pub fn phys_to_virt(phys: u64, hhdm_offset: u64) -> Option<u64> {
    phys.checked_add(hhdm_offset)
}

pub fn virt_to_phys(virt: u64, hhdm_offset: u64) -> Option<u64> {
    virt.checked_sub(hhdm_offset)
}

pub const CANONICAL_SHIFT: u32 = 47;

pub fn is_canonical(addr: u64) -> bool {
    const {
        assert!(
            CANONICAL_SHIFT == 47,
            "is_canonical assumes 4-level paging (48-bit VA)"
        )
    }
    let top_bits = addr >> CANONICAL_SHIFT;
    top_bits == 0 || top_bits == (u64::MAX >> CANONICAL_SHIFT)
}