[PATCH V1 23/26] vfio/iommufd: register container for cpr

[Steve Sistare <steven.sistare@oracle.com>]

Register a vfio iommufd container for CPR.  Add a blocker if the kernel does
not support IOMMU_IOAS_CHANGE_PROCESS.

This is mostly boiler plate.  The fields to to saved and restored are added
in subsequent patches.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
 hw/vfio/cpr-iommufd.c         | 96 +++++++++++++++++++++++++++++++++++++++++++
 hw/vfio/iommufd.c             | 12 +++---
 hw/vfio/meson.build           |  1 +
 include/hw/vfio/vfio-common.h |  6 +++
 4 files changed, 110 insertions(+), 5 deletions(-)
 create mode 100644 hw/vfio/cpr-iommufd.c

diff --git a/hw/vfio/cpr-iommufd.c b/hw/vfio/cpr-iommufd.c
new file mode 100644
index 0000000..4eb358a
--- /dev/null
+++ b/hw/vfio/cpr-iommufd.c
@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2024-2025 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "hw/vfio/vfio-common.h"
+#include "migration/blocker.h"
+#include "migration/cpr.h"
+#include "migration/migration.h"
+#include "migration/vmstate.h"
+#include "system/iommufd.h"
+
+static bool vfio_cpr_supported(VFIOIOMMUFDContainer *container, Error **errp)
+{
+    if (!iommufd_change_process_capable(container->be)) {
+        error_setg(errp,
+                   "VFIO container does not support IOMMU_IOAS_CHANGE_PROCESS");
+        return false;
+    }
+    return true;
+}
+
+static const VMStateDescription vfio_container_vmstate = {
+    .name = "vfio-iommufd-container",
+    .version_id = 0,
+    .minimum_version_id = 0,
+    .needed = cpr_needed_for_reuse,
+    .fields = (VMStateField[]) {
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription iommufd_cpr_vmstate = {
+    .name = "iommufd",
+    .version_id = 0,
+    .minimum_version_id = 0,
+    .needed = cpr_needed_for_reuse,
+    .fields = (VMStateField[]) {
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+bool vfio_iommufd_cpr_register_container(VFIOIOMMUFDContainer *container,
+                                         Error **errp)
+{
+    VFIOContainerBase *bcontainer = &container->bcontainer;
+    Error **cpr_blocker = &container->cpr_blocker;
+
+    if (!vfio_cpr_register_container(bcontainer, errp)) {
+        return false;
+    }
+
+    if (!vfio_cpr_supported(container, cpr_blocker)) {
+        return migrate_add_blocker_modes(cpr_blocker, errp,
+                                         MIG_MODE_CPR_TRANSFER, -1) == 0;
+    }
+
+    vmstate_register(NULL, -1, &vfio_container_vmstate, container);
+    vmstate_register(NULL, -1, &iommufd_cpr_vmstate, container->be);
+
+    return true;
+}
+
+void vfio_iommufd_cpr_unregister_container(VFIOIOMMUFDContainer *container)
+{
+    VFIOContainerBase *bcontainer = &container->bcontainer;
+
+    vmstate_unregister(NULL, &iommufd_cpr_vmstate, container->be);
+    vmstate_unregister(NULL, &vfio_container_vmstate, container);
+    migrate_del_blocker(&container->cpr_blocker);
+    vfio_cpr_unregister_container(bcontainer);
+}
+
+static const VMStateDescription vfio_device_vmstate = {
+    .name = "vfio-iommufd-device",
+    .version_id = 0,
+    .minimum_version_id = 0,
+    .needed = cpr_needed_for_reuse,
+    .fields = (VMStateField[]) {
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+void vfio_iommufd_cpr_register_device(VFIODevice *vbasedev)
+{
+    vmstate_register(NULL, -1, &vfio_device_vmstate, vbasedev);
+}
+
+void vfio_iommufd_cpr_unregister_device(VFIODevice *vbasedev)
+{
+    vmstate_unregister(NULL, &vfio_device_vmstate, vbasedev);
+}
diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index 8308715..ae78e00 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -592,6 +592,10 @@ static bool iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
 
     bcontainer->initialized = true;
 
+    if (!vfio_iommufd_cpr_register_container(container, errp)) {
+        goto err_listener_register;
+    }
+
 found_container:
     ret = ioctl(devfd, VFIO_DEVICE_GET_INFO, &dev_info);
     if (ret) {
@@ -599,10 +603,6 @@ found_container:
         goto err_listener_register;
     }
 
-    if (!vfio_cpr_register_container(bcontainer, errp)) {
-        goto err_listener_register;
-    }
-
     /*
      * TODO: examine RAM_BLOCK_DISCARD stuff, should we do group level
      * for discarding incompatibility check as well?
@@ -619,6 +619,7 @@ found_container:
     vbasedev->bcontainer = bcontainer;
     QLIST_INSERT_HEAD(&bcontainer->device_list, vbasedev, container_next);
     QLIST_INSERT_HEAD(&vfio_device_list, vbasedev, global_next);
+    vfio_iommufd_cpr_register_device(vbasedev);
 
     trace_iommufd_cdev_device_info(vbasedev->name, devfd, vbasedev->num_irqs,
                                    vbasedev->num_regions, vbasedev->flags);
@@ -653,12 +654,13 @@ static void iommufd_cdev_detach(VFIODevice *vbasedev)
         iommufd_cdev_ram_block_discard_disable(false);
     }
 
-    vfio_cpr_unregister_container(bcontainer);
+    vfio_iommufd_cpr_unregister_container(container);
     iommufd_cdev_detach_container(vbasedev, container);
     iommufd_cdev_container_destroy(container);
     vfio_put_address_space(space);
 
     migrate_del_blocker(&vbasedev->cpr_id_blocker);
+    vfio_iommufd_cpr_unregister_device(vbasedev);
     iommufd_cdev_unbind_and_disconnect(vbasedev);
     close(vbasedev->fd);
 }
diff --git a/hw/vfio/meson.build b/hw/vfio/meson.build
index 5487815..998adb5 100644
--- a/hw/vfio/meson.build
+++ b/hw/vfio/meson.build
@@ -13,6 +13,7 @@ vfio_ss.add(when: 'CONFIG_IOMMUFD', if_true: files(
 vfio_ss.add(when: 'CONFIG_VFIO_PCI', if_true: files(
   'cpr.c',
   'cpr-legacy.c',
+  'cpr-iommufd.c',
   'display.c',
   'pci-quirks.c',
   'pci.c',
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 37e7c26..add44d4 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -113,6 +113,7 @@ typedef struct VFIOIOASHwpt {
 typedef struct VFIOIOMMUFDContainer {
     VFIOContainerBase bcontainer;
     IOMMUFDBackend *be;
+    Error *cpr_blocker;
     uint32_t ioas_id;
     QLIST_HEAD(, VFIOIOASHwpt) hwpt_list;
 } VFIOIOMMUFDContainer;
@@ -271,6 +272,11 @@ bool vfio_legacy_cpr_register_container(VFIOContainer *container, Error **errp);
 void vfio_legacy_cpr_unregister_container(VFIOContainer *container);
 bool iommufd_cdev_get_info_iova_range(VFIOIOMMUFDContainer *container,
                                       uint32_t ioas_id, Error **errp);
+bool vfio_iommufd_cpr_register_container(VFIOIOMMUFDContainer *container,
+                                         Error **errp);
+void vfio_iommufd_cpr_unregister_container(VFIOIOMMUFDContainer *container);
+void vfio_iommufd_cpr_register_device(VFIODevice *vbasedev);
+void vfio_iommufd_cpr_unregister_device(VFIODevice *vbasedev);
 
 extern const MemoryRegionOps vfio_region_ops;
 typedef QLIST_HEAD(VFIOGroupList, VFIOGroup) VFIOGroupList;
-- 
1.8.3.1