vringh32_to_cpu
len = vringh32_to_cpu(vrh, desc->len);
len = vringh32_to_cpu(vrh, desc.len);
if (unlikely(len != vringh32_to_cpu(vrh, desc.len))) {
len = vringh32_to_cpu(vrh, desc.len);
if (unlikely(len != vringh32_to_cpu(vrh, desc.len))) {
vringh32_to_cpu(vrh, desc.len) - len);