/* * 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-common.h" #include "qemu/error-report.h" #include "sysemu/hostmem.h" #include "sysemu/sysemu.h" #include "qom/object_interfaces.h" /* hostmem-file.c */ /** * @TYPE_MEMORY_BACKEND_FILE: * name of backend that uses mmap on a file descriptor */ #define TYPE_MEMORY_BACKEND_FILE "memory-backend-file" #define MEMORY_BACKEND_FILE(obj) \ OBJECT_CHECK(HostMemoryBackendFile, (obj), TYPE_MEMORY_BACKEND_FILE) typedef struct HostMemoryBackendFile HostMemoryBackendFile; struct HostMemoryBackendFile { HostMemoryBackend parent_obj; char *mem_path; uint64_t align; bool discard_data; bool is_pmem; }; static void file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) { HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend); if (!backend->size) { error_setg(errp, "can't create backend with size 0"); return; } if (!fb->mem_path) { error_setg(errp, "mem-path property not set"); return; } #ifndef CONFIG_POSIX error_setg(errp, "-mem-path not supported on this host"); #else if (!host_memory_backend_mr_inited(backend)) { gchar *path; backend->force_prealloc = mem_prealloc; path = object_get_canonical_path(OBJECT(backend)); memory_region_init_ram_from_file(&backend->mr, OBJECT(backend), path, backend->size, fb->align, (backend->share ? RAM_SHARED : 0) | (fb->is_pmem ? RAM_PMEM : 0), fb->mem_path, errp); g_free(path); } #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 value"); 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); Error *local_err = NULL; uint64_t val; if (host_memory_backend_mr_inited(backend)) { error_setg(&local_err, "cannot change property value"); goto out; } visit_type_size(v, name, &val, &local_err); if (local_err) { goto out; } fb->align = val; out: error_propagate(errp, local_err); } 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 '%s'", object_get_typename(o), object_get_canonical_path_component(o)); return; } #ifndef CONFIG_LIBPMEM if (value) { Error *local_err = NULL; error_setg(&local_err, "Lack of libpmem support while setting the 'pmem=on'" " of %s '%s'. We can't ensure data persistence.", object_get_typename(o), object_get_canonical_path_component(o)); error_propagate(errp, local_err); return; } #endif fb->is_pmem = value; } 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, &error_abort); object_class_property_add_str(oc, "mem-path", get_mem_path, set_mem_path, &error_abort); object_class_property_add(oc, "align", "int", file_memory_backend_get_align, file_memory_backend_set_align, NULL, NULL, &error_abort); object_class_property_add_bool(oc, "pmem", file_memory_backend_get_pmem, file_memory_backend_set_pmem, &error_abort); } 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);