[Qemu-devel] [PATCH v9 03/22] virtio: introduce device specific migration calls

[Greg Kurz]

In order to migrate virtio subsections, they should be streamed after
the device itself. We need the device specific code to be called from
the common migration code to achieve this. This patch introduces load
and save methods for this purpose.

Suggested-by: Andreas Färber <afaer...@suse.de>
Signed-off-by: Greg Kurz <gk...@linux.vnet.ibm.com>
Reviewed-by: Alexander Graf <ag...@suse.de>
---
 hw/block/virtio-blk.c       |    2 +-
 hw/char/virtio-serial-bus.c |    2 +-
 hw/net/virtio-net.c         |    2 +-
 hw/scsi/virtio-scsi.c       |    2 +-
 hw/virtio/virtio-balloon.c  |    2 +-
 hw/virtio/virtio-rng.c      |    2 +-
 hw/virtio/virtio.c          |   13 ++++++++++++-
 include/hw/virtio/virtio.h  |    4 +++-
 8 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index 08562ea..3b34ce9 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -624,7 +624,7 @@ static int virtio_blk_load(QEMUFile *f, void *opaque, int 
version_id)
     if (version_id != 2)
         return -EINVAL;
 
-    ret = virtio_load(vdev, f);
+    ret = virtio_load(vdev, f, version_id);
     if (ret) {
         return ret;
     }
diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c
index ee1ba16..9f1df84 100644
--- a/hw/char/virtio-serial-bus.c
+++ b/hw/char/virtio-serial-bus.c
@@ -677,7 +677,7 @@ static int virtio_serial_load(QEMUFile *f, void *opaque, 
int version_id)
     }
 
     /* The virtio device */
-    ret = virtio_load(VIRTIO_DEVICE(s), f);
+    ret = virtio_load(VIRTIO_DEVICE(s), f, version_id);
     if (ret) {
         return ret;
     }
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index c39db7c..151d220 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -1362,7 +1362,7 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int 
version_id)
     if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)
         return -EINVAL;
 
-    ret = virtio_load(vdev, f);
+    ret = virtio_load(vdev, f, version_id);
     if (ret) {
         return ret;
     }
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index 8c8c9d1..6b4fd6f 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -549,7 +549,7 @@ static int virtio_scsi_load(QEMUFile *f, void *opaque, int 
version_id)
     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
     int ret;
 
-    ret = virtio_load(vdev, f);
+    ret = virtio_load(vdev, f, version_id);
     if (ret) {
         return ret;
     }
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index 2a2e58a..165592e 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -343,7 +343,7 @@ static int virtio_balloon_load(QEMUFile *f, void *opaque, 
int version_id)
     if (version_id != 1)
         return -EINVAL;
 
-    ret = virtio_load(vdev, f);
+    ret = virtio_load(vdev, f, version_id);
     if (ret) {
         return ret;
     }
diff --git a/hw/virtio/virtio-rng.c b/hw/virtio/virtio-rng.c
index b6ab361..025de81 100644
--- a/hw/virtio/virtio-rng.c
+++ b/hw/virtio/virtio-rng.c
@@ -113,7 +113,7 @@ static int virtio_rng_load(QEMUFile *f, void *opaque, int 
version_id)
     if (version_id != 1) {
         return -EINVAL;
     }
-    virtio_load(vdev, f);
+    virtio_load(vdev, f, version_id);
 
     /* We may have an element ready but couldn't process it due to a quota
      * limit.  Make sure to try again after live migration when the quota may
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index a3082d5..664923e 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -843,6 +843,7 @@ void virtio_save(VirtIODevice *vdev, QEMUFile *f)
 {
     BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
     int i;
 
     if (k->save_config) {
@@ -877,6 +878,10 @@ void virtio_save(VirtIODevice *vdev, QEMUFile *f)
             k->save_queue(qbus->parent, i, f);
         }
     }
+
+    if (vdc->save != NULL) {
+        vdc->save(vdev, f);
+    }
 }
 
 int virtio_set_features(VirtIODevice *vdev, uint32_t val)
@@ -895,7 +900,7 @@ int virtio_set_features(VirtIODevice *vdev, uint32_t val)
     return bad ? -1 : 0;
 }
 
-int virtio_load(VirtIODevice *vdev, QEMUFile *f)
+int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id)
 {
     int i, ret;
     int32_t config_len;
@@ -904,6 +909,7 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f)
     uint32_t supported_features;
     BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
 
     if (k->load_config) {
         ret = k->load_config(qbus->parent, f);
@@ -977,6 +983,11 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f)
     }
 
     virtio_notify_vector(vdev, VIRTIO_NO_VECTOR);
+
+    if (vdc->load != NULL) {
+        return vdc->load(vdev, f, version_id);
+    }
+
     return 0;
 }
 
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 3e54e90..3505ce5 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -150,6 +150,8 @@ typedef struct VirtioDeviceClass {
      * must mask in frontend instead.
      */
     void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
+    void (*save)(VirtIODevice *vdev, QEMUFile *f);
+    int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id);
 } VirtioDeviceClass;
 
 void virtio_init(VirtIODevice *vdev, const char *name,
@@ -184,7 +186,7 @@ void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
 
 void virtio_save(VirtIODevice *vdev, QEMUFile *f);
 
-int virtio_load(VirtIODevice *vdev, QEMUFile *f);
+int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id);
 
 void virtio_notify_config(VirtIODevice *vdev);