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[Qemu-devel] [PATCH v2 2/4] virtio-ccw: support ring size changes
From: |
Cornelia Huck |
Subject: |
[Qemu-devel] [PATCH v2 2/4] virtio-ccw: support ring size changes |
Date: |
Fri, 11 Sep 2015 15:16:42 +0200 |
Wire up changing the ring size for virtio-1 devices.
Signed-off-by: Cornelia Huck <address@hidden>
---
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 d36373e..85e2a5d 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 */
--
2.3.8