static uint64_t nvme_cmb_read(void *opaque, hwaddr addr, unsigned size)
{
    NvmeCtrl *n = (NvmeCtrl *)opaque;
    return ldn_le_p(&n->cmb.buf[addr], size);
}
static uint64_t nvme_cmb_read(void *opaque, hwaddr addr, unsigned size)
{
    NvmeCtrl *n = (NvmeCtrl *)opaque;
    return ldn_le_p(&n->cmb.buf[addr], size);
}