commit f7b803b377f74f7e109559e8e64f04c4c1fcd86b
author Peter Maydell <peter.maydell@linaro.org> Fri Jul 26 16:41:28 2013 +0100
committer Peter Maydell <peter.maydell@linaro.org> Mon Aug 12 11:57:56 2013 +0100
tree 600434f1e4f9cfa8af4d0595a3d35454225a476e
parent f6049f4483d61fa911a0693c2c48ce8308451d33

hw/virtio/virtio-mmio: Make QueueNumMax read 0 for unavailable queues

The virtio-mmio spec says that QueueNumMax must read zero for queues
which are unavailable; implement this, rather than always returning
VIRTQUEUE_MAX_SIZE.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1374853288-9912-3-git-send-email-peter.maydell@linaro.org
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

hw/virtio/virtio-mmio.c

diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
index 88cf994..4bd2953 100644
--- a/hw/virtio/virtio-mmio.c
+++ b/hw/virtio/virtio-mmio.c
@@ -151,6 +151,9 @@
         }
         return proxy->host_features;
     case VIRTIO_MMIO_QUEUENUMMAX:
+        if (!virtio_queue_get_num(vdev, vdev->queue_sel)) {
+            return 0;
+        }
         return VIRTQUEUE_MAX_SIZE;
     case VIRTIO_MMIO_QUEUEPFN:
         return virtio_queue_get_addr(vdev, vdev->queue_sel)