[Qemu-devel] [PATCH v2 03/15] virtio: expand offset calculation for packed ring

[wexu@redhat.com]

From: Wei Xu <wexu@redhat.com>

Expand 1.0 to 1.1 by adding offset calculation accordingly.

Signed-off-by: Wei Xu <wexu@redhat.com>
---
 hw/virtio/virtio.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 827e745..112845c 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -2336,14 +2336,28 @@ hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n)
 
 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n)
 {
-    return offsetof(VRingAvail, ring) +
-        sizeof(uint16_t) * vdev->vq[n].vring.num;
+    int s;
+
+    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
+        return sizeof(struct VRingPackedDescEvent);
+    } else {
+        s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
+        return offsetof(VRingAvail, ring) +
+            sizeof(uint16_t) * vdev->vq[n].vring.num + s;
+    }
 }
 
 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n)
 {
-    return offsetof(VRingUsed, ring) +
-        sizeof(VRingUsedElem) * vdev->vq[n].vring.num;
+    int s;
+
+    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
+        return sizeof(struct VRingPackedDescEvent);
+    } else {
+        s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
+        return offsetof(VRingUsed, ring) +
+            sizeof(VRingUsedElem) * vdev->vq[n].vring.num + s;
+    }
 }
 
 uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n)
-- 
1.8.3.1