From: David van Moolenbroek <david@minix3.org>
Date: Mon, 1 Dec 2014 17:30:45 +0000 (+0000)
Subject: libvirtio: expose result size on packet dequeue
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/zpipe.c?a=commitdiff_plain;h=d1db724f47546f27b96ba07a2046ee438e6df526;p=minix.git

libvirtio: expose result size on packet dequeue

Change-Id: I49304678895779849abc2528a9f78730f968e712
---

diff --git a/minix/drivers/net/virtio_net/virtio_net.c b/minix/drivers/net/virtio_net/virtio_net.c
index e7daa1a6e..2cb381a02 100644
--- a/minix/drivers/net/virtio_net/virtio_net.c
+++ b/minix/drivers/net/virtio_net/virtio_net.c
@@ -268,7 +268,7 @@ virtio_net_check_queues(void)
 	struct packet *p;
 
 	/* Put the received packets into the recv list */
-	while (virtio_from_queue(net_dev, RX_Q, (void **)&p) == 0) {
+	while (virtio_from_queue(net_dev, RX_Q, (void **)&p, NULL) == 0) {
 		STAILQ_INSERT_TAIL(&recv_list, p, next);
 		in_rx--;
 		virtio_net_stats.ets_packetR++;
@@ -277,7 +277,7 @@ virtio_net_check_queues(void)
 	/* Packets from the TX queue just indicated they are free to
 	 * be reused now. inet already knows about them as being sent.
 	 */
-	while (virtio_from_queue(net_dev, TX_Q, (void **)&p) == 0) {
+	while (virtio_from_queue(net_dev, TX_Q, (void **)&p, NULL) == 0) {
 		memset(p->vhdr, 0, sizeof(*p->vhdr));
 		memset(p->vdata, 0, MAX_PACK_SIZE);
 		STAILQ_INSERT_HEAD(&free_list, p, next);
diff --git a/minix/drivers/storage/virtio_blk/virtio_blk.c b/minix/drivers/storage/virtio_blk/virtio_blk.c
index 4583101c7..d7a3c7338 100644
--- a/minix/drivers/storage/virtio_blk/virtio_blk.c
+++ b/minix/drivers/storage/virtio_blk/virtio_blk.c
@@ -439,7 +439,7 @@ virtio_blk_device_intr(void)
 	thread_id_t *tid;
 
 	/* Multiple requests might have finished */
-	while (!virtio_from_queue(blk_dev, 0, (void**)&tid))
+	while (!virtio_from_queue(blk_dev, 0, (void**)&tid, NULL))
 		blockdriver_mt_wakeup(*tid);
 }
 
diff --git a/minix/include/minix/virtio.h b/minix/include/minix/virtio.h
index aec6d4b89..aee338e1c 100644
--- a/minix/include/minix/virtio.h
+++ b/minix/include/minix/virtio.h
@@ -98,11 +98,12 @@ int virtio_to_queue(struct virtio_device *dev, int qidx,
 			struct vumap_phys *bufs, size_t num, void *data);
 
 /*
- * If the host used a chain of descriptors, return 0 and set data
- * as was given to virtio_to_queue(). If the host has not processed
- * any element returns -1.
+ * If the host used a chain of descriptors, return 0, set data as was given to
+ * virtio_to_queue(), and if len is not NULL, set it to the resulting length.
+ * If the host has not processed any element, return -1.
  */
-int virtio_from_queue(struct virtio_device *dev, int qidx, void **data);
+int virtio_from_queue(struct virtio_device *dev, int qidx, void **data,
+	size_t *len);
 
 /* IRQ related functions */
 void virtio_irq_enable(struct virtio_device *dev);
diff --git a/minix/lib/libvirtio/virtio.c b/minix/lib/libvirtio/virtio.c
index 1ff715a04..95c64cbe0 100644
--- a/minix/lib/libvirtio/virtio.c
+++ b/minix/lib/libvirtio/virtio.c
@@ -639,7 +639,8 @@ virtio_to_queue(struct virtio_device *dev, int qidx, struct vumap_phys *bufs,
 }
 
 int
-virtio_from_queue(struct virtio_device *dev, int qidx, void **data)
+virtio_from_queue(struct virtio_device *dev, int qidx, void **data,
+	size_t *len)
 {
 	struct virtio_queue *q;
 	struct vring *vring;
@@ -718,6 +719,9 @@ virtio_from_queue(struct virtio_device *dev, int qidx, void **data)
 	*data = q->data[uel->id];
 	q->data[uel->id] = NULL;
 
+	if (len != NULL)
+		*len = uel->len;
+
 	return 0;
 }