| /* |
| * QEMU host memfd memory backend |
| * |
| * Copyright (C) 2018 Red Hat Inc |
| * |
| * Authors: |
| * Marc-André Lureau <marcandre.lureau@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 "sysemu/hostmem.h" |
| #include "sysemu/sysemu.h" |
| #include "qom/object_interfaces.h" |
| #include "qemu/memfd.h" |
| #include "qemu/module.h" |
| #include "qapi/error.h" |
| #include "qom/object.h" |
| |
| #define TYPE_MEMORY_BACKEND_MEMFD "memory-backend-memfd" |
| |
| typedef struct HostMemoryBackendMemfd HostMemoryBackendMemfd; |
| #define MEMORY_BACKEND_MEMFD(obj) \ |
| OBJECT_CHECK(HostMemoryBackendMemfd, (obj), TYPE_MEMORY_BACKEND_MEMFD) |
| |
| |
| struct HostMemoryBackendMemfd { |
| HostMemoryBackend parent_obj; |
| |
| bool hugetlb; |
| uint64_t hugetlbsize; |
| bool seal; |
| }; |
| |
| static void |
| memfd_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) |
| { |
| HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(backend); |
| char *name; |
| int fd; |
| |
| if (!backend->size) { |
| error_setg(errp, "can't create backend with size 0"); |
| return; |
| } |
| |
| fd = qemu_memfd_create(TYPE_MEMORY_BACKEND_MEMFD, backend->size, |
| m->hugetlb, m->hugetlbsize, m->seal ? |
| F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL : 0, |
| errp); |
| if (fd == -1) { |
| return; |
| } |
| |
| name = host_memory_backend_get_name(backend); |
| memory_region_init_ram_from_fd(&backend->mr, OBJECT(backend), |
| name, backend->size, |
| backend->share, fd, errp); |
| g_free(name); |
| } |
| |
| static bool |
| memfd_backend_get_hugetlb(Object *o, Error **errp) |
| { |
| return MEMORY_BACKEND_MEMFD(o)->hugetlb; |
| } |
| |
| static void |
| memfd_backend_set_hugetlb(Object *o, bool value, Error **errp) |
| { |
| MEMORY_BACKEND_MEMFD(o)->hugetlb = value; |
| } |
| |
| static void |
| memfd_backend_set_hugetlbsize(Object *obj, Visitor *v, const char *name, |
| void *opaque, Error **errp) |
| { |
| HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj); |
| uint64_t value; |
| |
| if (host_memory_backend_mr_inited(MEMORY_BACKEND(obj))) { |
| error_setg(errp, "cannot change property value"); |
| return; |
| } |
| |
| if (!visit_type_size(v, name, &value, errp)) { |
| return; |
| } |
| if (!value) { |
| error_setg(errp, "Property '%s.%s' doesn't take value '%" PRIu64 "'", |
| object_get_typename(obj), name, value); |
| return; |
| } |
| m->hugetlbsize = value; |
| } |
| |
| static void |
| memfd_backend_get_hugetlbsize(Object *obj, Visitor *v, const char *name, |
| void *opaque, Error **errp) |
| { |
| HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj); |
| uint64_t value = m->hugetlbsize; |
| |
| visit_type_size(v, name, &value, errp); |
| } |
| |
| static bool |
| memfd_backend_get_seal(Object *o, Error **errp) |
| { |
| return MEMORY_BACKEND_MEMFD(o)->seal; |
| } |
| |
| static void |
| memfd_backend_set_seal(Object *o, bool value, Error **errp) |
| { |
| MEMORY_BACKEND_MEMFD(o)->seal = value; |
| } |
| |
| static void |
| memfd_backend_instance_init(Object *obj) |
| { |
| HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj); |
| |
| /* default to sealed file */ |
| m->seal = true; |
| MEMORY_BACKEND(m)->share = true; |
| } |
| |
| static void |
| memfd_backend_class_init(ObjectClass *oc, void *data) |
| { |
| HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc); |
| |
| bc->alloc = memfd_backend_memory_alloc; |
| |
| if (qemu_memfd_check(MFD_HUGETLB)) { |
| object_class_property_add_bool(oc, "hugetlb", |
| memfd_backend_get_hugetlb, |
| memfd_backend_set_hugetlb); |
| object_class_property_set_description(oc, "hugetlb", |
| "Use huge pages"); |
| object_class_property_add(oc, "hugetlbsize", "int", |
| memfd_backend_get_hugetlbsize, |
| memfd_backend_set_hugetlbsize, |
| NULL, NULL); |
| object_class_property_set_description(oc, "hugetlbsize", |
| "Huge pages size (ex: 2M, 1G)"); |
| } |
| object_class_property_add_bool(oc, "seal", |
| memfd_backend_get_seal, |
| memfd_backend_set_seal); |
| object_class_property_set_description(oc, "seal", |
| "Seal growing & shrinking"); |
| } |
| |
| static const TypeInfo memfd_backend_info = { |
| .name = TYPE_MEMORY_BACKEND_MEMFD, |
| .parent = TYPE_MEMORY_BACKEND, |
| .instance_init = memfd_backend_instance_init, |
| .class_init = memfd_backend_class_init, |
| .instance_size = sizeof(HostMemoryBackendMemfd), |
| }; |
| |
| static void register_types(void) |
| { |
| if (qemu_memfd_check(MFD_ALLOW_SEALING)) { |
| type_register_static(&memfd_backend_info); |
| } |
| } |
| |
| type_init(register_types); |