From: Stefano Garzarella <sgarzare@redhat.com>
Date: Mon, 21 Sep 2020 14:25:06 +0200
Subject: [PATCH] vhost-vsock-ccw: force virtio version 1

virtio-vsock was introduced after the release of VIRTIO 1.0
specifications, so it should be 'modern-only'.

This patch forces virtio version 1 as done for vhost-vsock-pci.

To avoid migration issues, we force virtio version 1 only when
legacy check is enabled in the new machine types (>= 5.1).

Cc: qemu-stable@nongnu.org
Suggested-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20200921122506.82515-5-sgarzare@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit a6704a34cf02add13964149e0de6453ae62bd9db)
---
 hw/s390x/vhost-vsock-ccw.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/hw/s390x/vhost-vsock-ccw.c b/hw/s390x/vhost-vsock-ccw.c
index 0822ecca89..246416a8f9 100644
--- a/hw/s390x/vhost-vsock-ccw.c
+++ b/hw/s390x/vhost-vsock-ccw.c
@@ -40,9 +40,21 @@ static void vhost_vsock_ccw_class_init(ObjectClass *klass, void *data)
 static void vhost_vsock_ccw_instance_init(Object *obj)
 {
     VHostVSockCCWState *dev = VHOST_VSOCK_CCW(obj);
+    VirtioCcwDevice *ccw_dev = VIRTIO_CCW_DEVICE(obj);
+    VirtIODevice *virtio_dev;
 
     virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
                                 TYPE_VHOST_VSOCK);
+
+    virtio_dev = VIRTIO_DEVICE(&dev->vdev);
+
+    /*
+     * To avoid migration issues, we force virtio version 1 only when
+     * legacy check is enabled in the new machine types (>= 5.1).
+     */
+    if (!virtio_legacy_check_disabled(virtio_dev)) {
+        ccw_dev->force_revision_1 = true;
+    }
 }
 
 static const TypeInfo vhost_vsock_ccw_info = {