[PATCH v5 5/7] vfio/migration: Change vIOMMU blocker from global to per device

[Zhenzhong Duan]

vIOMMU migration blocker can be consolidated to per device default
blocker, then some vIOMMU global blocker related functions and data
could be removed.

This change also makes vfio_mig_active() more accurate as it doesn't
check for global blocker.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 hw/vfio/common.c              | 51 ++---------------------------------
 hw/vfio/migration.c           |  7 ++---
 hw/vfio/pci.c                 |  1 -
 include/hw/vfio/vfio-common.h |  3 +--
 4 files changed, 7 insertions(+), 55 deletions(-)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 00fef5aa08be..a8439447b990 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -362,7 +362,6 @@ bool vfio_mig_active(void)
 }
 
 static Error *multiple_devices_migration_blocker;
-static Error *giommu_migration_blocker;
 
 static unsigned int vfio_migratable_device_num(void)
 {
@@ -420,55 +419,9 @@ void vfio_unblock_multiple_devices_migration(void)
     multiple_devices_migration_blocker = NULL;
 }
 
-static bool vfio_viommu_preset(void)
+bool vfio_viommu_preset(VFIODevice *vbasedev)
 {
-    VFIOAddressSpace *space;
-
-    QLIST_FOREACH(space, &vfio_address_spaces, list) {
-        if (space->as != &address_space_memory) {
-            return true;
-        }
-    }
-
-    return false;
-}
-
-bool vfio_block_giommu_migration(VFIODevice *vbasedev, Error **errp)
-{
-    int ret;
-
-    if (giommu_migration_blocker ||
-        !vfio_viommu_preset()) {
-        return true;
-    }
-
-    if (vbasedev->enable_migration == ON_OFF_AUTO_ON) {
-        error_setg(errp,
-                   "Migration is currently not supported with vIOMMU enabled");
-        return false;
-    }
-
-    error_setg(&giommu_migration_blocker,
-               "Migration is currently not supported with vIOMMU enabled");
-    ret = migrate_add_blocker(giommu_migration_blocker, errp);
-    if (ret < 0) {
-        error_free(giommu_migration_blocker);
-        giommu_migration_blocker = NULL;
-    }
-
-    return !ret;
-}
-
-void vfio_migration_finalize(void)
-{
-    if (!giommu_migration_blocker ||
-        vfio_viommu_preset()) {
-        return;
-    }
-
-    migrate_del_blocker(giommu_migration_blocker);
-    error_free(giommu_migration_blocker);
-    giommu_migration_blocker = NULL;
+    return vbasedev->group->container->space->as != &address_space_memory;
 }
 
 static void vfio_set_migration_error(int err)
diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index 09fa4714a085..80509958f0d3 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -883,9 +883,10 @@ bool vfio_migration_realize(VFIODevice *vbasedev, Error 
**errp)
         return ret;
     }
 
-    ret = vfio_block_giommu_migration(vbasedev, errp);
-    if (!ret) {
-        return ret;
+    if (vfio_viommu_preset(vbasedev)) {
+        error_setg(&err, "%s: Migration is currently not supported "
+                   "with vIOMMU enabled", vbasedev->name);
+        return vfio_block_migration(vbasedev, err, errp);
     }
 
     trace_vfio_migration_realize(vbasedev->name);
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 31c4ab250fbe..c2cf7454ece6 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3255,7 +3255,6 @@ static void vfio_instance_finalize(Object *obj)
      */
     vfio_put_device(vdev);
     vfio_put_group(group);
-    vfio_migration_finalize();
 }
 
 static void vfio_exitfn(PCIDevice *pdev)
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index b3014ece2edf..3c18572322fc 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -227,7 +227,7 @@ extern VFIOGroupList vfio_group_list;
 bool vfio_mig_active(void);
 bool vfio_block_multiple_devices_migration(VFIODevice *vbasedev, Error **errp);
 void vfio_unblock_multiple_devices_migration(void);
-bool vfio_block_giommu_migration(VFIODevice *vbasedev, Error **errp);
+bool vfio_viommu_preset(VFIODevice *vbasedev);
 int64_t vfio_mig_bytes_transferred(void);
 void vfio_reset_bytes_transferred(void);
 
@@ -254,6 +254,5 @@ int vfio_spapr_remove_window(VFIOContainer *container,
 
 bool vfio_migration_realize(VFIODevice *vbasedev, Error **errp);
 void vfio_migration_exit(VFIODevice *vbasedev);
-void vfio_migration_finalize(void);
 
 #endif /* HW_VFIO_VFIO_COMMON_H */
-- 
2.34.1