vmm_gpt_node_next
node = vmm_gpt_node_next(node, false);
vmm_gpt_node_t *next = vmm_gpt_node_next(node, false);
vmm_gpt_node_next(node->vgn_parent, true);
node = vmm_gpt_node_next(prev, true);
parent = vmm_gpt_node_next(parent, true);
vmm_gpt_node_t *next = vmm_gpt_node_next(node, true);