[PULL v2 06/32] vfio: Add migration state change notifier

[Alex Williamson <alex.williamson@redhat.com>]

From: Kirti Wankhede <kwankhede@nvidia.com>

Added migration state change notifier to get notification on migration state
change. These states are translated to VFIO device state and conveyed to
vendor driver.

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 hw/vfio/migration.c           |   28 ++++++++++++++++++++++++++++
 hw/vfio/trace-events          |    1 +
 include/hw/vfio/vfio-common.h |    2 ++
 3 files changed, 31 insertions(+)

diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index e1ffae05e288..7ec85b6469c5 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -175,6 +175,30 @@ static void vfio_vmstate_change(void *opaque, int running, RunState state)
             (migration->device_state & mask) | value);
 }
 
+static void vfio_migration_state_notifier(Notifier *notifier, void *data)
+{
+    MigrationState *s = data;
+    VFIOMigration *migration = container_of(notifier, VFIOMigration,
+                                            migration_state);
+    VFIODevice *vbasedev = migration->vbasedev;
+    int ret;
+
+    trace_vfio_migration_state_notifier(vbasedev->name,
+                                        MigrationStatus_str(s->state));
+
+    switch (s->state) {
+    case MIGRATION_STATUS_CANCELLING:
+    case MIGRATION_STATUS_CANCELLED:
+    case MIGRATION_STATUS_FAILED:
+        ret = vfio_migration_set_state(vbasedev,
+                      ~(VFIO_DEVICE_STATE_SAVING | VFIO_DEVICE_STATE_RESUMING),
+                      VFIO_DEVICE_STATE_RUNNING);
+        if (ret) {
+            error_report("%s: Failed to set state RUNNING", vbasedev->name);
+        }
+    }
+}
+
 static void vfio_migration_exit(VFIODevice *vbasedev)
 {
     VFIOMigration *migration = vbasedev->migration;
@@ -219,8 +243,11 @@ static int vfio_migration_init(VFIODevice *vbasedev,
     }
 
     migration = vbasedev->migration;
+    migration->vbasedev = vbasedev;
     migration->vm_state = qemu_add_vm_change_state_handler(vfio_vmstate_change,
                                                            vbasedev);
+    migration->migration_state.notify = vfio_migration_state_notifier;
+    add_migration_state_change_notifier(&migration->migration_state);
     return 0;
 
 err:
@@ -270,6 +297,7 @@ void vfio_migration_finalize(VFIODevice *vbasedev)
     if (vbasedev->migration) {
         VFIOMigration *migration = vbasedev->migration;
 
+        remove_migration_state_change_notifier(&migration->migration_state);
         qemu_del_vm_change_state_handler(migration->vm_state);
         vfio_migration_exit(vbasedev);
     }
diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
index 41de81f12f60..78d7d83b5ef8 100644
--- a/hw/vfio/trace-events
+++ b/hw/vfio/trace-events
@@ -150,3 +150,4 @@ vfio_display_edid_write_error(void) ""
 vfio_migration_probe(const char *name, uint32_t index) " (%s) Region %d"
 vfio_migration_set_state(const char *name, uint32_t state) " (%s) state %d"
 vfio_vmstate_change(const char *name, int running, const char *reason, uint32_t dev_state) " (%s) running %d reason %s device state %d"
+vfio_migration_state_notifier(const char *name, const char *state) " (%s) state %s"
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 9a571f1fb552..2bd593ba38bb 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -59,10 +59,12 @@ typedef struct VFIORegion {
 } VFIORegion;
 
 typedef struct VFIOMigration {
+    struct VFIODevice *vbasedev;
     VMChangeStateEntry *vm_state;
     VFIORegion region;
     uint32_t device_state;
     int vm_running;
+    Notifier migration_state;
 } VFIOMigration;
 
 typedef struct VFIOAddressSpace {