[PATCH QEMU v23 05/18] vfio: Add migration region initialization and finalize function

[Kirti Wankhede]

- Migration functions are implemented for VFIO_DEVICE_TYPE_PCI device in this
  patch series.
- VFIO device supports migration or not is decided based of migration region
  query. If migration region query is successful and migration region
  initialization is successful then migration is supported else migration is
  blocked.

Signed-off-by: Kirti Wankhede <address@hidden>
Reviewed-by: Neo Jia <address@hidden>
---
 hw/vfio/Makefile.objs         |   2 +-
 hw/vfio/migration.c           | 138 ++++++++++++++++++++++++++++++++++++++++++
 hw/vfio/trace-events          |   3 +
 include/hw/vfio/vfio-common.h |   9 +++
 4 files changed, 151 insertions(+), 1 deletion(-)
 create mode 100644 hw/vfio/migration.c

diff --git a/hw/vfio/Makefile.objs b/hw/vfio/Makefile.objs
index 9bb1c09e8477..8b296c889ed9 100644
--- a/hw/vfio/Makefile.objs
+++ b/hw/vfio/Makefile.objs
@@ -1,4 +1,4 @@
-obj-y += common.o spapr.o
+obj-y += common.o spapr.o migration.o
 obj-$(CONFIG_VFIO_PCI) += pci.o pci-quirks.o display.o
 obj-$(CONFIG_VFIO_CCW) += ccw.o
 obj-$(CONFIG_VFIO_PLATFORM) += platform.o
diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
new file mode 100644
index 000000000000..bf9384907ec0
--- /dev/null
+++ b/hw/vfio/migration.c
@@ -0,0 +1,138 @@
+/*
+ * Migration support for VFIO devices
+ *
+ * Copyright NVIDIA, Inc. 2020
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include <linux/vfio.h>
+
+#include "hw/vfio/vfio-common.h"
+#include "cpu.h"
+#include "migration/migration.h"
+#include "migration/qemu-file.h"
+#include "migration/register.h"
+#include "migration/blocker.h"
+#include "migration/misc.h"
+#include "qapi/error.h"
+#include "exec/ramlist.h"
+#include "exec/ram_addr.h"
+#include "pci.h"
+#include "trace.h"
+
+static void vfio_migration_region_exit(VFIODevice *vbasedev)
+{
+    VFIOMigration *migration = vbasedev->migration;
+
+    if (!migration) {
+        return;
+    }
+
+    if (migration->region.size) {
+        vfio_region_exit(&migration->region);
+        vfio_region_finalize(&migration->region);
+    }
+}
+
+static int vfio_migration_region_init(VFIODevice *vbasedev, int index)
+{
+    VFIOMigration *migration = vbasedev->migration;
+    Object *obj = NULL;
+    int ret = -EINVAL;
+
+    if (!vbasedev->ops->vfio_get_object) {
+        return ret;
+    }
+
+    obj = vbasedev->ops->vfio_get_object(vbasedev);
+    if (!obj) {
+        return ret;
+    }
+
+    ret = vfio_region_setup(obj, vbasedev, &migration->region, index,
+                            "migration");
+    if (ret) {
+        error_report("%s: Failed to setup VFIO migration region %d: %s",
+                     vbasedev->name, index, strerror(-ret));
+        goto err;
+    }
+
+    if (!migration->region.size) {
+        ret = -EINVAL;
+        error_report("%s: Invalid region size of VFIO migration region %d: %s",
+                     vbasedev->name, index, strerror(-ret));
+        goto err;
+    }
+
+    return 0;
+
+err:
+    vfio_migration_region_exit(vbasedev);
+    return ret;
+}
+
+static int vfio_migration_init(VFIODevice *vbasedev,
+                               struct vfio_region_info *info)
+{
+    int ret;
+
+    vbasedev->migration = g_new0(VFIOMigration, 1);
+
+    ret = vfio_migration_region_init(vbasedev, info->index);
+    if (ret) {
+        error_report("%s: Failed to initialise migration region",
+                     vbasedev->name);
+        g_free(vbasedev->migration);
+        vbasedev->migration = NULL;
+        return ret;
+    }
+
+    return 0;
+}
+
+/* ---------------------------------------------------------------------- */
+
+int vfio_migration_probe(VFIODevice *vbasedev, Error **errp)
+{
+    struct vfio_region_info *info;
+    Error *local_err = NULL;
+    int ret;
+
+    ret = vfio_get_dev_region_info(vbasedev, VFIO_REGION_TYPE_MIGRATION,
+                                   VFIO_REGION_SUBTYPE_MIGRATION, &info);
+    if (ret) {
+        goto add_blocker;
+    }
+
+    ret = vfio_migration_init(vbasedev, info);
+    if (ret) {
+        goto add_blocker;
+    }
+
+    trace_vfio_migration_probe(vbasedev->name, info->index);
+    return 0;
+
+add_blocker:
+    error_setg(&vbasedev->migration_blocker,
+               "VFIO device doesn't support migration");
+    ret = migrate_add_blocker(vbasedev->migration_blocker, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        error_free(vbasedev->migration_blocker);
+    }
+    return ret;
+}
+
+void vfio_migration_finalize(VFIODevice *vbasedev)
+{
+    if (vbasedev->migration_blocker) {
+        migrate_del_blocker(vbasedev->migration_blocker);
+        error_free(vbasedev->migration_blocker);
+    }
+
+    vfio_migration_region_exit(vbasedev);
+    g_free(vbasedev->migration);
+}
diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
index 8cdc27946cb8..fd034ac53684 100644
--- a/hw/vfio/trace-events
+++ b/hw/vfio/trace-events
@@ -143,3 +143,6 @@ vfio_display_edid_link_up(void) ""
 vfio_display_edid_link_down(void) ""
 vfio_display_edid_update(uint32_t prefx, uint32_t prefy) "%ux%u"
 vfio_display_edid_write_error(void) ""
+
+# migration.c
+vfio_migration_probe(const char *name, uint32_t index) " (%s) Region %d"
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index d69a7f3ae31e..d4b268641173 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -57,6 +57,10 @@ typedef struct VFIORegion {
     uint8_t nr; /* cache the region number for debug */
 } VFIORegion;
 
+typedef struct VFIOMigration {
+    VFIORegion region;
+} VFIOMigration;
+
 typedef struct VFIOAddressSpace {
     AddressSpace *as;
     QLIST_HEAD(, VFIOContainer) containers;
@@ -113,6 +117,8 @@ typedef struct VFIODevice {
     unsigned int num_irqs;
     unsigned int num_regions;
     unsigned int flags;
+    VFIOMigration *migration;
+    Error *migration_blocker;
 } VFIODevice;
 
 struct VFIODeviceOps {
@@ -204,4 +210,7 @@ int vfio_spapr_create_window(VFIOContainer *container,
 int vfio_spapr_remove_window(VFIOContainer *container,
                              hwaddr offset_within_address_space);
 
+int vfio_migration_probe(VFIODevice *vbasedev, Error **errp);
+void vfio_migration_finalize(VFIODevice *vbasedev);
+
 #endif /* HW_VFIO_VFIO_COMMON_H */
-- 
2.7.0