[RFC 13/18] vfio/container-obj: Introduce VFIOContainer reset callback

[Yi Liu <yi.l.liu@intel.com>]

From: Eric Auger <eric.auger@redhat.com>

Reset implementation depends on the container backend. Let's
introduce a VFIOContainer class function and register a generic
reset handler that will be able to call the right reset function
depending on the container type. Also, let's move the
registration/unregistration to a place that is not backend-specific
(first vfio address space created instead of the first group).

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
 hw/vfio/as.c                         | 18 ++++++++++++++++++
 hw/vfio/container-obj.c              | 13 +++++++++++++
 hw/vfio/container.c                  | 26 ++++++++++++++------------
 include/hw/vfio/vfio-container-obj.h |  2 ++
 4 files changed, 47 insertions(+), 12 deletions(-)

diff --git a/hw/vfio/as.c b/hw/vfio/as.c
index 30e86f6833..4abaa4068f 100644
--- a/hw/vfio/as.c
+++ b/hw/vfio/as.c
@@ -847,6 +847,18 @@ const MemoryListener vfio_memory_listener = {
     .log_sync = vfio_listener_log_sync,
 };
 
+void vfio_reset_handler(void *opaque)
+{
+    VFIOAddressSpace *space;
+    VFIOContainer *bcontainer;
+
+    QLIST_FOREACH(space, &vfio_address_spaces, list) {
+         QLIST_FOREACH(bcontainer, &space->containers, next) {
+             vfio_container_reset(bcontainer);
+         }
+    }
+}
+
 VFIOAddressSpace *vfio_get_address_space(AddressSpace *as)
 {
     VFIOAddressSpace *space;
@@ -862,6 +874,9 @@ VFIOAddressSpace *vfio_get_address_space(AddressSpace *as)
     space->as = as;
     QLIST_INIT(&space->containers);
 
+    if (QLIST_EMPTY(&vfio_address_spaces)) {
+        qemu_register_reset(vfio_reset_handler, NULL);
+    }
     QLIST_INSERT_HEAD(&vfio_address_spaces, space, list);
 
     return space;
@@ -873,6 +888,9 @@ void vfio_put_address_space(VFIOAddressSpace *space)
         QLIST_REMOVE(space, list);
         g_free(space);
     }
+    if (QLIST_EMPTY(&vfio_address_spaces)) {
+        qemu_unregister_reset(vfio_reset_handler, NULL);
+    }
 }
 
 static VFIOContainerClass *
diff --git a/hw/vfio/container-obj.c b/hw/vfio/container-obj.c
index 40c1e2a2b5..c4220336af 100644
--- a/hw/vfio/container-obj.c
+++ b/hw/vfio/container-obj.c
@@ -68,6 +68,19 @@ int vfio_container_dma_unmap(VFIOContainer *container,
     return vccs->dma_unmap(container, iova, size, iotlb);
 }
 
+int vfio_container_reset(VFIOContainer *container)
+{
+    VFIOContainerClass *vccs = VFIO_CONTAINER_OBJ_GET_CLASS(container);
+
+    vccs = VFIO_CONTAINER_OBJ_GET_CLASS(container);
+
+    if (!vccs->reset) {
+        return -ENOENT;
+    }
+
+    return vccs->reset(container);
+}
+
 void vfio_container_set_dirty_page_tracking(VFIOContainer *container,
                                             bool start)
 {
diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 74febc1567..2f59422048 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -458,12 +458,15 @@ vfio_legacy_container_del_section_window(VFIOContainer *bcontainer,
     }
 }
 
-void vfio_reset_handler(void *opaque)
+static int vfio_legacy_container_reset(VFIOContainer *bcontainer)
 {
+    VFIOLegacyContainer *container = container_of(bcontainer,
+                                                  VFIOLegacyContainer, obj);
     VFIOGroup *group;
     VFIODevice *vbasedev;
+    int ret, final_ret = 0;
 
-    QLIST_FOREACH(group, &vfio_group_list, next) {
+    QLIST_FOREACH(group, &container->group_list, container_next) {
         QLIST_FOREACH(vbasedev, &group->device_list, next) {
             if (vbasedev->dev->realized) {
                 vbasedev->ops->vfio_compute_needs_reset(vbasedev);
@@ -471,13 +474,19 @@ void vfio_reset_handler(void *opaque)
         }
     }
 
-    QLIST_FOREACH(group, &vfio_group_list, next) {
+    QLIST_FOREACH(group, &container->group_list, next) {
         QLIST_FOREACH(vbasedev, &group->device_list, next) {
             if (vbasedev->dev->realized && vbasedev->needs_reset) {
-                vbasedev->ops->vfio_hot_reset_multi(vbasedev);
+                ret = vbasedev->ops->vfio_hot_reset_multi(vbasedev);
+                if (ret) {
+                    error_report("failed to reset %s (%d)",
+                                 vbasedev->name, ret);
+                    final_ret = ret;
+                }
             }
         }
     }
+    return final_ret;
 }
 
 static void vfio_kvm_device_add_group(VFIOGroup *group)
@@ -1004,10 +1013,6 @@ static VFIOGroup *vfio_get_group(int groupid, AddressSpace *as, Error **errp)
         goto close_fd_exit;
     }
 
-    if (QLIST_EMPTY(&vfio_group_list)) {
-        qemu_register_reset(vfio_reset_handler, NULL);
-    }
-
     QLIST_INSERT_HEAD(&vfio_group_list, group, next);
 
     return group;
@@ -1036,10 +1041,6 @@ static void vfio_put_group(VFIOGroup *group)
     trace_vfio_put_group(group->fd);
     close(group->fd);
     g_free(group);
-
-    if (QLIST_EMPTY(&vfio_group_list)) {
-        qemu_unregister_reset(vfio_reset_handler, NULL);
-    }
 }
 
 static int vfio_get_device(VFIOGroup *group, const char *name,
@@ -1293,6 +1294,7 @@ static void vfio_legacy_container_class_init(ObjectClass *klass,
     vccs->add_window = vfio_legacy_container_add_section_window;
     vccs->del_window = vfio_legacy_container_del_section_window;
     vccs->check_extension = vfio_legacy_container_check_extension;
+    vccs->reset = vfio_legacy_container_reset;
     vccs->attach_device = legacy_attach_device;
     vccs->detach_device = legacy_detach_device;
 }
diff --git a/include/hw/vfio/vfio-container-obj.h b/include/hw/vfio/vfio-container-obj.h
index ebc1340530..ffd8590ff8 100644
--- a/include/hw/vfio/vfio-container-obj.h
+++ b/include/hw/vfio/vfio-container-obj.h
@@ -118,6 +118,7 @@ typedef struct VFIOContainerClass {
     int (*dma_unmap)(VFIOContainer *container,
                      hwaddr iova, ram_addr_t size,
                      IOMMUTLBEntry *iotlb);
+    int (*reset)(VFIOContainer *container);
     /* migration feature */
     bool (*devices_all_dirty_tracking)(VFIOContainer *container);
     void (*set_dirty_page_tracking)(VFIOContainer *container, bool start);
@@ -142,6 +143,7 @@ int vfio_container_dma_map(VFIOContainer *container,
 int vfio_container_dma_unmap(VFIOContainer *container,
                              hwaddr iova, ram_addr_t size,
                              IOMMUTLBEntry *iotlb);
+int vfio_container_reset(VFIOContainer *container);
 bool vfio_container_devices_all_dirty_tracking(VFIOContainer *container);
 void vfio_container_set_dirty_page_tracking(VFIOContainer *container,
                                             bool start);
-- 
2.27.0