstring.h"
+#include "qapi/qobject-input-visitor.h"
 #include "qemu/config-file.h"
 #include "qemu/error-report.h"
 #include "qemu/help_option.h"
@@ -194,22 +196,6 @@ static void qdev_print_devinfos(bool show_no_user)
     g_slist_free(list);
 }
 
-static int set_property(void *opaque, const char *name, const char *value,
-                        Error **errp)
-{
-    Object *obj = opaque;
-
-    if (strcmp(name, "driver") == 0)
-        return 0;
-    if (strcmp(name, "bus") == 0)
-        return 0;
-
-    if (!object_property_parse(obj, name, value, errp)) {
-        return -1;
-    }
-    return 0;
-}
-
 static const char *find_typename_by_alias(const char *alias)
 {
     int i;
@@ -578,32 +564,49 @@ static BusState *qbus_find(const char *path, Error **errp)
     return bus;
 }
 
-void qdev_set_id(DeviceState *dev, const char *id)
+/* Takes ownership of @id, will be freed when deleting the device */
+const char *qdev_set_id(DeviceState *dev, char *id, Error **errp)
 {
-    if (id) {
-        dev->id = id;
-    }
+    ObjectProperty *prop;
+
+    assert(!dev->id && !dev->realized);
 
-    if (dev->id) {
-        object_property_add_child(qdev_get_peripheral(), dev->id,
-                                  OBJECT(dev));
+    /*
+     * object_property_[try_]add_child() below will assert the device
+     * has no parent
+     */
+    if (id) {
+        prop = object_property_try_add_child(qdev_get_peripheral(), id,
+                                             OBJECT(dev), NULL);
+        if (prop) {
+            dev->id = id;
+        } else {
+            g_free(id);
+            error_setg(errp, "Duplicate device ID '%s'", id);
+            return NULL;
+        }
     } else {
         static int anon_count;
         gchar *name = g_strdup_printf("device[%d]", anon_count++);
-        object_property_add_child(qdev_get_peripheral_anon(), name,
-                                  OBJECT(dev));
+        prop = object_property_add_child(qdev_get_peripheral_anon(), name,
+                                         OBJECT(dev));
         g_free(name);
     }
+
+    return prop->name;
 }
 
-DeviceState *qdev_device_add(QemuOpts *opts, Error **errp)
+DeviceState *qdev_device_add_from_qdict(const QDict *opts,
+                                        bool from_json, Error **errp)
 {
+    ERRP_GUARD();
     DeviceClass *dc;
     const char *driver, *path;
+    char *id;
     DeviceState *dev = NULL;
     BusState *bus = NULL;
 
-    driver = qemu_opt_get(opts, "driver");
+    driver = qdict_get_try_str(opts, "driver");
     if (!driver) {
         error_setg(errp, QERR_MISSING_PARAMETER, "driver");
         return NULL;
@@ -616,7 +619,7 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp)
     }
 
     /* find bus */
-    path = qemu_opt_get(opts, "bus");
+    path = qdict_get_try_str(opts, "bus");
     if (path != NULL) {
         bus = qbus_find(path, errp);
         if (!bus) {
@@ -636,16 +639,18 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp)
         }
     }
 
-    if (qemu_opt_get(opts, "failover_pair_id")) {
-        if (!opts->id) {
+    if (qdict_haskey(opts, "failover_pair_id")) {
+        if (!qdict_haskey(opts, "id")) {
             error_setg(errp, "Device with failover_pair_id don't have id");
             return NULL;
         }
-        if (qdev_should_hide_device(opts)) {
+        if (qdev_should_hide_device(opts, from_json, errp)) {
             if (bus && !qbus_is_hotpluggable(bus)) {
                 error_setg(errp, QERR_BUS_NO_HOTPLUG, bus->name);
             }
             return NULL;
+        } else if (*errp) {
+            return NULL;
         }
     }
 
@@ -676,16 +681,28 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp)
         }
     }
 
-    qdev_set_id(dev, qemu_opts_id(opts));
+    /*
+     * set dev's parent and register its id.
+     * If it fails it means the id is already taken.
+     */
+    id = g_strdup(qdict_get_try_str(opts, "id"));
+    if (!qdev_set_id(dev, id, errp)) {
+        goto err_del_dev;
+    }
 
     /* set properties */
-    if (qemu_opt_foreach(opts, set_property, dev, errp)) {
+    dev->opts = qdict_clone_shallow(opts);
+    qdict_del(dev->opts, "driver");
+    qdict_del(dev->opts, "bus");
+    qdict_del(dev->opts, "id");
+
+    object_set_properties_from_keyval(&dev->parent_obj, dev->opts, from_json,
+                                      errp);
+    if (*errp) {
         goto err_del_dev;
     }
 
-    dev->opts = opts;
     if (!qdev_realize(DEVICE(dev), bus, errp)) {
-        dev->opts = NULL;
         goto err_del_dev;
     }
     return dev;
@@ -698,6 +715,19 @@ err_del_dev:
     return NULL;
 }
 
+/* Takes ownership of @opts on success */
+DeviceState *qdev_device_add(QemuOpts *opts, Error **errp)
+{
+    QDict *qdict = qemu_opts_to_qdict(opts, NULL);
+    DeviceState *ret;
+
+    ret = qdev_device_add_from_qdict(qdict, false, errp);
+    if (ret) {
+        qemu_opts_del(opts);
+    }
+    qobject_unref(qdict);
+    return ret;
+}
 
 #define qdev_printf(fmt, ...) monitor_printf(mon, "%*s" fmt, indent, "", ## __VA_ARGS__)
 static void qbus_print(Monitor *mon, BusState *bus, int indent);
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 55ab70eb97..af0c4cbd99 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -144,6 +144,12 @@ typedef struct ObjectOption {
     QTAILQ_ENTRY(ObjectOption) next;
 } ObjectOption;
 
+typedef struct DeviceOption {
+    QDict *opts;
+    Location loc;
+    QTAILQ_ENTRY(DeviceOption) next;
+} DeviceOption;
+
 static const char *cpu_option;
 static const char *mem_path;
 static const char *incoming;
@@ -151,6 +157,7 @@ static const char *loadvm;
 static const char *accelerators;
 static QDict *machine_opts_dict;
 static QTAILQ_HEAD(, ObjectOption) object_opts = QTAILQ_HEAD_INITIALIZER(object_opts);
+static QTAILQ_HEAD(, DeviceOption) device_opts = QTAILQ_HEAD_INITIALIZER(device_opts);
 static ram_addr_t maxram_size;
 static uint64_t ram_slots;
 static int display_remote;
@@ -494,21 +501,39 @@ const char *qemu_get_vm_name(void)
     return qemu_name;
 }
 
-static int default_driver_check(void *opaque, QemuOpts *opts, Error **errp)
+static void default_driver_disable(const char *driver)
 {
-    const char *driver = qemu_opt_get(opts, "driver");
     int i;
 
-    if (!driver)
-        return 0;
+    if (!driver) {
+        return;
+    }
+
     for (i = 0; i < ARRAY_SIZE(default_list); i++) {
         if (strcmp(default_list[i].driver, driver) != 0)
             continue;
         *(default_list[i].flag) = 0;
     }
+}
+
+static int default_driver_check(void *opaque, QemuOpts *opts, Error **errp)
+{
+    const char *driver = qemu_opt_get(opts, "driver");
+
+    default_driver_disable(driver);
     return 0;
 }
 
+static void default_driver_check_json(void)
+{
+    DeviceOption *opt;
+
+    QTAILQ_FOREACH(opt, &device_opts, next) {
+        const char *driver = qdict_get_try_str(opt->opts, "driver");
+        default_driver_disable(driver);
+    }
+}
+
 static int parse_name(void *opaque, QemuOpts *opts, Error **errp)
 {
     const char *proc_name;
@@ -1311,6 +1336,7 @@ static void qemu_disable_default_devices(void)
 {
     MachineClass *machine_class = MACHINE_GET_CLASS(current_machine);
 
+    default_driver_check_json();
     qemu_opts_foreach(qemu_find_opts("device"),
                       default_driver_check, NULL, NULL);
     qemu_opts_foreach(qemu_find_opts("global"),
@@ -2637,6 +2663,8 @@ static void qemu_init_board(void)
 
 static void qemu_create_cli_devices(void)
 {
+    DeviceOption *opt;
+
     soundhw_init();
 
     qemu_opts_foreach(qemu_find_opts("fw_cfg"),
@@ -2652,6 +2680,18 @@ static void qemu_create_cli_devices(void)
     rom_set_order_override(FW_CFG_ORDER_OVERRIDE_DEVICE);
     qemu_opts_foreach(qemu_find_opts("device"),
                       device_init_func, NULL, &error_fatal);
+    QTAILQ_FOREACH(opt, &device_opts, next) {
+        loc_push_restore(&opt->loc);
+        /*
+         * TODO Eventually we should call qmp_device_add() here to make sure it
+         * behaves the same, but QMP still has to accept incorrectly typed
+         * options until libvirt is fixed and we want to be strict on the CLI
+         * from the start, so call qdev_device_add_from_qdict() directly for
+         * now.
+         */
+        qdev_device_add_from_qdict(opt->opts, true, &error_fatal);
+        loc_pop(&opt->loc);
+    }
     rom_reset_order_override();
 }
 
@@ -3352,9 +3392,18 @@ void qemu_init(int argc, char **argv, char **envp)
                 add_device_config(DEV_USB, optarg);
                 break;
             case QEMU_OPTION_device:
-                if (!qemu_opts_parse_noisily(qemu_find_opts("device"),
-                                             optarg, true)) {
-                    exit(1);
+                if (optarg[0] == '{') {
+                    QObject *obj = qobject_from_json(optarg, &error_fatal);
+                    DeviceOption *opt = g_new0(DeviceOption, 1);
+                    opt->opts = qobject_to(QDict, obj);
+                    loc_save(&opt->loc);
+                    assert(opt->opts != NULL);
+                    QTAILQ_INSERT_TAIL(&device_opts, opt, next);
+                } else {
+                    if (!qemu_opts_parse_noisily(qemu_find_opts("device"),
+                                                 optarg, true)) {
+                        exit(1);
+                    }
                 }
                 break;
             case QEMU_OPTION_smp:
diff --git a/tests/qemu-iotests/051 b/tests/qemu-iotests/051
index 7bf29343d7..1d2fa93a11 100755
--- a/tests/qemu-iotests/051
+++ b/tests/qemu-iotests/051
@@ -199,7 +199,7 @@ case "$QEMU_DEFAULT_MACHINE" in
         # virtio-blk enables the iothread only when the driver initialises the
         # device, so a second virtio-blk device can't be added even with the
         # same iothread. virtio-scsi allows this.
-        run_qemu $iothread -device virtio-blk-pci,drive=disk,iothread=iothread0,share-rw=on
+        run_qemu $iothread -device virtio-blk-pci,drive=disk,iothread=thread0,share-rw=on
         run_qemu $iothread -device virtio-scsi,id=virtio-scsi1,iothread=thread0 -device scsi-hd,bus=virtio-scsi1.0,drive=disk,share-rw=on
         ;;
      *)
diff --git a/tests/qemu-iotests/051.pc.out b/tests/qemu-iotests/051.pc.out
index afe7632964..063e4fc584 100644
--- a/tests/qemu-iotests/051.pc.out
+++ b/tests/qemu-iotests/051.pc.out
@@ -183,9 +183,9 @@ Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) QEMU_PROG: -device scsi-hd,bus=virtio-scsi1.0,drive=disk,share-rw=on: Cannot change iothread of active block backend
 
-Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device virtio-blk-pci,drive=disk,iothread=iothread0,share-rw=on
+Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device virtio-blk-pci,drive=disk,iothread=thread0,share-rw=on
 QEMU X.Y.Z monitor - type 'help' for more information
-(qemu) QEMU_PROG: -device virtio-blk-pci,drive=disk,iothread=iothread0,share-rw=on: Cannot change iothread of active block backend
+(qemu) QEMU_PROG: -device virtio-blk-pci,drive=disk,iothread=thread0,share-rw=on: Cannot change iothread of active block backend
 
 Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device virtio-scsi,id=virtio-scsi1,iothread=thread0 -device scsi-hd,bus=virtio-scsi1.0,drive=disk,share-rw=on
 QEMU X.Y.Z monitor - type 'help' for more information
diff --git a/tests/qemu-iotests/245 b/tests/qemu-iotests/245
index bf8261eec0..9b12b42eed 100755
--- a/tests/qemu-iotests/245
+++ b/tests/qemu-iotests/245
@@ -1189,10 +1189,10 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.run_test_iothreads('iothread0', 'iothread0')
 
     def test_iothreads_switch_backing(self):
-        self.run_test_iothreads('iothread0', None)
+        self.run_test_iothreads('iothread0', '')
 
     def test_iothreads_switch_overlay(self):
-        self.run_test_iothreads(None, 'iothread0')
+        self.run_test_iothreads('', 'iothread0')
 
 if __name__ == '__main__':
     iotests.activate_logging()
diff --git a/util/qemu-option.c b/util/qemu-option.c
index 61cb4a97bd..eedd08929b 100644
--- a/util/qemu-option.c
+++ b/util/qemu-option.c
@@ -1126,11 +1126,11 @@ int qemu_opts_foreach(QemuOptsList *list, qemu_opts_loopfunc func,
                       void *opaque, Error **errp)
 {
     Location loc;
-    QemuOpts *opts;
+    QemuOpts *opts, *next;
     int rc = 0;
 
     loc_push_none(&loc);
-    QTAILQ_FOREACH(opts, &list->head, next) {
+    QTAILQ_FOREACH_SAFE(opts, &list->head, next, next) {
         loc_restore(&opts->loc);
         rc = func(opaque, opts, errp);
         if (rc) {