qemu/hw/i386/amd_iommu.c:188: possible bad shift ?

qemu/hw/i386/amd_iommu.c:188]: (error) Shifting 32-bit value by 64 bits is undefined behaviour

Source code is

    uint64_t mask = ((1 << length) - 1) << bitpos;

Maybe better code

    uint64_t mask = ((1ULL << length) - 1) << bitpos;