ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev, const char *name, ram_addr_t size, void *host) { RAMBlock *new_block, *block; size = TARGET_PAGE_ALIGN(size); new_block = qemu_mallocz(sizeof(*new_block)); if (dev && dev->parent_bus && dev->parent_bus->info->get_dev_path) { char *id = dev->parent_bus->info->get_dev_path(dev); if (id) { snprintf(new_block->idstr, sizeof(new_block->idstr), "%s/", id); qemu_free(id); pstrcat(new_block->idstr, sizeof(new_block->idstr), name); QLIST_FOREACH(block, &ram_list.blocks, next) { if (!strcmp(block->idstr, new_block->idstr)) { fprintf(stderr, "RAMBlock \"%s\" already registered, abort!\n", new_block->idstr); new_block->offset = find_ram_offset(size); if (host) { new_block->host = host; new_block->flags |= RAM_PREALLOC_MASK; } else { if (mem_path) { #if defined (__linux__) && !defined(TARGET_S390X) new_block->host = file_ram_alloc(new_block, size, mem_path); if (!new_block->host) { new_block->host = qemu_vmalloc(size); qemu_madvise(new_block->host, size, QEMU_MADV_MERGEABLE); #else fprintf(stderr, "-mem-path option unsupported\n"); exit(1); #endif } else { #if defined(TARGET_S390X) && defined(CONFIG_KVM) /* S390 KVM requires the topmost vma of the RAM to be smaller than an system defined value, which is at least 256GB. Larger systems have larger values. We put the guest between the end of data segment (system break) and this value. We use 32GB as a base to have enough room for the system break to grow. */ new_block->host = mmap((void*)0x800000000, size, PROT_EXEC|PROT_READ|PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS | MAP_FIXED, -1, 0); #else if (xen_mapcache_enabled()) { xen_ram_alloc(new_block->offset, size); } else { new_block->host = qemu_vmalloc(size); #endif qemu_madvise(new_block->host, size, QEMU_MADV_MERGEABLE); new_block->length = size; QLIST_INSERT_HEAD(&ram_list.blocks, new_block, next); ram_list.phys_dirty = qemu_realloc(ram_list.phys_dirty, last_ram_offset() >> TARGET_PAGE_BITS); memset(ram_list.phys_dirty + (new_block->offset >> TARGET_PAGE_BITS), 0xff, size >> TARGET_PAGE_BITS); if (kvm_enabled()) kvm_setup_guest_memory(new_block->host, size); return new_block->offset;