Add 'group' properties to 'vfio-pci' device. This allows
to add vfio-pci device using precreated vfio container and group, e.g.

	-object vfio-container,id=ct,fd=5 \
        -object vfio-group,id=grp,fd=6,container=ct \
	-device vfio-pci,host=05:00.0,group=grp

Signed-off-by: Andrey Ryabinin <arbn@yandex-team.com>
---
 hw/vfio/ap.c                  |  2 +-
 hw/vfio/ccw.c                 |  2 +-
 hw/vfio/common.c              | 45 ++++++++++++++++++++---------------
 hw/vfio/pci.c                 | 10 +++++++-
 hw/vfio/platform.c            |  2 +-
 include/hw/vfio/vfio-common.h |  2 +-
 6 files changed, 39 insertions(+), 24 deletions(-)

diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
index e0dd561e85a..2a5c322883b 100644
--- a/hw/vfio/ap.c
+++ b/hw/vfio/ap.c
@@ -81,7 +81,7 @@ static VFIOGroup *vfio_ap_get_group(VFIOAPDevice *vapdev, Error **errp)
 
     g_free(group_path);
 
-    return vfio_get_group(groupid, &address_space_memory, errp);
+    return vfio_get_group(&vapdev->vdev, groupid, &address_space_memory, errp);
 }
 
 static void vfio_ap_realize(DeviceState *dev, Error **errp)
diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
index 0354737666a..500f0f62163 100644
--- a/hw/vfio/ccw.c
+++ b/hw/vfio/ccw.c
@@ -650,7 +650,7 @@ static VFIOGroup *vfio_ccw_get_group(S390CCWDevice *cdev, Error **errp)
         return NULL;
     }
 
-    return vfio_get_group(groupid, &address_space_memory, errp);
+    return vfio_get_group(NULL, groupid, &address_space_memory, errp);
 }
 
 static void vfio_ccw_realize(DeviceState *dev, Error **errp)
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 95722ecf96a..64ace47822d 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -2271,30 +2271,35 @@ static void vfio_disconnect_container(VFIOGroup *group)
     object_unref(OBJECT(container));
 }
 
-VFIOGroup *vfio_get_group(int groupid, AddressSpace *as, Error **errp)
+VFIOGroup *vfio_get_group(VFIODevice *vdev, int groupid, AddressSpace *as, Error **errp)
 {
     VFIOGroup *group;
     struct vfio_group_status status = { .argsz = sizeof(status) };
 
-    QLIST_FOREACH(group, &vfio_group_list, next) {
-        if (group->groupid == groupid) {
-            /* Found it.  Now is it already in the right context? */
-            if (group->container->space->as == as) {
-                return group;
-            } else {
-                error_setg(errp, "group %d used in multiple address spaces",
-                           group->groupid);
-                return NULL;
+    if (!vdev->group) {
+        QLIST_FOREACH(group, &vfio_group_list, next) {
+            if (group->groupid == groupid) {
+                /* Found it.  Now is it already in the right context? */
+                if (group->container->space->as == as) {
+                    return group;
+                } else {
+                    error_setg(errp, "group %d used in multiple address spaces",
+                               group->groupid);
+                    return NULL;
+                }
             }
         }
-    }
-
-    group = VFIO_GROUP(object_new(TYPE_VFIO_GROUP));
-    object_property_set_int(OBJECT(group), "groupid", groupid, errp);
-    user_creatable_complete(USER_CREATABLE(group), errp);
-    if (*errp) {
-        object_unref(OBJECT(group));
-        return NULL;
+        group = VFIO_GROUP(object_new(TYPE_VFIO_GROUP));
+        object_property_set_int(OBJECT(group), "groupid", groupid, errp);
+        user_creatable_complete(USER_CREATABLE(group), errp);
+        if (*errp) {
+            object_unref(OBJECT(group));
+            return NULL;
+        }
+    } else {
+        group = vdev->group;
+        group->groupid = groupid;
+        object_ref(OBJECT(group));
     }
 
     if (vfio_connect_container(group, as, errp)) {
@@ -2388,7 +2393,9 @@ void vfio_put_base_device(VFIODevice *vbasedev)
     if (!vbasedev->group) {
         return;
     }
-    QLIST_REMOVE(vbasedev, next);
+    if (!QLIST_EMPTY(&vbasedev->group->device_list)) {
+            QLIST_REMOVE(vbasedev, next);
+    }
     vbasedev->group = NULL;
     trace_vfio_put_base_device(vbasedev->fd);
     close(vbasedev->fd);
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 939dcc3d4a9..d671eb74881 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -29,6 +29,7 @@
 #include "hw/qdev-properties.h"
 #include "hw/qdev-properties-system.h"
 #include "migration/vmstate.h"
+#include "monitor/monitor.h"
 #include "qapi/qmp/qdict.h"
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
@@ -2902,7 +2903,8 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
 
     trace_vfio_realize(vbasedev->name, groupid);
 
-    group = vfio_get_group(groupid, pci_device_iommu_address_space(pdev), errp);
+    group = vfio_get_group(&vdev->vbasedev, groupid,
+                           pci_device_iommu_address_space(pdev), errp);
     if (!group) {
         goto error;
     }
@@ -3190,6 +3192,7 @@ static void vfio_instance_finalize(Object *obj)
 static void vfio_exitfn(PCIDevice *pdev)
 {
     VFIOPCIDevice *vdev = VFIO_PCI(pdev);
+    VFIOGroup *group = vdev->vbasedev.group;
 
     vfio_unregister_req_notifier(vdev);
     vfio_unregister_err_notifier(vdev);
@@ -3204,6 +3207,8 @@ static void vfio_exitfn(PCIDevice *pdev)
     vfio_teardown_msi(vdev);
     vfio_bars_exit(vdev);
     vfio_migration_finalize(&vdev->vbasedev);
+
+    vfio_put_group(group);
 }
 
 static void vfio_pci_reset(DeviceState *dev)
@@ -3330,6 +3335,9 @@ static void vfio_pci_dev_class_init(ObjectClass *klass, void *data)
     pdc->exit = vfio_exitfn;
     pdc->config_read = vfio_pci_read_config;
     pdc->config_write = vfio_pci_write_config;
+    object_class_property_add_link(klass, "group", TYPE_VFIO_GROUP,
+                                   offsetof(VFIOPCIDevice, vbasedev.group),
+                                   object_property_allow_set_link, 0);
 }
 
 static const TypeInfo vfio_pci_dev_info = {
diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
index 5af73f92876..3a72e085026 100644
--- a/hw/vfio/platform.c
+++ b/hw/vfio/platform.c
@@ -577,7 +577,7 @@ static int vfio_base_device_init(VFIODevice *vbasedev, Error **errp)
 
     trace_vfio_platform_base_device_init(vbasedev->name, groupid);
 
-    group = vfio_get_group(groupid, &address_space_memory, errp);
+    group = vfio_get_group(vbasedev, groupid, &address_space_memory, errp);
     if (!group) {
         return -ENOENT;
     }
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index f2d67093f44..79b43eb76b3 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -216,7 +216,7 @@ void vfio_region_unmap(VFIORegion *region);
 void vfio_region_exit(VFIORegion *region);
 void vfio_region_finalize(VFIORegion *region);
 void vfio_reset_handler(void *opaque);
-VFIOGroup *vfio_get_group(int groupid, AddressSpace *as, Error **errp);
+VFIOGroup *vfio_get_group(VFIODevice *vdev, int groupid, AddressSpace *as, Error **errp);
 void vfio_put_group(VFIOGroup *group);
 int vfio_get_device(VFIOGroup *group, const char *name,
                     VFIODevice *vbasedev, Error **errp);
-- 
2.37.3