[PATCH v26 09/17] vfio: Add load state functions to SaveVMHandlers

[Kirti Wankhede <kwankhede@nvidia.com>]

Sequence  during _RESUMING device state:
While data for this device is available, repeat below steps:
a. read data_offset from where user application should write data.
b. write data of data_size to migration region from data_offset.
c. write data_size which indicates vendor driver that data is written in
   staging buffer.

For user, data is opaque. User should write data in the same order as
received.

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 hw/vfio/migration.c  | 170 +++++++++++++++++++++++++++++++++++++++++++++++++++
 hw/vfio/trace-events |   3 +
 2 files changed, 173 insertions(+)

diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index 4611bb972228..ffd70282dd0e 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -328,6 +328,33 @@ static int vfio_save_device_config_state(QEMUFile *f, void *opaque)
     return qemu_file_get_error(f);
 }
 
+static int vfio_load_device_config_state(QEMUFile *f, void *opaque)
+{
+    VFIODevice *vbasedev = opaque;
+    uint64_t data;
+
+    if (vbasedev->ops && vbasedev->ops->vfio_load_config) {
+        int ret;
+
+        ret = vbasedev->ops->vfio_load_config(vbasedev, f);
+        if (ret) {
+            error_report("%s: Failed to load device config space",
+                         vbasedev->name);
+            return ret;
+        }
+    }
+
+    data = qemu_get_be64(f);
+    if (data != VFIO_MIG_FLAG_END_OF_STATE) {
+        error_report("%s: Failed loading device config space, "
+                     "end flag incorrect 0x%"PRIx64, vbasedev->name, data);
+        return -EINVAL;
+    }
+
+    trace_vfio_load_device_config_state(vbasedev->name);
+    return qemu_file_get_error(f);
+}
+
 /* ---------------------------------------------------------------------- */
 
 static int vfio_save_setup(QEMUFile *f, void *opaque)
@@ -502,12 +529,155 @@ static int vfio_save_complete_precopy(QEMUFile *f, void *opaque)
     return ret;
 }
 
+static int vfio_load_setup(QEMUFile *f, void *opaque)
+{
+    VFIODevice *vbasedev = opaque;
+    VFIOMigration *migration = vbasedev->migration;
+    int ret = 0;
+
+    if (migration->region.mmaps) {
+        ret = vfio_region_mmap(&migration->region);
+        if (ret) {
+            error_report("%s: Failed to mmap VFIO migration region %d: %s",
+                         vbasedev->name, migration->region.nr,
+                         strerror(-ret));
+            error_report("%s: Falling back to slow path", vbasedev->name);
+        }
+    }
+
+    ret = vfio_migration_set_state(vbasedev, ~VFIO_DEVICE_STATE_MASK,
+                                   VFIO_DEVICE_STATE_RESUMING);
+    if (ret) {
+        error_report("%s: Failed to set state RESUMING", vbasedev->name);
+    }
+    return ret;
+}
+
+static int vfio_load_cleanup(void *opaque)
+{
+    vfio_save_cleanup(opaque);
+    return 0;
+}
+
+static int vfio_load_state(QEMUFile *f, void *opaque, int version_id)
+{
+    VFIODevice *vbasedev = opaque;
+    VFIOMigration *migration = vbasedev->migration;
+    int ret = 0;
+    uint64_t data, data_size;
+
+    data = qemu_get_be64(f);
+    while (data != VFIO_MIG_FLAG_END_OF_STATE) {
+
+        trace_vfio_load_state(vbasedev->name, data);
+
+        switch (data) {
+        case VFIO_MIG_FLAG_DEV_CONFIG_STATE:
+        {
+            ret = vfio_load_device_config_state(f, opaque);
+            if (ret) {
+                return ret;
+            }
+            break;
+        }
+        case VFIO_MIG_FLAG_DEV_SETUP_STATE:
+        {
+            data = qemu_get_be64(f);
+            if (data == VFIO_MIG_FLAG_END_OF_STATE) {
+                return ret;
+            } else {
+                error_report("%s: SETUP STATE: EOS not found 0x%"PRIx64,
+                             vbasedev->name, data);
+                return -EINVAL;
+            }
+            break;
+        }
+        case VFIO_MIG_FLAG_DEV_DATA_STATE:
+        {
+            VFIORegion *region = &migration->region;
+            uint64_t data_offset = 0, size;
+
+            data_size = size = qemu_get_be64(f);
+            if (data_size == 0) {
+                break;
+            }
+
+            ret = vfio_mig_read(vbasedev, &data_offset, sizeof(data_offset),
+                                region->fd_offset +
+                                offsetof(struct vfio_device_migration_info,
+                                         data_offset));
+            if (ret < 0) {
+                return ret;
+            }
+
+            trace_vfio_load_state_device_data(vbasedev->name, data_offset,
+                                              data_size);
+
+            while (size) {
+                void *buf = NULL;
+                uint64_t sec_size;
+                bool buf_alloc = false;
+
+                buf = get_data_section_size(region, data_offset, size,
+                                            &sec_size);
+
+                if (!buf) {
+                    buf = g_try_malloc(sec_size);
+                    if (!buf) {
+                        error_report("%s: Error allocating buffer ", __func__);
+                        return -ENOMEM;
+                    }
+                    buf_alloc = true;
+                }
+
+                qemu_get_buffer(f, buf, sec_size);
+
+                if (buf_alloc) {
+                    ret = vfio_mig_write(vbasedev, buf, sec_size,
+                                         region->fd_offset + data_offset);
+                    g_free(buf);
+
+                    if (ret < 0) {
+                        return ret;
+                    }
+                }
+                size -= sec_size;
+                data_offset += sec_size;
+            }
+
+            ret = vfio_mig_write(vbasedev, &data_size, sizeof(data_size),
+                                 region->fd_offset +
+                       offsetof(struct vfio_device_migration_info, data_size));
+            if (ret < 0) {
+                return ret;
+            }
+            break;
+        }
+
+        default:
+            error_report("%s: Unknown tag 0x%"PRIx64, vbasedev->name, data);
+            return -EINVAL;
+        }
+
+        data = qemu_get_be64(f);
+        ret = qemu_file_get_error(f);
+        if (ret) {
+            return ret;
+        }
+    }
+
+    return ret;
+}
+
 static SaveVMHandlers savevm_vfio_handlers = {
     .save_setup = vfio_save_setup,
     .save_cleanup = vfio_save_cleanup,
     .save_live_pending = vfio_save_pending,
     .save_live_iterate = vfio_save_iterate,
     .save_live_complete_precopy = vfio_save_complete_precopy,
+    .load_setup = vfio_load_setup,
+    .load_cleanup = vfio_load_cleanup,
+    .load_state = vfio_load_state,
 };
 
 /* ---------------------------------------------------------------------- */
diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
index 118b5547c921..94ba4696f0c6 100644
--- a/hw/vfio/trace-events
+++ b/hw/vfio/trace-events
@@ -160,3 +160,6 @@ vfio_save_device_config_state(const char *name) " (%s)"
 vfio_save_pending(const char *name, uint64_t precopy, uint64_t postcopy, uint64_t compatible) " (%s) precopy 0x%"PRIx64" postcopy 0x%"PRIx64" compatible 0x%"PRIx64
 vfio_save_iterate(const char *name, int data_size) " (%s) data_size %d"
 vfio_save_complete_precopy(const char *name) " (%s)"
+vfio_load_device_config_state(const char *name) " (%s)"
+vfio_load_state(const char *name, uint64_t data) " (%s) data 0x%"PRIx64
+vfio_load_state_device_data(const char *name, uint64_t data_offset, uint64_t data_size) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64
-- 
2.7.0