[PATCH v6 11/11] xen: introduce ERRP_AUTO_PROPAGATE

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_AUTO_PROPAGATE macro.
Otherwise, this info will not be added when errp == &error_fatal
(the program will exit prior to the error_append_hint() or
error_prepend() call).  Fix such cases.

If we want to check error after errp-function call, we need to
introduce local_err and then propagate it to errp. Instead, use
ERRP_AUTO_PROPAGATE macro, benefits are:
1. No need of explicit error_propagate call
2. No need of explicit local_err variable: use errp directly
3. ERRP_AUTO_PROPAGATE leaves errp as is if it's not NULL or
   &error_fatal, this means that we don't break error_abort
   (we'll abort on error_set, not on error_propagate)

This commit is generated by command

    sed -n '/^X86 Xen CPUs$/,/^$/{s/^F: //p}' MAINTAINERS | \
    xargs git ls-files | grep '\.[hc]$' | \
    xargs spatch \
        --sp-file scripts/coccinelle/auto-propagated-errp.cocci \
        --macro-file scripts/cocci-macro-file.h \
        --in-place --no-show-diff --max-width 80

Reported-by: Kevin Wolf <kwolf@redhat.com>
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 hw/block/dataplane/xen-block.c |  17 ++---
 hw/block/xen-block.c           | 125 ++++++++++++++-------------------
 hw/pci-host/xen_igd_pt.c       |   7 +-
 hw/xen/xen-backend.c           |   7 +-
 hw/xen/xen-bus.c               | 100 ++++++++++++--------------
 hw/xen/xen-host-pci-device.c   |  27 ++++---
 hw/xen/xen_pt.c                |  25 +++----
 hw/xen/xen_pt_config_init.c    |  20 +++---
 8 files changed, 142 insertions(+), 186 deletions(-)

diff --git a/hw/block/dataplane/xen-block.c b/hw/block/dataplane/xen-block.c
index 3b9caeb2fa..c38e3c3d85 100644
--- a/hw/block/dataplane/xen-block.c
+++ b/hw/block/dataplane/xen-block.c
@@ -727,8 +727,8 @@ void xen_block_dataplane_start(XenBlockDataPlane *dataplane,
                                unsigned int protocol,
                                Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     XenDevice *xendev = dataplane->xendev;
-    Error *local_err = NULL;
     unsigned int ring_size;
     unsigned int i;
 
@@ -764,9 +764,8 @@ void xen_block_dataplane_start(XenBlockDataPlane *dataplane,
     }
 
     xen_device_set_max_grant_refs(xendev, dataplane->nr_ring_ref,
-                                  &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+                                  errp);
+    if (*errp) {
         goto stop;
     }
 
@@ -774,9 +773,8 @@ void xen_block_dataplane_start(XenBlockDataPlane *dataplane,
                                               dataplane->ring_ref,
                                               dataplane->nr_ring_ref,
                                               PROT_READ | PROT_WRITE,
-                                              &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+                                              errp);
+    if (*errp) {
         goto stop;
     }
 
@@ -809,9 +807,8 @@ void xen_block_dataplane_start(XenBlockDataPlane *dataplane,
     dataplane->event_channel =
         xen_device_bind_event_channel(xendev, dataplane->ctx, event_channel,
                                       xen_block_dataplane_event, dataplane,
-                                      &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+                                      errp);
+    if (*errp) {
         goto stop;
     }
 
diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c
index 879fc310a4..70428f5a79 100644
--- a/hw/block/xen-block.c
+++ b/hw/block/xen-block.c
@@ -194,6 +194,7 @@ static const BlockDevOps xen_block_dev_ops = {
 
 static void xen_block_realize(XenDevice *xendev, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
     XenBlockDeviceClass *blockdev_class =
         XEN_BLOCK_DEVICE_GET_CLASS(xendev);
@@ -201,7 +202,6 @@ static void xen_block_realize(XenDevice *xendev, Error **errp)
     XenBlockVdev *vdev = &blockdev->props.vdev;
     BlockConf *conf = &blockdev->props.conf;
     BlockBackend *blk = conf->blk;
-    Error *local_err = NULL;
 
     if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) {
         error_setg(errp, "vdev property not set");
@@ -211,9 +211,8 @@ static void xen_block_realize(XenDevice *xendev, Error **errp)
     trace_xen_block_realize(type, vdev->disk, vdev->partition);
 
     if (blockdev_class->realize) {
-        blockdev_class->realize(blockdev, &local_err);
-        if (local_err) {
-            error_propagate(errp, local_err);
+        blockdev_class->realize(blockdev, errp);
+        if (*errp) {
             return;
         }
     }
@@ -283,8 +282,8 @@ static void xen_block_frontend_changed(XenDevice *xendev,
                                        enum xenbus_state frontend_state,
                                        Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     enum xenbus_state backend_state = xen_device_backend_get_state(xendev);
-    Error *local_err = NULL;
 
     switch (frontend_state) {
     case XenbusStateInitialised:
@@ -293,15 +292,13 @@ static void xen_block_frontend_changed(XenDevice *xendev,
             break;
         }
 
-        xen_block_disconnect(xendev, &local_err);
-        if (local_err) {
-            error_propagate(errp, local_err);
+        xen_block_disconnect(xendev, errp);
+        if (*errp) {
             break;
         }
 
-        xen_block_connect(xendev, &local_err);
-        if (local_err) {
-            error_propagate(errp, local_err);
+        xen_block_connect(xendev, errp);
+        if (*errp) {
             break;
         }
 
@@ -314,9 +311,8 @@ static void xen_block_frontend_changed(XenDevice *xendev,
 
     case XenbusStateClosed:
     case XenbusStateUnknown:
-        xen_block_disconnect(xendev, &local_err);
-        if (local_err) {
-            error_propagate(errp, local_err);
+        xen_block_disconnect(xendev, errp);
+        if (*errp) {
             break;
         }
 
@@ -403,10 +399,10 @@ static int vbd_name_to_disk(const char *name, const char **endp,
 static void xen_block_set_vdev(Object *obj, Visitor *v, const char *name,
                                void *opaque, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     XenBlockVdev *vdev = qdev_get_prop_ptr(dev, prop);
-    Error *local_err = NULL;
     char *str, *p;
     const char *end;
 
@@ -415,9 +411,8 @@ static void xen_block_set_vdev(Object *obj, Visitor *v, const char *name,
         return;
     }
 
-    visit_type_str(v, name, &str, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    visit_type_str(v, name, &str, errp);
+    if (*errp) {
         return;
     }
 
@@ -671,9 +666,9 @@ static void xen_block_blockdev_del(const char *node_name, Error **errp)
 static char *xen_block_blockdev_add(const char *id, QDict *qdict,
                                     Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     const char *driver = qdict_get_try_str(qdict, "driver");
     BlockdevOptions *options = NULL;
-    Error *local_err = NULL;
     char *node_name;
     Visitor *v;
 
@@ -688,18 +683,16 @@ static char *xen_block_blockdev_add(const char *id, QDict *qdict,
     trace_xen_block_blockdev_add(node_name);
 
     v = qobject_input_visitor_new(QOBJECT(qdict));
-    visit_type_BlockdevOptions(v, NULL, &options, &local_err);
+    visit_type_BlockdevOptions(v, NULL, &options, errp);
     visit_free(v);
 
-    if (local_err) {
-        error_propagate(errp, local_err);
+    if (*errp) {
         goto fail;
     }
 
-    qmp_blockdev_add(options, &local_err);
+    qmp_blockdev_add(options, errp);
 
-    if (local_err) {
-        error_propagate(errp, local_err);
+    if (*errp) {
         goto fail;
     }
 
@@ -718,14 +711,12 @@ fail:
 
 static void xen_block_drive_destroy(XenBlockDrive *drive, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     char *node_name = drive->node_name;
 
     if (node_name) {
-        Error *local_err = NULL;
-
-        xen_block_blockdev_del(node_name, &local_err);
-        if (local_err) {
-            error_propagate(errp, local_err);
+        xen_block_blockdev_del(node_name, errp);
+        if (*errp) {
             return;
         }
         g_free(node_name);
@@ -739,6 +730,7 @@ static XenBlockDrive *xen_block_drive_create(const char *id,
                                              const char *device_type,
                                              QDict *opts, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     const char *params = qdict_get_try_str(opts, "params");
     const char *mode = qdict_get_try_str(opts, "mode");
     const char *direct_io_safe = qdict_get_try_str(opts, "direct-io-safe");
@@ -746,7 +738,6 @@ static XenBlockDrive *xen_block_drive_create(const char *id,
     char *driver = NULL;
     char *filename = NULL;
     XenBlockDrive *drive = NULL;
-    Error *local_err = NULL;
     QDict *file_layer;
     QDict *driver_layer;
 
@@ -825,13 +816,12 @@ static XenBlockDrive *xen_block_drive_create(const char *id,
 
     g_assert(!drive->node_name);
     drive->node_name = xen_block_blockdev_add(drive->id, driver_layer,
-                                              &local_err);
+                                              errp);
 
     qobject_unref(driver_layer);
 
 done:
-    if (local_err) {
-        error_propagate(errp, local_err);
+    if (*errp) {
         xen_block_drive_destroy(drive, NULL);
         return NULL;
     }
@@ -856,15 +846,13 @@ static void xen_block_iothread_destroy(XenBlockIOThread *iothread,
 static XenBlockIOThread *xen_block_iothread_create(const char *id,
                                                    Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     XenBlockIOThread *iothread = g_new(XenBlockIOThread, 1);
-    Error *local_err = NULL;
 
     iothread->id = g_strdup(id);
 
-    qmp_object_add(TYPE_IOTHREAD, id, false, NULL, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-
+    qmp_object_add(TYPE_IOTHREAD, id, false, NULL, errp);
+    if (*errp) {
         g_free(iothread->id);
         g_free(iothread);
         return NULL;
@@ -876,6 +864,7 @@ static XenBlockIOThread *xen_block_iothread_create(const char *id,
 static void xen_block_device_create(XenBackendInstance *backend,
                                     QDict *opts, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     XenBus *xenbus = xen_backend_get_bus(backend);
     const char *name = xen_backend_get_name(backend);
     unsigned long number;
@@ -883,7 +872,6 @@ static void xen_block_device_create(XenBackendInstance *backend,
     XenBlockDrive *drive = NULL;
     XenBlockIOThread *iothread = NULL;
     XenDevice *xendev = NULL;
-    Error *local_err = NULL;
     const char *type;
     XenBlockDevice *blockdev;
 
@@ -915,52 +903,48 @@ static void xen_block_device_create(XenBackendInstance *backend,
         goto fail;
     }
 
-    drive = xen_block_drive_create(vdev, device_type, opts, &local_err);
+    drive = xen_block_drive_create(vdev, device_type, opts, errp);
     if (!drive) {
-        error_propagate_prepend(errp, local_err, "failed to create drive: ");
+        error_prepend(errp, "failed to create drive: ");
         goto fail;
     }
 
-    iothread = xen_block_iothread_create(vdev, &local_err);
-    if (local_err) {
-        error_propagate_prepend(errp, local_err,
-                                "failed to create iothread: ");
+    iothread = xen_block_iothread_create(vdev, errp);
+    if (*errp) {
+        error_prepend(errp, "failed to create iothread: ");
         goto fail;
     }
 
     xendev = XEN_DEVICE(qdev_create(BUS(xenbus), type));
     blockdev = XEN_BLOCK_DEVICE(xendev);
 
-    object_property_set_str(OBJECT(xendev), vdev, "vdev", &local_err);
-    if (local_err) {
-        error_propagate_prepend(errp, local_err, "failed to set 'vdev': ");
+    object_property_set_str(OBJECT(xendev), vdev, "vdev", errp);
+    if (*errp) {
+        error_prepend(errp, "failed to set 'vdev': ");
         goto fail;
     }
 
     object_property_set_str(OBJECT(xendev),
                             xen_block_drive_get_node_name(drive), "drive",
-                            &local_err);
-    if (local_err) {
-        error_propagate_prepend(errp, local_err, "failed to set 'drive': ");
+                            errp);
+    if (*errp) {
+        error_prepend(errp, "failed to set 'drive': ");
         goto fail;
     }
 
     object_property_set_str(OBJECT(xendev), iothread->id, "iothread",
-                            &local_err);
-    if (local_err) {
-        error_propagate_prepend(errp, local_err,
-                                "failed to set 'iothread': ");
+                            errp);
+    if (*errp) {
+        error_prepend(errp, "failed to set 'iothread': ");
         goto fail;
     }
 
     blockdev->iothread = iothread;
     blockdev->drive = drive;
 
-    object_property_set_bool(OBJECT(xendev), true, "realized", &local_err);
-    if (local_err) {
-        error_propagate_prepend(errp, local_err,
-                                "realization of device %s failed: ",
-                                type);
+    object_property_set_bool(OBJECT(xendev), true, "realized", errp);
+    if (*errp) {
+        error_prepend(errp, "realization of device %s failed: ", type);
         goto fail;
     }
 
@@ -984,6 +968,7 @@ fail:
 static void xen_block_device_destroy(XenBackendInstance *backend,
                                      Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     XenDevice *xendev = xen_backend_get_device(backend);
     XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
     XenBlockVdev *vdev = &blockdev->props.vdev;
@@ -995,23 +980,17 @@ static void xen_block_device_destroy(XenBackendInstance *backend,
     object_unparent(OBJECT(xendev));
 
     if (iothread) {
-        Error *local_err = NULL;
-
-        xen_block_iothread_destroy(iothread, &local_err);
-        if (local_err) {
-            error_propagate_prepend(errp, local_err,
-                                "failed to destroy iothread: ");
+        xen_block_iothread_destroy(iothread, errp);
+        if (*errp) {
+            error_prepend(errp, "failed to destroy iothread: ");
             return;
         }
     }
 
     if (drive) {
-        Error *local_err = NULL;
-
-        xen_block_drive_destroy(drive, &local_err);
-        if (local_err) {
-            error_propagate_prepend(errp, local_err,
-                                "failed to destroy drive: ");
+        xen_block_drive_destroy(drive, errp);
+        if (*errp) {
+            error_prepend(errp, "failed to destroy drive: ");
         }
     }
 }
diff --git a/hw/pci-host/xen_igd_pt.c b/hw/pci-host/xen_igd_pt.c
index efcc9347ff..29ade9ca25 100644
--- a/hw/pci-host/xen_igd_pt.c
+++ b/hw/pci-host/xen_igd_pt.c
@@ -79,17 +79,16 @@ static void host_pci_config_read(int pos, int len, uint32_t *val, Error **errp)
 
 static void igd_pt_i440fx_realize(PCIDevice *pci_dev, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     uint32_t val = 0;
     size_t i;
     int pos, len;
-    Error *local_err = NULL;
 
     for (i = 0; i < ARRAY_SIZE(igd_host_bridge_infos); i++) {
         pos = igd_host_bridge_infos[i].offset;
         len = igd_host_bridge_infos[i].len;
-        host_pci_config_read(pos, len, &val, &local_err);
-        if (local_err) {
-            error_propagate(errp, local_err);
+        host_pci_config_read(pos, len, &val, errp);
+        if (*errp) {
             return;
         }
         pci_default_write_config(pci_dev, pos, val, len);
diff --git a/hw/xen/xen-backend.c b/hw/xen/xen-backend.c
index da065f81b7..1cc0694053 100644
--- a/hw/xen/xen-backend.c
+++ b/hw/xen/xen-backend.c
@@ -98,9 +98,9 @@ static void xen_backend_list_remove(XenBackendInstance *backend)
 void xen_backend_device_create(XenBus *xenbus, const char *type,
                                const char *name, QDict *opts, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     const XenBackendImpl *impl = xen_backend_table_lookup(type);
     XenBackendInstance *backend;
-    Error *local_error = NULL;
 
     if (!impl) {
         return;
@@ -110,9 +110,8 @@ void xen_backend_device_create(XenBus *xenbus, const char *type,
     backend->xenbus = xenbus;
     backend->name = g_strdup(name);
 
-    impl->create(backend, opts, &local_error);
-    if (local_error) {
-        error_propagate(errp, local_error);
+    impl->create(backend, opts, errp);
+    if (*errp) {
         g_free(backend->name);
         g_free(backend);
         return;
diff --git a/hw/xen/xen-bus.c b/hw/xen/xen-bus.c
index c2ad22a42d..270ee31aa5 100644
--- a/hw/xen/xen-bus.c
+++ b/hw/xen/xen-bus.c
@@ -53,9 +53,9 @@ static char *xen_device_get_frontend_path(XenDevice *xendev)
 
 static void xen_device_unplug(XenDevice *xendev, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
     const char *type = object_get_typename(OBJECT(xendev));
-    Error *local_err = NULL;
     xs_transaction_t tid;
 
     trace_xen_device_unplug(type, xendev->name);
@@ -69,14 +69,14 @@ again:
     }
 
     xs_node_printf(xenbus->xsh, tid, xendev->backend_path, "online",
-                   &local_err, "%u", 0);
-    if (local_err) {
+                   errp, "%u", 0);
+    if (*errp) {
         goto abort;
     }
 
     xs_node_printf(xenbus->xsh, tid, xendev->backend_path, "state",
-                   &local_err, "%u", XenbusStateClosing);
-    if (local_err) {
+                   errp, "%u", XenbusStateClosing);
+    if (*errp) {
         goto abort;
     }
 
@@ -96,7 +96,6 @@ abort:
      * from ending the transaction.
      */
     xs_transaction_end(xenbus->xsh, tid, true);
-    error_propagate(errp, local_err);
 }
 
 static void xen_bus_print_dev(Monitor *mon, DeviceState *dev, int indent)
@@ -205,15 +204,13 @@ static XenWatch *watch_list_add(XenWatchList *watch_list, const char *node,
                                 const char *key, XenWatchHandler handler,
                                 void *opaque, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     XenWatch *watch = new_watch(node, key, handler, opaque);
-    Error *local_err = NULL;
 
     notifier_list_add(&watch_list->notifiers, &watch->notifier);
 
-    xs_node_watch(watch_list->xsh, node, key, watch->token, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-
+    xs_node_watch(watch_list->xsh, node, key, watch->token, errp);
+    if (*errp) {
         notifier_remove(&watch->notifier);
         free_watch(watch);
 
@@ -255,11 +252,11 @@ static void xen_bus_backend_create(XenBus *xenbus, const char *type,
                                    const char *name, char *path,
                                    Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     xs_transaction_t tid;
     char **key;
     QDict *opts;
     unsigned int i, n;
-    Error *local_err = NULL;
 
     trace_xen_bus_backend_create(type, path);
 
@@ -314,13 +311,11 @@ again:
         return;
     }
 
-    xen_backend_device_create(xenbus, type, name, opts, &local_err);
+    xen_backend_device_create(xenbus, type, name, opts, errp);
     qobject_unref(opts);
 
-    if (local_err) {
-        error_propagate_prepend(errp, local_err,
-                                "failed to create '%s' device '%s': ",
-                                type, name);
+    if (*errp) {
+        error_prepend(errp, "failed to create '%s' device '%s': ", type, name);
     }
 }
 
@@ -451,9 +446,9 @@ static void xen_bus_unrealize(BusState *bus, Error **errp)
 
 static void xen_bus_realize(BusState *bus, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     XenBus *xenbus = XEN_BUS(bus);
     unsigned int domid;
-    Error *local_err = NULL;
 
     trace_xen_bus_realize();
 
@@ -476,10 +471,10 @@ static void xen_bus_realize(BusState *bus, Error **errp)
 
     xenbus->backend_watch =
         xen_bus_add_watch(xenbus, "", /* domain root node */
-                          "backend", xen_bus_backend_changed, &local_err);
-    if (local_err) {
+                          "backend", xen_bus_backend_changed, errp);
+    if (*errp) {
         /* This need not be treated as a hard error so don't propagate */
-        error_reportf_err(local_err,
+        error_reportf_err(*errp,
                           "failed to set up enumeration watch: ");
     }
 
@@ -692,9 +687,9 @@ static void xen_device_remove_watch(XenDevice *xendev, XenWatch *watch,
 
 static void xen_device_backend_create(XenDevice *xendev, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
     struct xs_permissions perms[2];
-    Error *local_err = NULL;
 
     xendev->backend_path = xen_device_get_backend_path(xendev);
 
@@ -706,30 +701,27 @@ static void xen_device_backend_create(XenDevice *xendev, Error **errp)
     g_assert(xenbus->xsh);
 
     xs_node_create(xenbus->xsh, XBT_NULL, xendev->backend_path, perms,
-                   ARRAY_SIZE(perms), &local_err);
-    if (local_err) {
-        error_propagate_prepend(errp, local_err,
-                                "failed to create backend: ");
+                   ARRAY_SIZE(perms), errp);
+    if (*errp) {
+        error_prepend(errp, "failed to create backend: ");
         return;
     }
 
     xendev->backend_state_watch =
         xen_device_add_watch(xendev, xendev->backend_path,
                              "state", xen_device_backend_changed,
-                             &local_err);
-    if (local_err) {
-        error_propagate_prepend(errp, local_err,
-                                "failed to watch backend state: ");
+                             errp);
+    if (*errp) {
+        error_prepend(errp, "failed to watch backend state: ");
         return;
     }
 
     xendev->backend_online_watch =
         xen_device_add_watch(xendev, xendev->backend_path,
                              "online", xen_device_backend_changed,
-                             &local_err);
-    if (local_err) {
-        error_propagate_prepend(errp, local_err,
-                                "failed to watch backend online: ");
+                             errp);
+    if (*errp) {
+        error_prepend(errp, "failed to watch backend online: ");
         return;
     }
 }
@@ -866,9 +858,9 @@ static bool xen_device_frontend_exists(XenDevice *xendev)
 
 static void xen_device_frontend_create(XenDevice *xendev, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
     struct xs_permissions perms[2];
-    Error *local_err = NULL;
 
     xendev->frontend_path = xen_device_get_frontend_path(xendev);
 
@@ -885,20 +877,18 @@ static void xen_device_frontend_create(XenDevice *xendev, Error **errp)
         g_assert(xenbus->xsh);
 
         xs_node_create(xenbus->xsh, XBT_NULL, xendev->frontend_path, perms,
-                       ARRAY_SIZE(perms), &local_err);
-        if (local_err) {
-            error_propagate_prepend(errp, local_err,
-                                    "failed to create frontend: ");
+                       ARRAY_SIZE(perms), errp);
+        if (*errp) {
+            error_prepend(errp, "failed to create frontend: ");
             return;
         }
     }
 
     xendev->frontend_state_watch =
         xen_device_add_watch(xendev, xendev->frontend_path, "state",
-                             xen_device_frontend_changed, &local_err);
-    if (local_err) {
-        error_propagate_prepend(errp, local_err,
-                                "failed to watch frontend state: ");
+                             xen_device_frontend_changed, errp);
+    if (*errp) {
+        error_prepend(errp, "failed to watch frontend state: ");
     }
 }
 
@@ -1228,11 +1218,11 @@ static void xen_device_exit(Notifier *n, void *data)
 
 static void xen_device_realize(DeviceState *dev, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     XenDevice *xendev = XEN_DEVICE(dev);
     XenDeviceClass *xendev_class = XEN_DEVICE_GET_CLASS(xendev);
     XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
     const char *type = object_get_typename(OBJECT(xendev));
-    Error *local_err = NULL;
 
     if (xendev->frontend_id == DOMID_INVALID) {
         xendev->frontend_id = xen_domid;
@@ -1248,10 +1238,9 @@ static void xen_device_realize(DeviceState *dev, Error **errp)
         goto unrealize;
     }
 
-    xendev->name = xendev_class->get_name(xendev, &local_err);
-    if (local_err) {
-        error_propagate_prepend(errp, local_err,
-                                "failed to get device name: ");
+    xendev->name = xendev_class->get_name(xendev, errp);
+    if (*errp) {
+        error_prepend(errp, "failed to get device name: ");
         goto unrealize;
     }
 
@@ -1274,22 +1263,19 @@ static void xen_device_realize(DeviceState *dev, Error **errp)
     xendev->feature_grant_copy =
         (xengnttab_grant_copy(xendev->xgth, 0, NULL) == 0);
 
-    xen_device_backend_create(xendev, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    xen_device_backend_create(xendev, errp);
+    if (*errp) {
         goto unrealize;
     }
 
-    xen_device_frontend_create(xendev, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    xen_device_frontend_create(xendev, errp);
+    if (*errp) {
         goto unrealize;
     }
 
     if (xendev_class->realize) {
-        xendev_class->realize(xendev, &local_err);
-        if (local_err) {
-            error_propagate(errp, local_err);
+        xendev_class->realize(xendev, errp);
+        if (*errp) {
             goto unrealize;
         }
     }
diff --git a/hw/xen/xen-host-pci-device.c b/hw/xen/xen-host-pci-device.c
index 1b44dcafaf..02379c341c 100644
--- a/hw/xen/xen-host-pci-device.c
+++ b/hw/xen/xen-host-pci-device.c
@@ -333,8 +333,8 @@ void xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain,
                              uint8_t bus, uint8_t dev, uint8_t func,
                              Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     unsigned int v;
-    Error *err = NULL;
 
     d->config_fd = -1;
     d->domain = domain;
@@ -342,36 +342,36 @@ void xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain,
     d->dev = dev;
     d->func = func;
 
-    xen_host_pci_config_open(d, &err);
-    if (err) {
+    xen_host_pci_config_open(d, errp);
+    if (*errp) {
         goto error;
     }
 
-    xen_host_pci_get_resource(d, &err);
-    if (err) {
+    xen_host_pci_get_resource(d, errp);
+    if (*errp) {
         goto error;
     }
 
-    xen_host_pci_get_hex_value(d, "vendor", &v, &err);
-    if (err) {
+    xen_host_pci_get_hex_value(d, "vendor", &v, errp);
+    if (*errp) {
         goto error;
     }
     d->vendor_id = v;
 
-    xen_host_pci_get_hex_value(d, "device", &v, &err);
-    if (err) {
+    xen_host_pci_get_hex_value(d, "device", &v, errp);
+    if (*errp) {
         goto error;
     }
     d->device_id = v;
 
-    xen_host_pci_get_dec_value(d, "irq", &v, &err);
-    if (err) {
+    xen_host_pci_get_dec_value(d, "irq", &v, errp);
+    if (*errp) {
         goto error;
     }
     d->irq = v;
 
-    xen_host_pci_get_hex_value(d, "class", &v, &err);
-    if (err) {
+    xen_host_pci_get_hex_value(d, "class", &v, errp);
+    if (*errp) {
         goto error;
     }
     d->class_code = v;
@@ -381,7 +381,6 @@ void xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain,
     return;
 
 error:
-    error_propagate(errp, err);
 
     if (d->config_fd >= 0) {
         close(d->config_fd);
diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c
index 9e767d4244..33b68dfcb8 100644
--- a/hw/xen/xen_pt.c
+++ b/hw/xen/xen_pt.c
@@ -767,12 +767,12 @@ static void xen_pt_destroy(PCIDevice *d) {
 
 static void xen_pt_realize(PCIDevice *d, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     XenPCIPassthroughState *s = XEN_PT_DEVICE(d);
     int i, rc = 0;
     uint8_t machine_irq = 0, scratch;
     uint16_t cmd = 0;
     int pirq = XEN_PT_UNASSIGNED_PIRQ;
-    Error *err = NULL;
 
     /* register real device */
     XEN_PT_LOG(d, "Assigning real physical device %02x:%02x.%d"
@@ -783,10 +783,9 @@ static void xen_pt_realize(PCIDevice *d, Error **errp)
     xen_host_pci_device_get(&s->real_device,
                             s->hostaddr.domain, s->hostaddr.bus,
                             s->hostaddr.slot, s->hostaddr.function,
-                            &err);
-    if (err) {
-        error_append_hint(&err, "Failed to \"open\" the real pci device");
-        error_propagate(errp, err);
+                            errp);
+    if (*errp) {
+        error_append_hint(errp, "Failed to \"open\" the real pci device");
         return;
     }
 
@@ -813,11 +812,10 @@ static void xen_pt_realize(PCIDevice *d, Error **errp)
             return;
         }
 
-        xen_pt_setup_vga(s, &s->real_device, &err);
-        if (err) {
-            error_append_hint(&err, "Setup VGA BIOS of passthrough"
-                    " GFX failed");
-            error_propagate(errp, err);
+        xen_pt_setup_vga(s, &s->real_device, errp);
+        if (*errp) {
+            error_append_hint(errp, "Setup VGA BIOS of passthrough"
+                              " GFX failed");
             xen_host_pci_device_put(&s->real_device);
             return;
         }
@@ -830,10 +828,9 @@ static void xen_pt_realize(PCIDevice *d, Error **errp)
     xen_pt_register_regions(s, &cmd);
 
     /* reinitialize each config register to be emulated */
-    xen_pt_config_init(s, &err);
-    if (err) {
-        error_append_hint(&err, "PCI Config space initialisation failed");
-        error_propagate(errp, err);
+    xen_pt_config_init(s, errp);
+    if (*errp) {
+        error_append_hint(errp, "PCI Config space initialisation failed");
         rc = -1;
         goto err_out;
     }
diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c
index 31ec5add1d..af3fbd1bfb 100644
--- a/hw/xen/xen_pt_config_init.c
+++ b/hw/xen/xen_pt_config_init.c
@@ -2008,8 +2008,8 @@ static void xen_pt_config_reg_init(XenPCIPassthroughState *s,
 
 void xen_pt_config_init(XenPCIPassthroughState *s, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     int i, rc;
-    Error *err = NULL;
 
     QLIST_INIT(&s->reg_grps);
 
@@ -2052,10 +2052,9 @@ void xen_pt_config_init(XenPCIPassthroughState *s, Error **errp)
                                                   reg_grp_offset,
                                                   &reg_grp_entry->size);
             if (rc < 0) {
-                error_setg(&err, "Failed to initialize %d/%zu, type = 0x%x,"
+                error_setg(errp, "Failed to initialize %d/%zu, type = 0x%x,"
                            " rc: %d", i, ARRAY_SIZE(xen_pt_emu_reg_grps),
                            xen_pt_emu_reg_grps[i].grp_type, rc);
-                error_propagate(errp, err);
                 xen_pt_config_delete(s);
                 return;
             }
@@ -2068,13 +2067,14 @@ void xen_pt_config_init(XenPCIPassthroughState *s, Error **errp)
 
                 /* initialize capability register */
                 for (j = 0; regs->size != 0; j++, regs++) {
-                    xen_pt_config_reg_init(s, reg_grp_entry, regs, &err);
-                    if (err) {
-                        error_append_hint(&err, "Failed to init register %d"
-                                " offsets 0x%x in grp_type = 0x%x (%d/%zu)", j,
-                                regs->offset, xen_pt_emu_reg_grps[i].grp_type,
-                                i, ARRAY_SIZE(xen_pt_emu_reg_grps));
-                        error_propagate(errp, err);
+                    xen_pt_config_reg_init(s, reg_grp_entry, regs, errp);
+                    if (*errp) {
+                        error_append_hint(errp, "Failed to init register %d"
+                                          " offsets 0x%x in grp_type = 0x%x (%d/%zu)",
+                                          j,
+                                          regs->offset,
+                                          xen_pt_emu_reg_grps[i].grp_type,
+                                          i, ARRAY_SIZE(xen_pt_emu_reg_grps));
                         xen_pt_config_delete(s);
                         return;
                     }
-- 
2.21.0