virtio: remove unused next argument from virtqueue_split_read_next_desc()

The 'next' was converted from a local variable to an output parameter
in commit:
  412e0e81b1 ("virtio: handle virtqueue_read_next_desc() errors")

But all the actual uses of the 'i/next' as an output were removed a few
months prior in commit:
  aa570d6fb6 ("virtio: combine the read of a descriptor")

Remove the unused argument to simplify the code.

Also, adding a comment to the function to describe what it is actually
doing, as it is not obvious that the 'desc' is both an input and an
output argument.

Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Message-Id: <20230927140016.2317404-3-i.maximets@ovn.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Ilya Maximets 2023-09-27 15:59:42 +02:00 committed by Michael S. Tsirkin
parent d501f97d96
commit 70f88436aa

View File

@ -1049,9 +1049,10 @@ enum {
VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */ VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */
}; };
/* Reads the 'desc->next' descriptor into '*desc'. */
static int virtqueue_split_read_next_desc(VirtIODevice *vdev, VRingDesc *desc, static int virtqueue_split_read_next_desc(VirtIODevice *vdev, VRingDesc *desc,
MemoryRegionCache *desc_cache, MemoryRegionCache *desc_cache,
unsigned int max, unsigned int *next) unsigned int max)
{ {
/* If this descriptor says it doesn't chain, we're done. */ /* If this descriptor says it doesn't chain, we're done. */
if (!(desc->flags & VRING_DESC_F_NEXT)) { if (!(desc->flags & VRING_DESC_F_NEXT)) {
@ -1059,14 +1060,12 @@ static int virtqueue_split_read_next_desc(VirtIODevice *vdev, VRingDesc *desc,
} }
/* Check they're not leading us off end of descriptors. */ /* Check they're not leading us off end of descriptors. */
*next = desc->next; if (desc->next >= max) {
virtio_error(vdev, "Desc next is %u", desc->next);
if (*next >= max) {
virtio_error(vdev, "Desc next is %u", *next);
return VIRTQUEUE_READ_DESC_ERROR; return VIRTQUEUE_READ_DESC_ERROR;
} }
vring_split_desc_read(vdev, desc, desc_cache, *next); vring_split_desc_read(vdev, desc, desc_cache, desc->next);
return VIRTQUEUE_READ_DESC_MORE; return VIRTQUEUE_READ_DESC_MORE;
} }
@ -1146,7 +1145,7 @@ static void virtqueue_split_get_avail_bytes(VirtQueue *vq,
goto done; goto done;
} }
rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, max, &i); rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, max);
} while (rc == VIRTQUEUE_READ_DESC_MORE); } while (rc == VIRTQUEUE_READ_DESC_MORE);
if (rc == VIRTQUEUE_READ_DESC_ERROR) { if (rc == VIRTQUEUE_READ_DESC_ERROR) {
@ -1601,7 +1600,7 @@ static void *virtqueue_split_pop(VirtQueue *vq, size_t sz)
goto err_undo_map; goto err_undo_map;
} }
rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, max, &i); rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, max);
} while (rc == VIRTQUEUE_READ_DESC_MORE); } while (rc == VIRTQUEUE_READ_DESC_MORE);
if (rc == VIRTQUEUE_READ_DESC_ERROR) { if (rc == VIRTQUEUE_READ_DESC_ERROR) {
@ -4055,8 +4054,7 @@ VirtioQueueElement *qmp_x_query_virtio_queue_element(const char *path,
list = node; list = node;
ndescs++; ndescs++;
rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, max);
max, &i);
} while (rc == VIRTQUEUE_READ_DESC_MORE); } while (rc == VIRTQUEUE_READ_DESC_MORE);
element->descs = list; element->descs = list;
done: done: