[PATCH v2 14/15] qdev: Base object creation on QDict rather than QemuOpts

Kevin Wolf posted 15 patches 1 month, 2 weeks ago

[PATCH v2 14/15] qdev: Base object creation on QDict rather than QemuOpts

Posted by Kevin Wolf 1 month, 2 weeks ago
QDicts are both what QMP natively uses and what the keyval parser
produces. Going through QemuOpts isn't useful for either one, so switch
the main device creation function to QDicts. By sharing more code with
the -object/object-add code path, we can even reduce the code size a
bit.

This commit doesn't remove the detour through QemuOpts from any code
path yet, but it allows the following commits to do so.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/hw/qdev-core.h         | 11 +++---
 include/hw/virtio/virtio-net.h |  3 +-
 include/monitor/qdev.h         |  2 +
 hw/core/qdev.c                 |  7 ++--
 hw/net/virtio-net.c            | 23 +++++++-----
 hw/vfio/pci.c                  |  4 +-
 softmmu/qdev-monitor.c         | 69 +++++++++++++++-------------------
 7 files changed, 60 insertions(+), 59 deletions(-)

diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index 74d8b614a7..910042c650 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -180,7 +180,7 @@ struct DeviceState {
     char *canonical_path;
     bool realized;
     bool pending_deleted_event;
-    QemuOpts *opts;
+    QDict *opts;
     int hotplugged;
     bool allow_unplug_during_migration;
     BusState *parent_bus;
@@ -205,8 +205,8 @@ struct DeviceListener {
      * On errors, it returns false and errp is set. Device creation
      * should fail in this case.
      */
-    bool (*hide_device)(DeviceListener *listener, QemuOpts *device_opts,
-                        Error **errp);
+    bool (*hide_device)(DeviceListener *listener, const QDict *device_opts,
+                        bool from_json, Error **errp);
     QTAILQ_ENTRY(DeviceListener) link;
 };
 
@@ -835,13 +835,14 @@ 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
  *
  * 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, Error **errp);
+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 d118c95f69..74a10ebe85 100644
--- a/include/hw/virtio/virtio-net.h
+++ b/include/hw/virtio/virtio-net.h
@@ -209,7 +209,8 @@ struct VirtIONet {
     bool failover_primary_hidden;
     bool failover;
     DeviceListener primary_listener;
-    QemuOpts *primary_opts;
+    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 74e6c55a2b..1d57bf6577 100644
--- a/include/monitor/qdev.h
+++ b/include/monitor/qdev.h
@@ -9,6 +9,8 @@ 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);
+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.
diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index c3a021c444..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 +212,14 @@ void device_listener_unregister(DeviceListener *listener)
     QTAILQ_REMOVE(&device_listeners, listener, link);
 }
 
-bool qdev_should_hide_device(QemuOpts *opts, Error **errp)
+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, errp)) {
+            if (listener->hide_device(listener, opts, from_json, errp)) {
                 return true;
             } else if (*errp) {
                 return false;
@@ -958,7 +959,7 @@ static void device_finalize(Object *obj)
         dev->canonical_path = NULL;
     }
 
-    qemu_opts_del(dev->opts);
+    qobject_unref(dev->opts);
     g_free(dev->id);
 }
 
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index f503f28c00..09e173a558 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -858,9 +858,11 @@ static void failover_add_primary(VirtIONet *n, Error **errp)
         return;
     }
 
-    dev = qdev_device_add(n->primary_opts, &err);
+    dev = qdev_device_add_from_qdict(n->primary_opts,
+                                     n->primary_opts_from_json,
+                                     &err);
     if (err) {
-        qemu_opts_del(n->primary_opts);
+        qobject_unref(n->primary_opts);
         n->primary_opts = NULL;
     } else {
         object_unref(OBJECT(dev));
@@ -3287,7 +3289,9 @@ static void virtio_net_migration_state_notifier(Notifier *notifier, void *data)
 }
 
 static bool failover_hide_primary_device(DeviceListener *listener,
-                                         QemuOpts *device_opts, Error **errp)
+                                         const QDict *device_opts,
+                                         bool from_json,
+                                         Error **errp)
 {
     VirtIONet *n = container_of(listener, VirtIONet, primary_listener);
     const char *standby_id;
@@ -3295,7 +3299,7 @@ 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;
     }
@@ -3306,12 +3310,8 @@ static bool failover_hide_primary_device(DeviceListener *listener,
         return false;
     }
 
-    /*
-     * Having a weak reference here should be okay because a device can't be
-     * deleted while it's hidden. This will be replaced soon with a QDict that
-     * has a clearer ownership model.
-     */
-    n->primary_opts = device_opts;
+    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);
@@ -3502,8 +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/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/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c
index ccc3c11563..90882f1571 100644
--- a/softmmu/qdev-monitor.c
+++ b/softmmu/qdev-monitor.c
@@ -196,34 +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;
-    QString *val;
-    Visitor *v;
-    int ret;
-
-    if (strcmp(name, "driver") == 0)
-        return 0;
-    if (strcmp(name, "bus") == 0)
-        return 0;
-
-    val = qstring_from_str(value);
-    v = qobject_input_visitor_new_keyval(QOBJECT(val));
-
-    if (!object_property_set(obj, name, v, errp)) {
-        ret = -1;
-        goto out;
-    }
-
-    ret = 0;
-out:
-    visit_free(v);
-    qobject_unref(val);
-    return ret;
-}
-
 static const char *find_typename_by_alias(const char *alias)
 {
     int i;
@@ -623,15 +595,17 @@ const char *qdev_set_id(DeviceState *dev, char *id, Error **errp)
     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;
@@ -644,7 +618,7 @@ 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) {
@@ -664,12 +638,12 @@ 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, errp)) {
+        if (qdev_should_hide_device(opts, from_json, errp)) {
             if (bus && !qbus_is_hotpluggable(bus)) {
                 error_setg(errp, QERR_BUS_NO_HOTPLUG, bus->name);
             }
@@ -710,18 +684,24 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp)
      * set dev's parent and register its id.
      * If it fails it means the id is already taken.
      */
-    if (!qdev_set_id(dev, g_strdup(qemu_opts_id(opts)), errp)) {
+    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;
@@ -734,6 +714,19 @@ 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);
-- 
2.31.1

Re: [PATCH v2 14/15] qdev: Base object creation on QDict rather than QemuOpts

Posted by Laurent Vivier 1 month, 2 weeks ago
On 08/10/2021 15:34, Kevin Wolf wrote:
> QDicts are both what QMP natively uses and what the keyval parser
> produces. Going through QemuOpts isn't useful for either one, so switch
> the main device creation function to QDicts. By sharing more code with
> the -object/object-add code path, we can even reduce the code size a
> bit.
> 
> This commit doesn't remove the detour through QemuOpts from any code
> path yet, but it allows the following commits to do so.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>   include/hw/qdev-core.h         | 11 +++---
>   include/hw/virtio/virtio-net.h |  3 +-
>   include/monitor/qdev.h         |  2 +
>   hw/core/qdev.c                 |  7 ++--
>   hw/net/virtio-net.c            | 23 +++++++-----
>   hw/vfio/pci.c                  |  4 +-
>   softmmu/qdev-monitor.c         | 69 +++++++++++++++-------------------
>   7 files changed, 60 insertions(+), 59 deletions(-)
> 
> diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> index 74d8b614a7..910042c650 100644
> --- a/include/hw/qdev-core.h
> +++ b/include/hw/qdev-core.h
> @@ -180,7 +180,7 @@ struct DeviceState {
>       char *canonical_path;
>       bool realized;
>       bool pending_deleted_event;
> -    QemuOpts *opts;
> +    QDict *opts;
>       int hotplugged;
>       bool allow_unplug_during_migration;
>       BusState *parent_bus;
> @@ -205,8 +205,8 @@ struct DeviceListener {
>        * On errors, it returns false and errp is set. Device creation
>        * should fail in this case.
>        */
> -    bool (*hide_device)(DeviceListener *listener, QemuOpts *device_opts,
> -                        Error **errp);
> +    bool (*hide_device)(DeviceListener *listener, const QDict *device_opts,
> +                        bool from_json, Error **errp);
>       QTAILQ_ENTRY(DeviceListener) link;
>   };
>   
> @@ -835,13 +835,14 @@ 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

Add the errp here too:

     * @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, Error **errp);
> +bool qdev_should_hide_device(const QDict *opts, bool from_json, Error **errp);
>   
>   typedef enum MachineInitPhase {
>       /* current_machine is NULL.  */

Thank you to have added the errp pointer in the hide_device helpers, it helps in my series.

Laurent