/* * QEMU Host Memory Backend for hugetlbfs * * Copyright (C) 2013-2014 Red Hat Inc * * Authors: * Paolo Bonzini <pbonzini@redhat.com> * * This work is licensed under the terms of the GNU GPL, version 2 or later. * See the COPYING file in the top-level directory. */ #include "qemu/osdep.h" #include "qapi/error.h" #include "qemu/error-report.h" #include "qemu/module.h" #include "qemu/madvise.h" #include "sysemu/hostmem.h" #include "qom/object_interfaces.h" #include "qom/object.h" #include "qapi/visitor.h" #include "qapi/qapi-visit-common.h" OBJECT_DECLARE_SIMPLE_TYPE(HostMemoryBackendFile, MEMORY_BACKEND_FILE) struct HostMemoryBackendFile { HostMemoryBackend parent_obj; char *mem_path; uint64_t align; uint64_t offset; bool discard_data; bool is_pmem; bool readonly; OnOffAuto rom; }; static bool file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) { #ifndef CONFIG_POSIX error_setg(errp, "backend '%s' not supported on this host", object_get_typename(OBJECT(backend))); return false; #else HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend); g_autofree gchar *name = NULL; uint32_t ram_flags; if (!backend->size) { error_setg(errp, "can't create backend with size 0"); return false; } if (!fb->mem_path) { error_setg(errp, "mem-path property not set"); return false; } switch (fb->rom) { case ON_OFF_AUTO_AUTO: /* Traditionally, opening the file readonly always resulted in ROM. */ fb->rom = fb->readonly ? ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF; break; case ON_OFF_AUTO_ON: if (!fb->readonly) { error_setg(errp, "property 'rom' = 'on' is not supported with" " 'readonly' = 'off'"); return false; } break; case ON_OFF_AUTO_OFF: if (fb->readonly && backend->share) { error_setg(errp, "property 'rom' = 'off' is incompatible with" " 'readonly' = 'on' and 'share' = 'on'"); return false; } break; default: g_assert_not_reached(); } backend->aligned = true; name = host_memory_backend_get_name(backend); ram_flags = backend->share ? RAM_SHARED : 0; ram_flags |= fb->readonly ? RAM_READONLY_FD : 0; ram_flags |= fb->rom == ON_OFF_AUTO_ON ? RAM_READONLY : 0; ram_flags |= backend->reserve ? 0 : RAM_NORESERVE; ram_flags |= backend->guest_memfd ? RAM_GUEST_MEMFD : 0; ram_flags |= fb->is_pmem ? RAM_PMEM : 0; ram_flags |= RAM_NAMED_FILE; return memory_region_init_ram_from_file(&backend->mr, OBJECT(backend), name, backend->size, fb->align, ram_flags, fb->mem_path, fb->offset, errp); #endif } static char *get_mem_path(Object *o, Error **errp) { HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o); return g_strdup(fb->mem_path); } static void set_mem_path(Object *o, const char *str, Error **errp) { HostMemoryBackend *backend = MEMORY_BACKEND(o); HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o); if (host_memory_backend_mr_inited(backend)) { error_setg(errp, "cannot change property 'mem-path' of %s", object_get_typename(o)); return; } g_free(fb->mem_path); fb->mem_path = g_strdup(str); } static bool file_memory_backend_get_discard_data(Object *o, Error **errp) { return MEMORY_BACKEND_FILE(o)->discard_data; } static void file_memory_backend_set_discard_data(Object *o, bool value, Error **errp) { MEMORY_BACKEND_FILE(o)->discard_data = value; } static void file_memory_backend_get_align(Object *o, Visitor *v, const char *name, void *opaque, Error **errp) { HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o); uint64_t val = fb->align; visit_type_size(v, name, &val, errp); } static void file_memory_backend_set_align(Object *o, Visitor *v, const char *name, void *opaque, Error **errp) { HostMemoryBackend *backend = MEMORY_BACKEND(o); HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o); uint64_t val; if (host_memory_backend_mr_inited(backend)) { error_setg(errp, "cannot change property '%s' of %s", name, object_get_typename(o)); return; } if (!visit_type_size(v, name, &val, errp)) { return; } fb->align = val; } static void file_memory_backend_get_offset(Object *o, Visitor *v, const char *name, void *opaque, Error **errp) { HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o); uint64_t val = fb->offset; visit_type_size(v, name, &val, errp); } static void file_memory_backend_set_offset(Object *o, Visitor *v, const char *name, void *opaque, Error **errp) { HostMemoryBackend *backend = MEMORY_BACKEND(o); HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o); uint64_t val; if (host_memory_backend_mr_inited(backend)) { error_setg(errp, "cannot change property '%s' of %s", name, object_get_typename(o)); return; } if (!visit_type_size(v, name, &val, errp)) { return; } fb->offset = val; } #ifdef CONFIG_LIBPMEM static bool file_memory_backend_get_pmem(Object *o, Error **errp) { return MEMORY_BACKEND_FILE(o)->is_pmem; } static void file_memory_backend_set_pmem(Object *o, bool value, Error **errp) { HostMemoryBackend *backend = MEMORY_BACKEND(o); HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o); if (host_memory_backend_mr_inited(backend)) { error_setg(errp, "cannot change property 'pmem' of %s.", object_get_typename(o)); return; } fb->is_pmem = value; } #endif /* CONFIG_LIBPMEM */ static bool file_memory_backend_get_readonly(Object *obj, Error **errp) { HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(obj); return fb->readonly; } static void file_memory_backend_set_readonly(Object *obj, bool value, Error **errp) { HostMemoryBackend *backend = MEMORY_BACKEND(obj); HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(obj); if (host_memory_backend_mr_inited(backend)) { error_setg(errp, "cannot change property 'readonly' of %s.", object_get_typename(obj)); return; } fb->readonly = value; } static void file_memory_backend_get_rom(Object *obj, Visitor *v, const char *name, void *opaque, Error **errp) { HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(obj); OnOffAuto rom = fb->rom; visit_type_OnOffAuto(v, name, &rom, errp); } static void file_memory_backend_set_rom(Object *obj, Visitor *v, const char *name, void *opaque, Error **errp) { HostMemoryBackend *backend = MEMORY_BACKEND(obj); HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(obj); if (host_memory_backend_mr_inited(backend)) { error_setg(errp, "cannot change property '%s' of %s.", name, object_get_typename(obj)); return; } visit_type_OnOffAuto(v, name, &fb->rom, errp); } static void file_backend_unparent(Object *obj) { HostMemoryBackend *backend = MEMORY_BACKEND(obj); HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(obj); if (host_memory_backend_mr_inited(backend) && fb->discard_data) { void *ptr = memory_region_get_ram_ptr(&backend->mr); uint64_t sz = memory_region_size(&backend->mr); qemu_madvise(ptr, sz, QEMU_MADV_REMOVE); } } static void file_backend_class_init(ObjectClass *oc, void *data) { HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc); bc->alloc = file_backend_memory_alloc; oc->unparent = file_backend_unparent; object_class_property_add_bool(oc, "discard-data", file_memory_backend_get_discard_data, file_memory_backend_set_discard_data); object_class_property_add_str(oc, "mem-path", get_mem_path, set_mem_path); object_class_property_add(oc, "align", "int", file_memory_backend_get_align, file_memory_backend_set_align, NULL, NULL); object_class_property_add(oc, "offset", "int", file_memory_backend_get_offset, file_memory_backend_set_offset, NULL, NULL); object_class_property_set_description(oc, "offset", "Offset into the target file (ex: 1G)"); #ifdef CONFIG_LIBPMEM object_class_property_add_bool(oc, "pmem", file_memory_backend_get_pmem, file_memory_backend_set_pmem); #endif object_class_property_add_bool(oc, "readonly", file_memory_backend_get_readonly, file_memory_backend_set_readonly); object_class_property_add(oc, "rom", "OnOffAuto", file_memory_backend_get_rom, file_memory_backend_set_rom, NULL, NULL); object_class_property_set_description(oc, "rom", "Whether to create Read Only Memory (ROM)"); } static void file_backend_instance_finalize(Object *o) { HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o); g_free(fb->mem_path); } static const TypeInfo file_backend_info = { .name = TYPE_MEMORY_BACKEND_FILE, .parent = TYPE_MEMORY_BACKEND, .class_init = file_backend_class_init, .instance_finalize = file_backend_instance_finalize, .instance_size = sizeof(HostMemoryBackendFile), }; static void register_types(void) { type_register_static(&file_backend_info); } type_init(register_types);