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authorTimos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>2023-10-10 11:40:56 +0000
committerTimos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>2023-10-10 11:40:56 +0000
commite02cda008591317b1625707ff8e115a4841aa889 (patch)
treeaee302e3cf8b59ec2d32ec481be3d1afddfc8968 /migration/savevm.c
parentcc668e6b7e0ffd8c9d130513d12053cf5eda1d3b (diff)
Introduce Virtio-loopback epsilon release:
Epsilon release introduces a new compatibility layer which make virtio-loopback design to work with QEMU and rust-vmm vhost-user backend without require any changes. Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com> Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9
Diffstat (limited to 'migration/savevm.c')
-rw-r--r--migration/savevm.c3303
1 files changed, 3303 insertions, 0 deletions
diff --git a/migration/savevm.c b/migration/savevm.c
new file mode 100644
index 000000000..d59e976d5
--- /dev/null
+++ b/migration/savevm.c
@@ -0,0 +1,3303 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ * Copyright (c) 2009-2015 Red Hat Inc
+ *
+ * Authors:
+ * Juan Quintela <quintela@redhat.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/boards.h"
+#include "net/net.h"
+#include "migration.h"
+#include "migration/snapshot.h"
+#include "migration/vmstate.h"
+#include "migration/misc.h"
+#include "migration/register.h"
+#include "migration/global_state.h"
+#include "ram.h"
+#include "qemu-file-channel.h"
+#include "qemu-file.h"
+#include "savevm.h"
+#include "postcopy-ram.h"
+#include "qapi/error.h"
+#include "qapi/qapi-commands-migration.h"
+#include "qapi/qmp/json-writer.h"
+#include "qapi/clone-visitor.h"
+#include "qapi/qapi-builtin-visit.h"
+#include "qapi/qmp/qerror.h"
+#include "qemu/error-report.h"
+#include "sysemu/cpus.h"
+#include "exec/memory.h"
+#include "exec/target_page.h"
+#include "trace.h"
+#include "qemu/iov.h"
+#include "qemu/main-loop.h"
+#include "block/snapshot.h"
+#include "qemu/cutils.h"
+#include "io/channel-buffer.h"
+#include "io/channel-file.h"
+#include "sysemu/replay.h"
+#include "sysemu/runstate.h"
+#include "sysemu/sysemu.h"
+#include "sysemu/xen.h"
+#include "migration/colo.h"
+#include "qemu/bitmap.h"
+#include "net/announce.h"
+#include "qemu/yank.h"
+#include "yank_functions.h"
+
+const unsigned int postcopy_ram_discard_version;
+
+/* Subcommands for QEMU_VM_COMMAND */
+enum qemu_vm_cmd {
+ MIG_CMD_INVALID = 0, /* Must be 0 */
+ MIG_CMD_OPEN_RETURN_PATH, /* Tell the dest to open the Return path */
+ MIG_CMD_PING, /* Request a PONG on the RP */
+
+ MIG_CMD_POSTCOPY_ADVISE, /* Prior to any page transfers, just
+ warn we might want to do PC */
+ MIG_CMD_POSTCOPY_LISTEN, /* Start listening for incoming
+ pages as it's running. */
+ MIG_CMD_POSTCOPY_RUN, /* Start execution */
+
+ MIG_CMD_POSTCOPY_RAM_DISCARD, /* A list of pages to discard that
+ were previously sent during
+ precopy but are dirty. */
+ MIG_CMD_PACKAGED, /* Send a wrapped stream within this stream */
+ MIG_CMD_ENABLE_COLO, /* Enable COLO */
+ MIG_CMD_POSTCOPY_RESUME, /* resume postcopy on dest */
+ MIG_CMD_RECV_BITMAP, /* Request for recved bitmap on dst */
+ MIG_CMD_MAX
+};
+
+#define MAX_VM_CMD_PACKAGED_SIZE UINT32_MAX
+static struct mig_cmd_args {
+ ssize_t len; /* -1 = variable */
+ const char *name;
+} mig_cmd_args[] = {
+ [MIG_CMD_INVALID] = { .len = -1, .name = "INVALID" },
+ [MIG_CMD_OPEN_RETURN_PATH] = { .len = 0, .name = "OPEN_RETURN_PATH" },
+ [MIG_CMD_PING] = { .len = sizeof(uint32_t), .name = "PING" },
+ [MIG_CMD_POSTCOPY_ADVISE] = { .len = -1, .name = "POSTCOPY_ADVISE" },
+ [MIG_CMD_POSTCOPY_LISTEN] = { .len = 0, .name = "POSTCOPY_LISTEN" },
+ [MIG_CMD_POSTCOPY_RUN] = { .len = 0, .name = "POSTCOPY_RUN" },
+ [MIG_CMD_POSTCOPY_RAM_DISCARD] = {
+ .len = -1, .name = "POSTCOPY_RAM_DISCARD" },
+ [MIG_CMD_POSTCOPY_RESUME] = { .len = 0, .name = "POSTCOPY_RESUME" },
+ [MIG_CMD_PACKAGED] = { .len = 4, .name = "PACKAGED" },
+ [MIG_CMD_RECV_BITMAP] = { .len = -1, .name = "RECV_BITMAP" },
+ [MIG_CMD_MAX] = { .len = -1, .name = "MAX" },
+};
+
+/* Note for MIG_CMD_POSTCOPY_ADVISE:
+ * The format of arguments is depending on postcopy mode:
+ * - postcopy RAM only
+ * uint64_t host page size
+ * uint64_t taget page size
+ *
+ * - postcopy RAM and postcopy dirty bitmaps
+ * format is the same as for postcopy RAM only
+ *
+ * - postcopy dirty bitmaps only
+ * Nothing. Command length field is 0.
+ *
+ * Be careful: adding a new postcopy entity with some other parameters should
+ * not break format self-description ability. Good way is to introduce some
+ * generic extendable format with an exception for two old entities.
+ */
+
+/***********************************************************/
+/* savevm/loadvm support */
+
+static ssize_t block_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
+ int64_t pos, Error **errp)
+{
+ int ret;
+ QEMUIOVector qiov;
+
+ qemu_iovec_init_external(&qiov, iov, iovcnt);
+ ret = bdrv_writev_vmstate(opaque, &qiov, pos);
+ if (ret < 0) {
+ return ret;
+ }
+
+ return qiov.size;
+}
+
+static ssize_t block_get_buffer(void *opaque, uint8_t *buf, int64_t pos,
+ size_t size, Error **errp)
+{
+ return bdrv_load_vmstate(opaque, buf, pos, size);
+}
+
+static int bdrv_fclose(void *opaque, Error **errp)
+{
+ return bdrv_flush(opaque);
+}
+
+static const QEMUFileOps bdrv_read_ops = {
+ .get_buffer = block_get_buffer,
+ .close = bdrv_fclose
+};
+
+static const QEMUFileOps bdrv_write_ops = {
+ .writev_buffer = block_writev_buffer,
+ .close = bdrv_fclose
+};
+
+static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int is_writable)
+{
+ if (is_writable) {
+ return qemu_fopen_ops(bs, &bdrv_write_ops, false);
+ }
+ return qemu_fopen_ops(bs, &bdrv_read_ops, false);
+}
+
+
+/* QEMUFile timer support.
+ * Not in qemu-file.c to not add qemu-timer.c as dependency to qemu-file.c
+ */
+
+void timer_put(QEMUFile *f, QEMUTimer *ts)
+{
+ uint64_t expire_time;
+
+ expire_time = timer_expire_time_ns(ts);
+ qemu_put_be64(f, expire_time);
+}
+
+void timer_get(QEMUFile *f, QEMUTimer *ts)
+{
+ uint64_t expire_time;
+
+ expire_time = qemu_get_be64(f);
+ if (expire_time != -1) {
+ timer_mod_ns(ts, expire_time);
+ } else {
+ timer_del(ts);
+ }
+}
+
+
+/* VMState timer support.
+ * Not in vmstate.c to not add qemu-timer.c as dependency to vmstate.c
+ */
+
+static int get_timer(QEMUFile *f, void *pv, size_t size,
+ const VMStateField *field)
+{
+ QEMUTimer *v = pv;
+ timer_get(f, v);
+ return 0;
+}
+
+static int put_timer(QEMUFile *f, void *pv, size_t size,
+ const VMStateField *field, JSONWriter *vmdesc)
+{
+ QEMUTimer *v = pv;
+ timer_put(f, v);
+
+ return 0;
+}
+
+const VMStateInfo vmstate_info_timer = {
+ .name = "timer",
+ .get = get_timer,
+ .put = put_timer,
+};
+
+
+typedef struct CompatEntry {
+ char idstr[256];
+ int instance_id;
+} CompatEntry;
+
+typedef struct SaveStateEntry {
+ QTAILQ_ENTRY(SaveStateEntry) entry;
+ char idstr[256];
+ uint32_t instance_id;
+ int alias_id;
+ int version_id;
+ /* version id read from the stream */
+ int load_version_id;
+ int section_id;
+ /* section id read from the stream */
+ int load_section_id;
+ const SaveVMHandlers *ops;
+ const VMStateDescription *vmsd;
+ void *opaque;
+ CompatEntry *compat;
+ int is_ram;
+} SaveStateEntry;
+
+typedef struct SaveState {
+ QTAILQ_HEAD(, SaveStateEntry) handlers;
+ SaveStateEntry *handler_pri_head[MIG_PRI_MAX + 1];
+ int global_section_id;
+ uint32_t len;
+ const char *name;
+ uint32_t target_page_bits;
+ uint32_t caps_count;
+ MigrationCapability *capabilities;
+ QemuUUID uuid;
+} SaveState;
+
+static SaveState savevm_state = {
+ .handlers = QTAILQ_HEAD_INITIALIZER(savevm_state.handlers),
+ .handler_pri_head = { [MIG_PRI_DEFAULT ... MIG_PRI_MAX] = NULL },
+ .global_section_id = 0,
+};
+
+static bool should_validate_capability(int capability)
+{
+ assert(capability >= 0 && capability < MIGRATION_CAPABILITY__MAX);
+ /* Validate only new capabilities to keep compatibility. */
+ switch (capability) {
+ case MIGRATION_CAPABILITY_X_IGNORE_SHARED:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static uint32_t get_validatable_capabilities_count(void)
+{
+ MigrationState *s = migrate_get_current();
+ uint32_t result = 0;
+ int i;
+ for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
+ if (should_validate_capability(i) && s->enabled_capabilities[i]) {
+ result++;
+ }
+ }
+ return result;
+}
+
+static int configuration_pre_save(void *opaque)
+{
+ SaveState *state = opaque;
+ const char *current_name = MACHINE_GET_CLASS(current_machine)->name;
+ MigrationState *s = migrate_get_current();
+ int i, j;
+
+ state->len = strlen(current_name);
+ state->name = current_name;
+ state->target_page_bits = qemu_target_page_bits();
+
+ state->caps_count = get_validatable_capabilities_count();
+ state->capabilities = g_renew(MigrationCapability, state->capabilities,
+ state->caps_count);
+ for (i = j = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
+ if (should_validate_capability(i) && s->enabled_capabilities[i]) {
+ state->capabilities[j++] = i;
+ }
+ }
+ state->uuid = qemu_uuid;
+
+ return 0;
+}
+
+static int configuration_post_save(void *opaque)
+{
+ SaveState *state = opaque;
+
+ g_free(state->capabilities);
+ state->capabilities = NULL;
+ state->caps_count = 0;
+ return 0;
+}
+
+static int configuration_pre_load(void *opaque)
+{
+ SaveState *state = opaque;
+
+ /* If there is no target-page-bits subsection it means the source
+ * predates the variable-target-page-bits support and is using the
+ * minimum possible value for this CPU.
+ */
+ state->target_page_bits = qemu_target_page_bits_min();
+ return 0;
+}
+
+static bool configuration_validate_capabilities(SaveState *state)
+{
+ bool ret = true;
+ MigrationState *s = migrate_get_current();
+ unsigned long *source_caps_bm;
+ int i;
+
+ source_caps_bm = bitmap_new(MIGRATION_CAPABILITY__MAX);
+ for (i = 0; i < state->caps_count; i++) {
+ MigrationCapability capability = state->capabilities[i];
+ set_bit(capability, source_caps_bm);
+ }
+
+ for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
+ bool source_state, target_state;
+ if (!should_validate_capability(i)) {
+ continue;
+ }
+ source_state = test_bit(i, source_caps_bm);
+ target_state = s->enabled_capabilities[i];
+ if (source_state != target_state) {
+ error_report("Capability %s is %s, but received capability is %s",
+ MigrationCapability_str(i),
+ target_state ? "on" : "off",
+ source_state ? "on" : "off");
+ ret = false;
+ /* Don't break here to report all failed capabilities */
+ }
+ }
+
+ g_free(source_caps_bm);
+ return ret;
+}
+
+static int configuration_post_load(void *opaque, int version_id)
+{
+ SaveState *state = opaque;
+ const char *current_name = MACHINE_GET_CLASS(current_machine)->name;
+ int ret = 0;
+
+ if (strncmp(state->name, current_name, state->len) != 0) {
+ error_report("Machine type received is '%.*s' and local is '%s'",
+ (int) state->len, state->name, current_name);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (state->target_page_bits != qemu_target_page_bits()) {
+ error_report("Received TARGET_PAGE_BITS is %d but local is %d",
+ state->target_page_bits, qemu_target_page_bits());
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (!configuration_validate_capabilities(state)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+out:
+ g_free((void *)state->name);
+ state->name = NULL;
+ state->len = 0;
+ g_free(state->capabilities);
+ state->capabilities = NULL;
+ state->caps_count = 0;
+
+ return ret;
+}
+
+static int get_capability(QEMUFile *f, void *pv, size_t size,
+ const VMStateField *field)
+{
+ MigrationCapability *capability = pv;
+ char capability_str[UINT8_MAX + 1];
+ uint8_t len;
+ int i;
+
+ len = qemu_get_byte(f);
+ qemu_get_buffer(f, (uint8_t *)capability_str, len);
+ capability_str[len] = '\0';
+ for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
+ if (!strcmp(MigrationCapability_str(i), capability_str)) {
+ *capability = i;
+ return 0;
+ }
+ }
+ error_report("Received unknown capability %s", capability_str);
+ return -EINVAL;
+}
+
+static int put_capability(QEMUFile *f, void *pv, size_t size,
+ const VMStateField *field, JSONWriter *vmdesc)
+{
+ MigrationCapability *capability = pv;
+ const char *capability_str = MigrationCapability_str(*capability);
+ size_t len = strlen(capability_str);
+ assert(len <= UINT8_MAX);
+
+ qemu_put_byte(f, len);
+ qemu_put_buffer(f, (uint8_t *)capability_str, len);
+ return 0;
+}
+
+static const VMStateInfo vmstate_info_capability = {
+ .name = "capability",
+ .get = get_capability,
+ .put = put_capability,
+};
+
+/* The target-page-bits subsection is present only if the
+ * target page size is not the same as the default (ie the
+ * minimum page size for a variable-page-size guest CPU).
+ * If it is present then it contains the actual target page
+ * bits for the machine, and migration will fail if the
+ * two ends don't agree about it.
+ */
+static bool vmstate_target_page_bits_needed(void *opaque)
+{
+ return qemu_target_page_bits()
+ > qemu_target_page_bits_min();
+}
+
+static const VMStateDescription vmstate_target_page_bits = {
+ .name = "configuration/target-page-bits",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = vmstate_target_page_bits_needed,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT32(target_page_bits, SaveState),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static bool vmstate_capabilites_needed(void *opaque)
+{
+ return get_validatable_capabilities_count() > 0;
+}
+
+static const VMStateDescription vmstate_capabilites = {
+ .name = "configuration/capabilities",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = vmstate_capabilites_needed,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT32_V(caps_count, SaveState, 1),
+ VMSTATE_VARRAY_UINT32_ALLOC(capabilities, SaveState, caps_count, 1,
+ vmstate_info_capability,
+ MigrationCapability),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static bool vmstate_uuid_needed(void *opaque)
+{
+ return qemu_uuid_set && migrate_validate_uuid();
+}
+
+static int vmstate_uuid_post_load(void *opaque, int version_id)
+{
+ SaveState *state = opaque;
+ char uuid_src[UUID_FMT_LEN + 1];
+ char uuid_dst[UUID_FMT_LEN + 1];
+
+ if (!qemu_uuid_set) {
+ /*
+ * It's warning because user might not know UUID in some cases,
+ * e.g. load an old snapshot
+ */
+ qemu_uuid_unparse(&state->uuid, uuid_src);
+ warn_report("UUID is received %s, but local uuid isn't set",
+ uuid_src);
+ return 0;
+ }
+ if (!qemu_uuid_is_equal(&state->uuid, &qemu_uuid)) {
+ qemu_uuid_unparse(&state->uuid, uuid_src);
+ qemu_uuid_unparse(&qemu_uuid, uuid_dst);
+ error_report("UUID received is %s and local is %s", uuid_src, uuid_dst);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static const VMStateDescription vmstate_uuid = {
+ .name = "configuration/uuid",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = vmstate_uuid_needed,
+ .post_load = vmstate_uuid_post_load,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT8_ARRAY_V(uuid.data, SaveState, sizeof(QemuUUID), 1),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static const VMStateDescription vmstate_configuration = {
+ .name = "configuration",
+ .version_id = 1,
+ .pre_load = configuration_pre_load,
+ .post_load = configuration_post_load,
+ .pre_save = configuration_pre_save,
+ .post_save = configuration_post_save,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT32(len, SaveState),
+ VMSTATE_VBUFFER_ALLOC_UINT32(name, SaveState, 0, NULL, len),
+ VMSTATE_END_OF_LIST()
+ },
+ .subsections = (const VMStateDescription *[]) {
+ &vmstate_target_page_bits,
+ &vmstate_capabilites,
+ &vmstate_uuid,
+ NULL
+ }
+};
+
+static void dump_vmstate_vmsd(FILE *out_file,
+ const VMStateDescription *vmsd, int indent,
+ bool is_subsection);
+
+static void dump_vmstate_vmsf(FILE *out_file, const VMStateField *field,
+ int indent)
+{
+ fprintf(out_file, "%*s{\n", indent, "");
+ indent += 2;
+ fprintf(out_file, "%*s\"field\": \"%s\",\n", indent, "", field->name);
+ fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "",
+ field->version_id);
+ fprintf(out_file, "%*s\"field_exists\": %s,\n", indent, "",
+ field->field_exists ? "true" : "false");
+ fprintf(out_file, "%*s\"size\": %zu", indent, "", field->size);
+ if (field->vmsd != NULL) {
+ fprintf(out_file, ",\n");
+ dump_vmstate_vmsd(out_file, field->vmsd, indent, false);
+ }
+ fprintf(out_file, "\n%*s}", indent - 2, "");
+}
+
+static void dump_vmstate_vmss(FILE *out_file,
+ const VMStateDescription **subsection,
+ int indent)
+{
+ if (*subsection != NULL) {
+ dump_vmstate_vmsd(out_file, *subsection, indent, true);
+ }
+}
+
+static void dump_vmstate_vmsd(FILE *out_file,
+ const VMStateDescription *vmsd, int indent,
+ bool is_subsection)
+{
+ if (is_subsection) {
+ fprintf(out_file, "%*s{\n", indent, "");
+ } else {
+ fprintf(out_file, "%*s\"%s\": {\n", indent, "", "Description");
+ }
+ indent += 2;
+ fprintf(out_file, "%*s\"name\": \"%s\",\n", indent, "", vmsd->name);
+ fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "",
+ vmsd->version_id);
+ fprintf(out_file, "%*s\"minimum_version_id\": %d", indent, "",
+ vmsd->minimum_version_id);
+ if (vmsd->fields != NULL) {
+ const VMStateField *field = vmsd->fields;
+ bool first;
+
+ fprintf(out_file, ",\n%*s\"Fields\": [\n", indent, "");
+ first = true;
+ while (field->name != NULL) {
+ if (field->flags & VMS_MUST_EXIST) {
+ /* Ignore VMSTATE_VALIDATE bits; these don't get migrated */
+ field++;
+ continue;
+ }
+ if (!first) {
+ fprintf(out_file, ",\n");
+ }
+ dump_vmstate_vmsf(out_file, field, indent + 2);
+ field++;
+ first = false;
+ }
+ fprintf(out_file, "\n%*s]", indent, "");
+ }
+ if (vmsd->subsections != NULL) {
+ const VMStateDescription **subsection = vmsd->subsections;
+ bool first;
+
+ fprintf(out_file, ",\n%*s\"Subsections\": [\n", indent, "");
+ first = true;
+ while (*subsection != NULL) {
+ if (!first) {
+ fprintf(out_file, ",\n");
+ }
+ dump_vmstate_vmss(out_file, subsection, indent + 2);
+ subsection++;
+ first = false;
+ }
+ fprintf(out_file, "\n%*s]", indent, "");
+ }
+ fprintf(out_file, "\n%*s}", indent - 2, "");
+}
+
+static void dump_machine_type(FILE *out_file)
+{
+ MachineClass *mc;
+
+ mc = MACHINE_GET_CLASS(current_machine);
+
+ fprintf(out_file, " \"vmschkmachine\": {\n");
+ fprintf(out_file, " \"Name\": \"%s\"\n", mc->name);
+ fprintf(out_file, " },\n");
+}
+
+void dump_vmstate_json_to_file(FILE *out_file)
+{
+ GSList *list, *elt;
+ bool first;
+
+ fprintf(out_file, "{\n");
+ dump_machine_type(out_file);
+
+ first = true;
+ list = object_class_get_list(TYPE_DEVICE, true);
+ for (elt = list; elt; elt = elt->next) {
+ DeviceClass *dc = OBJECT_CLASS_CHECK(DeviceClass, elt->data,
+ TYPE_DEVICE);
+ const char *name;
+ int indent = 2;
+
+ if (!dc->vmsd) {
+ continue;
+ }
+
+ if (!first) {
+ fprintf(out_file, ",\n");
+ }
+ name = object_class_get_name(OBJECT_CLASS(dc));
+ fprintf(out_file, "%*s\"%s\": {\n", indent, "", name);
+ indent += 2;
+ fprintf(out_file, "%*s\"Name\": \"%s\",\n", indent, "", name);
+ fprintf(out_file, "%*s\"version_id\": %d,\n", indent, "",
+ dc->vmsd->version_id);
+ fprintf(out_file, "%*s\"minimum_version_id\": %d,\n", indent, "",
+ dc->vmsd->minimum_version_id);
+
+ dump_vmstate_vmsd(out_file, dc->vmsd, indent, false);
+
+ fprintf(out_file, "\n%*s}", indent - 2, "");
+ first = false;
+ }
+ fprintf(out_file, "\n}\n");
+ fclose(out_file);
+ g_slist_free(list);
+}
+
+static uint32_t calculate_new_instance_id(const char *idstr)
+{
+ SaveStateEntry *se;
+ uint32_t instance_id = 0;
+
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (strcmp(idstr, se->idstr) == 0
+ && instance_id <= se->instance_id) {
+ instance_id = se->instance_id + 1;
+ }
+ }
+ /* Make sure we never loop over without being noticed */
+ assert(instance_id != VMSTATE_INSTANCE_ID_ANY);
+ return instance_id;
+}
+
+static int calculate_compat_instance_id(const char *idstr)
+{
+ SaveStateEntry *se;
+ int instance_id = 0;
+
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (!se->compat) {
+ continue;
+ }
+
+ if (strcmp(idstr, se->compat->idstr) == 0
+ && instance_id <= se->compat->instance_id) {
+ instance_id = se->compat->instance_id + 1;
+ }
+ }
+ return instance_id;
+}
+
+static inline MigrationPriority save_state_priority(SaveStateEntry *se)
+{
+ if (se->vmsd) {
+ return se->vmsd->priority;
+ }
+ return MIG_PRI_DEFAULT;
+}
+
+static void savevm_state_handler_insert(SaveStateEntry *nse)
+{
+ MigrationPriority priority = save_state_priority(nse);
+ SaveStateEntry *se;
+ int i;
+
+ assert(priority <= MIG_PRI_MAX);
+
+ for (i = priority - 1; i >= 0; i--) {
+ se = savevm_state.handler_pri_head[i];
+ if (se != NULL) {
+ assert(save_state_priority(se) < priority);
+ break;
+ }
+ }
+
+ if (i >= 0) {
+ QTAILQ_INSERT_BEFORE(se, nse, entry);
+ } else {
+ QTAILQ_INSERT_TAIL(&savevm_state.handlers, nse, entry);
+ }
+
+ if (savevm_state.handler_pri_head[priority] == NULL) {
+ savevm_state.handler_pri_head[priority] = nse;
+ }
+}
+
+static void savevm_state_handler_remove(SaveStateEntry *se)
+{
+ SaveStateEntry *next;
+ MigrationPriority priority = save_state_priority(se);
+
+ if (se == savevm_state.handler_pri_head[priority]) {
+ next = QTAILQ_NEXT(se, entry);
+ if (next != NULL && save_state_priority(next) == priority) {
+ savevm_state.handler_pri_head[priority] = next;
+ } else {
+ savevm_state.handler_pri_head[priority] = NULL;
+ }
+ }
+ QTAILQ_REMOVE(&savevm_state.handlers, se, entry);
+}
+
+/* TODO: Individual devices generally have very little idea about the rest
+ of the system, so instance_id should be removed/replaced.
+ Meanwhile pass -1 as instance_id if you do not already have a clearly
+ distinguishing id for all instances of your device class. */
+int register_savevm_live(const char *idstr,
+ uint32_t instance_id,
+ int version_id,
+ const SaveVMHandlers *ops,
+ void *opaque)
+{
+ SaveStateEntry *se;
+
+ se = g_new0(SaveStateEntry, 1);
+ se->version_id = version_id;
+ se->section_id = savevm_state.global_section_id++;
+ se->ops = ops;
+ se->opaque = opaque;
+ se->vmsd = NULL;
+ /* if this is a live_savem then set is_ram */
+ if (ops->save_setup != NULL) {
+ se->is_ram = 1;
+ }
+
+ pstrcat(se->idstr, sizeof(se->idstr), idstr);
+
+ if (instance_id == VMSTATE_INSTANCE_ID_ANY) {
+ se->instance_id = calculate_new_instance_id(se->idstr);
+ } else {
+ se->instance_id = instance_id;
+ }
+ assert(!se->compat || se->instance_id == 0);
+ savevm_state_handler_insert(se);
+ return 0;
+}
+
+void unregister_savevm(VMStateIf *obj, const char *idstr, void *opaque)
+{
+ SaveStateEntry *se, *new_se;
+ char id[256] = "";
+
+ if (obj) {
+ char *oid = vmstate_if_get_id(obj);
+ if (oid) {
+ pstrcpy(id, sizeof(id), oid);
+ pstrcat(id, sizeof(id), "/");
+ g_free(oid);
+ }
+ }
+ pstrcat(id, sizeof(id), idstr);
+
+ QTAILQ_FOREACH_SAFE(se, &savevm_state.handlers, entry, new_se) {
+ if (strcmp(se->idstr, id) == 0 && se->opaque == opaque) {
+ savevm_state_handler_remove(se);
+ g_free(se->compat);
+ g_free(se);
+ }
+ }
+}
+
+int vmstate_register_with_alias_id(VMStateIf *obj, uint32_t instance_id,
+ const VMStateDescription *vmsd,
+ void *opaque, int alias_id,
+ int required_for_version,
+ Error **errp)
+{
+ SaveStateEntry *se;
+
+ /* If this triggers, alias support can be dropped for the vmsd. */
+ assert(alias_id == -1 || required_for_version >= vmsd->minimum_version_id);
+
+ se = g_new0(SaveStateEntry, 1);
+ se->version_id = vmsd->version_id;
+ se->section_id = savevm_state.global_section_id++;
+ se->opaque = opaque;
+ se->vmsd = vmsd;
+ se->alias_id = alias_id;
+
+ if (obj) {
+ char *id = vmstate_if_get_id(obj);
+ if (id) {
+ if (snprintf(se->idstr, sizeof(se->idstr), "%s/", id) >=
+ sizeof(se->idstr)) {
+ error_setg(errp, "Path too long for VMState (%s)", id);
+ g_free(id);
+ g_free(se);
+
+ return -1;
+ }
+ g_free(id);
+
+ se->compat = g_new0(CompatEntry, 1);
+ pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), vmsd->name);
+ se->compat->instance_id = instance_id == VMSTATE_INSTANCE_ID_ANY ?
+ calculate_compat_instance_id(vmsd->name) : instance_id;
+ instance_id = VMSTATE_INSTANCE_ID_ANY;
+ }
+ }
+ pstrcat(se->idstr, sizeof(se->idstr), vmsd->name);
+
+ if (instance_id == VMSTATE_INSTANCE_ID_ANY) {
+ se->instance_id = calculate_new_instance_id(se->idstr);
+ } else {
+ se->instance_id = instance_id;
+ }
+ assert(!se->compat || se->instance_id == 0);
+ savevm_state_handler_insert(se);
+ return 0;
+}
+
+void vmstate_unregister(VMStateIf *obj, const VMStateDescription *vmsd,
+ void *opaque)
+{
+ SaveStateEntry *se, *new_se;
+
+ QTAILQ_FOREACH_SAFE(se, &savevm_state.handlers, entry, new_se) {
+ if (se->vmsd == vmsd && se->opaque == opaque) {
+ savevm_state_handler_remove(se);
+ g_free(se->compat);
+ g_free(se);
+ }
+ }
+}
+
+static int vmstate_load(QEMUFile *f, SaveStateEntry *se)
+{
+ trace_vmstate_load(se->idstr, se->vmsd ? se->vmsd->name : "(old)");
+ if (!se->vmsd) { /* Old style */
+ return se->ops->load_state(f, se->opaque, se->load_version_id);
+ }
+ return vmstate_load_state(f, se->vmsd, se->opaque, se->load_version_id);
+}
+
+static void vmstate_save_old_style(QEMUFile *f, SaveStateEntry *se,
+ JSONWriter *vmdesc)
+{
+ int64_t old_offset, size;
+
+ old_offset = qemu_ftell_fast(f);
+ se->ops->save_state(f, se->opaque);
+ size = qemu_ftell_fast(f) - old_offset;
+
+ if (vmdesc) {
+ json_writer_int64(vmdesc, "size", size);
+ json_writer_start_array(vmdesc, "fields");
+ json_writer_start_object(vmdesc, NULL);
+ json_writer_str(vmdesc, "name", "data");
+ json_writer_int64(vmdesc, "size", size);
+ json_writer_str(vmdesc, "type", "buffer");
+ json_writer_end_object(vmdesc);
+ json_writer_end_array(vmdesc);
+ }
+}
+
+static int vmstate_save(QEMUFile *f, SaveStateEntry *se,
+ JSONWriter *vmdesc)
+{
+ trace_vmstate_save(se->idstr, se->vmsd ? se->vmsd->name : "(old)");
+ if (!se->vmsd) {
+ vmstate_save_old_style(f, se, vmdesc);
+ return 0;
+ }
+ return vmstate_save_state(f, se->vmsd, se->opaque, vmdesc);
+}
+
+/*
+ * Write the header for device section (QEMU_VM_SECTION START/END/PART/FULL)
+ */
+static void save_section_header(QEMUFile *f, SaveStateEntry *se,
+ uint8_t section_type)
+{
+ qemu_put_byte(f, section_type);
+ qemu_put_be32(f, se->section_id);
+
+ if (section_type == QEMU_VM_SECTION_FULL ||
+ section_type == QEMU_VM_SECTION_START) {
+ /* ID string */
+ size_t len = strlen(se->idstr);
+ qemu_put_byte(f, len);
+ qemu_put_buffer(f, (uint8_t *)se->idstr, len);
+
+ qemu_put_be32(f, se->instance_id);
+ qemu_put_be32(f, se->version_id);
+ }
+}
+
+/*
+ * Write a footer onto device sections that catches cases misformatted device
+ * sections.
+ */
+static void save_section_footer(QEMUFile *f, SaveStateEntry *se)
+{
+ if (migrate_get_current()->send_section_footer) {
+ qemu_put_byte(f, QEMU_VM_SECTION_FOOTER);
+ qemu_put_be32(f, se->section_id);
+ }
+}
+
+/**
+ * qemu_savevm_command_send: Send a 'QEMU_VM_COMMAND' type element with the
+ * command and associated data.
+ *
+ * @f: File to send command on
+ * @command: Command type to send
+ * @len: Length of associated data
+ * @data: Data associated with command.
+ */
+static void qemu_savevm_command_send(QEMUFile *f,
+ enum qemu_vm_cmd command,
+ uint16_t len,
+ uint8_t *data)
+{
+ trace_savevm_command_send(command, len);
+ qemu_put_byte(f, QEMU_VM_COMMAND);
+ qemu_put_be16(f, (uint16_t)command);
+ qemu_put_be16(f, len);
+ qemu_put_buffer(f, data, len);
+ qemu_fflush(f);
+}
+
+void qemu_savevm_send_colo_enable(QEMUFile *f)
+{
+ trace_savevm_send_colo_enable();
+ qemu_savevm_command_send(f, MIG_CMD_ENABLE_COLO, 0, NULL);
+}
+
+void qemu_savevm_send_ping(QEMUFile *f, uint32_t value)
+{
+ uint32_t buf;
+
+ trace_savevm_send_ping(value);
+ buf = cpu_to_be32(value);
+ qemu_savevm_command_send(f, MIG_CMD_PING, sizeof(value), (uint8_t *)&buf);
+}
+
+void qemu_savevm_send_open_return_path(QEMUFile *f)
+{
+ trace_savevm_send_open_return_path();
+ qemu_savevm_command_send(f, MIG_CMD_OPEN_RETURN_PATH, 0, NULL);
+}
+
+/* We have a buffer of data to send; we don't want that all to be loaded
+ * by the command itself, so the command contains just the length of the
+ * extra buffer that we then send straight after it.
+ * TODO: Must be a better way to organise that
+ *
+ * Returns:
+ * 0 on success
+ * -ve on error
+ */
+int qemu_savevm_send_packaged(QEMUFile *f, const uint8_t *buf, size_t len)
+{
+ uint32_t tmp;
+
+ if (len > MAX_VM_CMD_PACKAGED_SIZE) {
+ error_report("%s: Unreasonably large packaged state: %zu",
+ __func__, len);
+ return -1;
+ }
+
+ tmp = cpu_to_be32(len);
+
+ trace_qemu_savevm_send_packaged();
+ qemu_savevm_command_send(f, MIG_CMD_PACKAGED, 4, (uint8_t *)&tmp);
+
+ qemu_put_buffer(f, buf, len);
+
+ return 0;
+}
+
+/* Send prior to any postcopy transfer */
+void qemu_savevm_send_postcopy_advise(QEMUFile *f)
+{
+ if (migrate_postcopy_ram()) {
+ uint64_t tmp[2];
+ tmp[0] = cpu_to_be64(ram_pagesize_summary());
+ tmp[1] = cpu_to_be64(qemu_target_page_size());
+
+ trace_qemu_savevm_send_postcopy_advise();
+ qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE,
+ 16, (uint8_t *)tmp);
+ } else {
+ qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE, 0, NULL);
+ }
+}
+
+/* Sent prior to starting the destination running in postcopy, discard pages
+ * that have already been sent but redirtied on the source.
+ * CMD_POSTCOPY_RAM_DISCARD consist of:
+ * byte version (0)
+ * byte Length of name field (not including 0)
+ * n x byte RAM block name
+ * byte 0 terminator (just for safety)
+ * n x Byte ranges within the named RAMBlock
+ * be64 Start of the range
+ * be64 Length
+ *
+ * name: RAMBlock name that these entries are part of
+ * len: Number of page entries
+ * start_list: 'len' addresses
+ * length_list: 'len' addresses
+ *
+ */
+void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name,
+ uint16_t len,
+ uint64_t *start_list,
+ uint64_t *length_list)
+{
+ uint8_t *buf;
+ uint16_t tmplen;
+ uint16_t t;
+ size_t name_len = strlen(name);
+
+ trace_qemu_savevm_send_postcopy_ram_discard(name, len);
+ assert(name_len < 256);
+ buf = g_malloc0(1 + 1 + name_len + 1 + (8 + 8) * len);
+ buf[0] = postcopy_ram_discard_version;
+ buf[1] = name_len;
+ memcpy(buf + 2, name, name_len);
+ tmplen = 2 + name_len;
+ buf[tmplen++] = '\0';
+
+ for (t = 0; t < len; t++) {
+ stq_be_p(buf + tmplen, start_list[t]);
+ tmplen += 8;
+ stq_be_p(buf + tmplen, length_list[t]);
+ tmplen += 8;
+ }
+ qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RAM_DISCARD, tmplen, buf);
+ g_free(buf);
+}
+
+/* Get the destination into a state where it can receive postcopy data. */
+void qemu_savevm_send_postcopy_listen(QEMUFile *f)
+{
+ trace_savevm_send_postcopy_listen();
+ qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_LISTEN, 0, NULL);
+}
+
+/* Kick the destination into running */
+void qemu_savevm_send_postcopy_run(QEMUFile *f)
+{
+ trace_savevm_send_postcopy_run();
+ qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RUN, 0, NULL);
+}
+
+void qemu_savevm_send_postcopy_resume(QEMUFile *f)
+{
+ trace_savevm_send_postcopy_resume();
+ qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RESUME, 0, NULL);
+}
+
+void qemu_savevm_send_recv_bitmap(QEMUFile *f, char *block_name)
+{
+ size_t len;
+ char buf[256];
+
+ trace_savevm_send_recv_bitmap(block_name);
+
+ buf[0] = len = strlen(block_name);
+ memcpy(buf + 1, block_name, len);
+
+ qemu_savevm_command_send(f, MIG_CMD_RECV_BITMAP, len + 1, (uint8_t *)buf);
+}
+
+bool qemu_savevm_state_blocked(Error **errp)
+{
+ SaveStateEntry *se;
+
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (se->vmsd && se->vmsd->unmigratable) {
+ error_setg(errp, "State blocked by non-migratable device '%s'",
+ se->idstr);
+ return true;
+ }
+ }
+ return false;
+}
+
+void qemu_savevm_non_migratable_list(strList **reasons)
+{
+ SaveStateEntry *se;
+
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (se->vmsd && se->vmsd->unmigratable) {
+ QAPI_LIST_PREPEND(*reasons,
+ g_strdup_printf("non-migratable device: %s",
+ se->idstr));
+ }
+ }
+}
+
+void qemu_savevm_state_header(QEMUFile *f)
+{
+ trace_savevm_state_header();
+ qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
+ qemu_put_be32(f, QEMU_VM_FILE_VERSION);
+
+ if (migrate_get_current()->send_configuration) {
+ qemu_put_byte(f, QEMU_VM_CONFIGURATION);
+ vmstate_save_state(f, &vmstate_configuration, &savevm_state, 0);
+ }
+}
+
+bool qemu_savevm_state_guest_unplug_pending(void)
+{
+ SaveStateEntry *se;
+
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (se->vmsd && se->vmsd->dev_unplug_pending &&
+ se->vmsd->dev_unplug_pending(se->opaque)) {
+ return true;
+ }
+ }
+
+ return false;
+}
+
+void qemu_savevm_state_setup(QEMUFile *f)
+{
+ SaveStateEntry *se;
+ Error *local_err = NULL;
+ int ret;
+
+ trace_savevm_state_setup();
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (!se->ops || !se->ops->save_setup) {
+ continue;
+ }
+ if (se->ops->is_active) {
+ if (!se->ops->is_active(se->opaque)) {
+ continue;
+ }
+ }
+ save_section_header(f, se, QEMU_VM_SECTION_START);
+
+ ret = se->ops->save_setup(f, se->opaque);
+ save_section_footer(f, se);
+ if (ret < 0) {
+ qemu_file_set_error(f, ret);
+ break;
+ }
+ }
+
+ if (precopy_notify(PRECOPY_NOTIFY_SETUP, &local_err)) {
+ error_report_err(local_err);
+ }
+}
+
+int qemu_savevm_state_resume_prepare(MigrationState *s)
+{
+ SaveStateEntry *se;
+ int ret;
+
+ trace_savevm_state_resume_prepare();
+
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (!se->ops || !se->ops->resume_prepare) {
+ continue;
+ }
+ if (se->ops->is_active) {
+ if (!se->ops->is_active(se->opaque)) {
+ continue;
+ }
+ }
+ ret = se->ops->resume_prepare(s, se->opaque);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * this function has three return values:
+ * negative: there was one error, and we have -errno.
+ * 0 : We haven't finished, caller have to go again
+ * 1 : We have finished, we can go to complete phase
+ */
+int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy)
+{
+ SaveStateEntry *se;
+ int ret = 1;
+
+ trace_savevm_state_iterate();
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (!se->ops || !se->ops->save_live_iterate) {
+ continue;
+ }
+ if (se->ops->is_active &&
+ !se->ops->is_active(se->opaque)) {
+ continue;
+ }
+ if (se->ops->is_active_iterate &&
+ !se->ops->is_active_iterate(se->opaque)) {
+ continue;
+ }
+ /*
+ * In the postcopy phase, any device that doesn't know how to
+ * do postcopy should have saved it's state in the _complete
+ * call that's already run, it might get confused if we call
+ * iterate afterwards.
+ */
+ if (postcopy &&
+ !(se->ops->has_postcopy && se->ops->has_postcopy(se->opaque))) {
+ continue;
+ }
+ if (qemu_file_rate_limit(f)) {
+ return 0;
+ }
+ trace_savevm_section_start(se->idstr, se->section_id);
+
+ save_section_header(f, se, QEMU_VM_SECTION_PART);
+
+ ret = se->ops->save_live_iterate(f, se->opaque);
+ trace_savevm_section_end(se->idstr, se->section_id, ret);
+ save_section_footer(f, se);
+
+ if (ret < 0) {
+ error_report("failed to save SaveStateEntry with id(name): %d(%s)",
+ se->section_id, se->idstr);
+ qemu_file_set_error(f, ret);
+ }
+ if (ret <= 0) {
+ /* Do not proceed to the next vmstate before this one reported
+ completion of the current stage. This serializes the migration
+ and reduces the probability that a faster changing state is
+ synchronized over and over again. */
+ break;
+ }
+ }
+ return ret;
+}
+
+static bool should_send_vmdesc(void)
+{
+ MachineState *machine = MACHINE(qdev_get_machine());
+ bool in_postcopy = migration_in_postcopy();
+ return !machine->suppress_vmdesc && !in_postcopy;
+}
+
+/*
+ * Calls the save_live_complete_postcopy methods
+ * causing the last few pages to be sent immediately and doing any associated
+ * cleanup.
+ * Note postcopy also calls qemu_savevm_state_complete_precopy to complete
+ * all the other devices, but that happens at the point we switch to postcopy.
+ */
+void qemu_savevm_state_complete_postcopy(QEMUFile *f)
+{
+ SaveStateEntry *se;
+ int ret;
+
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (!se->ops || !se->ops->save_live_complete_postcopy) {
+ continue;
+ }
+ if (se->ops->is_active) {
+ if (!se->ops->is_active(se->opaque)) {
+ continue;
+ }
+ }
+ trace_savevm_section_start(se->idstr, se->section_id);
+ /* Section type */
+ qemu_put_byte(f, QEMU_VM_SECTION_END);
+ qemu_put_be32(f, se->section_id);
+
+ ret = se->ops->save_live_complete_postcopy(f, se->opaque);
+ trace_savevm_section_end(se->idstr, se->section_id, ret);
+ save_section_footer(f, se);
+ if (ret < 0) {
+ qemu_file_set_error(f, ret);
+ return;
+ }
+ }
+
+ qemu_put_byte(f, QEMU_VM_EOF);
+ qemu_fflush(f);
+}
+
+static
+int qemu_savevm_state_complete_precopy_iterable(QEMUFile *f, bool in_postcopy)
+{
+ SaveStateEntry *se;
+ int ret;
+
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (!se->ops ||
+ (in_postcopy && se->ops->has_postcopy &&
+ se->ops->has_postcopy(se->opaque)) ||
+ !se->ops->save_live_complete_precopy) {
+ continue;
+ }
+
+ if (se->ops->is_active) {
+ if (!se->ops->is_active(se->opaque)) {
+ continue;
+ }
+ }
+ trace_savevm_section_start(se->idstr, se->section_id);
+
+ save_section_header(f, se, QEMU_VM_SECTION_END);
+
+ ret = se->ops->save_live_complete_precopy(f, se->opaque);
+ trace_savevm_section_end(se->idstr, se->section_id, ret);
+ save_section_footer(f, se);
+ if (ret < 0) {
+ qemu_file_set_error(f, ret);
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f,
+ bool in_postcopy,
+ bool inactivate_disks)
+{
+ g_autoptr(JSONWriter) vmdesc = NULL;
+ int vmdesc_len;
+ SaveStateEntry *se;
+ int ret;
+
+ vmdesc = json_writer_new(false);
+ json_writer_start_object(vmdesc, NULL);
+ json_writer_int64(vmdesc, "page_size", qemu_target_page_size());
+ json_writer_start_array(vmdesc, "devices");
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+
+ if ((!se->ops || !se->ops->save_state) && !se->vmsd) {
+ continue;
+ }
+ if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) {
+ trace_savevm_section_skip(se->idstr, se->section_id);
+ continue;
+ }
+
+ trace_savevm_section_start(se->idstr, se->section_id);
+
+ json_writer_start_object(vmdesc, NULL);
+ json_writer_str(vmdesc, "name", se->idstr);
+ json_writer_int64(vmdesc, "instance_id", se->instance_id);
+
+ save_section_header(f, se, QEMU_VM_SECTION_FULL);
+ ret = vmstate_save(f, se, vmdesc);
+ if (ret) {
+ qemu_file_set_error(f, ret);
+ return ret;
+ }
+ trace_savevm_section_end(se->idstr, se->section_id, 0);
+ save_section_footer(f, se);
+
+ json_writer_end_object(vmdesc);
+ }
+
+ if (inactivate_disks) {
+ /* Inactivate before sending QEMU_VM_EOF so that the
+ * bdrv_invalidate_cache_all() on the other end won't fail. */
+ ret = bdrv_inactivate_all();
+ if (ret) {
+ error_report("%s: bdrv_inactivate_all() failed (%d)",
+ __func__, ret);
+ qemu_file_set_error(f, ret);
+ return ret;
+ }
+ }
+ if (!in_postcopy) {
+ /* Postcopy stream will still be going */
+ qemu_put_byte(f, QEMU_VM_EOF);
+ }
+
+ json_writer_end_array(vmdesc);
+ json_writer_end_object(vmdesc);
+ vmdesc_len = strlen(json_writer_get(vmdesc));
+
+ if (should_send_vmdesc()) {
+ qemu_put_byte(f, QEMU_VM_VMDESCRIPTION);
+ qemu_put_be32(f, vmdesc_len);
+ qemu_put_buffer(f, (uint8_t *)json_writer_get(vmdesc), vmdesc_len);
+ }
+
+ return 0;
+}
+
+int qemu_savevm_state_complete_precopy(QEMUFile *f, bool iterable_only,
+ bool inactivate_disks)
+{
+ int ret;
+ Error *local_err = NULL;
+ bool in_postcopy = migration_in_postcopy();
+
+ if (precopy_notify(PRECOPY_NOTIFY_COMPLETE, &local_err)) {
+ error_report_err(local_err);
+ }
+
+ trace_savevm_state_complete_precopy();
+
+ cpu_synchronize_all_states();
+
+ if (!in_postcopy || iterable_only) {
+ ret = qemu_savevm_state_complete_precopy_iterable(f, in_postcopy);
+ if (ret) {
+ return ret;
+ }
+ }
+
+ if (iterable_only) {
+ goto flush;
+ }
+
+ ret = qemu_savevm_state_complete_precopy_non_iterable(f, in_postcopy,
+ inactivate_disks);
+ if (ret) {
+ return ret;
+ }
+
+flush:
+ qemu_fflush(f);
+ return 0;
+}
+
+/* Give an estimate of the amount left to be transferred,
+ * the result is split into the amount for units that can and
+ * for units that can't do postcopy.
+ */
+void qemu_savevm_state_pending(QEMUFile *f, uint64_t threshold_size,
+ uint64_t *res_precopy_only,
+ uint64_t *res_compatible,
+ uint64_t *res_postcopy_only)
+{
+ SaveStateEntry *se;
+
+ *res_precopy_only = 0;
+ *res_compatible = 0;
+ *res_postcopy_only = 0;
+
+
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (!se->ops || !se->ops->save_live_pending) {
+ continue;
+ }
+ if (se->ops->is_active) {
+ if (!se->ops->is_active(se->opaque)) {
+ continue;
+ }
+ }
+ se->ops->save_live_pending(f, se->opaque, threshold_size,
+ res_precopy_only, res_compatible,
+ res_postcopy_only);
+ }
+}
+
+void qemu_savevm_state_cleanup(void)
+{
+ SaveStateEntry *se;
+ Error *local_err = NULL;
+
+ if (precopy_notify(PRECOPY_NOTIFY_CLEANUP, &local_err)) {
+ error_report_err(local_err);
+ }
+
+ trace_savevm_state_cleanup();
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (se->ops && se->ops->save_cleanup) {
+ se->ops->save_cleanup(se->opaque);
+ }
+ }
+}
+
+static int qemu_savevm_state(QEMUFile *f, Error **errp)
+{
+ int ret;
+ MigrationState *ms = migrate_get_current();
+ MigrationStatus status;
+
+ if (migration_is_running(ms->state)) {
+ error_setg(errp, QERR_MIGRATION_ACTIVE);
+ return -EINVAL;
+ }
+
+ if (migrate_use_block()) {
+ error_setg(errp, "Block migration and snapshots are incompatible");
+ return -EINVAL;
+ }
+
+ migrate_init(ms);
+ memset(&ram_counters, 0, sizeof(ram_counters));
+ memset(&compression_counters, 0, sizeof(compression_counters));
+ ms->to_dst_file = f;
+
+ qemu_mutex_unlock_iothread();
+ qemu_savevm_state_header(f);
+ qemu_savevm_state_setup(f);
+ qemu_mutex_lock_iothread();
+
+ while (qemu_file_get_error(f) == 0) {
+ if (qemu_savevm_state_iterate(f, false) > 0) {
+ break;
+ }
+ }
+
+ ret = qemu_file_get_error(f);
+ if (ret == 0) {
+ qemu_savevm_state_complete_precopy(f, false, false);
+ ret = qemu_file_get_error(f);
+ }
+ qemu_savevm_state_cleanup();
+ if (ret != 0) {
+ error_setg_errno(errp, -ret, "Error while writing VM state");
+ }
+
+ if (ret != 0) {
+ status = MIGRATION_STATUS_FAILED;
+ } else {
+ status = MIGRATION_STATUS_COMPLETED;
+ }
+ migrate_set_state(&ms->state, MIGRATION_STATUS_SETUP, status);
+
+ /* f is outer parameter, it should not stay in global migration state after
+ * this function finished */
+ ms->to_dst_file = NULL;
+
+ return ret;
+}
+
+void qemu_savevm_live_state(QEMUFile *f)
+{
+ /* save QEMU_VM_SECTION_END section */
+ qemu_savevm_state_complete_precopy(f, true, false);
+ qemu_put_byte(f, QEMU_VM_EOF);
+}
+
+int qemu_save_device_state(QEMUFile *f)
+{
+ SaveStateEntry *se;
+
+ if (!migration_in_colo_state()) {
+ qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
+ qemu_put_be32(f, QEMU_VM_FILE_VERSION);
+ }
+ cpu_synchronize_all_states();
+
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ int ret;
+
+ if (se->is_ram) {
+ continue;
+ }
+ if ((!se->ops || !se->ops->save_state) && !se->vmsd) {
+ continue;
+ }
+ if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) {
+ continue;
+ }
+
+ save_section_header(f, se, QEMU_VM_SECTION_FULL);
+
+ ret = vmstate_save(f, se, NULL);
+ if (ret) {
+ return ret;
+ }
+
+ save_section_footer(f, se);
+ }
+
+ qemu_put_byte(f, QEMU_VM_EOF);
+
+ return qemu_file_get_error(f);
+}
+
+static SaveStateEntry *find_se(const char *idstr, uint32_t instance_id)
+{
+ SaveStateEntry *se;
+
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (!strcmp(se->idstr, idstr) &&
+ (instance_id == se->instance_id ||
+ instance_id == se->alias_id))
+ return se;
+ /* Migrating from an older version? */
+ if (strstr(se->idstr, idstr) && se->compat) {
+ if (!strcmp(se->compat->idstr, idstr) &&
+ (instance_id == se->compat->instance_id ||
+ instance_id == se->alias_id))
+ return se;
+ }
+ }
+ return NULL;
+}
+
+enum LoadVMExitCodes {
+ /* Allow a command to quit all layers of nested loadvm loops */
+ LOADVM_QUIT = 1,
+};
+
+/* ------ incoming postcopy messages ------ */
+/* 'advise' arrives before any transfers just to tell us that a postcopy
+ * *might* happen - it might be skipped if precopy transferred everything
+ * quickly.
+ */
+static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis,
+ uint16_t len)
+{
+ PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_ADVISE);
+ uint64_t remote_pagesize_summary, local_pagesize_summary, remote_tps;
+ Error *local_err = NULL;
+
+ trace_loadvm_postcopy_handle_advise();
+ if (ps != POSTCOPY_INCOMING_NONE) {
+ error_report("CMD_POSTCOPY_ADVISE in wrong postcopy state (%d)", ps);
+ return -1;
+ }
+
+ switch (len) {
+ case 0:
+ if (migrate_postcopy_ram()) {
+ error_report("RAM postcopy is enabled but have 0 byte advise");
+ return -EINVAL;
+ }
+ return 0;
+ case 8 + 8:
+ if (!migrate_postcopy_ram()) {
+ error_report("RAM postcopy is disabled but have 16 byte advise");
+ return -EINVAL;
+ }
+ break;
+ default:
+ error_report("CMD_POSTCOPY_ADVISE invalid length (%d)", len);
+ return -EINVAL;
+ }
+
+ if (!postcopy_ram_supported_by_host(mis)) {
+ postcopy_state_set(POSTCOPY_INCOMING_NONE);
+ return -1;
+ }
+
+ remote_pagesize_summary = qemu_get_be64(mis->from_src_file);
+ local_pagesize_summary = ram_pagesize_summary();
+
+ if (remote_pagesize_summary != local_pagesize_summary) {
+ /*
+ * This detects two potential causes of mismatch:
+ * a) A mismatch in host page sizes
+ * Some combinations of mismatch are probably possible but it gets
+ * a bit more complicated. In particular we need to place whole
+ * host pages on the dest at once, and we need to ensure that we
+ * handle dirtying to make sure we never end up sending part of
+ * a hostpage on it's own.
+ * b) The use of different huge page sizes on source/destination
+ * a more fine grain test is performed during RAM block migration
+ * but this test here causes a nice early clear failure, and
+ * also fails when passed to an older qemu that doesn't
+ * do huge pages.
+ */
+ error_report("Postcopy needs matching RAM page sizes (s=%" PRIx64
+ " d=%" PRIx64 ")",
+ remote_pagesize_summary, local_pagesize_summary);
+ return -1;
+ }
+
+ remote_tps = qemu_get_be64(mis->from_src_file);
+ if (remote_tps != qemu_target_page_size()) {
+ /*
+ * Again, some differences could be dealt with, but for now keep it
+ * simple.
+ */
+ error_report("Postcopy needs matching target page sizes (s=%d d=%zd)",
+ (int)remote_tps, qemu_target_page_size());
+ return -1;
+ }
+
+ if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_ADVISE, &local_err)) {
+ error_report_err(local_err);
+ return -1;
+ }
+
+ if (ram_postcopy_incoming_init(mis)) {
+ return -1;
+ }
+
+ return 0;
+}
+
+/* After postcopy we will be told to throw some pages away since they're
+ * dirty and will have to be demand fetched. Must happen before CPU is
+ * started.
+ * There can be 0..many of these messages, each encoding multiple pages.
+ */
+static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
+ uint16_t len)
+{
+ int tmp;
+ char ramid[256];
+ PostcopyState ps = postcopy_state_get();
+
+ trace_loadvm_postcopy_ram_handle_discard();
+
+ switch (ps) {
+ case POSTCOPY_INCOMING_ADVISE:
+ /* 1st discard */
+ tmp = postcopy_ram_prepare_discard(mis);
+ if (tmp) {
+ return tmp;
+ }
+ break;
+
+ case POSTCOPY_INCOMING_DISCARD:
+ /* Expected state */
+ break;
+
+ default:
+ error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)",
+ ps);
+ return -1;
+ }
+ /* We're expecting a
+ * Version (0)
+ * a RAM ID string (length byte, name, 0 term)
+ * then at least 1 16 byte chunk
+ */
+ if (len < (1 + 1 + 1 + 1 + 2 * 8)) {
+ error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
+ return -1;
+ }
+
+ tmp = qemu_get_byte(mis->from_src_file);
+ if (tmp != postcopy_ram_discard_version) {
+ error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp);
+ return -1;
+ }
+
+ if (!qemu_get_counted_string(mis->from_src_file, ramid)) {
+ error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID");
+ return -1;
+ }
+ tmp = qemu_get_byte(mis->from_src_file);
+ if (tmp != 0) {
+ error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp);
+ return -1;
+ }
+
+ len -= 3 + strlen(ramid);
+ if (len % 16) {
+ error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
+ return -1;
+ }
+ trace_loadvm_postcopy_ram_handle_discard_header(ramid, len);
+ while (len) {
+ uint64_t start_addr, block_length;
+ start_addr = qemu_get_be64(mis->from_src_file);
+ block_length = qemu_get_be64(mis->from_src_file);
+
+ len -= 16;
+ int ret = ram_discard_range(ramid, start_addr, block_length);
+ if (ret) {
+ return ret;
+ }
+ }
+ trace_loadvm_postcopy_ram_handle_discard_end();
+
+ return 0;
+}
+
+/*
+ * Triggered by a postcopy_listen command; this thread takes over reading
+ * the input stream, leaving the main thread free to carry on loading the rest
+ * of the device state (from RAM).
+ * (TODO:This could do with being in a postcopy file - but there again it's
+ * just another input loop, not that postcopy specific)
+ */
+static void *postcopy_ram_listen_thread(void *opaque)
+{
+ MigrationIncomingState *mis = migration_incoming_get_current();
+ QEMUFile *f = mis->from_src_file;
+ int load_res;
+ MigrationState *migr = migrate_get_current();
+
+ object_ref(OBJECT(migr));
+
+ migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
+ MIGRATION_STATUS_POSTCOPY_ACTIVE);
+ qemu_sem_post(&mis->listen_thread_sem);
+ trace_postcopy_ram_listen_thread_start();
+
+ rcu_register_thread();
+ /*
+ * Because we're a thread and not a coroutine we can't yield
+ * in qemu_file, and thus we must be blocking now.
+ */
+ qemu_file_set_blocking(f, true);
+ load_res = qemu_loadvm_state_main(f, mis);
+
+ /*
+ * This is tricky, but, mis->from_src_file can change after it
+ * returns, when postcopy recovery happened. In the future, we may
+ * want a wrapper for the QEMUFile handle.
+ */
+ f = mis->from_src_file;
+
+ /* And non-blocking again so we don't block in any cleanup */
+ qemu_file_set_blocking(f, false);
+
+ trace_postcopy_ram_listen_thread_exit();
+ if (load_res < 0) {
+ qemu_file_set_error(f, load_res);
+ dirty_bitmap_mig_cancel_incoming();
+ if (postcopy_state_get() == POSTCOPY_INCOMING_RUNNING &&
+ !migrate_postcopy_ram() && migrate_dirty_bitmaps())
+ {
+ error_report("%s: loadvm failed during postcopy: %d. All states "
+ "are migrated except dirty bitmaps. Some dirty "
+ "bitmaps may be lost, and present migrated dirty "
+ "bitmaps are correctly migrated and valid.",
+ __func__, load_res);
+ load_res = 0; /* prevent further exit() */
+ } else {
+ error_report("%s: loadvm failed: %d", __func__, load_res);
+ migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
+ MIGRATION_STATUS_FAILED);
+ }
+ }
+ if (load_res >= 0) {
+ /*
+ * This looks good, but it's possible that the device loading in the
+ * main thread hasn't finished yet, and so we might not be in 'RUN'
+ * state yet; wait for the end of the main thread.
+ */
+ qemu_event_wait(&mis->main_thread_load_event);
+ }
+ postcopy_ram_incoming_cleanup(mis);
+
+ if (load_res < 0) {
+ /*
+ * If something went wrong then we have a bad state so exit;
+ * depending how far we got it might be possible at this point
+ * to leave the guest running and fire MCEs for pages that never
+ * arrived as a desperate recovery step.
+ */
+ rcu_unregister_thread();
+ exit(EXIT_FAILURE);
+ }
+
+ migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
+ MIGRATION_STATUS_COMPLETED);
+ /*
+ * If everything has worked fine, then the main thread has waited
+ * for us to start, and we're the last use of the mis.
+ * (If something broke then qemu will have to exit anyway since it's
+ * got a bad migration state).
+ */
+ migration_incoming_state_destroy();
+ qemu_loadvm_state_cleanup();
+
+ rcu_unregister_thread();
+ mis->have_listen_thread = false;
+ postcopy_state_set(POSTCOPY_INCOMING_END);
+
+ object_unref(OBJECT(migr));
+
+ return NULL;
+}
+
+/* After this message we must be able to immediately receive postcopy data */
+static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
+{
+ PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_LISTENING);
+ trace_loadvm_postcopy_handle_listen();
+ Error *local_err = NULL;
+
+ if (ps != POSTCOPY_INCOMING_ADVISE && ps != POSTCOPY_INCOMING_DISCARD) {
+ error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps);
+ return -1;
+ }
+ if (ps == POSTCOPY_INCOMING_ADVISE) {
+ /*
+ * A rare case, we entered listen without having to do any discards,
+ * so do the setup that's normally done at the time of the 1st discard.
+ */
+ if (migrate_postcopy_ram()) {
+ postcopy_ram_prepare_discard(mis);
+ }
+ }
+
+ /*
+ * Sensitise RAM - can now generate requests for blocks that don't exist
+ * However, at this point the CPU shouldn't be running, and the IO
+ * shouldn't be doing anything yet so don't actually expect requests
+ */
+ if (migrate_postcopy_ram()) {
+ if (postcopy_ram_incoming_setup(mis)) {
+ postcopy_ram_incoming_cleanup(mis);
+ return -1;
+ }
+ }
+
+ if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_LISTEN, &local_err)) {
+ error_report_err(local_err);
+ return -1;
+ }
+
+ mis->have_listen_thread = true;
+ /* Start up the listening thread and wait for it to signal ready */
+ qemu_sem_init(&mis->listen_thread_sem, 0);
+ qemu_thread_create(&mis->listen_thread, "postcopy/listen",
+ postcopy_ram_listen_thread, NULL,
+ QEMU_THREAD_DETACHED);
+ qemu_sem_wait(&mis->listen_thread_sem);
+ qemu_sem_destroy(&mis->listen_thread_sem);
+
+ return 0;
+}
+
+static void loadvm_postcopy_handle_run_bh(void *opaque)
+{
+ Error *local_err = NULL;
+ MigrationIncomingState *mis = opaque;
+
+ /* TODO we should move all of this lot into postcopy_ram.c or a shared code
+ * in migration.c
+ */
+ cpu_synchronize_all_post_init();
+
+ qemu_announce_self(&mis->announce_timer, migrate_announce_params());
+
+ /* Make sure all file formats flush their mutable metadata.
+ * If we get an error here, just don't restart the VM yet. */
+ bdrv_invalidate_cache_all(&local_err);
+ if (local_err) {
+ error_report_err(local_err);
+ local_err = NULL;
+ autostart = false;
+ }
+
+ trace_loadvm_postcopy_handle_run_cpu_sync();
+
+ trace_loadvm_postcopy_handle_run_vmstart();
+
+ dirty_bitmap_mig_before_vm_start();
+
+ if (autostart) {
+ /* Hold onto your hats, starting the CPU */
+ vm_start();
+ } else {
+ /* leave it paused and let management decide when to start the CPU */
+ runstate_set(RUN_STATE_PAUSED);
+ }
+
+ qemu_bh_delete(mis->bh);
+}
+
+/* After all discards we can start running and asking for pages */
+static int loadvm_postcopy_handle_run(MigrationIncomingState *mis)
+{
+ PostcopyState ps = postcopy_state_get();
+
+ trace_loadvm_postcopy_handle_run();
+ if (ps != POSTCOPY_INCOMING_LISTENING) {
+ error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps);
+ return -1;
+ }
+
+ postcopy_state_set(POSTCOPY_INCOMING_RUNNING);
+ mis->bh = qemu_bh_new(loadvm_postcopy_handle_run_bh, mis);
+ qemu_bh_schedule(mis->bh);
+
+ /* We need to finish reading the stream from the package
+ * and also stop reading anything more from the stream that loaded the
+ * package (since it's now being read by the listener thread).
+ * LOADVM_QUIT will quit all the layers of nested loadvm loops.
+ */
+ return LOADVM_QUIT;
+}
+
+/* We must be with page_request_mutex held */
+static gboolean postcopy_sync_page_req(gpointer key, gpointer value,
+ gpointer data)
+{
+ MigrationIncomingState *mis = data;
+ void *host_addr = (void *) key;
+ ram_addr_t rb_offset;
+ RAMBlock *rb;
+ int ret;
+
+ rb = qemu_ram_block_from_host(host_addr, true, &rb_offset);
+ if (!rb) {
+ /*
+ * This should _never_ happen. However be nice for a migrating VM to
+ * not crash/assert. Post an error (note: intended to not use *_once
+ * because we do want to see all the illegal addresses; and this can
+ * never be triggered by the guest so we're safe) and move on next.
+ */
+ error_report("%s: illegal host addr %p", __func__, host_addr);
+ /* Try the next entry */
+ return FALSE;
+ }
+
+ ret = migrate_send_rp_message_req_pages(mis, rb, rb_offset);
+ if (ret) {
+ /* Please refer to above comment. */
+ error_report("%s: send rp message failed for addr %p",
+ __func__, host_addr);
+ return FALSE;
+ }
+
+ trace_postcopy_page_req_sync(host_addr);
+
+ return FALSE;
+}
+
+static void migrate_send_rp_req_pages_pending(MigrationIncomingState *mis)
+{
+ WITH_QEMU_LOCK_GUARD(&mis->page_request_mutex) {
+ g_tree_foreach(mis->page_requested, postcopy_sync_page_req, mis);
+ }
+}
+
+static int loadvm_postcopy_handle_resume(MigrationIncomingState *mis)
+{
+ if (mis->state != MIGRATION_STATUS_POSTCOPY_RECOVER) {
+ error_report("%s: illegal resume received", __func__);
+ /* Don't fail the load, only for this. */
+ return 0;
+ }
+
+ /*
+ * Reset the last_rb before we resend any page req to source again, since
+ * the source should have it reset already.
+ */
+ mis->last_rb = NULL;
+
+ /*
+ * This means source VM is ready to resume the postcopy migration.
+ */
+ migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_RECOVER,
+ MIGRATION_STATUS_POSTCOPY_ACTIVE);
+
+ trace_loadvm_postcopy_handle_resume();
+
+ /* Tell source that "we are ready" */
+ migrate_send_rp_resume_ack(mis, MIGRATION_RESUME_ACK_VALUE);
+
+ /*
+ * After a postcopy recovery, the source should have lost the postcopy
+ * queue, or potentially the requested pages could have been lost during
+ * the network down phase. Let's re-sync with the source VM by re-sending
+ * all the pending pages that we eagerly need, so these threads won't get
+ * blocked too long due to the recovery.
+ *
+ * Without this procedure, the faulted destination VM threads (waiting for
+ * page requests right before the postcopy is interrupted) can keep hanging
+ * until the pages are sent by the source during the background copying of
+ * pages, or another thread faulted on the same address accidentally.
+ */
+ migrate_send_rp_req_pages_pending(mis);
+
+ /*
+ * It's time to switch state and release the fault thread to continue
+ * service page faults. Note that this should be explicitly after the
+ * above call to migrate_send_rp_req_pages_pending(). In short:
+ * migrate_send_rp_message_req_pages() is not thread safe, yet.
+ */
+ qemu_sem_post(&mis->postcopy_pause_sem_fault);
+
+ return 0;
+}
+
+/**
+ * Immediately following this command is a blob of data containing an embedded
+ * chunk of migration stream; read it and load it.
+ *
+ * @mis: Incoming state
+ * @length: Length of packaged data to read
+ *
+ * Returns: Negative values on error
+ *
+ */
+static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis)
+{
+ int ret;
+ size_t length;
+ QIOChannelBuffer *bioc;
+
+ length = qemu_get_be32(mis->from_src_file);
+ trace_loadvm_handle_cmd_packaged(length);
+
+ if (length > MAX_VM_CMD_PACKAGED_SIZE) {
+ error_report("Unreasonably large packaged state: %zu", length);
+ return -1;
+ }
+
+ bioc = qio_channel_buffer_new(length);
+ qio_channel_set_name(QIO_CHANNEL(bioc), "migration-loadvm-buffer");
+ ret = qemu_get_buffer(mis->from_src_file,
+ bioc->data,
+ length);
+ if (ret != length) {
+ object_unref(OBJECT(bioc));
+ error_report("CMD_PACKAGED: Buffer receive fail ret=%d length=%zu",
+ ret, length);
+ return (ret < 0) ? ret : -EAGAIN;
+ }
+ bioc->usage += length;
+ trace_loadvm_handle_cmd_packaged_received(ret);
+
+ QEMUFile *packf = qemu_fopen_channel_input(QIO_CHANNEL(bioc));
+
+ ret = qemu_loadvm_state_main(packf, mis);
+ trace_loadvm_handle_cmd_packaged_main(ret);
+ qemu_fclose(packf);
+ object_unref(OBJECT(bioc));
+
+ return ret;
+}
+
+/*
+ * Handle request that source requests for recved_bitmap on
+ * destination. Payload format:
+ *
+ * len (1 byte) + ramblock_name (<255 bytes)
+ */
+static int loadvm_handle_recv_bitmap(MigrationIncomingState *mis,
+ uint16_t len)
+{
+ QEMUFile *file = mis->from_src_file;
+ RAMBlock *rb;
+ char block_name[256];
+ size_t cnt;
+
+ cnt = qemu_get_counted_string(file, block_name);
+ if (!cnt) {
+ error_report("%s: failed to read block name", __func__);
+ return -EINVAL;
+ }
+
+ /* Validate before using the data */
+ if (qemu_file_get_error(file)) {
+ return qemu_file_get_error(file);
+ }
+
+ if (len != cnt + 1) {
+ error_report("%s: invalid payload length (%d)", __func__, len);
+ return -EINVAL;
+ }
+
+ rb = qemu_ram_block_by_name(block_name);
+ if (!rb) {
+ error_report("%s: block '%s' not found", __func__, block_name);
+ return -EINVAL;
+ }
+
+ migrate_send_rp_recv_bitmap(mis, block_name);
+
+ trace_loadvm_handle_recv_bitmap(block_name);
+
+ return 0;
+}
+
+static int loadvm_process_enable_colo(MigrationIncomingState *mis)
+{
+ int ret = migration_incoming_enable_colo();
+
+ if (!ret) {
+ ret = colo_init_ram_cache();
+ if (ret) {
+ migration_incoming_disable_colo();
+ }
+ }
+ return ret;
+}
+
+/*
+ * Process an incoming 'QEMU_VM_COMMAND'
+ * 0 just a normal return
+ * LOADVM_QUIT All good, but exit the loop
+ * <0 Error
+ */
+static int loadvm_process_command(QEMUFile *f)
+{
+ MigrationIncomingState *mis = migration_incoming_get_current();
+ uint16_t cmd;
+ uint16_t len;
+ uint32_t tmp32;
+
+ cmd = qemu_get_be16(f);
+ len = qemu_get_be16(f);
+
+ /* Check validity before continue processing of cmds */
+ if (qemu_file_get_error(f)) {
+ return qemu_file_get_error(f);
+ }
+
+ trace_loadvm_process_command(cmd, len);
+ if (cmd >= MIG_CMD_MAX || cmd == MIG_CMD_INVALID) {
+ error_report("MIG_CMD 0x%x unknown (len 0x%x)", cmd, len);
+ return -EINVAL;
+ }
+
+ if (mig_cmd_args[cmd].len != -1 && mig_cmd_args[cmd].len != len) {
+ error_report("%s received with bad length - expecting %zu, got %d",
+ mig_cmd_args[cmd].name,
+ (size_t)mig_cmd_args[cmd].len, len);
+ return -ERANGE;
+ }
+
+ switch (cmd) {
+ case MIG_CMD_OPEN_RETURN_PATH:
+ if (mis->to_src_file) {
+ error_report("CMD_OPEN_RETURN_PATH called when RP already open");
+ /* Not really a problem, so don't give up */
+ return 0;
+ }
+ mis->to_src_file = qemu_file_get_return_path(f);
+ if (!mis->to_src_file) {
+ error_report("CMD_OPEN_RETURN_PATH failed");
+ return -1;
+ }
+ break;
+
+ case MIG_CMD_PING:
+ tmp32 = qemu_get_be32(f);
+ trace_loadvm_process_command_ping(tmp32);
+ if (!mis->to_src_file) {
+ error_report("CMD_PING (0x%x) received with no return path",
+ tmp32);
+ return -1;
+ }
+ migrate_send_rp_pong(mis, tmp32);
+ break;
+
+ case MIG_CMD_PACKAGED:
+ return loadvm_handle_cmd_packaged(mis);
+
+ case MIG_CMD_POSTCOPY_ADVISE:
+ return loadvm_postcopy_handle_advise(mis, len);
+
+ case MIG_CMD_POSTCOPY_LISTEN:
+ return loadvm_postcopy_handle_listen(mis);
+
+ case MIG_CMD_POSTCOPY_RUN:
+ return loadvm_postcopy_handle_run(mis);
+
+ case MIG_CMD_POSTCOPY_RAM_DISCARD:
+ return loadvm_postcopy_ram_handle_discard(mis, len);
+
+ case MIG_CMD_POSTCOPY_RESUME:
+ return loadvm_postcopy_handle_resume(mis);
+
+ case MIG_CMD_RECV_BITMAP:
+ return loadvm_handle_recv_bitmap(mis, len);
+
+ case MIG_CMD_ENABLE_COLO:
+ return loadvm_process_enable_colo(mis);
+ }
+
+ return 0;
+}
+
+/*
+ * Read a footer off the wire and check that it matches the expected section
+ *
+ * Returns: true if the footer was good
+ * false if there is a problem (and calls error_report to say why)
+ */
+static bool check_section_footer(QEMUFile *f, SaveStateEntry *se)
+{
+ int ret;
+ uint8_t read_mark;
+ uint32_t read_section_id;
+
+ if (!migrate_get_current()->send_section_footer) {
+ /* No footer to check */
+ return true;
+ }
+
+ read_mark = qemu_get_byte(f);
+
+ ret = qemu_file_get_error(f);
+ if (ret) {
+ error_report("%s: Read section footer failed: %d",
+ __func__, ret);
+ return false;
+ }
+
+ if (read_mark != QEMU_VM_SECTION_FOOTER) {
+ error_report("Missing section footer for %s", se->idstr);
+ return false;
+ }
+
+ read_section_id = qemu_get_be32(f);
+ if (read_section_id != se->load_section_id) {
+ error_report("Mismatched section id in footer for %s -"
+ " read 0x%x expected 0x%x",
+ se->idstr, read_section_id, se->load_section_id);
+ return false;
+ }
+
+ /* All good */
+ return true;
+}
+
+static int
+qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis)
+{
+ uint32_t instance_id, version_id, section_id;
+ SaveStateEntry *se;
+ char idstr[256];
+ int ret;
+
+ /* Read section start */
+ section_id = qemu_get_be32(f);
+ if (!qemu_get_counted_string(f, idstr)) {
+ error_report("Unable to read ID string for section %u",
+ section_id);
+ return -EINVAL;
+ }
+ instance_id = qemu_get_be32(f);
+ version_id = qemu_get_be32(f);
+
+ ret = qemu_file_get_error(f);
+ if (ret) {
+ error_report("%s: Failed to read instance/version ID: %d",
+ __func__, ret);
+ return ret;
+ }
+
+ trace_qemu_loadvm_state_section_startfull(section_id, idstr,
+ instance_id, version_id);
+ /* Find savevm section */
+ se = find_se(idstr, instance_id);
+ if (se == NULL) {
+ error_report("Unknown savevm section or instance '%s' %"PRIu32". "
+ "Make sure that your current VM setup matches your "
+ "saved VM setup, including any hotplugged devices",
+ idstr, instance_id);
+ return -EINVAL;
+ }
+
+ /* Validate version */
+ if (version_id > se->version_id) {
+ error_report("savevm: unsupported version %d for '%s' v%d",
+ version_id, idstr, se->version_id);
+ return -EINVAL;
+ }
+ se->load_version_id = version_id;
+ se->load_section_id = section_id;
+
+ /* Validate if it is a device's state */
+ if (xen_enabled() && se->is_ram) {
+ error_report("loadvm: %s RAM loading not allowed on Xen", idstr);
+ return -EINVAL;
+ }
+
+ ret = vmstate_load(f, se);
+ if (ret < 0) {
+ error_report("error while loading state for instance 0x%"PRIx32" of"
+ " device '%s'", instance_id, idstr);
+ return ret;
+ }
+ if (!check_section_footer(f, se)) {
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int
+qemu_loadvm_section_part_end(QEMUFile *f, MigrationIncomingState *mis)
+{
+ uint32_t section_id;
+ SaveStateEntry *se;
+ int ret;
+
+ section_id = qemu_get_be32(f);
+
+ ret = qemu_file_get_error(f);
+ if (ret) {
+ error_report("%s: Failed to read section ID: %d",
+ __func__, ret);
+ return ret;
+ }
+
+ trace_qemu_loadvm_state_section_partend(section_id);
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (se->load_section_id == section_id) {
+ break;
+ }
+ }
+ if (se == NULL) {
+ error_report("Unknown savevm section %d", section_id);
+ return -EINVAL;
+ }
+
+ ret = vmstate_load(f, se);
+ if (ret < 0) {
+ error_report("error while loading state section id %d(%s)",
+ section_id, se->idstr);
+ return ret;
+ }
+ if (!check_section_footer(f, se)) {
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int qemu_loadvm_state_header(QEMUFile *f)
+{
+ unsigned int v;
+ int ret;
+
+ v = qemu_get_be32(f);
+ if (v != QEMU_VM_FILE_MAGIC) {
+ error_report("Not a migration stream");
+ return -EINVAL;
+ }
+
+ v = qemu_get_be32(f);
+ if (v == QEMU_VM_FILE_VERSION_COMPAT) {
+ error_report("SaveVM v2 format is obsolete and don't work anymore");
+ return -ENOTSUP;
+ }
+ if (v != QEMU_VM_FILE_VERSION) {
+ error_report("Unsupported migration stream version");
+ return -ENOTSUP;
+ }
+
+ if (migrate_get_current()->send_configuration) {
+ if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
+ error_report("Configuration section missing");
+ qemu_loadvm_state_cleanup();
+ return -EINVAL;
+ }
+ ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0);
+
+ if (ret) {
+ qemu_loadvm_state_cleanup();
+ return ret;
+ }
+ }
+ return 0;
+}
+
+static int qemu_loadvm_state_setup(QEMUFile *f)
+{
+ SaveStateEntry *se;
+ int ret;
+
+ trace_loadvm_state_setup();
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (!se->ops || !se->ops->load_setup) {
+ continue;
+ }
+ if (se->ops->is_active) {
+ if (!se->ops->is_active(se->opaque)) {
+ continue;
+ }
+ }
+
+ ret = se->ops->load_setup(f, se->opaque);
+ if (ret < 0) {
+ qemu_file_set_error(f, ret);
+ error_report("Load state of device %s failed", se->idstr);
+ return ret;
+ }
+ }
+ return 0;
+}
+
+void qemu_loadvm_state_cleanup(void)
+{
+ SaveStateEntry *se;
+
+ trace_loadvm_state_cleanup();
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (se->ops && se->ops->load_cleanup) {
+ se->ops->load_cleanup(se->opaque);
+ }
+ }
+}
+
+/* Return true if we should continue the migration, or false. */
+static bool postcopy_pause_incoming(MigrationIncomingState *mis)
+{
+ trace_postcopy_pause_incoming();
+
+ assert(migrate_postcopy_ram());
+
+ /* Clear the triggered bit to allow one recovery */
+ mis->postcopy_recover_triggered = false;
+
+ /*
+ * Unregister yank with either from/to src would work, since ioc behind it
+ * is the same
+ */
+ migration_ioc_unregister_yank_from_file(mis->from_src_file);
+
+ assert(mis->from_src_file);
+ qemu_file_shutdown(mis->from_src_file);
+ qemu_fclose(mis->from_src_file);
+ mis->from_src_file = NULL;
+
+ assert(mis->to_src_file);
+ qemu_file_shutdown(mis->to_src_file);
+ qemu_mutex_lock(&mis->rp_mutex);
+ qemu_fclose(mis->to_src_file);
+ mis->to_src_file = NULL;
+ qemu_mutex_unlock(&mis->rp_mutex);
+
+ migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
+ MIGRATION_STATUS_POSTCOPY_PAUSED);
+
+ /* Notify the fault thread for the invalidated file handle */
+ postcopy_fault_thread_notify(mis);
+
+ error_report("Detected IO failure for postcopy. "
+ "Migration paused.");
+
+ while (mis->state == MIGRATION_STATUS_POSTCOPY_PAUSED) {
+ qemu_sem_wait(&mis->postcopy_pause_sem_dst);
+ }
+
+ trace_postcopy_pause_incoming_continued();
+
+ return true;
+}
+
+int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
+{
+ uint8_t section_type;
+ int ret = 0;
+
+retry:
+ while (true) {
+ section_type = qemu_get_byte(f);
+
+ if (qemu_file_get_error(f)) {
+ ret = qemu_file_get_error(f);
+ break;
+ }
+
+ trace_qemu_loadvm_state_section(section_type);
+ switch (section_type) {
+ case QEMU_VM_SECTION_START:
+ case QEMU_VM_SECTION_FULL:
+ ret = qemu_loadvm_section_start_full(f, mis);
+ if (ret < 0) {
+ goto out;
+ }
+ break;
+ case QEMU_VM_SECTION_PART:
+ case QEMU_VM_SECTION_END:
+ ret = qemu_loadvm_section_part_end(f, mis);
+ if (ret < 0) {
+ goto out;
+ }
+ break;
+ case QEMU_VM_COMMAND:
+ ret = loadvm_process_command(f);
+ trace_qemu_loadvm_state_section_command(ret);
+ if ((ret < 0) || (ret == LOADVM_QUIT)) {
+ goto out;
+ }
+ break;
+ case QEMU_VM_EOF:
+ /* This is the end of migration */
+ goto out;
+ default:
+ error_report("Unknown savevm section type %d", section_type);
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+out:
+ if (ret < 0) {
+ qemu_file_set_error(f, ret);
+
+ /* Cancel bitmaps incoming regardless of recovery */
+ dirty_bitmap_mig_cancel_incoming();
+
+ /*
+ * If we are during an active postcopy, then we pause instead
+ * of bail out to at least keep the VM's dirty data. Note
+ * that POSTCOPY_INCOMING_LISTENING stage is still not enough,
+ * during which we're still receiving device states and we
+ * still haven't yet started the VM on destination.
+ *
+ * Only RAM postcopy supports recovery. Still, if RAM postcopy is
+ * enabled, canceled bitmaps postcopy will not affect RAM postcopy
+ * recovering.
+ */
+ if (postcopy_state_get() == POSTCOPY_INCOMING_RUNNING &&
+ migrate_postcopy_ram() && postcopy_pause_incoming(mis)) {
+ /* Reset f to point to the newly created channel */
+ f = mis->from_src_file;
+ goto retry;
+ }
+ }
+ return ret;
+}
+
+int qemu_loadvm_state(QEMUFile *f)
+{
+ MigrationIncomingState *mis = migration_incoming_get_current();
+ Error *local_err = NULL;
+ int ret;
+
+ if (qemu_savevm_state_blocked(&local_err)) {
+ error_report_err(local_err);
+ return -EINVAL;
+ }
+
+ ret = qemu_loadvm_state_header(f);
+ if (ret) {
+ return ret;
+ }
+
+ if (qemu_loadvm_state_setup(f) != 0) {
+ return -EINVAL;
+ }
+
+ cpu_synchronize_all_pre_loadvm();
+
+ ret = qemu_loadvm_state_main(f, mis);
+ qemu_event_set(&mis->main_thread_load_event);
+
+ trace_qemu_loadvm_state_post_main(ret);
+
+ if (mis->have_listen_thread) {
+ /* Listen thread still going, can't clean up yet */
+ return ret;
+ }
+
+ if (ret == 0) {
+ ret = qemu_file_get_error(f);
+ }
+
+ /*
+ * Try to read in the VMDESC section as well, so that dumping tools that
+ * intercept our migration stream have the chance to see it.
+ */
+
+ /* We've got to be careful; if we don't read the data and just shut the fd
+ * then the sender can error if we close while it's still sending.
+ * We also mustn't read data that isn't there; some transports (RDMA)
+ * will stall waiting for that data when the source has already closed.
+ */
+ if (ret == 0 && should_send_vmdesc()) {
+ uint8_t *buf;
+ uint32_t size;
+ uint8_t section_type = qemu_get_byte(f);
+
+ if (section_type != QEMU_VM_VMDESCRIPTION) {
+ error_report("Expected vmdescription section, but got %d",
+ section_type);
+ /*
+ * It doesn't seem worth failing at this point since
+ * we apparently have an otherwise valid VM state
+ */
+ } else {
+ buf = g_malloc(0x1000);
+ size = qemu_get_be32(f);
+
+ while (size > 0) {
+ uint32_t read_chunk = MIN(size, 0x1000);
+ qemu_get_buffer(f, buf, read_chunk);
+ size -= read_chunk;
+ }
+ g_free(buf);
+ }
+ }
+
+ qemu_loadvm_state_cleanup();
+ cpu_synchronize_all_post_init();
+
+ return ret;
+}
+
+int qemu_load_device_state(QEMUFile *f)
+{
+ MigrationIncomingState *mis = migration_incoming_get_current();
+ int ret;
+
+ /* Load QEMU_VM_SECTION_FULL section */
+ ret = qemu_loadvm_state_main(f, mis);
+ if (ret < 0) {
+ error_report("Failed to load device state: %d", ret);
+ return ret;
+ }
+
+ cpu_synchronize_all_post_init();
+ return 0;
+}
+
+bool save_snapshot(const char *name, bool overwrite, const char *vmstate,
+ bool has_devices, strList *devices, Error **errp)
+{
+ BlockDriverState *bs;
+ QEMUSnapshotInfo sn1, *sn = &sn1;
+ int ret = -1, ret2;
+ QEMUFile *f;
+ int saved_vm_running;
+ uint64_t vm_state_size;
+ g_autoptr(GDateTime) now = g_date_time_new_now_local();
+ AioContext *aio_context;
+
+ if (migration_is_blocked(errp)) {
+ return false;
+ }
+
+ if (!replay_can_snapshot()) {
+ error_setg(errp, "Record/replay does not allow making snapshot "
+ "right now. Try once more later.");
+ return false;
+ }
+
+ if (!bdrv_all_can_snapshot(has_devices, devices, errp)) {
+ return false;
+ }
+
+ /* Delete old snapshots of the same name */
+ if (name) {
+ if (overwrite) {
+ if (bdrv_all_delete_snapshot(name, has_devices,
+ devices, errp) < 0) {
+ return false;
+ }
+ } else {
+ ret2 = bdrv_all_has_snapshot(name, has_devices, devices, errp);
+ if (ret2 < 0) {
+ return false;
+ }
+ if (ret2 == 1) {
+ error_setg(errp,
+ "Snapshot '%s' already exists in one or more devices",
+ name);
+ return false;
+ }
+ }
+ }
+
+ bs = bdrv_all_find_vmstate_bs(vmstate, has_devices, devices, errp);
+ if (bs == NULL) {
+ return false;
+ }
+ aio_context = bdrv_get_aio_context(bs);
+
+ saved_vm_running = runstate_is_running();
+
+ ret = global_state_store();
+ if (ret) {
+ error_setg(errp, "Error saving global state");
+ return false;
+ }
+ vm_stop(RUN_STATE_SAVE_VM);
+
+ bdrv_drain_all_begin();
+
+ aio_context_acquire(aio_context);
+
+ memset(sn, 0, sizeof(*sn));
+
+ /* fill auxiliary fields */
+ sn->date_sec = g_date_time_to_unix(now);
+ sn->date_nsec = g_date_time_get_microsecond(now) * 1000;
+ sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+ if (replay_mode != REPLAY_MODE_NONE) {
+ sn->icount = replay_get_current_icount();
+ } else {
+ sn->icount = -1ULL;
+ }
+
+ if (name) {
+ pstrcpy(sn->name, sizeof(sn->name), name);
+ } else {
+ g_autofree char *autoname = g_date_time_format(now, "vm-%Y%m%d%H%M%S");
+ pstrcpy(sn->name, sizeof(sn->name), autoname);
+ }
+
+ /* save the VM state */
+ f = qemu_fopen_bdrv(bs, 1);
+ if (!f) {
+ error_setg(errp, "Could not open VM state file");
+ goto the_end;
+ }
+ ret = qemu_savevm_state(f, errp);
+ vm_state_size = qemu_ftell(f);
+ ret2 = qemu_fclose(f);
+ if (ret < 0) {
+ goto the_end;
+ }
+ if (ret2 < 0) {
+ ret = ret2;
+ goto the_end;
+ }
+
+ /* The bdrv_all_create_snapshot() call that follows acquires the AioContext
+ * for itself. BDRV_POLL_WHILE() does not support nested locking because
+ * it only releases the lock once. Therefore synchronous I/O will deadlock
+ * unless we release the AioContext before bdrv_all_create_snapshot().
+ */
+ aio_context_release(aio_context);
+ aio_context = NULL;
+
+ ret = bdrv_all_create_snapshot(sn, bs, vm_state_size,
+ has_devices, devices, errp);
+ if (ret < 0) {
+ bdrv_all_delete_snapshot(sn->name, has_devices, devices, NULL);
+ goto the_end;
+ }
+
+ ret = 0;
+
+ the_end:
+ if (aio_context) {
+ aio_context_release(aio_context);
+ }
+
+ bdrv_drain_all_end();
+
+ if (saved_vm_running) {
+ vm_start();
+ }
+ return ret == 0;
+}
+
+void qmp_xen_save_devices_state(const char *filename, bool has_live, bool live,
+ Error **errp)
+{
+ QEMUFile *f;
+ QIOChannelFile *ioc;
+ int saved_vm_running;
+ int ret;
+
+ if (!has_live) {
+ /* live default to true so old version of Xen tool stack can have a
+ * successful live migration */
+ live = true;
+ }
+
+ saved_vm_running = runstate_is_running();
+ vm_stop(RUN_STATE_SAVE_VM);
+ global_state_store_running();
+
+ ioc = qio_channel_file_new_path(filename, O_WRONLY | O_CREAT | O_TRUNC,
+ 0660, errp);
+ if (!ioc) {
+ goto the_end;
+ }
+ qio_channel_set_name(QIO_CHANNEL(ioc), "migration-xen-save-state");
+ f = qemu_fopen_channel_output(QIO_CHANNEL(ioc));
+ object_unref(OBJECT(ioc));
+ ret = qemu_save_device_state(f);
+ if (ret < 0 || qemu_fclose(f) < 0) {
+ error_setg(errp, QERR_IO_ERROR);
+ } else {
+ /* libxl calls the QMP command "stop" before calling
+ * "xen-save-devices-state" and in case of migration failure, libxl
+ * would call "cont".
+ * So call bdrv_inactivate_all (release locks) here to let the other
+ * side of the migration take control of the images.
+ */
+ if (live && !saved_vm_running) {
+ ret = bdrv_inactivate_all();
+ if (ret) {
+ error_setg(errp, "%s: bdrv_inactivate_all() failed (%d)",
+ __func__, ret);
+ }
+ }
+ }
+
+ the_end:
+ if (saved_vm_running) {
+ vm_start();
+ }
+}
+
+void qmp_xen_load_devices_state(const char *filename, Error **errp)
+{
+ QEMUFile *f;
+ QIOChannelFile *ioc;
+ int ret;
+
+ /* Guest must be paused before loading the device state; the RAM state
+ * will already have been loaded by xc
+ */
+ if (runstate_is_running()) {
+ error_setg(errp, "Cannot update device state while vm is running");
+ return;
+ }
+ vm_stop(RUN_STATE_RESTORE_VM);
+
+ ioc = qio_channel_file_new_path(filename, O_RDONLY | O_BINARY, 0, errp);
+ if (!ioc) {
+ return;
+ }
+ qio_channel_set_name(QIO_CHANNEL(ioc), "migration-xen-load-state");
+ f = qemu_fopen_channel_input(QIO_CHANNEL(ioc));
+ object_unref(OBJECT(ioc));
+
+ ret = qemu_loadvm_state(f);
+ qemu_fclose(f);
+ if (ret < 0) {
+ error_setg(errp, QERR_IO_ERROR);
+ }
+ migration_incoming_state_destroy();
+}
+
+bool load_snapshot(const char *name, const char *vmstate,
+ bool has_devices, strList *devices, Error **errp)
+{
+ BlockDriverState *bs_vm_state;
+ QEMUSnapshotInfo sn;
+ QEMUFile *f;
+ int ret;
+ AioContext *aio_context;
+ MigrationIncomingState *mis = migration_incoming_get_current();
+
+ if (!bdrv_all_can_snapshot(has_devices, devices, errp)) {
+ return false;
+ }
+ ret = bdrv_all_has_snapshot(name, has_devices, devices, errp);
+ if (ret < 0) {
+ return false;
+ }
+ if (ret == 0) {
+ error_setg(errp, "Snapshot '%s' does not exist in one or more devices",
+ name);
+ return false;
+ }
+
+ bs_vm_state = bdrv_all_find_vmstate_bs(vmstate, has_devices, devices, errp);
+ if (!bs_vm_state) {
+ return false;
+ }
+ aio_context = bdrv_get_aio_context(bs_vm_state);
+
+ /* Don't even try to load empty VM states */
+ aio_context_acquire(aio_context);
+ ret = bdrv_snapshot_find(bs_vm_state, &sn, name);
+ aio_context_release(aio_context);
+ if (ret < 0) {
+ return false;
+ } else if (sn.vm_state_size == 0) {
+ error_setg(errp, "This is a disk-only snapshot. Revert to it "
+ " offline using qemu-img");
+ return false;
+ }
+
+ /*
+ * Flush the record/replay queue. Now the VM state is going
+ * to change. Therefore we don't need to preserve its consistency
+ */
+ replay_flush_events();
+
+ /* Flush all IO requests so they don't interfere with the new state. */
+ bdrv_drain_all_begin();
+
+ ret = bdrv_all_goto_snapshot(name, has_devices, devices, errp);
+ if (ret < 0) {
+ goto err_drain;
+ }
+
+ /* restore the VM state */
+ f = qemu_fopen_bdrv(bs_vm_state, 0);
+ if (!f) {
+ error_setg(errp, "Could not open VM state file");
+ goto err_drain;
+ }
+
+ qemu_system_reset(SHUTDOWN_CAUSE_NONE);
+ mis->from_src_file = f;
+
+ if (!yank_register_instance(MIGRATION_YANK_INSTANCE, errp)) {
+ ret = -EINVAL;
+ goto err_drain;
+ }
+ aio_context_acquire(aio_context);
+ ret = qemu_loadvm_state(f);
+ migration_incoming_state_destroy();
+ aio_context_release(aio_context);
+
+ bdrv_drain_all_end();
+
+ if (ret < 0) {
+ error_setg(errp, "Error %d while loading VM state", ret);
+ return false;
+ }
+
+ return true;
+
+err_drain:
+ bdrv_drain_all_end();
+ return false;
+}
+
+bool delete_snapshot(const char *name, bool has_devices,
+ strList *devices, Error **errp)
+{
+ if (!bdrv_all_can_snapshot(has_devices, devices, errp)) {
+ return false;
+ }
+
+ if (bdrv_all_delete_snapshot(name, has_devices, devices, errp) < 0) {
+ return false;
+ }
+
+ return true;
+}
+
+void vmstate_register_ram(MemoryRegion *mr, DeviceState *dev)
+{
+ qemu_ram_set_idstr(mr->ram_block,
+ memory_region_name(mr), dev);
+ qemu_ram_set_migratable(mr->ram_block);
+}
+
+void vmstate_unregister_ram(MemoryRegion *mr, DeviceState *dev)
+{
+ qemu_ram_unset_idstr(mr->ram_block);
+ qemu_ram_unset_migratable(mr->ram_block);
+}
+
+void vmstate_register_ram_global(MemoryRegion *mr)
+{
+ vmstate_register_ram(mr, NULL);
+}
+
+bool vmstate_check_only_migratable(const VMStateDescription *vmsd)
+{
+ /* check needed if --only-migratable is specified */
+ if (!only_migratable) {
+ return true;
+ }
+
+ return !(vmsd && vmsd->unmigratable);
+}
+
+typedef struct SnapshotJob {
+ Job common;
+ char *tag;
+ char *vmstate;
+ strList *devices;
+ Coroutine *co;
+ Error **errp;
+ bool ret;
+} SnapshotJob;
+
+static void qmp_snapshot_job_free(SnapshotJob *s)
+{
+ g_free(s->tag);
+ g_free(s->vmstate);
+ qapi_free_strList(s->devices);
+}
+
+
+static void snapshot_load_job_bh(void *opaque)
+{
+ Job *job = opaque;
+ SnapshotJob *s = container_of(job, SnapshotJob, common);
+ int orig_vm_running;
+
+ job_progress_set_remaining(&s->common, 1);
+
+ orig_vm_running = runstate_is_running();
+ vm_stop(RUN_STATE_RESTORE_VM);
+
+ s->ret = load_snapshot(s->tag, s->vmstate, true, s->devices, s->errp);
+ if (s->ret && orig_vm_running) {
+ vm_start();
+ }
+
+ job_progress_update(&s->common, 1);
+
+ qmp_snapshot_job_free(s);
+ aio_co_wake(s->co);
+}
+
+static void snapshot_save_job_bh(void *opaque)
+{
+ Job *job = opaque;
+ SnapshotJob *s = container_of(job, SnapshotJob, common);
+
+ job_progress_set_remaining(&s->common, 1);
+ s->ret = save_snapshot(s->tag, false, s->vmstate,
+ true, s->devices, s->errp);
+ job_progress_update(&s->common, 1);
+
+ qmp_snapshot_job_free(s);
+ aio_co_wake(s->co);
+}
+
+static void snapshot_delete_job_bh(void *opaque)
+{
+ Job *job = opaque;
+ SnapshotJob *s = container_of(job, SnapshotJob, common);
+
+ job_progress_set_remaining(&s->common, 1);
+ s->ret = delete_snapshot(s->tag, true, s->devices, s->errp);
+ job_progress_update(&s->common, 1);
+
+ qmp_snapshot_job_free(s);
+ aio_co_wake(s->co);
+}
+
+static int coroutine_fn snapshot_save_job_run(Job *job, Error **errp)
+{
+ SnapshotJob *s = container_of(job, SnapshotJob, common);
+ s->errp = errp;
+ s->co = qemu_coroutine_self();
+ aio_bh_schedule_oneshot(qemu_get_aio_context(),
+ snapshot_save_job_bh, job);
+ qemu_coroutine_yield();
+ return s->ret ? 0 : -1;
+}
+
+static int coroutine_fn snapshot_load_job_run(Job *job, Error **errp)
+{
+ SnapshotJob *s = container_of(job, SnapshotJob, common);
+ s->errp = errp;
+ s->co = qemu_coroutine_self();
+ aio_bh_schedule_oneshot(qemu_get_aio_context(),
+ snapshot_load_job_bh, job);
+ qemu_coroutine_yield();
+ return s->ret ? 0 : -1;
+}
+
+static int coroutine_fn snapshot_delete_job_run(Job *job, Error **errp)
+{
+ SnapshotJob *s = container_of(job, SnapshotJob, common);
+ s->errp = errp;
+ s->co = qemu_coroutine_self();
+ aio_bh_schedule_oneshot(qemu_get_aio_context(),
+ snapshot_delete_job_bh, job);
+ qemu_coroutine_yield();
+ return s->ret ? 0 : -1;
+}
+
+
+static const JobDriver snapshot_load_job_driver = {
+ .instance_size = sizeof(SnapshotJob),
+ .job_type = JOB_TYPE_SNAPSHOT_LOAD,
+ .run = snapshot_load_job_run,
+};
+
+static const JobDriver snapshot_save_job_driver = {
+ .instance_size = sizeof(SnapshotJob),
+ .job_type = JOB_TYPE_SNAPSHOT_SAVE,
+ .run = snapshot_save_job_run,
+};
+
+static const JobDriver snapshot_delete_job_driver = {
+ .instance_size = sizeof(SnapshotJob),
+ .job_type = JOB_TYPE_SNAPSHOT_DELETE,
+ .run = snapshot_delete_job_run,
+};
+
+
+void qmp_snapshot_save(const char *job_id,
+ const char *tag,
+ const char *vmstate,
+ strList *devices,
+ Error **errp)
+{
+ SnapshotJob *s;
+
+ s = job_create(job_id, &snapshot_save_job_driver, NULL,
+ qemu_get_aio_context(), JOB_MANUAL_DISMISS,
+ NULL, NULL, errp);
+ if (!s) {
+ return;
+ }
+
+ s->tag = g_strdup(tag);
+ s->vmstate = g_strdup(vmstate);
+ s->devices = QAPI_CLONE(strList, devices);
+
+ job_start(&s->common);
+}
+
+void qmp_snapshot_load(const char *job_id,
+ const char *tag,
+ const char *vmstate,
+ strList *devices,
+ Error **errp)
+{
+ SnapshotJob *s;
+
+ s = job_create(job_id, &snapshot_load_job_driver, NULL,
+ qemu_get_aio_context(), JOB_MANUAL_DISMISS,
+ NULL, NULL, errp);
+ if (!s) {
+ return;
+ }
+
+ s->tag = g_strdup(tag);
+ s->vmstate = g_strdup(vmstate);
+ s->devices = QAPI_CLONE(strList, devices);
+
+ job_start(&s->common);
+}
+
+void qmp_snapshot_delete(const char *job_id,
+ const char *tag,
+ strList *devices,
+ Error **errp)
+{
+ SnapshotJob *s;
+
+ s = job_create(job_id, &snapshot_delete_job_driver, NULL,
+ qemu_get_aio_context(), JOB_MANUAL_DISMISS,
+ NULL, NULL, errp);
+ if (!s) {
+ return;
+ }
+
+ s->tag = g_strdup(tag);
+ s->devices = QAPI_CLONE(strList, devices);
+
+ job_start(&s->common);
+}