| /* | |
| * 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/error.h" | |
| #include "qobject/json-writer.h" | |
| #include "qemu-file.h" | |
| #include "qemu/bitops.h" | |
| #include "qemu/error-report.h" | |
| #include "trace.h" | |
| static bool vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd, | |
| void *opaque, JSONWriter *vmdesc, | |
| Error **errp); | |
| static bool vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, | |
| void *opaque, Error **errp); | |
| static bool vmstate_save_vmsd_v(QEMUFile *f, const VMStateDescription *vmsd, | |
| void *opaque, JSONWriter *vmdesc, | |
| int version_id, Error **errp); | |
| /* Whether this field should exist for either save or load the VM? */ | |
| static bool | |
| vmstate_field_exists(const VMStateDescription *vmsd, const VMStateField *field, | |
| void *opaque, int version_id) | |
| { | |
| bool result; | |
| if (field->field_exists) { | |
| /* If there's the function checker, that's the solo truth */ | |
| result = field->field_exists(opaque, version_id); | |
| trace_vmstate_field_exists(vmsd->name, field->name, field->version_id, | |
| version_id, result); | |
| } else { | |
| /* | |
| * Otherwise, we only save/load if field version is same or older. | |
| * For example, when loading from an old binary with old version, | |
| * we ignore new fields with newer version_ids. | |
| */ | |
| result = field->version_id <= version_id; | |
| } | |
| return result; | |
| } | |
| /* | |
| * Create a ptr marker field when there's a NULL pointer detected in the | |
| * array of a VMS_ARRAY_OF_POINTER VMSD field. It's needed because we | |
| * can't dereference the NULL pointer. | |
| */ | |
| static void | |
| vmsd_init_ptr_marker_field(VMStateField *fake, const VMStateField *field) | |
| { | |
| /* It can only happen on an array of pointers! */ | |
| assert(field->flags & VMS_ARRAY_OF_POINTER); | |
| /* See vmstate_info_ptr_marker - 1 byte represents ptr status */ | |
| *fake = (VMStateField) { | |
| .name = field->name, | |
| .version_id = field->version_id, | |
| /* Marker always exists, no field_exists callback needed */ | |
| .field_exists = NULL, | |
| .size = 1, | |
| .info = &vmstate_info_ptr_marker, | |
| .flags = VMS_SINGLE, | |
| /* All other fields stay zero-initialised */ | |
| }; | |
| } | |
| static uint64_t vmstate_read_from_offset(const VMStateStructMember *member, | |
| void *opaque) | |
| { | |
| uint8_t *ptr = (uint8_t *)opaque + member->offset; | |
| switch (member->size) { | |
| case 1: { | |
| uint8_t v; | |
| memcpy(&v, ptr, 1); | |
| return v; | |
| } | |
| case 2: { | |
| uint16_t v; | |
| memcpy(&v, ptr, 2); | |
| return v; | |
| } | |
| case 4: { | |
| uint32_t v; | |
| memcpy(&v, ptr, 4); | |
| return v; | |
| } | |
| case 8: { | |
| uint64_t v; | |
| memcpy(&v, ptr, 8); | |
| return v; | |
| } | |
| } | |
| g_assert_not_reached(); | |
| } | |
| static uint64_t vmstate_n_elems(void *opaque, const VMStateField *field) | |
| { | |
| uint64_t n_elems; | |
| if (field->flags & VMS_ARRAY) { | |
| n_elems = field->num; | |
| } else if (field->flags & VMS_VARRAY) { | |
| n_elems = vmstate_read_from_offset(&field->num_indirect, opaque); | |
| } else if (field->flags & VMS_MUST_EXIST && field->flags & VMS_NO_STATE) { | |
| n_elems = 0; | |
| } else { | |
| n_elems = 1; | |
| } | |
| trace_vmstate_n_elems(field->name, n_elems); | |
| return n_elems; | |
| } | |
| static bool vmstate_size(void *opaque, const VMStateField *field, | |
| uint64_t *sz, Error **errp) | |
| { | |
| uint64_t size; | |
| *sz = 0; | |
| if (field->flags & VMS_VBUFFER) { | |
| size = vmstate_read_from_offset(&field->size_indirect, opaque); | |
| if ((field->flags & VMS_MULTIPLY) && | |
| umul64_overflow(size, field->size, &size)) { | |
| error_setg(errp, "%s: VMState field '%s' multiply overflow", | |
| __func__, field->name); | |
| return false; | |
| } | |
| } else if (field->flags & VMS_ARRAY_OF_POINTER) { | |
| /* | |
| * For an array of pointer, the each element is always size of a | |
| * host pointer. | |
| */ | |
| size = sizeof(void *); | |
| } else { | |
| size = field->size; | |
| } | |
| *sz = size; | |
| return true; | |
| } | |
| static bool vmstate_handle_alloc(void *ptr, const VMStateField *field, | |
| uint64_t n, uint64_t size, Error **errp) | |
| { | |
| void *p; | |
| if (field->flags & VMS_POINTER && field->flags & VMS_ALLOC) { | |
| if (size && n) { | |
| if (umul64_overflow(size, n, &size)) { | |
| error_setg(errp, "%s: field '%s' multiply overflow", | |
| __func__, field->name); | |
| return false; | |
| } | |
| p = g_try_malloc(size); | |
| if (!p) { | |
| error_setg(errp, "%s: Could not allocate memory for field '%s'", | |
| __func__, field->name); | |
| return false; | |
| } | |
| *(void **)ptr = p; | |
| } | |
| } | |
| return true; | |
| } | |
| static bool vmstate_ptr_marker_load(QEMUFile *f, bool *load_field, | |
| Error **errp) | |
| { | |
| int byte = qemu_get_byte(f); | |
| if (byte == VMS_MARKER_PTR_NULL) { | |
| /* When it's a null ptr marker, do not continue the load */ | |
| *load_field = false; | |
| return true; | |
| } | |
| if (byte == VMS_MARKER_PTR_VALID) { | |
| /* We need to load the field right after the marker */ | |
| *load_field = true; | |
| return true; | |
| } | |
| error_setg(errp, "Unexpected ptr marker: %d", byte); | |
| return false; | |
| } | |
| static bool vmstate_pre_load(const VMStateDescription *vmsd, void *opaque, | |
| Error **errp) | |
| { | |
| ERRP_GUARD(); | |
| if (vmsd->pre_load_errp) { | |
| if (!vmsd->pre_load_errp(opaque, errp)) { | |
| error_prepend(errp, "pre load hook failed for: '%s', " | |
| "version_id: %d, minimum version_id: %d: ", | |
| vmsd->name, vmsd->version_id, | |
| vmsd->minimum_version_id); | |
| return false; | |
| } | |
| } else if (vmsd->pre_load) { | |
| int ret = vmsd->pre_load(opaque); | |
| if (ret) { | |
| error_setg(errp, "pre load hook failed for: '%s', " | |
| "version_id: %d, minimum version_id: %d, ret: %d", | |
| vmsd->name, vmsd->version_id, vmsd->minimum_version_id, | |
| ret); | |
| return false; | |
| } | |
| } | |
| return true; | |
| } | |
| static bool vmstate_load_field(QEMUFile *f, void *pv, size_t size, | |
| const VMStateField *field, Error **errp) | |
| { | |
| if (field->flags & VMS_STRUCT) { | |
| return vmstate_load_vmsd(f, field->vmsd, pv, field->vmsd->version_id, | |
| errp); | |
| } else if (field->flags & VMS_VSTRUCT) { | |
| return vmstate_load_vmsd(f, field->vmsd, pv, field->struct_version_id, | |
| errp); | |
| } else if (field->info->load) { | |
| return field->info->load(f, pv, size, field, errp); | |
| } | |
| if (field->info->get(f, pv, size, field) < 0) { | |
| error_setg(errp, | |
| "Failed to load element of type %s for %s", | |
| field->info->name, field->name); | |
| return false; | |
| } | |
| return true; | |
| } | |
| static bool vmstate_post_load(const VMStateDescription *vmsd, | |
| void *opaque, int version_id, Error **errp) | |
| { | |
| ERRP_GUARD(); | |
| if (vmsd->post_load_errp) { | |
| if (!vmsd->post_load_errp(opaque, version_id, errp)) { | |
| error_prepend(errp, "post load hook failed for: %s, version_id: " | |
| "%d, minimum_version: %d: ", vmsd->name, | |
| vmsd->version_id, vmsd->minimum_version_id); | |
| return false; | |
| } | |
| } else if (vmsd->post_load) { | |
| int ret = vmsd->post_load(opaque, version_id); | |
| if (ret < 0) { | |
| error_setg(errp, | |
| "post load hook failed for: %s, version_id: %d, " | |
| "minimum_version: %d, ret: %d", | |
| vmsd->name, vmsd->version_id, vmsd->minimum_version_id, | |
| ret); | |
| return false; | |
| } | |
| } | |
| return true; | |
| } | |
| /* | |
| * Try to prepare loading the next element, the object pointer to be put | |
| * into @next_elem. When @next_elem is NULL, it means we should skip | |
| * loading this element. | |
| * | |
| * Returns false for errors, in which case *errp will be set, migration | |
| * must be aborted. | |
| */ | |
| static bool vmstate_load_next(QEMUFile *f, const VMStateField *field, | |
| void *first_elem, void **next_elem, | |
| int size, int i, Error **errp) | |
| { | |
| bool auto_alloc = field->flags & VMS_ARRAY_OF_POINTER_AUTO_ALLOC; | |
| void *ptr = first_elem + size * i, **pptr; | |
| bool load_field; | |
| if (!(field->flags & VMS_ARRAY_OF_POINTER)) { | |
| /* Simplest case, no pointer involved */ | |
| *next_elem = ptr; | |
| return true; | |
| } | |
| /* | |
| * We're loading an array of pointers, switch to use pptr to make it | |
| * easier to read later | |
| */ | |
| pptr = (void **)ptr; | |
| /* | |
| * If auto_alloc is on, making sure the user provided an array of NULL | |
| * pointers to start with | |
| */ | |
| assert(!auto_alloc || *pptr == NULL); | |
| /* | |
| * When pointer is null, we must expect a ptr marker first. Use cases: | |
| * | |
| * (1) _AUTO_ALLOC implies a ptr marker will always exist, or, | |
| * | |
| * (2) the element on destination is NULL, which expects the src to send a | |
| * NULL-only marker. | |
| * | |
| * Here, checking against a NULL pointer will work for both. | |
| */ | |
| if (!*pptr) { | |
| if (!vmstate_ptr_marker_load(f, &load_field, errp)) { | |
| trace_vmstate_load_field_error(field->name, -EINVAL); | |
| return false; | |
| } | |
| /* | |
| * If loading is needed, do pre-allocation first (otherwise keeping | |
| * *pptr==NULL to imply a skip below) | |
| */ | |
| if (load_field) { | |
| /* Only applies when auto_alloc=on on the field */ | |
| assert(auto_alloc); | |
| /* | |
| * NOTE: do not use vmstate_size() here, because we need the | |
| * object size, not entry size of the array. | |
| */ | |
| *pptr = g_malloc0(field->size); | |
| } | |
| } | |
| /* Move the cursor to the next element for loading */ | |
| *next_elem = *pptr; | |
| return true; | |
| } | |
| bool vmstate_load_vmsd(QEMUFile *f, const VMStateDescription *vmsd, | |
| void *opaque, int version_id, Error **errp) | |
| { | |
| ERRP_GUARD(); | |
| const VMStateField *field = vmsd->fields; | |
| trace_vmstate_load_state(vmsd->name, version_id); | |
| if (version_id > vmsd->version_id) { | |
| error_setg(errp, "%s: incoming version_id %d is too new " | |
| "for local version_id %d", | |
| vmsd->name, version_id, vmsd->version_id); | |
| trace_vmstate_load_state_fail(vmsd->name, "too new"); | |
| return false; | |
| } | |
| if (version_id < vmsd->minimum_version_id) { | |
| error_setg(errp, "%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_fail(vmsd->name, "too old"); | |
| return false; | |
| } | |
| if (!vmstate_pre_load(vmsd, opaque, errp)) { | |
| return false; | |
| } | |
| while (field->name) { | |
| bool exists = vmstate_field_exists(vmsd, field, opaque, version_id); | |
| trace_vmstate_load_state_field(vmsd->name, field->name, exists); | |
| if (exists) { | |
| void *first_elem = opaque + field->offset; | |
| int i; | |
| uint64_t n_elems = vmstate_n_elems(opaque, field); | |
| uint64_t size; | |
| if (!vmstate_size(opaque, field, &size, errp)) { | |
| return false; | |
| } | |
| if (!vmstate_handle_alloc(first_elem, field, n_elems, size, errp)) { | |
| return false; | |
| } | |
| 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; | |
| bool ok; | |
| ok = vmstate_load_next(f, field, first_elem, &curr_elem, | |
| size, i, errp); | |
| if (!ok) { | |
| return false; | |
| } | |
| if (!curr_elem) { | |
| /* Implies a skip */ | |
| continue; | |
| } | |
| ok = vmstate_load_field(f, curr_elem, size, field, errp); | |
| if (ok) { | |
| int ret = qemu_file_get_error(f); | |
| if (ret < 0) { | |
| error_setg(errp, | |
| "Failed to load %s state: stream error: %d", | |
| vmsd->name, ret); | |
| trace_vmstate_load_field_error(field->name, ret); | |
| return false; | |
| } | |
| } else { | |
| qemu_file_set_error(f, -EINVAL); | |
| trace_vmstate_load_field_error(field->name, -EINVAL); | |
| return false; | |
| } | |
| } | |
| } else if (field->flags & VMS_MUST_EXIST) { | |
| error_setg(errp, "Input validation failed: %s/%s version_id: %d", | |
| vmsd->name, field->name, vmsd->version_id); | |
| return false; | |
| } | |
| field++; | |
| } | |
| assert(field->flags == VMS_END); | |
| if (!vmstate_subsection_load(f, vmsd, opaque, errp)) { | |
| qemu_file_set_error(f, -EINVAL); | |
| return false; | |
| } | |
| if (!vmstate_post_load(vmsd, opaque, version_id, errp)) { | |
| trace_vmstate_load_state_fail(vmsd->name, "post-load"); | |
| return false; | |
| } | |
| trace_vmstate_load_state_success(vmsd->name); | |
| return true; | |
| } | |
| 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_ARRAY_OF_POINTER_AUTO_ALLOC) { | |
| /* | |
| * This may involve two VMSD fields to be saved, one for the | |
| * marker to show if the pointer is NULL, followed by the real | |
| * vmstate object. To make it simple at least for now, skip | |
| * compression for this one. | |
| */ | |
| 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) | |
| { | |
| 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_section_needed(const VMStateDescription *vmsd, void *opaque) | |
| { | |
| if (vmsd->needed && !vmsd->needed(opaque)) { | |
| /* optional section not needed */ | |
| return false; | |
| } | |
| return true; | |
| } | |
| static bool vmstate_pre_save(const VMStateDescription *vmsd, void *opaque, | |
| Error **errp) | |
| { | |
| ERRP_GUARD(); | |
| if (vmsd->pre_save_errp) { | |
| if (!vmsd->pre_save_errp(opaque, errp)) { | |
| error_prepend(errp, "pre-save for %s failed: ", vmsd->name); | |
| return false; | |
| } | |
| } else if (vmsd->pre_save) { | |
| if (vmsd->pre_save(opaque) < 0) { | |
| error_setg(errp, "pre-save failed: %s", vmsd->name); | |
| return false; | |
| } | |
| } | |
| return true; | |
| } | |
| static bool vmstate_save_field(QEMUFile *f, void *pv, size_t size, | |
| const VMStateField *field, | |
| JSONWriter *vmdesc, Error **errp) | |
| { | |
| if (field->flags & VMS_STRUCT) { | |
| return vmstate_save_vmsd(f, field->vmsd, pv, vmdesc, errp); | |
| } else if (field->flags & VMS_VSTRUCT) { | |
| return vmstate_save_vmsd_v(f, field->vmsd, pv, vmdesc, | |
| field->struct_version_id, errp); | |
| } else if (field->info->save) { | |
| return field->info->save(f, pv, size, field, vmdesc, errp); | |
| } | |
| if (field->info->put(f, pv, size, field, vmdesc) < 0) { | |
| error_setg(errp, "put failed"); | |
| return false; | |
| } | |
| return true; | |
| } | |
| /* | |
| * Save a whole VMSD field, including its JSON blob separately when @vmdesc | |
| * is specified. | |
| */ | |
| static inline bool | |
| vmstate_save_field_with_vmdesc(QEMUFile *f, void *pv, size_t size, | |
| const VMStateDescription *vmsd, | |
| const VMStateField *field, JSONWriter *vmdesc, | |
| int i, int max, Error **errp) | |
| { | |
| uint64_t old_offset, written_bytes; | |
| bool ok; | |
| vmsd_desc_field_start(vmsd, vmdesc, field, i, max); | |
| old_offset = qemu_file_transferred(f); | |
| ok = vmstate_save_field(f, pv, size, field, vmdesc, errp); | |
| written_bytes = qemu_file_transferred(f) - old_offset; | |
| vmsd_desc_field_end(vmsd, vmdesc, field, written_bytes); | |
| if (!ok) { | |
| error_prepend(errp, "Save of field %s/%s failed: ", | |
| vmsd->name, field->name); | |
| } | |
| return ok; | |
| } | |
| static bool vmstate_save_vmsd_v(QEMUFile *f, const VMStateDescription *vmsd, | |
| void *opaque, JSONWriter *vmdesc, | |
| int version_id, Error **errp) | |
| { | |
| ERRP_GUARD(); | |
| bool ok = true; | |
| const VMStateField *field = vmsd->fields; | |
| trace_vmstate_save_state_top(vmsd->name); | |
| if (!vmstate_pre_save(vmsd, opaque, errp)) { | |
| trace_vmstate_save_state_pre_save_fail(vmsd->name); | |
| return false; | |
| } | |
| trace_vmstate_save_state_pre_save_success(vmsd->name); | |
| 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 (vmstate_field_exists(vmsd, field, opaque, version_id)) { | |
| void *first_elem = opaque + field->offset; | |
| int i; | |
| uint64_t n_elems = vmstate_n_elems(opaque, field); | |
| uint64_t size; | |
| JSONWriter *vmdesc_loop = vmdesc; | |
| bool is_prev_null = false; | |
| /* | |
| * When this is enabled, it means we will always push a ptr | |
| * marker first for each element saying if it's populated. | |
| */ | |
| bool use_dynamic_array = | |
| field->flags & VMS_ARRAY_OF_POINTER_AUTO_ALLOC; | |
| if (!vmstate_size(opaque, field, &size, errp)) { | |
| return false; | |
| } | |
| 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; | |
| const VMStateField *inner_field; | |
| VMStateField marker_field; | |
| /* maximum number of elements to compress in the JSON blob */ | |
| int max_elems = vmsd_can_compress(field) ? (n_elems - i) : 1; | |
| bool use_marker_field, is_null = false; | |
| if (field->flags & VMS_ARRAY_OF_POINTER) { | |
| assert(curr_elem); | |
| curr_elem = *(void **)curr_elem; | |
| is_null = !curr_elem; | |
| } | |
| use_marker_field = use_dynamic_array || is_null; | |
| if (use_marker_field) { | |
| vmsd_init_ptr_marker_field(&marker_field, field); | |
| inner_field = &marker_field; | |
| } else { | |
| inner_field = field; | |
| } | |
| /* | |
| * This logic only matters when dumping VM Desc. | |
| * | |
| * Due to the fake nullptr handling above, if there's mixed | |
| * null/non-null data, it doesn't make sense to emit a | |
| * compressed array representation spanning the entire array | |
| * because the field types will be different (e.g. struct | |
| * vs. nullptr). Search ahead for the next null/non-null element | |
| * and start a new compressed array if found. | |
| */ | |
| if (vmdesc && max_elems > 1 && | |
| (field->flags & VMS_ARRAY_OF_POINTER) && | |
| is_null != is_prev_null) { | |
| is_prev_null = is_null; | |
| vmdesc_loop = vmdesc; | |
| for (int j = i + 1; j < n_elems; j++) { | |
| void *elem = *(void **)(first_elem + size * j); | |
| bool elem_is_null = !elem; | |
| if (is_null != elem_is_null) { | |
| max_elems = j - i; | |
| break; | |
| } | |
| } | |
| } | |
| ok = vmstate_save_field_with_vmdesc(f, curr_elem, size, vmsd, | |
| inner_field, vmdesc_loop, | |
| i, max_elems, errp); | |
| if (!ok) { | |
| goto out; | |
| } | |
| /* | |
| * If we're using dynamic array and the element is | |
| * populated, save the real object right after the marker. | |
| */ | |
| if (use_dynamic_array && curr_elem) { | |
| /* | |
| * NOTE: do not use vmstate_size() here because we want | |
| * to save the real VMSD object now. | |
| */ | |
| ok = vmstate_save_field_with_vmdesc(f, curr_elem, | |
| field->size, vmsd, | |
| field, vmdesc_loop, | |
| i, max_elems, errp); | |
| if (!ok) { | |
| goto out; | |
| } | |
| } | |
| /* Compressed arrays only care about the first element */ | |
| if (vmdesc_loop && max_elems > 1) { | |
| 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); | |
| } | |
| ok = vmstate_subsection_save(f, vmsd, opaque, vmdesc, errp); | |
| out: | |
| if (vmsd->post_save) { | |
| vmsd->post_save(opaque); | |
| } | |
| return ok; | |
| } | |
| static const VMStateDescription * | |
| vmstate_get_subsection(const VMStateDescription * const *sub, | |
| const char *idstr) | |
| { | |
| if (sub) { | |
| for (const VMStateDescription *s = *sub; s ; s = *++sub) { | |
| if (strcmp(idstr, s->name) == 0) { | |
| return s; | |
| } | |
| } | |
| } | |
| return NULL; | |
| } | |
| bool vmstate_save_vmsd(QEMUFile *f, const VMStateDescription *vmsd, | |
| void *opaque, JSONWriter *vmdesc_id, Error **errp) | |
| { | |
| return vmstate_save_vmsd_v(f, vmsd, opaque, vmdesc_id, vmsd->version_id, | |
| errp); | |
| } | |
| static bool vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, | |
| void *opaque, Error **errp) | |
| { | |
| ERRP_GUARD(); | |
| trace_vmstate_subsection_load(vmsd->name); | |
| while (qemu_peek_byte(f, 0) == QEMU_VM_SUBSECTION) { | |
| char idstr[256], *idstr_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 to be "section_name/a" */ | |
| trace_vmstate_subsection_load_bad(vmsd->name, "(short)", ""); | |
| return true; | |
| } | |
| size = qemu_peek_buffer(f, (uint8_t **)&idstr_ret, len, 2); | |
| if (size != len) { | |
| trace_vmstate_subsection_load_bad(vmsd->name, "(peek fail)", ""); | |
| return true; | |
| } | |
| 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 true; | |
| } | |
| sub_vmsd = vmstate_get_subsection(vmsd->subsections, idstr); | |
| if (sub_vmsd == NULL) { | |
| trace_vmstate_subsection_load_bad(vmsd->name, idstr, "(lookup)"); | |
| error_setg(errp, "VM subsection '%s' in '%s' does not exist", | |
| idstr, vmsd->name); | |
| return false; | |
| } | |
| qemu_file_skip(f, 1); /* subsection */ | |
| qemu_file_skip(f, 1); /* len */ | |
| qemu_file_skip(f, len); /* idstr */ | |
| version_id = qemu_get_be32(f); | |
| if (!vmstate_load_vmsd(f, sub_vmsd, opaque, version_id, errp)) { | |
| trace_vmstate_subsection_load_bad(vmsd->name, idstr, "(child)"); | |
| error_prepend(errp, | |
| "Loading VM subsection '%s' in '%s' failed: ", | |
| idstr, vmsd->name); | |
| return false; | |
| } | |
| } | |
| trace_vmstate_subsection_load_good(vmsd->name); | |
| return true; | |
| } | |
| static bool vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd, | |
| void *opaque, JSONWriter *vmdesc, | |
| Error **errp) | |
| { | |
| const VMStateDescription * const *sub = vmsd->subsections; | |
| bool vmdesc_has_subsections = false; | |
| trace_vmstate_subsection_save_top(vmsd->name); | |
| while (sub && *sub) { | |
| if (vmstate_section_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); | |
| if (!vmstate_save_vmsd(f, vmsdsub, opaque, vmdesc, errp)) { | |
| return false; | |
| } | |
| if (vmdesc) { | |
| json_writer_end_object(vmdesc); | |
| } | |
| } | |
| sub++; | |
| } | |
| if (vmdesc_has_subsections) { | |
| json_writer_end_array(vmdesc); | |
| } | |
| return true; | |
| } | |
| int vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd, | |
| void *opaque, JSONWriter *vmdesc_id, Error **errp) | |
| { | |
| return vmstate_save_vmsd(f, vmsd, opaque, vmdesc_id, errp) ? 0 : -EINVAL; | |
| } | |
| int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd, | |
| void *opaque, int version_id, Error **errp) | |
| { | |
| return vmstate_load_vmsd(f, vmsd, opaque, version_id, errp) ? 0 : -EINVAL; | |
| } |