hv_sgl_node
struct hv_sgl_node *sgl_node = NULL;
sgl_node = malloc(sizeof(struct hv_sgl_node),
LIST_ENTRY(hv_sgl_node) link;
LIST_HEAD(, hv_sgl_node) in_use_sgl_list;
LIST_HEAD(, hv_sgl_node) free_sgl_list;
struct hv_sgl_node *sgl_node = NULL;
struct hv_sgl_node *sgl_node = NULL;
struct hv_sgl_node *sgl_node = NULL;