From: Wei Xu <w...@redhat.com>
Signed-off-by: Wei Xu <w...@redhat.com>
---
hw/virtio/virtio.c | 104 +++++++++++++++++++++++++++++++++++++++++++++--------
1 file changed, 90 insertions(+), 14 deletions(-)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 95a4681..def07c6 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -26,6 +26,7 @@
#define AVAIL_DESC_PACKED(b) ((b) << 7)
#define USED_DESC_PACKED(b) ((b) << 15)
+#define VIRTQ_F_DESC_USED(w) (AVAIL_DESC_PACKED(w) | USED_DESC_PACKED(w))
/*
* The alignment to use between consumer and producer parts of vring.
@@ -636,19 +637,11 @@ bool virtqueue_rewind(VirtQueue *vq, unsigned int num)
}
/* Called within rcu_read_lock(). */
-void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
+static void virtqueue_fill_split(VirtQueue *vq, const VirtQueueElement *elem,
unsigned int len, unsigned int idx)
{
VRingUsedElem uelem;
- trace_virtqueue_fill(vq, elem, len, idx);
-
- virtqueue_unmap_sg(vq, elem, len);
-
- if (unlikely(vq->vdev->broken)) {
- return;
- }
-
if (unlikely(!vq->vring.used)) {
return;
}
@@ -660,16 +653,66 @@ void virtqueue_fill(VirtQueue *vq, const VirtQueueElement
*elem,
vring_used_write(vq, &uelem, idx);
}
-/* Called within rcu_read_lock(). */
-void virtqueue_flush(VirtQueue *vq, unsigned int count)
+static void virtqueue_fill_packed(VirtQueue *vq, const VirtQueueElement *elem)
{
- uint16_t old, new;
+ uint16_t i, w, head;
+ VRingMemoryRegionCaches *caches;
+ VRingDescPacked desc = {
+ .addr = 0,
+ .flags = 0,
+ };
+
+ if (unlikely(!vq->packed.desc)) {
+ return;
+ }
+
+ w = elem->wrap_counter;
+ caches = vring_get_region_caches(vq);
+ for (i = 0; i < elem->count; i++) {
+ head = (elem->index + i) % vq->packed.num;
+ /* Don't toggle the first one since it is the originally one */
+ if ((i > 0) && (!head)) {
+ w ^= 1;
+ }
+
+ desc.id = elem->index;
+ desc.flags = VIRTQ_F_DESC_USED(w);
+ desc.len = elem->len[i];
+ virtio_tswap16s(vq->vdev, &desc.id);
+ virtio_tswap32s(vq->vdev, &desc.len);
+ virtio_tswap16s(vq->vdev, &desc.flags);
+ address_space_write_cached(&caches->desc,
+ sizeof(VRingDescPacked) * head, &desc,
+ sizeof(VRingDescPacked));
+ address_space_cache_invalidate(&caches->desc,
+ sizeof(VRingDescPacked) * head,
+ sizeof(VRingDescPacked));
+ }
+}
+
+void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
+ unsigned int len, unsigned int idx)
+{
+ trace_virtqueue_fill(vq, elem, len, idx);
+
+ virtqueue_unmap_sg(vq, elem, len);
if (unlikely(vq->vdev->broken)) {
- vq->inuse -= count;
return;
}
+ if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) {
+ virtqueue_fill_packed(vq, elem);
+ } else {
+ virtqueue_fill_split(vq, elem, len, idx);
+ }
+}
+
+/* Called within rcu_read_lock(). */
+static void virtqueue_flush_split(VirtQueue *vq, unsigned int count)
+{
+ uint16_t old, new;
+
if (unlikely(!vq->vring.used)) {
return;
}
@@ -685,12 +728,45 @@ void virtqueue_flush(VirtQueue *vq, unsigned int count)
vq->signalled_used_valid = false;
}
+static void virtqueue_flush_packed(VirtQueue *vq, unsigned int count)
+{
+ if (unlikely(!vq->packed.desc)) {
+ return;
+ }
+
+ vq->inuse -= count;
+
+ /* FIXME: is this correct? */
+ if (vq->inuse) {
+ return;
+ }
+}
+
+void virtqueue_flush(VirtQueue *vq, unsigned int count)
+{
+ if (unlikely(vq->vdev->broken)) {
+ vq->inuse -= count;
+ return;
+ }
+
+ if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) {
+ virtqueue_flush_packed(vq, count);
+ } else {
+ virtqueue_flush_split(vq, count);
+ }
+}
+
void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
unsigned int len)
{
rcu_read_lock();
virtqueue_fill(vq, elem, len, 0);
- virtqueue_flush(vq, 1);
+ if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) {
+ /* FIXME: How to deal with the length field for chained desc */
+ virtqueue_flush(vq, elem->count);
+ } else {
+ virtqueue_flush(vq, 1);
+ }
rcu_read_unlock();
}
--
2.7.4
