From 79cd0c80f82215a32890e3d30ff621b32ece5156 Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Fri, 11 Sep 2015 15:16:42 +0200 Subject: [PATCH] virtio-ccw: support ring size changes Wire up changing the ring size for virtio-1 devices. Signed-off-by: Cornelia Huck Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/s390x/virtio-ccw.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c index d36373e88a..85e2a5d29e 100644 --- a/hw/s390x/virtio-ccw.c +++ b/hw/s390x/virtio-ccw.c @@ -307,11 +307,18 @@ static int virtio_ccw_set_vqs(SubchDev *sch, VqInfoBlock *info, if (!desc) { virtio_queue_set_vector(vdev, index, VIRTIO_NO_VECTOR); } else { - /* Fail if we don't have a big enough queue. */ - /* TODO: Add interface to handle vring.num changing */ - if (virtio_queue_get_num(vdev, index) > num) { + if (info) { + /* virtio-1 allows changing the ring size. */ + if (virtio_queue_get_num(vdev, index) < num) { + /* Fail if we exceed the maximum number. */ + return -EINVAL; + } + virtio_queue_set_num(vdev, index, num); + } else if (virtio_queue_get_num(vdev, index) > num) { + /* Fail if we don't have a big enough queue. */ return -EINVAL; } + /* We ignore possible increased num for legacy for compatibility. */ virtio_queue_set_vector(vdev, index, index); } /* tell notify handler in case of config change */