[V3,07/22] cpr

diff --git a/include/migration/cpr.h b/include/migration/cpr.h
new file mode 100644
index 0000000..42dec4e
--- /dev/null
+++ b/include/migration/cpr.h
@@ -0,0 +1,17 @@ 
+/*
+ * Copyright (c) 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef MIGRATION_CPR_H
+#define MIGRATION_CPR_H
+
+#include "qapi/qapi-types-cpr.h"
+
+bool cpr_active(void);
+void cprsave(const char *file, CprMode mode, Error **errp);
+void cprload(const char *file, Error **errp);
+
+#endif
diff --git a/include/sysemu/runstate.h b/include/sysemu/runstate.h
index 50c84af..d69dc2d 100644
--- a/include/sysemu/runstate.h
+++ b/include/sysemu/runstate.h
@@ -51,6 +51,7 @@  void qemu_system_reset_request(ShutdownCause reason);
 void qemu_system_suspend_request(void);
 void qemu_register_suspend_notifier(Notifier *notifier);
 bool qemu_wakeup_suspend_enabled(void);
+void qemu_system_start_on_wake_request(void);
 void qemu_system_wakeup_request(WakeupReason reason, Error **errp);
 void qemu_system_wakeup_enable(WakeupReason reason, bool enabled);
 void qemu_register_wakeup_notifier(Notifier *notifier);
diff --git a/migration/cpr.c b/migration/cpr.c
new file mode 100644
index 0000000..e0da1cf
--- /dev/null
+++ b/migration/cpr.c
@@ -0,0 +1,188 @@ 
+/*
+ * Copyright (c) 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "monitor/monitor.h"
+#include "migration.h"
+#include "migration/snapshot.h"
+#include "chardev/char.h"
+#include "migration/misc.h"
+#include "migration/cpr.h"
+#include "migration/global_state.h"
+#include "qemu-file-channel.h"
+#include "qemu-file.h"
+#include "savevm.h"
+#include "qapi/error.h"
+#include "qapi/qmp/qerror.h"
+#include "qemu/error-report.h"
+#include "io/channel-buffer.h"
+#include "io/channel-file.h"
+#include "sysemu/cpu-timers.h"
+#include "sysemu/runstate.h"
+#include "sysemu/runstate-action.h"
+#include "sysemu/sysemu.h"
+#include "sysemu/replay.h"
+#include "sysemu/xen.h"
+#include "hw/vfio/vfio-common.h"
+#include "hw/virtio/vhost.h"
+#include "qemu/env.h"
+
+static int cpr_is_active;
+
+bool cpr_active(void)
+{
+    return cpr_is_active;
+}
+
+QEMUFile *qf_file_open(const char *path, int flags, int mode,
+                              const char *name, Error **errp)
+{
+    QIOChannelFile *fioc;
+    QIOChannel *ioc;
+    QEMUFile *f;
+
+    if (flags & O_RDWR) {
+        error_setg(errp, "qf_file_open %s: O_RDWR not supported", path);
+        return 0;
+    }
+
+    fioc = qio_channel_file_new_path(path, flags, mode, errp);
+    if (!fioc) {
+        return 0;
+    }
+
+    ioc = QIO_CHANNEL(fioc);
+    qio_channel_set_name(ioc, name);
+    f = (flags & O_WRONLY) ? qemu_fopen_channel_output(ioc) :
+                             qemu_fopen_channel_input(ioc);
+    object_unref(OBJECT(fioc));
+    return f;
+}
+
+static int preserve_fd(const char *name, const char *val, void *handle)
+{
+    qemu_clr_cloexec(atoi(val));
+    return 0;
+}
+
+void cprsave(const char *file, CprMode mode, Error **errp)
+{
+    int ret = 0;
+    QEMUFile *f;
+    int saved_vm_running = runstate_is_running();
+    bool restart = (mode == CPR_MODE_RESTART);
+    bool reboot = (mode == CPR_MODE_REBOOT);
+
+    if (reboot && qemu_ram_volatile(errp)) {
+        return;
+    }
+
+    if (restart && xen_enabled()) {
+        error_setg(errp, "xen does not support cprsave restart");
+        return;
+    }
+
+    if (migrate_colo_enabled()) {
+        error_setg(errp, "error: cprsave does not support x-colo");
+        return;
+    }
+
+    if (replay_mode != REPLAY_MODE_NONE) {
+        error_setg(errp, "error: cprsave does not support replay");
+        return;
+    }
+
+    f = qf_file_open(file, O_CREAT | O_WRONLY | O_TRUNC, 0600, "cprsave", errp);
+    if (!f) {
+        return;
+    }
+
+    ret = global_state_store();
+    if (ret) {
+        error_setg(errp, "Error saving global state");
+        qemu_fclose(f);
+        return;
+    }
+    if (runstate_check(RUN_STATE_SUSPENDED)) {
+        /* Update timers_state before saving.  Suspend did not so do. */
+        cpu_disable_ticks();
+    }
+    vm_stop(RUN_STATE_SAVE_VM);
+
+    cpr_is_active = true;
+    ret = qemu_save_device_state(f);
+    qemu_fclose(f);
+    if (ret < 0) {
+        error_setg(errp, QERR_IO_ERROR);
+        goto err;
+    }
+
+    if (ret < 0) {
+        if (!*errp) {
+            error_setg(errp, "Error %d while saving VM state", ret);
+        }
+        goto err;
+    }
+
+    if (reboot) {
+        shutdown_action = SHUTDOWN_ACTION_POWEROFF;
+        qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
+    } else if (restart) {
+        walkenv(FD_PREFIX, preserve_fd, 0);
+        setenv("QEMU_START_FREEZE", "", 1);
+        qemu_system_exec_request();
+    }
+    goto done;
+
+err:
+    if (saved_vm_running) {
+        vm_start();
+    }
+done:
+    cpr_is_active = false;
+    return;
+}
+
+void cprload(const char *file, Error **errp)
+{
+    QEMUFile *f;
+    int ret;
+    RunState state;
+
+    if (runstate_is_running()) {
+        error_setg(errp, "cprload called for a running VM");
+        return;
+    }
+
+    f = qf_file_open(file, O_RDONLY, 0, "cprload", errp);
+    if (!f) {
+        return;
+    }
+
+    if (qemu_get_be32(f) != QEMU_VM_FILE_MAGIC ||
+        qemu_get_be32(f) != QEMU_VM_FILE_VERSION) {
+        error_setg(errp, "error: %s is not a vmstate file", file);
+        return;
+    }
+
+    ret = qemu_load_device_state(f);
+    qemu_fclose(f);
+    if (ret < 0) {
+        error_setg(errp, "Error %d while loading VM state", ret);
+        return;
+    }
+
+    state = global_state_get_runstate();
+    if (state == RUN_STATE_RUNNING) {
+        vm_start();
+    } else {
+        runstate_set(state);
+        if (runstate_check(RUN_STATE_SUSPENDED)) {
+            qemu_system_start_on_wake_request();
+        }
+    }
+}
diff --git a/migration/meson.build b/migration/meson.build
index 3ecedce..c756374 100644
--- a/migration/meson.build
+++ b/migration/meson.build
@@ -15,6 +15,7 @@  softmmu_ss.add(files(
   'channel.c',
   'colo-failover.c',
   'colo.c',
+  'cpr.c',
   'exec.c',
   'fd.c',
   'global_state.c',
diff --git a/migration/savevm.h b/migration/savevm.h
index 6461342..ce5d710 100644
--- a/migration/savevm.h
+++ b/migration/savevm.h
@@ -67,5 +67,7 @@  int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
 int qemu_load_device_state(QEMUFile *f);
 int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f,
         bool in_postcopy, bool inactivate_disks);
+QEMUFile *qf_file_open(const char *path, int flags, int mode,
+                       const char *name, Error **errp);
 
 #endif
diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index 695aa10..b79f408 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -68,6 +68,7 @@ 
 #include "qemu/pmem.h"
 
 #include "qemu/memfd.h"
+#include "qemu/env.h"
 #include "migration/vmstate.h"
 
 #include "qemu/range.h"
@@ -1957,7 +1958,7 @@  static void ram_block_add(RAMBlock *new_block, Error **errp, bool shared)
         } else {
             name = memory_region_name(new_block->mr);
             if (ms->memfd_alloc) {
-                int mfd = -1;          /* placeholder until next patch */
+                int mfd = getenv_fd(name);
                 mr->align = QEMU_VMALLOC_ALIGN;
                 if (mfd < 0) {
                     mfd = qemu_memfd_create(name, maxlen + mr->align,
@@ -1965,7 +1966,9 @@  static void ram_block_add(RAMBlock *new_block, Error **errp, bool shared)
                     if (mfd < 0) {
                         return;
                     }
+                    setenv_fd(name, mfd);
                 }
+                qemu_clr_cloexec(mfd);
                 new_block->flags |= RAM_SHARED;
                 addr = file_ram_alloc(new_block, maxlen, mfd,
                                       false, false, 0, errp);
@@ -2214,6 +2217,7 @@  void qemu_ram_free(RAMBlock *block)
     }
 
     qemu_mutex_lock_ramlist();
+    unsetenv_fd(memory_region_name(block->mr));
     QLIST_REMOVE_RCU(block, next);
     ram_list.mru_block = NULL;
     /* Write list before version */
diff --git a/softmmu/runstate.c b/softmmu/runstate.c
index bea7513..07952cc 100644
--- a/softmmu/runstate.c
+++ b/softmmu/runstate.c
@@ -115,6 +115,8 @@  static const RunStateTransition runstate_transitions_def[] = {
     { RUN_STATE_PRELAUNCH, RUN_STATE_RUNNING },
     { RUN_STATE_PRELAUNCH, RUN_STATE_FINISH_MIGRATE },
     { RUN_STATE_PRELAUNCH, RUN_STATE_INMIGRATE },
+    { RUN_STATE_PRELAUNCH, RUN_STATE_SUSPENDED },
+    { RUN_STATE_PRELAUNCH, RUN_STATE_PAUSED },
 
     { RUN_STATE_FINISH_MIGRATE, RUN_STATE_RUNNING },
     { RUN_STATE_FINISH_MIGRATE, RUN_STATE_PAUSED },
@@ -334,6 +336,7 @@  void vm_state_notify(bool running, RunState state)
     }
 }
 
+static bool start_on_wake_requested;
 static ShutdownCause reset_requested;
 static ShutdownCause shutdown_requested;
 static int shutdown_signal;
@@ -567,6 +570,11 @@  void qemu_register_suspend_notifier(Notifier *notifier)
     notifier_list_add(&suspend_notifiers, notifier);
 }
 
+void qemu_system_start_on_wake_request(void)
+{
+    start_on_wake_requested = true;
+}
+
 void qemu_system_wakeup_request(WakeupReason reason, Error **errp)
 {
     trace_system_wakeup_request(reason);
@@ -579,7 +587,18 @@  void qemu_system_wakeup_request(WakeupReason reason, Error **errp)
     if (!(wakeup_reason_mask & (1 << reason))) {
         return;
     }
-    runstate_set(RUN_STATE_RUNNING);
+
+    /*
+     * Must call vm_start if it has never been called, to invoke the state
+     * change callbacks for the first time.
+     */
+    if (start_on_wake_requested) {
+        start_on_wake_requested = false;
+        vm_start();
+    } else {
+        runstate_set(RUN_STATE_RUNNING);
+    }
+
     wakeup_reason = reason;
     qemu_notify_event();
 }
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 04ab752..4654693 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -3510,6 +3510,12 @@  void qemu_init(int argc, char **argv, char **envp)
      */
     loc_set_none();
 
+    /* Equivalent to -S, but no need for parent to modify argv. */
+    if (getenv("QEMU_START_FREEZE")) {
+        unsetenv("QEMU_START_FREEZE");
+        autostart = 0;
+    }
+
     qemu_validate_options();
     qemu_process_sugar_options();