MemoryRegion *address_space_translate(AddressSpace *as, hwaddr addr, hwaddr *xlat, hwaddr *plen, bool is_write) { IOMMUTLBEntry iotlb; MemoryRegionSection *section; MemoryRegion *mr; hwaddr len = *plen; for (;;) { section = address_space_translate_internal(as->dispatch, addr, &addr, &len, true); mr = section->mr; if (!mr->iommu_ops) { break; } iotlb = mr->iommu_ops->translate(mr, addr); addr = ((iotlb.translated_addr & ~iotlb.addr_mask) | (addr & iotlb.addr_mask)); len = MIN(len, (addr | iotlb.addr_mask) - addr + 1); if (!(iotlb.perm & (1 << is_write))) { mr = &io_mem_unassigned; break; } as = iotlb.target_as; } *plen = len; *xlat = addr; return mr; }