diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index b9da6c08ef..a7b6fc8f46 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -198,8 +198,8 @@ void vfio_region_exit(VFIORegion *region);
 void vfio_region_finalize(VFIORegion *region);
 void vfio_reset_handler(void *opaque);
 struct vfio_device_info *vfio_get_device_info(int fd);
-int vfio_attach_device(char *name, VFIODevice *vbasedev,
-                       AddressSpace *as, Error **errp);
+bool vfio_attach_device(char *name, VFIODevice *vbasedev,
+                        AddressSpace *as, Error **errp);
 void vfio_detach_device(VFIODevice *vbasedev);
 
 int vfio_kvm_device_add_fd(int fd, Error **errp);
diff --git a/include/hw/vfio/vfio-container-base.h b/include/hw/vfio/vfio-container-base.h
index 3582d5f97a..c839cfd9cb 100644
--- a/include/hw/vfio/vfio-container-base.h
+++ b/include/hw/vfio/vfio-container-base.h
@@ -118,8 +118,8 @@ struct VFIOIOMMUClass {
     int (*dma_unmap)(const VFIOContainerBase *bcontainer,
                      hwaddr iova, ram_addr_t size,
                      IOMMUTLBEntry *iotlb);
-    int (*attach_device)(const char *name, VFIODevice *vbasedev,
-                         AddressSpace *as, Error **errp);
+    bool (*attach_device)(const char *name, VFIODevice *vbasedev,
+                          AddressSpace *as, Error **errp);
     void (*detach_device)(VFIODevice *vbasedev);
     /* migration feature */
     int (*set_dirty_page_tracking)(const VFIOContainerBase *bcontainer,
diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
index 7c4caa5938..d50600b702 100644
--- a/hw/vfio/ap.c
+++ b/hw/vfio/ap.c
@@ -156,7 +156,6 @@ static void vfio_ap_unregister_irq_notifier(VFIOAPDevice *vapdev,
 static void vfio_ap_realize(DeviceState *dev, Error **errp)
 {
     ERRP_GUARD();
-    int ret;
     Error *err = NULL;
     VFIOAPDevice *vapdev = VFIO_AP_DEVICE(dev);
     VFIODevice *vbasedev = &vapdev->vdev;
@@ -165,9 +164,8 @@ static void vfio_ap_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    ret = vfio_attach_device(vbasedev->name, vbasedev,
-                             &address_space_memory, errp);
-    if (ret) {
+    if (!vfio_attach_device(vbasedev->name, vbasedev,
+                            &address_space_memory, errp)) {
         goto error;
     }
 
diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
index 90e4a53437..782bd4bed7 100644
--- a/hw/vfio/ccw.c
+++ b/hw/vfio/ccw.c
@@ -580,7 +580,6 @@ static void vfio_ccw_realize(DeviceState *dev, Error **errp)
     S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
     VFIODevice *vbasedev = &vcdev->vdev;
     Error *err = NULL;
-    int ret;
 
     /* Call the class init function for subchannel. */
     if (cdc->realize) {
@@ -594,9 +593,8 @@ static void vfio_ccw_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    ret = vfio_attach_device(cdev->mdevid, vbasedev,
-                             &address_space_memory, errp);
-    if (ret) {
+    if (!vfio_attach_device(cdev->mdevid, vbasedev,
+                            &address_space_memory, errp)) {
         goto out_attach_dev_err;
     }
 
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 8f9cbdc026..890d30910e 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -1492,8 +1492,8 @@ retry:
     return info;
 }
 
-int vfio_attach_device(char *name, VFIODevice *vbasedev,
-                       AddressSpace *as, Error **errp)
+bool vfio_attach_device(char *name, VFIODevice *vbasedev,
+                        AddressSpace *as, Error **errp)
 {
     const VFIOIOMMUClass *ops =
         VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_LEGACY));
diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 77bdec276e..ea3b145913 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -908,8 +908,8 @@ static int vfio_device_groupid(VFIODevice *vbasedev, Error **errp)
  * @name and @vbasedev->name are likely to be different depending
  * on the type of the device, hence the need for passing @name
  */
-static int vfio_legacy_attach_device(const char *name, VFIODevice *vbasedev,
-                                     AddressSpace *as, Error **errp)
+static bool vfio_legacy_attach_device(const char *name, VFIODevice *vbasedev,
+                                      AddressSpace *as, Error **errp)
 {
     int groupid = vfio_device_groupid(vbasedev, errp);
     VFIODevice *vbasedev_iter;
@@ -918,27 +918,27 @@ static int vfio_legacy_attach_device(const char *name, VFIODevice *vbasedev,
     int ret;
 
     if (groupid < 0) {
-        return groupid;
+        return false;
     }
 
     trace_vfio_attach_device(vbasedev->name, groupid);
 
     group = vfio_get_group(groupid, as, errp);
     if (!group) {
-        return -ENOENT;
+        return false;
     }
 
     QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
         if (strcmp(vbasedev_iter->name, vbasedev->name) == 0) {
             error_setg(errp, "device is already attached");
             vfio_put_group(group);
-            return -EBUSY;
+            return false;
         }
     }
     ret = vfio_get_device(group, name, vbasedev, errp);
     if (ret) {
         vfio_put_group(group);
-        return ret;
+        return false;
     }
 
     bcontainer = &group->container->bcontainer;
@@ -946,7 +946,7 @@ static int vfio_legacy_attach_device(const char *name, VFIODevice *vbasedev,
     QLIST_INSERT_HEAD(&bcontainer->device_list, vbasedev, container_next);
     QLIST_INSERT_HEAD(&vfio_device_list, vbasedev, global_next);
 
-    return ret;
+    return true;
 }
 
 static void vfio_legacy_detach_device(VFIODevice *vbasedev)
diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index c644127972..4c6992fca1 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -299,8 +299,8 @@ error:
     return ret;
 }
 
-static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
-                               AddressSpace *as, Error **errp)
+static bool iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
+                                AddressSpace *as, Error **errp)
 {
     VFIOContainerBase *bcontainer;
     VFIOIOMMUFDContainer *container;
@@ -315,7 +315,7 @@ static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
     if (vbasedev->fd < 0) {
         devfd = iommufd_cdev_getfd(vbasedev->sysfsdev, errp);
         if (devfd < 0) {
-            return devfd;
+            return false;
         }
         vbasedev->fd = devfd;
     } else {
@@ -392,7 +392,6 @@ static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
     memory_listener_register(&bcontainer->listener, bcontainer->space->as);
 
     if (bcontainer->error) {
-        ret = -1;
         error_propagate_prepend(errp, bcontainer->error,
                                 "memory listener initialization failed: ");
         goto err_listener_register;
@@ -431,7 +430,7 @@ found_container:
 
     trace_iommufd_cdev_device_info(vbasedev->name, devfd, vbasedev->num_irqs,
                                    vbasedev->num_regions, vbasedev->flags);
-    return 0;
+    return true;
 
 err_listener_register:
     iommufd_cdev_ram_block_discard_disable(false);
@@ -444,7 +443,7 @@ err_alloc_ioas:
     iommufd_cdev_unbind_and_disconnect(vbasedev);
 err_connect_bind:
     close(vbasedev->fd);
-    return ret;
+    return false;
 }
 
 static void iommufd_cdev_detach(VFIODevice *vbasedev)
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 576b21e2bb..d3beb15514 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3001,9 +3001,8 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
         name = g_strdup(vbasedev->name);
     }
 
-    ret = vfio_attach_device(name, vbasedev,
-                             pci_device_iommu_address_space(pdev), errp);
-    if (ret) {
+    if (!vfio_attach_device(name, vbasedev,
+                            pci_device_iommu_address_space(pdev), errp)) {
         goto error;
     }
 
diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
index dcd2365fb3..2bd16096bb 100644
--- a/hw/vfio/platform.c
+++ b/hw/vfio/platform.c
@@ -552,10 +552,9 @@ static int vfio_base_device_init(VFIODevice *vbasedev, Error **errp)
         return ret;
     }
 
-    ret = vfio_attach_device(vbasedev->name, vbasedev,
-                             &address_space_memory, errp);
-    if (ret) {
-        return ret;
+    if (!vfio_attach_device(vbasedev->name, vbasedev,
+                            &address_space_memory, errp)) {
+        return -EINVAL;
     }
 
     ret = vfio_populate_device(vbasedev, errp);
