static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq) { VirtIOBalloon *s = VIRTIO_BALLOON(vdev); VirtQueueElement *elem = &s->stats_vq_elem; VirtIOBalloonStat stat; size_t offset = 0; qemu_timeval tv; if (!virtqueue_pop(vq, elem)) { goto out; } /* Initialize the stats to get rid of any stale values. This is only * needed to handle the case where a guest supports fewer stats than it * used to (ie. it has booted into an old kernel). */ reset_stats(s); while (iov_to_buf(elem->out_sg, elem->out_num, offset, &stat, sizeof(stat)) == sizeof(stat)) { uint16_t tag = virtio_tswap16(vdev, stat.tag); uint64_t val = virtio_tswap64(vdev, stat.val); offset += sizeof(stat); if (tag < VIRTIO_BALLOON_S_NR) s->stats[tag] = val; } s->stats_vq_offset = offset; if (qemu_gettimeofday(&tv) < 0) { fprintf(stderr, "warning: %s: failed to get time of day\n", __func__); goto out; } s->stats_last_update = tv.tv_sec; out: if (balloon_stats_enabled(s)) { balloon_stats_change_timer(s, s->stats_poll_interval); } }