| /* |
| * VMState interpreter |
| * |
| * Copyright (c) 2009-2017 Red Hat Inc |
| * |
| * Authors: |
| * Juan Quintela <quintela@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 "migration.h" |
| #include "migration/vmstate.h" |
| #include "savevm.h" |
| #include "qapi/qmp/json-writer.h" |
| #include "qemu-file.h" |
| #include "qemu/bitops.h" |
| #include "qemu/error-report.h" |
| #include "trace.h" |
| |
| static int vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd, |
| void *opaque, JSONWriter *vmdesc); |
| static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, |
| void *opaque); |
| |
| static int vmstate_n_elems(void *opaque, const VMStateField *field) |
| { |
| int n_elems = 1; |
| |
| if (field->flags & VMS_ARRAY) { |
| n_elems = field->num; |
| } else if (field->flags & VMS_VARRAY_INT32) { |
| n_elems = *(int32_t *)(opaque + field->num_offset); |
| } else if (field->flags & VMS_VARRAY_UINT32) { |
| n_elems = *(uint32_t *)(opaque + field->num_offset); |
| } else if (field->flags & VMS_VARRAY_UINT16) { |
| n_elems = *(uint16_t *)(opaque + field->num_offset); |
| } else if (field->flags & VMS_VARRAY_UINT8) { |
| n_elems = *(uint8_t *)(opaque + field->num_offset); |
| } |
| |
| if (field->flags & VMS_MULTIPLY_ELEMENTS) { |
| n_elems *= field->num; |
| } |
| |
| trace_vmstate_n_elems(field->name, n_elems); |
| return n_elems; |
| } |
| |
| static int vmstate_size(void *opaque, const VMStateField *field) |
| { |
| int size = field->size; |
| |
| if (field->flags & VMS_VBUFFER) { |
| size = *(int32_t *)(opaque + field->size_offset); |
| if (field->flags & VMS_MULTIPLY) { |
| size *= field->size; |
| } |
| } |
| |
| return size; |
| } |
| |
| static void vmstate_handle_alloc(void *ptr, const VMStateField *field, |
| void *opaque) |
| { |
| if (field->flags & VMS_POINTER && field->flags & VMS_ALLOC) { |
| gsize size = vmstate_size(opaque, field); |
| size *= vmstate_n_elems(opaque, field); |
| if (size) { |
| *(void **)ptr = g_malloc(size); |
| } |
| } |
| } |
| |
| int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd, |
| void *opaque, int version_id) |
| { |
| const VMStateField *field = vmsd->fields; |
| int ret = 0; |
| |
| trace_vmstate_load_state(vmsd->name, version_id); |
| if (version_id > vmsd->version_id) { |
| error_report("%s: incoming version_id %d is too new " |
| "for local version_id %d", |
| vmsd->name, version_id, vmsd->version_id); |
| trace_vmstate_load_state_end(vmsd->name, "too new", -EINVAL); |
| return -EINVAL; |
| } |
| if (version_id < vmsd->minimum_version_id) { |
| error_report("%s: incoming version_id %d is too old " |
| "for local minimum version_id %d", |
| vmsd->name, version_id, vmsd->minimum_version_id); |
| trace_vmstate_load_state_end(vmsd->name, "too old", -EINVAL); |
| return -EINVAL; |
| } |
| if (vmsd->pre_load) { |
| int ret = vmsd->pre_load(opaque); |
| if (ret) { |
| return ret; |
| } |
| } |
| while (field->name) { |
| trace_vmstate_load_state_field(vmsd->name, field->name); |
| if ((field->field_exists && |
| field->field_exists(opaque, version_id)) || |
| (!field->field_exists && |
| field->version_id <= version_id)) { |
| void *first_elem = opaque + field->offset; |
| int i, n_elems = vmstate_n_elems(opaque, field); |
| int size = vmstate_size(opaque, field); |
| |
| vmstate_handle_alloc(first_elem, field, opaque); |
| if (field->flags & VMS_POINTER) { |
| first_elem = *(void **)first_elem; |
| assert(first_elem || !n_elems || !size); |
| } |
| for (i = 0; i < n_elems; i++) { |
| void *curr_elem = first_elem + size * i; |
| |
| if (field->flags & VMS_ARRAY_OF_POINTER) { |
| curr_elem = *(void **)curr_elem; |
| } |
| if (!curr_elem && size) { |
| /* if null pointer check placeholder and do not follow */ |
| assert(field->flags & VMS_ARRAY_OF_POINTER); |
| ret = vmstate_info_nullptr.get(f, curr_elem, size, NULL); |
| } else if (field->flags & VMS_STRUCT) { |
| ret = vmstate_load_state(f, field->vmsd, curr_elem, |
| field->vmsd->version_id); |
| } else if (field->flags & VMS_VSTRUCT) { |
| ret = vmstate_load_state(f, field->vmsd, curr_elem, |
| field->struct_version_id); |
| } else { |
| ret = field->info->get(f, curr_elem, size, field); |
| } |
| if (ret >= 0) { |
| ret = qemu_file_get_error(f); |
| } |
| if (ret < 0) { |
| qemu_file_set_error(f, ret); |
| error_report("Failed to load %s:%s", vmsd->name, |
| field->name); |
| trace_vmstate_load_field_error(field->name, ret); |
| return ret; |
| } |
| } |
| } else if (field->flags & VMS_MUST_EXIST) { |
| error_report("Input validation failed: %s/%s", |
| vmsd->name, field->name); |
| return -1; |
| } |
| field++; |
| } |
| assert(field->flags == VMS_END); |
| ret = vmstate_subsection_load(f, vmsd, opaque); |
| if (ret != 0) { |
| return ret; |
| } |
| if (vmsd->post_load) { |
| ret = vmsd->post_load(opaque, version_id); |
| } |
| trace_vmstate_load_state_end(vmsd->name, "end", ret); |
| return ret; |
| } |
| |
| static int vmfield_name_num(const VMStateField *start, |
| const VMStateField *search) |
| { |
| const VMStateField *field; |
| int found = 0; |
| |
| for (field = start; field->name; field++) { |
| if (!strcmp(field->name, search->name)) { |
| if (field == search) { |
| return found; |
| } |
| found++; |
| } |
| } |
| |
| return -1; |
| } |
| |
| static bool vmfield_name_is_unique(const VMStateField *start, |
| const VMStateField *search) |
| { |
| const VMStateField *field; |
| int found = 0; |
| |
| for (field = start; field->name; field++) { |
| if (!strcmp(field->name, search->name)) { |
| found++; |
| /* name found more than once, so it's not unique */ |
| if (found > 1) { |
| return false; |
| } |
| } |
| } |
| |
| return true; |
| } |
| |
| static const char *vmfield_get_type_name(const VMStateField *field) |
| { |
| const char *type = "unknown"; |
| |
| if (field->flags & VMS_STRUCT) { |
| type = "struct"; |
| } else if (field->flags & VMS_VSTRUCT) { |
| type = "vstruct"; |
| } else if (field->info->name) { |
| type = field->info->name; |
| } |
| |
| return type; |
| } |
| |
| static bool vmsd_can_compress(const VMStateField *field) |
| { |
| if (field->field_exists) { |
| /* Dynamically existing fields mess up compression */ |
| return false; |
| } |
| |
| if (field->flags & VMS_STRUCT) { |
| const VMStateField *sfield = field->vmsd->fields; |
| while (sfield->name) { |
| if (!vmsd_can_compress(sfield)) { |
| /* Child elements can't compress, so can't we */ |
| return false; |
| } |
| sfield++; |
| } |
| |
| if (field->vmsd->subsections) { |
| /* Subsections may come and go, better don't compress */ |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| static void vmsd_desc_field_start(const VMStateDescription *vmsd, |
| JSONWriter *vmdesc, |
| const VMStateField *field, int i, int max) |
| { |
| char *name, *old_name; |
| bool is_array = max > 1; |
| bool can_compress = vmsd_can_compress(field); |
| |
| if (!vmdesc) { |
| return; |
| } |
| |
| name = g_strdup(field->name); |
| |
| /* Field name is not unique, need to make it unique */ |
| if (!vmfield_name_is_unique(vmsd->fields, field)) { |
| int num = vmfield_name_num(vmsd->fields, field); |
| old_name = name; |
| name = g_strdup_printf("%s[%d]", name, num); |
| g_free(old_name); |
| } |
| |
| json_writer_start_object(vmdesc, NULL); |
| json_writer_str(vmdesc, "name", name); |
| if (is_array) { |
| if (can_compress) { |
| json_writer_int64(vmdesc, "array_len", max); |
| } else { |
| json_writer_int64(vmdesc, "index", i); |
| } |
| } |
| json_writer_str(vmdesc, "type", vmfield_get_type_name(field)); |
| |
| if (field->flags & VMS_STRUCT) { |
| json_writer_start_object(vmdesc, "struct"); |
| } |
| |
| g_free(name); |
| } |
| |
| static void vmsd_desc_field_end(const VMStateDescription *vmsd, |
| JSONWriter *vmdesc, |
| const VMStateField *field, size_t size, int i) |
| { |
| if (!vmdesc) { |
| return; |
| } |
| |
| if (field->flags & VMS_STRUCT) { |
| /* We printed a struct in between, close its child object */ |
| json_writer_end_object(vmdesc); |
| } |
| |
| json_writer_int64(vmdesc, "size", size); |
| json_writer_end_object(vmdesc); |
| } |
| |
| |
| bool vmstate_save_needed(const VMStateDescription *vmsd, void *opaque) |
| { |
| if (vmsd->needed && !vmsd->needed(opaque)) { |
| /* optional section not needed */ |
| return false; |
| } |
| return true; |
| } |
| |
| |
| int vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd, |
| void *opaque, JSONWriter *vmdesc_id) |
| { |
| return vmstate_save_state_v(f, vmsd, opaque, vmdesc_id, vmsd->version_id); |
| } |
| |
| int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd, |
| void *opaque, JSONWriter *vmdesc, int version_id) |
| { |
| int ret = 0; |
| const VMStateField *field = vmsd->fields; |
| |
| trace_vmstate_save_state_top(vmsd->name); |
| |
| if (vmsd->pre_save) { |
| ret = vmsd->pre_save(opaque); |
| trace_vmstate_save_state_pre_save_res(vmsd->name, ret); |
| if (ret) { |
| error_report("pre-save failed: %s", vmsd->name); |
| return ret; |
| } |
| } |
| |
| if (vmdesc) { |
| json_writer_str(vmdesc, "vmsd_name", vmsd->name); |
| json_writer_int64(vmdesc, "version", version_id); |
| json_writer_start_array(vmdesc, "fields"); |
| } |
| |
| while (field->name) { |
| if ((field->field_exists && |
| field->field_exists(opaque, version_id)) || |
| (!field->field_exists && |
| field->version_id <= version_id)) { |
| void *first_elem = opaque + field->offset; |
| int i, n_elems = vmstate_n_elems(opaque, field); |
| int size = vmstate_size(opaque, field); |
| uint64_t old_offset, written_bytes; |
| JSONWriter *vmdesc_loop = vmdesc; |
| |
| trace_vmstate_save_state_loop(vmsd->name, field->name, n_elems); |
| if (field->flags & VMS_POINTER) { |
| first_elem = *(void **)first_elem; |
| assert(first_elem || !n_elems || !size); |
| } |
| for (i = 0; i < n_elems; i++) { |
| void *curr_elem = first_elem + size * i; |
| |
| vmsd_desc_field_start(vmsd, vmdesc_loop, field, i, n_elems); |
| old_offset = qemu_file_total_transferred_fast(f); |
| if (field->flags & VMS_ARRAY_OF_POINTER) { |
| assert(curr_elem); |
| curr_elem = *(void **)curr_elem; |
| } |
| if (!curr_elem && size) { |
| /* if null pointer write placeholder and do not follow */ |
| assert(field->flags & VMS_ARRAY_OF_POINTER); |
| ret = vmstate_info_nullptr.put(f, curr_elem, size, NULL, |
| NULL); |
| } else if (field->flags & VMS_STRUCT) { |
| ret = vmstate_save_state(f, field->vmsd, curr_elem, |
| vmdesc_loop); |
| } else if (field->flags & VMS_VSTRUCT) { |
| ret = vmstate_save_state_v(f, field->vmsd, curr_elem, |
| vmdesc_loop, |
| field->struct_version_id); |
| } else { |
| ret = field->info->put(f, curr_elem, size, field, |
| vmdesc_loop); |
| } |
| if (ret) { |
| error_report("Save of field %s/%s failed", |
| vmsd->name, field->name); |
| if (vmsd->post_save) { |
| vmsd->post_save(opaque); |
| } |
| return ret; |
| } |
| |
| written_bytes = qemu_file_total_transferred_fast(f) - |
| old_offset; |
| vmsd_desc_field_end(vmsd, vmdesc_loop, field, written_bytes, i); |
| |
| /* Compressed arrays only care about the first element */ |
| if (vmdesc_loop && vmsd_can_compress(field)) { |
| vmdesc_loop = NULL; |
| } |
| } |
| } else { |
| if (field->flags & VMS_MUST_EXIST) { |
| error_report("Output state validation failed: %s/%s", |
| vmsd->name, field->name); |
| assert(!(field->flags & VMS_MUST_EXIST)); |
| } |
| } |
| field++; |
| } |
| assert(field->flags == VMS_END); |
| |
| if (vmdesc) { |
| json_writer_end_array(vmdesc); |
| } |
| |
| ret = vmstate_subsection_save(f, vmsd, opaque, vmdesc); |
| |
| if (vmsd->post_save) { |
| int ps_ret = vmsd->post_save(opaque); |
| if (!ret) { |
| ret = ps_ret; |
| } |
| } |
| return ret; |
| } |
| |
| static const VMStateDescription * |
| vmstate_get_subsection(const VMStateDescription **sub, char *idstr) |
| { |
| while (sub && *sub) { |
| if (strcmp(idstr, (*sub)->name) == 0) { |
| return *sub; |
| } |
| sub++; |
| } |
| return NULL; |
| } |
| |
| static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, |
| void *opaque) |
| { |
| trace_vmstate_subsection_load(vmsd->name); |
| |
| while (qemu_peek_byte(f, 0) == QEMU_VM_SUBSECTION) { |
| char idstr[256], *idstr_ret; |
| int ret; |
| uint8_t version_id, len, size; |
| const VMStateDescription *sub_vmsd; |
| |
| len = qemu_peek_byte(f, 1); |
| if (len < strlen(vmsd->name) + 1) { |
| /* subsection name has be be "section_name/a" */ |
| trace_vmstate_subsection_load_bad(vmsd->name, "(short)", ""); |
| return 0; |
| } |
| size = qemu_peek_buffer(f, (uint8_t **)&idstr_ret, len, 2); |
| if (size != len) { |
| trace_vmstate_subsection_load_bad(vmsd->name, "(peek fail)", ""); |
| return 0; |
| } |
| memcpy(idstr, idstr_ret, size); |
| idstr[size] = 0; |
| |
| if (strncmp(vmsd->name, idstr, strlen(vmsd->name)) != 0) { |
| trace_vmstate_subsection_load_bad(vmsd->name, idstr, "(prefix)"); |
| /* it doesn't have a valid subsection name */ |
| return 0; |
| } |
| sub_vmsd = vmstate_get_subsection(vmsd->subsections, idstr); |
| if (sub_vmsd == NULL) { |
| trace_vmstate_subsection_load_bad(vmsd->name, idstr, "(lookup)"); |
| return -ENOENT; |
| } |
| qemu_file_skip(f, 1); /* subsection */ |
| qemu_file_skip(f, 1); /* len */ |
| qemu_file_skip(f, len); /* idstr */ |
| version_id = qemu_get_be32(f); |
| |
| ret = vmstate_load_state(f, sub_vmsd, opaque, version_id); |
| if (ret) { |
| trace_vmstate_subsection_load_bad(vmsd->name, idstr, "(child)"); |
| return ret; |
| } |
| } |
| |
| trace_vmstate_subsection_load_good(vmsd->name); |
| return 0; |
| } |
| |
| static int vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd, |
| void *opaque, JSONWriter *vmdesc) |
| { |
| const VMStateDescription **sub = vmsd->subsections; |
| bool vmdesc_has_subsections = false; |
| int ret = 0; |
| |
| trace_vmstate_subsection_save_top(vmsd->name); |
| while (sub && *sub) { |
| if (vmstate_save_needed(*sub, opaque)) { |
| const VMStateDescription *vmsdsub = *sub; |
| uint8_t len; |
| |
| trace_vmstate_subsection_save_loop(vmsd->name, vmsdsub->name); |
| if (vmdesc) { |
| /* Only create subsection array when we have any */ |
| if (!vmdesc_has_subsections) { |
| json_writer_start_array(vmdesc, "subsections"); |
| vmdesc_has_subsections = true; |
| } |
| |
| json_writer_start_object(vmdesc, NULL); |
| } |
| |
| qemu_put_byte(f, QEMU_VM_SUBSECTION); |
| len = strlen(vmsdsub->name); |
| qemu_put_byte(f, len); |
| qemu_put_buffer(f, (uint8_t *)vmsdsub->name, len); |
| qemu_put_be32(f, vmsdsub->version_id); |
| ret = vmstate_save_state(f, vmsdsub, opaque, vmdesc); |
| if (ret) { |
| return ret; |
| } |
| |
| if (vmdesc) { |
| json_writer_end_object(vmdesc); |
| } |
| } |
| sub++; |
| } |
| |
| if (vmdesc_has_subsections) { |
| json_writer_end_array(vmdesc); |
| } |
| |
| return ret; |
| } |
