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authorAmit Shah <amit.shah@redhat.com>2012-09-25 00:05:15 +0530
committerMichael S. Tsirkin <mst@redhat.com>2012-09-28 12:16:27 +0200
commit0d8d7690850eb0cf2b2b60933cf47669a6b6f18f (patch)
treeab991cfc0a7b72f27ad4e2e927605e240d353114 /hw
parent385ce95d9d060f20870402c8b2b503d0b6ab8af0 (diff)
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virtio: Introduce virtqueue_get_avail_bytes()
The current virtqueue_avail_bytes() is oddly named, and checks if a particular number of bytes are available in a vq. A better API is to fetch the number of bytes available in the vq, and let the caller do what's interesting with the numbers. Introduce virtqueue_get_avail_bytes(), which returns the number of bytes for buffers marked for both, in as well as out. virtqueue_avail_bytes() is made a wrapper over this new function. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw')
-rw-r--r--hw/virtio.c28
-rw-r--r--hw/virtio.h5
2 files changed, 25 insertions, 8 deletions
diff --git a/hw/virtio.c b/hw/virtio.c
index cfad363..6821092 100644
--- a/hw/virtio.c
+++ b/hw/virtio.c
@@ -335,7 +335,8 @@ static unsigned virtqueue_next_desc(target_phys_addr_t desc_pa,
return next;
}
-int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes)
+void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
+ unsigned int *out_bytes)
{
unsigned int idx;
unsigned int total_bufs, in_total, out_total;
@@ -380,13 +381,9 @@ int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes)
}
if (vring_desc_flags(desc_pa, i) & VRING_DESC_F_WRITE) {
- if (in_bytes > 0 &&
- (in_total += vring_desc_len(desc_pa, i)) >= in_bytes)
- return 1;
+ in_total += vring_desc_len(desc_pa, i);
} else {
- if (out_bytes > 0 &&
- (out_total += vring_desc_len(desc_pa, i)) >= out_bytes)
- return 1;
+ out_total += vring_desc_len(desc_pa, i);
}
} while ((i = virtqueue_next_desc(desc_pa, i, max)) != max);
@@ -395,7 +392,24 @@ int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes)
else
total_bufs++;
}
+ if (in_bytes) {
+ *in_bytes = in_total;
+ }
+ if (out_bytes) {
+ *out_bytes = out_total;
+ }
+}
+int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
+ unsigned int out_bytes)
+{
+ unsigned int in_total, out_total;
+
+ virtqueue_get_avail_bytes(vq, &in_total, &out_total);
+ if ((in_bytes && in_bytes < in_total)
+ || (out_bytes && out_bytes < out_total)) {
+ return 1;
+ }
return 0;
}
diff --git a/hw/virtio.h b/hw/virtio.h
index 7a4f564..80de375 100644
--- a/hw/virtio.h
+++ b/hw/virtio.h
@@ -147,7 +147,10 @@ void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
void virtqueue_map_sg(struct iovec *sg, target_phys_addr_t *addr,
size_t num_sg, int is_write);
int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem);
-int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes);
+int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
+ unsigned int out_bytes);
+void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
+ unsigned int *out_bytes);
void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);