level1Range
constexpr uint64_t level1Range = level2Range * 512;
constexpr uint64_t level0Range = level1Range * 512;
end / level1Range + 1 - start / level1Range,
level2Range = (uint64_t)level1Range * pteCount,
size_t requiredLevel1 = end / level1Range + 1 - start / level1Range;