void *virtqueue_pop(VirtQueue *vq, size_t sz)
{
    unsigned int i, head, max;
    hwaddr desc_pa = vq->vring.desc;
    VirtIODevice *vdev = vq->vdev;
    VirtQueueElement *elem;
    unsigned out_num, in_num;
    hwaddr addr[VIRTQUEUE_MAX_SIZE];
    struct iovec iov[VIRTQUEUE_MAX_SIZE];
    VRingDesc desc;
    if (virtio_queue_empty(vq)) {
        return NULL;
    /* Needed after virtio_queue_empty(), see comment in
     * virtqueue_num_heads(). */
    smp_rmb();
    /* When we start there are none of either input nor output. */
    out_num = in_num = 0;
    max = vq->vring.num;
    i = head = virtqueue_get_head(vq, vq->last_avail_idx++);
    if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
        vring_set_avail_event(vq, vq->last_avail_idx);
    vring_desc_read(vdev, &desc, desc_pa, i);
    if (desc.flags & VRING_DESC_F_INDIRECT) {
        if (desc.len % sizeof(VRingDesc)) {
            error_report("Invalid size for indirect buffer table");
        /* loop over the indirect descriptor table */
        max = desc.len / sizeof(VRingDesc);
        desc_pa = desc.addr;
        i = 0;
        vring_desc_read(vdev, &desc, desc_pa, i);
    /* Collect all the descriptors */
    do {
        if (desc.flags & VRING_DESC_F_WRITE) {
            virtqueue_map_desc(&in_num, addr + out_num, iov + out_num,
                               VIRTQUEUE_MAX_SIZE - out_num, true, desc.addr, desc.len);
        } else {
            if (in_num) {
                error_report("Incorrect order for descriptors");
            virtqueue_map_desc(&out_num, addr, iov,
                               VIRTQUEUE_MAX_SIZE, false, desc.addr, desc.len);
        /* If we've got too many, that implies a descriptor loop. */
        if ((in_num + out_num) > max) {
            error_report("Looped descriptor");
    } while ((i = virtqueue_read_next_desc(vdev, &desc, desc_pa, max)) != max);
    /* Now copy what we have collected and mapped */
    elem = virtqueue_alloc_element(sz, out_num, in_num);
    elem->index = head;
    for (i = 0; i < out_num; i++) {
        elem->out_addr[i] = addr[i];
        elem->out_sg[i] = iov[i];
    for (i = 0; i < in_num; i++) {
        elem->in_addr[i] = addr[out_num + i];
        elem->in_sg[i] = iov[out_num + i];
    vq->inuse++;
    trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num);
    return elem;
void *virtqueue_pop(VirtQueue *vq, size_t sz)
{
    unsigned int i, head, max;
    hwaddr desc_pa = vq->vring.desc;
    VirtIODevice *vdev = vq->vdev;
    VirtQueueElement *elem;
    unsigned out_num, in_num;
    hwaddr addr[VIRTQUEUE_MAX_SIZE];
    struct iovec iov[VIRTQUEUE_MAX_SIZE];
    VRingDesc desc;
    if (virtio_queue_empty(vq)) {
        return NULL;
    

    smp_rmb();
    
    out_num = in_num = 0;
    max = vq->vring.num;
    i = head = virtqueue_get_head(vq, vq->last_avail_idx++);
    if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
        vring_set_avail_event(vq, vq->last_avail_idx);
    vring_desc_read(vdev, &desc, desc_pa, i);
    if (desc.flags & VRING_DESC_F_INDIRECT) {
        if (desc.len % sizeof(VRingDesc)) {
            error_report("Invalid size for indirect buffer table");
        
        max = desc.len / sizeof(VRingDesc);
        desc_pa = desc.addr;
        i = 0;
        vring_desc_read(vdev, &desc, desc_pa, i);
    
    do {
        if (desc.flags & VRING_DESC_F_WRITE) {
            virtqueue_map_desc(&in_num, addr + out_num, iov + out_num,
                               VIRTQUEUE_MAX_SIZE - out_num, true, desc.addr, desc.len);
        } else {
            if (in_num) {
                error_report("Incorrect order for descriptors");
            virtqueue_map_desc(&out_num, addr, iov,
                               VIRTQUEUE_MAX_SIZE, false, desc.addr, desc.len);
        
        if ((in_num + out_num) > max) {
            error_report("Looped descriptor");
    } while ((i = virtqueue_read_next_desc(vdev, &desc, desc_pa, max)) != max);
    
    elem = virtqueue_alloc_element(sz, out_num, in_num);
    elem->index = head;
    for (i = 0; i < out_num; i++) {
        elem->out_addr[i] = addr[i];
        elem->out_sg[i] = iov[i];
    for (i = 0; i < in_num; i++) {
        elem->in_addr[i] = addr[out_num + i];
        elem->in_sg[i] = iov[out_num + i];
    vq->inuse++;
    trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num);
    return elem;
void *FUNC_0(VirtQueue *VAR_0, size_t VAR_1)
{
    unsigned int VAR_2, VAR_3, VAR_4;
    hwaddr desc_pa = VAR_0->vring.desc;
    VirtIODevice *vdev = VAR_0->vdev;
    VirtQueueElement *elem;
    unsigned VAR_5, VAR_6;
    hwaddr addr[VIRTQUEUE_MAX_SIZE];
    struct iovec VAR_7[VIRTQUEUE_MAX_SIZE];
    VRingDesc desc;
    if (virtio_queue_empty(VAR_0)) {
        return NULL;
    

    smp_rmb();
    
    VAR_5 = VAR_6 = 0;
    VAR_4 = VAR_0->vring.num;
    VAR_2 = VAR_3 = virtqueue_get_head(VAR_0, VAR_0->last_avail_idx++);
    if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
        vring_set_avail_event(VAR_0, VAR_0->last_avail_idx);
    vring_desc_read(vdev, &desc, desc_pa, VAR_2);
    if (desc.flags & VRING_DESC_F_INDIRECT) {
        if (desc.len % sizeof(VRingDesc)) {
            error_report("Invalid size for indirect buffer table");
        
        VAR_4 = desc.len / sizeof(VRingDesc);
        desc_pa = desc.addr;
        VAR_2 = 0;
        vring_desc_read(vdev, &desc, desc_pa, VAR_2);
    
    do {
        if (desc.flags & VRING_DESC_F_WRITE) {
            virtqueue_map_desc(&VAR_6, addr + VAR_5, VAR_7 + VAR_5,
                               VIRTQUEUE_MAX_SIZE - VAR_5, true, desc.addr, desc.len);
        } else {
            if (VAR_6) {
                error_report("Incorrect order for descriptors");
            virtqueue_map_desc(&VAR_5, addr, VAR_7,
                               VIRTQUEUE_MAX_SIZE, false, desc.addr, desc.len);
        
        if ((VAR_6 + VAR_5) > VAR_4) {
            error_report("Looped descriptor");
    } while ((VAR_2 = virtqueue_read_next_desc(vdev, &desc, desc_pa, VAR_4)) != VAR_4);
    
    elem = virtqueue_alloc_element(VAR_1, VAR_5, VAR_6);
    elem->index = VAR_3;
    for (VAR_2 = 0; VAR_2 < VAR_5; VAR_2++) {
        elem->out_addr[VAR_2] = addr[VAR_2];
        elem->out_sg[VAR_2] = VAR_7[VAR_2];
    for (VAR_2 = 0; VAR_2 < VAR_6; VAR_2++) {
        elem->in_addr[VAR_2] = addr[VAR_5 + VAR_2];
        elem->in_sg[VAR_2] = VAR_7[VAR_5 + VAR_2];
    VAR_0->inuse++;
    trace_virtqueue_pop(VAR_0, elem, elem->VAR_6, elem->VAR_5);
    return elem;
void *FUNC_0(VirtQueue *VAR_0, size_t VAR_1)
{ unsigned int VAR_2, VAR_3, VAR_4; hwaddr desc_pa = VAR_0->vring.desc; VirtIODevice *vdev = VAR_0->vdev; VirtQueueElement *elem; unsigned VAR_5, VAR_6; hwaddr addr[VIRTQUEUE_MAX_SIZE]; struct iovec VAR_7[VIRTQUEUE_MAX_SIZE]; VRingDesc desc; if (virtio_queue_empty(VAR_0)) { return NULL; smp_rmb(); VAR_5 = VAR_6 = 0; VAR_4 = VAR_0->vring.num; VAR_2 = VAR_3 = virtqueue_get_head(VAR_0, VAR_0->last_avail_idx++); if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) { vring_set_avail_event(VAR_0, VAR_0->last_avail_idx); vring_desc_read(vdev, &desc, desc_pa, VAR_2); if (desc.flags & VRING_DESC_F_INDIRECT) { if (desc.len % sizeof(VRingDesc)) { error_report("Invalid size for indirect buffer table"); VAR_4 = desc.len / sizeof(VRingDesc); desc_pa = desc.addr; VAR_2 = 0; vring_desc_read(vdev, &desc, desc_pa, VAR_2); do { if (desc.flags & VRING_DESC_F_WRITE) { virtqueue_map_desc(&VAR_6, addr + VAR_5, VAR_7 + VAR_5,
VIRTQUEUE_MAX_SIZE - VAR_5, true, desc.addr, desc.len); } else { if (VAR_6) { error_report("Incorrect order for descriptors"); virtqueue_map_desc(&VAR_5, addr, VAR_7,
VIRTQUEUE_MAX_SIZE, false, desc.addr, desc.len); if ((VAR_6 + VAR_5) > VAR_4) { error_report("Looped descriptor"); } while ((VAR_2 = virtqueue_read_next_desc(vdev, &desc, desc_pa, VAR_4)) != VAR_4); elem = virtqueue_alloc_element(VAR_1, VAR_5, VAR_6); elem->index = VAR_3; for (VAR_2 = 0; VAR_2 < VAR_5; VAR_2++) { elem->out_addr[VAR_2] = addr[VAR_2]; elem->out_sg[VAR_2] = VAR_7[VAR_2]; for (VAR_2 = 0; VAR_2 < VAR_6; VAR_2++) { elem->in_addr[VAR_2] = addr[VAR_5 + VAR_2]; elem->in_sg[VAR_2] = VAR_7[VAR_5 + VAR_2]; VAR_0->inuse++; trace_virtqueue_pop(VAR_0, elem, elem->VAR_6, elem->VAR_5); return elem;