migration: move savevm.c inside migration/

Now, everything is in place.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

1 files changed, 1435 insertions, 0 deletions

diff --git a/migration/savevm.c b/migration/savevm.c
new file mode 100644
index 0000000000..3b0e222cb3
--- /dev/null
+++ b/migration/savevm.c
@@ -0,0 +1,1435 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * 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 "config-host.h"
+#include "qemu-common.h"
+#include "hw/boards.h"
+#include "hw/hw.h"
+#include "hw/qdev.h"
+#include "net/net.h"
+#include "monitor/monitor.h"
+#include "sysemu/sysemu.h"
+#include "qemu/timer.h"
+#include "audio/audio.h"
+#include "migration/migration.h"
+#include "qemu/sockets.h"
+#include "qemu/queue.h"
+#include "sysemu/cpus.h"
+#include "exec/memory.h"
+#include "qmp-commands.h"
+#include "trace.h"
+#include "qemu/iov.h"
+#include "block/snapshot.h"
+#include "block/qapi.h"
+
+
+#ifndef ETH_P_RARP
+#define ETH_P_RARP 0x8035
+#endif
+#define ARP_HTYPE_ETH 0x0001
+#define ARP_PTYPE_IP 0x0800
+#define ARP_OP_REQUEST_REV 0x3
+
+static int announce_self_create(uint8_t *buf,
+                                uint8_t *mac_addr)
+{
+    /* Ethernet header. */
+    memset(buf, 0xff, 6);         /* destination MAC addr */
+    memcpy(buf + 6, mac_addr, 6); /* source MAC addr */
+    *(uint16_t *)(buf + 12) = htons(ETH_P_RARP); /* ethertype */
+
+    /* RARP header. */
+    *(uint16_t *)(buf + 14) = htons(ARP_HTYPE_ETH); /* hardware addr space */
+    *(uint16_t *)(buf + 16) = htons(ARP_PTYPE_IP); /* protocol addr space */
+    *(buf + 18) = 6; /* hardware addr length (ethernet) */
+    *(buf + 19) = 4; /* protocol addr length (IPv4) */
+    *(uint16_t *)(buf + 20) = htons(ARP_OP_REQUEST_REV); /* opcode */
+    memcpy(buf + 22, mac_addr, 6); /* source hw addr */
+    memset(buf + 28, 0x00, 4);     /* source protocol addr */
+    memcpy(buf + 32, mac_addr, 6); /* target hw addr */
+    memset(buf + 38, 0x00, 4);     /* target protocol addr */
+
+    /* Padding to get up to 60 bytes (ethernet min packet size, minus FCS). */
+    memset(buf + 42, 0x00, 18);
+
+    return 60; /* len (FCS will be added by hardware) */
+}
+
+static void qemu_announce_self_iter(NICState *nic, void *opaque)
+{
+    uint8_t buf[60];
+    int len;
+
+    trace_qemu_announce_self_iter(qemu_ether_ntoa(&nic->conf->macaddr));
+    len = announce_self_create(buf, nic->conf->macaddr.a);
+
+    qemu_send_packet_raw(qemu_get_queue(nic), buf, len);
+}
+
+
+static void qemu_announce_self_once(void *opaque)
+{
+    static int count = SELF_ANNOUNCE_ROUNDS;
+    QEMUTimer *timer = *(QEMUTimer **)opaque;
+
+    qemu_foreach_nic(qemu_announce_self_iter, NULL);
+
+    if (--count) {
+        /* delay 50ms, 150ms, 250ms, ... */
+        timer_mod(timer, qemu_clock_get_ms(QEMU_CLOCK_REALTIME) +
+                  self_announce_delay(count));
+    } else {
+            timer_del(timer);
+            timer_free(timer);
+    }
+}
+
+void qemu_announce_self(void)
+{
+    static QEMUTimer *timer;
+    timer = timer_new_ms(QEMU_CLOCK_REALTIME, qemu_announce_self_once, &timer);
+    qemu_announce_self_once(&timer);
+}
+
+/***********************************************************/
+/* savevm/loadvm support */
+
+static ssize_t block_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
+                                   int64_t pos)
+{
+    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 int block_put_buffer(void *opaque, const uint8_t *buf,
+                           int64_t pos, int size)
+{
+    bdrv_save_vmstate(opaque, buf, pos, size);
+    return size;
+}
+
+static int block_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
+{
+    return bdrv_load_vmstate(opaque, buf, pos, size);
+}
+
+static int bdrv_fclose(void *opaque)
+{
+    return bdrv_flush(opaque);
+}
+
+static const QEMUFileOps bdrv_read_ops = {
+    .get_buffer = block_get_buffer,
+    .close =      bdrv_fclose
+};
+
+static const QEMUFileOps bdrv_write_ops = {
+    .put_buffer     = block_put_buffer,
+    .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);
+    }
+    return qemu_fopen_ops(bs, &bdrv_read_ops);
+}
+
+
+/* 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)
+{
+    QEMUTimer *v = pv;
+    timer_get(f, v);
+    return 0;
+}
+
+static void put_timer(QEMUFile *f, void *pv, size_t size)
+{
+    QEMUTimer *v = pv;
+    timer_put(f, v);
+}
+
+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];
+    int instance_id;
+    int alias_id;
+    int version_id;
+    int section_id;
+    SaveVMHandlers *ops;
+    const VMStateDescription *vmsd;
+    void *opaque;
+    CompatEntry *compat;
+    int is_ram;
+} SaveStateEntry;
+
+
+static QTAILQ_HEAD(savevm_handlers, SaveStateEntry) savevm_handlers =
+    QTAILQ_HEAD_INITIALIZER(savevm_handlers);
+static int global_section_id;
+
+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 VMStateSubsection *subsection,
+                              int indent)
+{
+    if (subsection->vmsd != NULL) {
+        dump_vmstate_vmsd(out_file, subsection->vmsd, 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 VMStateSubsection *subsection = vmsd->subsections;
+        bool first;
+
+        fprintf(out_file, ",\n%*s\"Subsections\": [\n", indent, "");
+        first = true;
+        while (subsection->vmsd != 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);
+}
+
+static int calculate_new_instance_id(const char *idstr)
+{
+    SaveStateEntry *se;
+    int instance_id = 0;
+
+    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+        if (strcmp(idstr, se->idstr) == 0
+            && instance_id <= se->instance_id) {
+            instance_id = se->instance_id + 1;
+        }
+    }
+    return instance_id;
+}
+
+static int calculate_compat_instance_id(const char *idstr)
+{
+    SaveStateEntry *se;
+    int instance_id = 0;
+
+    QTAILQ_FOREACH(se, &savevm_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;
+}
+
+/* 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(DeviceState *dev,
+                         const char *idstr,
+                         int instance_id,
+                         int version_id,
+                         SaveVMHandlers *ops,
+                         void *opaque)
+{
+    SaveStateEntry *se;
+
+    se = g_malloc0(sizeof(SaveStateEntry));
+    se->version_id = version_id;
+    se->section_id = 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_live_setup != NULL) {
+        se->is_ram = 1;
+    }
+
+    if (dev) {
+        char *id = qdev_get_dev_path(dev);
+        if (id) {
+            pstrcpy(se->idstr, sizeof(se->idstr), id);
+            pstrcat(se->idstr, sizeof(se->idstr), "/");
+            g_free(id);
+
+            se->compat = g_malloc0(sizeof(CompatEntry));
+            pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), idstr);
+            se->compat->instance_id = instance_id == -1 ?
+                         calculate_compat_instance_id(idstr) : instance_id;
+            instance_id = -1;
+        }
+    }
+    pstrcat(se->idstr, sizeof(se->idstr), idstr);
+
+    if (instance_id == -1) {
+        se->instance_id = calculate_new_instance_id(se->idstr);
+    } else {
+        se->instance_id = instance_id;
+    }
+    assert(!se->compat || se->instance_id == 0);
+    /* add at the end of list */
+    QTAILQ_INSERT_TAIL(&savevm_handlers, se, entry);
+    return 0;
+}
+
+int register_savevm(DeviceState *dev,
+                    const char *idstr,
+                    int instance_id,
+                    int version_id,
+                    SaveStateHandler *save_state,
+                    LoadStateHandler *load_state,
+                    void *opaque)
+{
+    SaveVMHandlers *ops = g_malloc0(sizeof(SaveVMHandlers));
+    ops->save_state = save_state;
+    ops->load_state = load_state;
+    return register_savevm_live(dev, idstr, instance_id, version_id,
+                                ops, opaque);
+}
+
+void unregister_savevm(DeviceState *dev, const char *idstr, void *opaque)
+{
+    SaveStateEntry *se, *new_se;
+    char id[256] = "";
+
+    if (dev) {
+        char *path = qdev_get_dev_path(dev);
+        if (path) {
+            pstrcpy(id, sizeof(id), path);
+            pstrcat(id, sizeof(id), "/");
+            g_free(path);
+        }
+    }
+    pstrcat(id, sizeof(id), idstr);
+
+    QTAILQ_FOREACH_SAFE(se, &savevm_handlers, entry, new_se) {
+        if (strcmp(se->idstr, id) == 0 && se->opaque == opaque) {
+            QTAILQ_REMOVE(&savevm_handlers, se, entry);
+            if (se->compat) {
+                g_free(se->compat);
+            }
+            g_free(se->ops);
+            g_free(se);
+        }
+    }
+}
+
+int vmstate_register_with_alias_id(DeviceState *dev, int instance_id,
+                                   const VMStateDescription *vmsd,
+                                   void *opaque, int alias_id,
+                                   int required_for_version)
+{
+    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_malloc0(sizeof(SaveStateEntry));
+    se->version_id = vmsd->version_id;
+    se->section_id = global_section_id++;
+    se->opaque = opaque;
+    se->vmsd = vmsd;
+    se->alias_id = alias_id;
+
+    if (dev) {
+        char *id = qdev_get_dev_path(dev);
+        if (id) {
+            pstrcpy(se->idstr, sizeof(se->idstr), id);
+            pstrcat(se->idstr, sizeof(se->idstr), "/");
+            g_free(id);
+
+            se->compat = g_malloc0(sizeof(CompatEntry));
+            pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), vmsd->name);
+            se->compat->instance_id = instance_id == -1 ?
+                         calculate_compat_instance_id(vmsd->name) : instance_id;
+            instance_id = -1;
+        }
+    }
+    pstrcat(se->idstr, sizeof(se->idstr), vmsd->name);
+
+    if (instance_id == -1) {
+        se->instance_id = calculate_new_instance_id(se->idstr);
+    } else {
+        se->instance_id = instance_id;
+    }
+    assert(!se->compat || se->instance_id == 0);
+    /* add at the end of list */
+    QTAILQ_INSERT_TAIL(&savevm_handlers, se, entry);
+    return 0;
+}
+
+void vmstate_unregister(DeviceState *dev, const VMStateDescription *vmsd,
+                        void *opaque)
+{
+    SaveStateEntry *se, *new_se;
+
+    QTAILQ_FOREACH_SAFE(se, &savevm_handlers, entry, new_se) {
+        if (se->vmsd == vmsd && se->opaque == opaque) {
+            QTAILQ_REMOVE(&savevm_handlers, se, entry);
+            if (se->compat) {
+                g_free(se->compat);
+            }
+            g_free(se);
+        }
+    }
+}
+
+static int vmstate_load(QEMUFile *f, SaveStateEntry *se, int version_id)
+{
+    trace_vmstate_load(se->idstr, se->vmsd ? se->vmsd->name : "(old)");
+    if (!se->vmsd) {         /* Old style */
+        return se->ops->load_state(f, se->opaque, version_id);
+    }
+    return vmstate_load_state(f, se->vmsd, se->opaque, version_id);
+}
+
+static void vmstate_save_old_style(QEMUFile *f, SaveStateEntry *se, QJSON *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_prop_int(vmdesc, "size", size);
+        json_start_array(vmdesc, "fields");
+        json_start_object(vmdesc, NULL);
+        json_prop_str(vmdesc, "name", "data");
+        json_prop_int(vmdesc, "size", size);
+        json_prop_str(vmdesc, "type", "buffer");
+        json_end_object(vmdesc);
+        json_end_array(vmdesc);
+    }
+}
+
+static void vmstate_save(QEMUFile *f, SaveStateEntry *se, QJSON *vmdesc)
+{
+    trace_vmstate_save(se->idstr, se->vmsd ? se->vmsd->name : "(old)");
+    if (!se->vmsd) {
+        vmstate_save_old_style(f, se, vmdesc);
+        return;
+    }
+    vmstate_save_state(f, se->vmsd, se->opaque, vmdesc);
+}
+
+bool qemu_savevm_state_blocked(Error **errp)
+{
+    SaveStateEntry *se;
+
+    QTAILQ_FOREACH(se, &savevm_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_state_begin(QEMUFile *f,
+                             const MigrationParams *params)
+{
+    SaveStateEntry *se;
+    int ret;
+
+    trace_savevm_state_begin();
+    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+        if (!se->ops || !se->ops->set_params) {
+            continue;
+        }
+        se->ops->set_params(params, se->opaque);
+    }
+
+    qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
+    qemu_put_be32(f, QEMU_VM_FILE_VERSION);
+
+    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+        int len;
+
+        if (!se->ops || !se->ops->save_live_setup) {
+            continue;
+        }
+        if (se->ops && se->ops->is_active) {
+            if (!se->ops->is_active(se->opaque)) {
+                continue;
+            }
+        }
+        /* Section type */
+        qemu_put_byte(f, QEMU_VM_SECTION_START);
+        qemu_put_be32(f, se->section_id);
+
+        /* ID string */
+        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);
+
+        ret = se->ops->save_live_setup(f, se->opaque);
+        if (ret < 0) {
+            qemu_file_set_error(f, ret);
+            break;
+        }
+    }
+}
+
+/*
+ * 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)
+{
+    SaveStateEntry *se;
+    int ret = 1;
+
+    trace_savevm_state_iterate();
+    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+        if (!se->ops || !se->ops->save_live_iterate) {
+            continue;
+        }
+        if (se->ops && se->ops->is_active) {
+            if (!se->ops->is_active(se->opaque)) {
+                continue;
+            }
+        }
+        if (qemu_file_rate_limit(f)) {
+            return 0;
+        }
+        trace_savevm_section_start(se->idstr, se->section_id);
+        /* Section type */
+        qemu_put_byte(f, QEMU_VM_SECTION_PART);
+        qemu_put_be32(f, se->section_id);
+
+        ret = se->ops->save_live_iterate(f, se->opaque);
+        trace_savevm_section_end(se->idstr, se->section_id, ret);
+
+        if (ret < 0) {
+            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());
+    return !machine->suppress_vmdesc;
+}
+
+void qemu_savevm_state_complete(QEMUFile *f)
+{
+    QJSON *vmdesc;
+    int vmdesc_len;
+    SaveStateEntry *se;
+    int ret;
+
+    trace_savevm_state_complete();
+
+    cpu_synchronize_all_states();
+
+    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+        if (!se->ops || !se->ops->save_live_complete) {
+            continue;
+        }
+        if (se->ops && 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(f, se->opaque);
+        trace_savevm_section_end(se->idstr, se->section_id, ret);
+        if (ret < 0) {
+            qemu_file_set_error(f, ret);
+            return;
+        }
+    }
+
+    vmdesc = qjson_new();
+    json_prop_int(vmdesc, "page_size", TARGET_PAGE_SIZE);
+    json_start_array(vmdesc, "devices");
+    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+        int len;
+
+        if ((!se->ops || !se->ops->save_state) && !se->vmsd) {
+            continue;
+        }
+        trace_savevm_section_start(se->idstr, se->section_id);
+
+        json_start_object(vmdesc, NULL);
+        json_prop_str(vmdesc, "name", se->idstr);
+        json_prop_int(vmdesc, "instance_id", se->instance_id);
+
+        /* Section type */
+        qemu_put_byte(f, QEMU_VM_SECTION_FULL);
+        qemu_put_be32(f, se->section_id);
+
+        /* ID string */
+        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);
+
+        vmstate_save(f, se, vmdesc);
+
+        json_end_object(vmdesc);
+        trace_savevm_section_end(se->idstr, se->section_id, 0);
+    }
+
+    qemu_put_byte(f, QEMU_VM_EOF);
+
+    json_end_array(vmdesc);
+    qjson_finish(vmdesc);
+    vmdesc_len = strlen(qjson_get_str(vmdesc));
+
+    if (should_send_vmdesc()) {
+        qemu_put_byte(f, QEMU_VM_VMDESCRIPTION);
+        qemu_put_be32(f, vmdesc_len);
+        qemu_put_buffer(f, (uint8_t *)qjson_get_str(vmdesc), vmdesc_len);
+    }
+    object_unref(OBJECT(vmdesc));
+
+    qemu_fflush(f);
+}
+
+uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size)
+{
+    SaveStateEntry *se;
+    uint64_t ret = 0;
+
+    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+        if (!se->ops || !se->ops->save_live_pending) {
+            continue;
+        }
+        if (se->ops && se->ops->is_active) {
+            if (!se->ops->is_active(se->opaque)) {
+                continue;
+            }
+        }
+        ret += se->ops->save_live_pending(f, se->opaque, max_size);
+    }
+    return ret;
+}
+
+void qemu_savevm_state_cancel(void)
+{
+    SaveStateEntry *se;
+
+    trace_savevm_state_cancel();
+    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+        if (se->ops && se->ops->cancel) {
+            se->ops->cancel(se->opaque);
+        }
+    }
+}
+
+static int qemu_savevm_state(QEMUFile *f, Error **errp)
+{
+    int ret;
+    MigrationParams params = {
+        .blk = 0,
+        .shared = 0
+    };
+
+    if (qemu_savevm_state_blocked(errp)) {
+        return -EINVAL;
+    }
+
+    qemu_mutex_unlock_iothread();
+    qemu_savevm_state_begin(f, &params);
+    qemu_mutex_lock_iothread();
+
+    while (qemu_file_get_error(f) == 0) {
+        if (qemu_savevm_state_iterate(f) > 0) {
+            break;
+        }
+    }
+
+    ret = qemu_file_get_error(f);
+    if (ret == 0) {
+        qemu_savevm_state_complete(f);
+        ret = qemu_file_get_error(f);
+    }
+    if (ret != 0) {
+        qemu_savevm_state_cancel();
+        error_setg_errno(errp, -ret, "Error while writing VM state");
+    }
+    return ret;
+}
+
+static int qemu_save_device_state(QEMUFile *f)
+{
+    SaveStateEntry *se;
+
+    qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
+    qemu_put_be32(f, QEMU_VM_FILE_VERSION);
+
+    cpu_synchronize_all_states();
+
+    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+        int len;
+
+        if (se->is_ram) {
+            continue;
+        }
+        if ((!se->ops || !se->ops->save_state) && !se->vmsd) {
+            continue;
+        }
+
+        /* Section type */
+        qemu_put_byte(f, QEMU_VM_SECTION_FULL);
+        qemu_put_be32(f, se->section_id);
+
+        /* ID string */
+        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);
+
+        vmstate_save(f, se, NULL);
+    }
+
+    qemu_put_byte(f, QEMU_VM_EOF);
+
+    return qemu_file_get_error(f);
+}
+
+static SaveStateEntry *find_se(const char *idstr, int instance_id)
+{
+    SaveStateEntry *se;
+
+    QTAILQ_FOREACH(se, &savevm_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;
+}
+
+typedef struct LoadStateEntry {
+    QLIST_ENTRY(LoadStateEntry) entry;
+    SaveStateEntry *se;
+    int section_id;
+    int version_id;
+} LoadStateEntry;
+
+int qemu_loadvm_state(QEMUFile *f)
+{
+    QLIST_HEAD(, LoadStateEntry) loadvm_handlers =
+        QLIST_HEAD_INITIALIZER(loadvm_handlers);
+    LoadStateEntry *le, *new_le;
+    Error *local_err = NULL;
+    uint8_t section_type;
+    unsigned int v;
+    int ret;
+    int file_error_after_eof = -1;
+
+    if (qemu_savevm_state_blocked(&local_err)) {
+        error_report_err(local_err);
+        return -EINVAL;
+    }
+
+    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;
+    }
+
+    while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) {
+        uint32_t instance_id, version_id, section_id;
+        SaveStateEntry *se;
+        char idstr[257];
+        int len;
+
+        trace_qemu_loadvm_state_section(section_type);
+        switch (section_type) {
+        case QEMU_VM_SECTION_START:
+        case QEMU_VM_SECTION_FULL:
+            /* Read section start */
+            section_id = qemu_get_be32(f);
+            len = qemu_get_byte(f);
+            qemu_get_buffer(f, (uint8_t *)idstr, len);
+            idstr[len] = 0;
+            instance_id = qemu_get_be32(f);
+            version_id = qemu_get_be32(f);
+
+            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' %d",
+                             idstr, instance_id);
+                ret = -EINVAL;
+                goto out;
+            }
+
+            /* Validate version */
+            if (version_id > se->version_id) {
+                error_report("savevm: unsupported version %d for '%s' v%d",
+                             version_id, idstr, se->version_id);
+                ret = -EINVAL;
+                goto out;
+            }
+
+            /* Add entry */
+            le = g_malloc0(sizeof(*le));
+
+            le->se = se;
+            le->section_id = section_id;
+            le->version_id = version_id;
+            QLIST_INSERT_HEAD(&loadvm_handlers, le, entry);
+
+            ret = vmstate_load(f, le->se, le->version_id);
+            if (ret < 0) {
+                error_report("error while loading state for instance 0x%x of"
+                             " device '%s'", instance_id, idstr);
+                goto out;
+            }
+            break;
+        case QEMU_VM_SECTION_PART:
+        case QEMU_VM_SECTION_END:
+            section_id = qemu_get_be32(f);
+
+            trace_qemu_loadvm_state_section_partend(section_id);
+            QLIST_FOREACH(le, &loadvm_handlers, entry) {
+                if (le->section_id == section_id) {
+                    break;
+                }
+            }
+            if (le == NULL) {
+                error_report("Unknown savevm section %d", section_id);
+                ret = -EINVAL;
+                goto out;
+            }
+
+            ret = vmstate_load(f, le->se, le->version_id);
+            if (ret < 0) {
+                error_report("error while loading state section id %d(%s)",
+                             section_id, le->se->idstr);
+                goto out;
+            }
+            break;
+        default:
+            error_report("Unknown savevm section type %d", section_type);
+            ret = -EINVAL;
+            goto out;
+        }
+    }
+
+    file_error_after_eof = 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.
+     */
+    if (qemu_get_byte(f) == QEMU_VM_VMDESCRIPTION) {
+        uint32_t size = qemu_get_be32(f);
+        uint8_t *buf = g_malloc(0x1000);
+
+        while (size > 0) {
+            uint32_t read_chunk = MIN(size, 0x1000);
+            qemu_get_buffer(f, buf, read_chunk);
+            size -= read_chunk;
+        }
+        g_free(buf);
+    }
+
+    cpu_synchronize_all_post_init();
+
+    ret = 0;
+
+out:
+    QLIST_FOREACH_SAFE(le, &loadvm_handlers, entry, new_le) {
+        QLIST_REMOVE(le, entry);
+        g_free(le);
+    }
+
+    if (ret == 0) {
+        /* We may not have a VMDESC section, so ignore relative errors */
+        ret = file_error_after_eof;
+    }
+
+    return ret;
+}
+
+static BlockDriverState *find_vmstate_bs(void)
+{
+    BlockDriverState *bs = NULL;
+    while ((bs = bdrv_next(bs))) {
+        if (bdrv_can_snapshot(bs)) {
+            return bs;
+        }
+    }
+    return NULL;
+}
+
+/*
+ * Deletes snapshots of a given name in all opened images.
+ */
+static int del_existing_snapshots(Monitor *mon, const char *name)
+{
+    BlockDriverState *bs;
+    QEMUSnapshotInfo sn1, *snapshot = &sn1;
+    Error *err = NULL;
+
+    bs = NULL;
+    while ((bs = bdrv_next(bs))) {
+        if (bdrv_can_snapshot(bs) &&
+            bdrv_snapshot_find(bs, snapshot, name) >= 0) {
+            bdrv_snapshot_delete_by_id_or_name(bs, name, &err);
+            if (err) {
+                monitor_printf(mon,
+                               "Error while deleting snapshot on device '%s':"
+                               " %s\n",
+                               bdrv_get_device_name(bs),
+                               error_get_pretty(err));
+                error_free(err);
+                return -1;
+            }
+        }
+    }
+
+    return 0;
+}
+
+void hmp_savevm(Monitor *mon, const QDict *qdict)
+{
+    BlockDriverState *bs, *bs1;
+    QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1;
+    int ret;
+    QEMUFile *f;
+    int saved_vm_running;
+    uint64_t vm_state_size;
+    qemu_timeval tv;
+    struct tm tm;
+    const char *name = qdict_get_try_str(qdict, "name");
+    Error *local_err = NULL;
+
+    /* Verify if there is a device that doesn't support snapshots and is writable */
+    bs = NULL;
+    while ((bs = bdrv_next(bs))) {
+
+        if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
+            continue;
+        }
+
+        if (!bdrv_can_snapshot(bs)) {
+            monitor_printf(mon, "Device '%s' is writable but does not support snapshots.\n",
+                               bdrv_get_device_name(bs));
+            return;
+        }
+    }
+
+    bs = find_vmstate_bs();
+    if (!bs) {
+        monitor_printf(mon, "No block device can accept snapshots\n");
+        return;
+    }
+
+    saved_vm_running = runstate_is_running();
+    vm_stop(RUN_STATE_SAVE_VM);
+
+    memset(sn, 0, sizeof(*sn));
+
+    /* fill auxiliary fields */
+    qemu_gettimeofday(&tv);
+    sn->date_sec = tv.tv_sec;
+    sn->date_nsec = tv.tv_usec * 1000;
+    sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+
+    if (name) {
+        ret = bdrv_snapshot_find(bs, old_sn, name);
+        if (ret >= 0) {
+            pstrcpy(sn->name, sizeof(sn->name), old_sn->name);
+            pstrcpy(sn->id_str, sizeof(sn->id_str), old_sn->id_str);
+        } else {
+            pstrcpy(sn->name, sizeof(sn->name), name);
+        }
+    } else {
+        /* cast below needed for OpenBSD where tv_sec is still 'long' */
+        localtime_r((const time_t *)&tv.tv_sec, &tm);
+        strftime(sn->name, sizeof(sn->name), "vm-%Y%m%d%H%M%S", &tm);
+    }
+
+    /* Delete old snapshots of the same name */
+    if (name && del_existing_snapshots(mon, name) < 0) {
+        goto the_end;
+    }
+
+    /* save the VM state */
+    f = qemu_fopen_bdrv(bs, 1);
+    if (!f) {
+        monitor_printf(mon, "Could not open VM state file\n");
+        goto the_end;
+    }
+    ret = qemu_savevm_state(f, &local_err);
+    vm_state_size = qemu_ftell(f);
+    qemu_fclose(f);
+    if (ret < 0) {
+        monitor_printf(mon, "%s\n", error_get_pretty(local_err));
+        error_free(local_err);
+        goto the_end;
+    }
+
+    /* create the snapshots */
+
+    bs1 = NULL;
+    while ((bs1 = bdrv_next(bs1))) {
+        if (bdrv_can_snapshot(bs1)) {
+            /* Write VM state size only to the image that contains the state */
+            sn->vm_state_size = (bs == bs1 ? vm_state_size : 0);
+            ret = bdrv_snapshot_create(bs1, sn);
+            if (ret < 0) {
+                monitor_printf(mon, "Error while creating snapshot on '%s'\n",
+                               bdrv_get_device_name(bs1));
+            }
+        }
+    }
+
+ the_end:
+    if (saved_vm_running) {
+        vm_start();
+    }
+}
+
+void qmp_xen_save_devices_state(const char *filename, Error **errp)
+{
+    QEMUFile *f;
+    int saved_vm_running;
+    int ret;
+
+    saved_vm_running = runstate_is_running();
+    vm_stop(RUN_STATE_SAVE_VM);
+
+    f = qemu_fopen(filename, "wb");
+    if (!f) {
+        error_setg_file_open(errp, errno, filename);
+        goto the_end;
+    }
+    ret = qemu_save_device_state(f);
+    qemu_fclose(f);
+    if (ret < 0) {
+        error_set(errp, QERR_IO_ERROR);
+    }
+
+ the_end:
+    if (saved_vm_running) {
+        vm_start();
+    }
+}
+
+int load_vmstate(const char *name)
+{
+    BlockDriverState *bs, *bs_vm_state;
+    QEMUSnapshotInfo sn;
+    QEMUFile *f;
+    int ret;
+
+    bs_vm_state = find_vmstate_bs();
+    if (!bs_vm_state) {
+        error_report("No block device supports snapshots");
+        return -ENOTSUP;
+    }
+
+    /* Don't even try to load empty VM states */
+    ret = bdrv_snapshot_find(bs_vm_state, &sn, name);
+    if (ret < 0) {
+        return ret;
+    } else if (sn.vm_state_size == 0) {
+        error_report("This is a disk-only snapshot. Revert to it offline "
+            "using qemu-img.");
+        return -EINVAL;
+    }
+
+    /* Verify if there is any device that doesn't support snapshots and is
+    writable and check if the requested snapshot is available too. */
+    bs = NULL;
+    while ((bs = bdrv_next(bs))) {
+
+        if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
+            continue;
+        }
+
+        if (!bdrv_can_snapshot(bs)) {
+            error_report("Device '%s' is writable but does not support snapshots.",
+                               bdrv_get_device_name(bs));
+            return -ENOTSUP;
+        }
+
+        ret = bdrv_snapshot_find(bs, &sn, name);
+        if (ret < 0) {
+            error_report("Device '%s' does not have the requested snapshot '%s'",
+                           bdrv_get_device_name(bs), name);
+            return ret;
+        }
+    }
+
+    /* Flush all IO requests so they don't interfere with the new state.  */
+    bdrv_drain_all();
+
+    bs = NULL;
+    while ((bs = bdrv_next(bs))) {
+        if (bdrv_can_snapshot(bs)) {
+            ret = bdrv_snapshot_goto(bs, name);
+            if (ret < 0) {
+                error_report("Error %d while activating snapshot '%s' on '%s'",
+                             ret, name, bdrv_get_device_name(bs));
+                return ret;
+            }
+        }
+    }
+
+    /* restore the VM state */
+    f = qemu_fopen_bdrv(bs_vm_state, 0);
+    if (!f) {
+        error_report("Could not open VM state file");
+        return -EINVAL;
+    }
+
+    qemu_system_reset(VMRESET_SILENT);
+    ret = qemu_loadvm_state(f);
+
+    qemu_fclose(f);
+    if (ret < 0) {
+        error_report("Error %d while loading VM state", ret);
+        return ret;
+    }
+
+    return 0;
+}
+
+void hmp_delvm(Monitor *mon, const QDict *qdict)
+{
+    BlockDriverState *bs;
+    Error *err;
+    const char *name = qdict_get_str(qdict, "name");
+
+    if (!find_vmstate_bs()) {
+        monitor_printf(mon, "No block device supports snapshots\n");
+        return;
+    }
+
+    bs = NULL;
+    while ((bs = bdrv_next(bs))) {
+        if (bdrv_can_snapshot(bs)) {
+            err = NULL;
+            bdrv_snapshot_delete_by_id_or_name(bs, name, &err);
+            if (err) {
+                monitor_printf(mon,
+                               "Error while deleting snapshot on device '%s':"
+                               " %s\n",
+                               bdrv_get_device_name(bs),
+                               error_get_pretty(err));
+                error_free(err);
+            }
+        }
+    }
+}
+
+void hmp_info_snapshots(Monitor *mon, const QDict *qdict)
+{
+    BlockDriverState *bs, *bs1;
+    QEMUSnapshotInfo *sn_tab, *sn, s, *sn_info = &s;
+    int nb_sns, i, ret, available;
+    int total;
+    int *available_snapshots;
+
+    bs = find_vmstate_bs();
+    if (!bs) {
+        monitor_printf(mon, "No available block device supports snapshots\n");
+        return;
+    }
+
+    nb_sns = bdrv_snapshot_list(bs, &sn_tab);
+    if (nb_sns < 0) {
+        monitor_printf(mon, "bdrv_snapshot_list: error %d\n", nb_sns);
+        return;
+    }
+
+    if (nb_sns == 0) {
+        monitor_printf(mon, "There is no snapshot available.\n");
+        return;
+    }
+
+    available_snapshots = g_malloc0(sizeof(int) * nb_sns);
+    total = 0;
+    for (i = 0; i < nb_sns; i++) {
+        sn = &sn_tab[i];
+        available = 1;
+        bs1 = NULL;
+
+        while ((bs1 = bdrv_next(bs1))) {
+            if (bdrv_can_snapshot(bs1) && bs1 != bs) {
+                ret = bdrv_snapshot_find(bs1, sn_info, sn->id_str);
+                if (ret < 0) {
+                    available = 0;
+                    break;
+                }
+            }
+        }
+
+        if (available) {
+            available_snapshots[total] = i;
+            total++;
+        }
+    }
+
+    if (total > 0) {
+        bdrv_snapshot_dump((fprintf_function)monitor_printf, mon, NULL);
+        monitor_printf(mon, "\n");
+        for (i = 0; i < total; i++) {
+            sn = &sn_tab[available_snapshots[i]];
+            bdrv_snapshot_dump((fprintf_function)monitor_printf, mon, sn);
+            monitor_printf(mon, "\n");
+        }
+    } else {
+        monitor_printf(mon, "There is no suitable snapshot available\n");
+    }
+
+    g_free(sn_tab);
+    g_free(available_snapshots);
+
+}
+
+void vmstate_register_ram(MemoryRegion *mr, DeviceState *dev)
+{
+    qemu_ram_set_idstr(memory_region_get_ram_addr(mr) & TARGET_PAGE_MASK,
+                       memory_region_name(mr), dev);
+}
+
+void vmstate_unregister_ram(MemoryRegion *mr, DeviceState *dev)
+{
+    qemu_ram_unset_idstr(memory_region_get_ram_addr(mr) & TARGET_PAGE_MASK);
+}
+
+void vmstate_register_ram_global(MemoryRegion *mr)
+{
+    vmstate_register_ram(mr, NULL);
+}