Commit 0d8d7690 authored by Amit Shah's avatar Amit Shah Committed by Michael S. Tsirkin
Browse files

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: default avatarAmit Shah <amit.shah@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 385ce95d

hw/virtio.c

+21 −7
Original line number Diff line number Diff line
@@ -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;

}

hw/virtio.h

+4 −1
Original line number Diff line number Diff line
@@ -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);