[PATCH V1 04/26] vfio/container: register container for cpr

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

Register a legacy container for cpr-transfer.  Add a blocker if the kernel
does not support VFIO_UPDATE_VADDR or VFIO_UNMAP_ALL.

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/container.c           |  6 ++--
 hw/vfio/cpr-legacy.c          | 68 +++++++++++++++++++++++++++++++++++++++++++
 hw/vfio/meson.build           |  3 +-
 include/hw/vfio/vfio-common.h |  3 ++
 4 files changed, 76 insertions(+), 4 deletions(-)
 create mode 100644 hw/vfio/cpr-legacy.c

diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 4ebb526..a90ce6c 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -618,7 +618,7 @@ static bool vfio_connect_container(VFIOGroup *group, AddressSpace *as,
     }
     bcontainer = &container->bcontainer;
 
-    if (!vfio_cpr_register_container(bcontainer, errp)) {
+    if (!vfio_legacy_cpr_register_container(container, errp)) {
         goto free_container_exit;
     }
 
@@ -666,7 +666,7 @@ enable_discards_exit:
     vfio_ram_block_discard_disable(container, false);
 
 unregister_container_exit:
-    vfio_cpr_unregister_container(bcontainer);
+    vfio_legacy_cpr_unregister_container(container);
 
 free_container_exit:
     object_unref(container);
@@ -710,7 +710,7 @@ static void vfio_disconnect_container(VFIOGroup *group)
         VFIOAddressSpace *space = bcontainer->space;
 
         trace_vfio_disconnect_container(container->fd);
-        vfio_cpr_unregister_container(bcontainer);
+        vfio_legacy_cpr_unregister_container(container);
         close(container->fd);
         object_unref(container);
 
diff --git a/hw/vfio/cpr-legacy.c b/hw/vfio/cpr-legacy.c
new file mode 100644
index 0000000..d3bbc05
--- /dev/null
+++ b/hw/vfio/cpr-legacy.c
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2021-2025 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 <sys/ioctl.h>
+#include "qemu/osdep.h"
+#include "hw/vfio/vfio-common.h"
+#include "migration/blocker.h"
+#include "migration/cpr.h"
+#include "migration/migration.h"
+#include "migration/vmstate.h"
+#include "qapi/error.h"
+
+static bool vfio_cpr_supported(VFIOContainer *container, Error **errp)
+{
+    if (!ioctl(container->fd, VFIO_CHECK_EXTENSION, VFIO_UPDATE_VADDR)) {
+        error_setg(errp, "VFIO container does not support VFIO_UPDATE_VADDR");
+        return false;
+
+    } else if (!ioctl(container->fd, VFIO_CHECK_EXTENSION, VFIO_UNMAP_ALL)) {
+        error_setg(errp, "VFIO container does not support VFIO_UNMAP_ALL");
+        return false;
+
+    } else {
+        return true;
+    }
+}
+
+static const VMStateDescription vfio_container_vmstate = {
+    .name = "vfio-container",
+    .version_id = 0,
+    .minimum_version_id = 0,
+    .needed = cpr_needed_for_reuse,
+    .fields = (VMStateField[]) {
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+bool vfio_legacy_cpr_register_container(VFIOContainer *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);
+
+    return true;
+}
+
+void vfio_legacy_cpr_unregister_container(VFIOContainer *container)
+{
+    VFIOContainerBase *bcontainer = &container->bcontainer;
+
+    vfio_cpr_unregister_container(bcontainer);
+    migrate_del_blocker(&container->cpr_blocker);
+    vmstate_unregister(NULL, &vfio_container_vmstate, container);
+}
diff --git a/hw/vfio/meson.build b/hw/vfio/meson.build
index bba776f..5487815 100644
--- a/hw/vfio/meson.build
+++ b/hw/vfio/meson.build
@@ -5,13 +5,14 @@ vfio_ss.add(files(
   'container-base.c',
   'container.c',
   'migration.c',
-  'cpr.c',
 ))
 vfio_ss.add(when: 'CONFIG_PSERIES', if_true: files('spapr.c'))
 vfio_ss.add(when: 'CONFIG_IOMMUFD', if_true: files(
   'iommufd.c',
 ))
 vfio_ss.add(when: 'CONFIG_VFIO_PCI', if_true: files(
+  'cpr.c',
+  'cpr-legacy.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 0c60be5..53e554f 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -84,6 +84,7 @@ typedef struct VFIOContainer {
     VFIOContainerBase bcontainer;
     int fd; /* /dev/vfio/vfio, empowered by the attached groups */
     unsigned iommu_type;
+    Error *cpr_blocker;
     QLIST_HEAD(, VFIOGroup) group_list;
 } VFIOContainer;
 
@@ -258,6 +259,8 @@ int vfio_kvm_device_del_fd(int fd, Error **errp);
 
 bool vfio_cpr_register_container(VFIOContainerBase *bcontainer, Error **errp);
 void vfio_cpr_unregister_container(VFIOContainerBase *bcontainer);
+bool vfio_legacy_cpr_register_container(VFIOContainer *container, Error **errp);
+void vfio_legacy_cpr_unregister_container(VFIOContainer *container);
 
 extern const MemoryRegionOps vfio_region_ops;
 typedef QLIST_HEAD(VFIOGroupList, VFIOGroup) VFIOGroupList;
-- 
1.8.3.1