From 2f243f0313211d416fa24a1db39b923216ce267f Mon Sep 17 00:00:00 2001

From: Amit Shah <amit.shah@redhat.com>

Date: Fri, 11 Jul 2014 10:08:58 -0500

Subject: [CHANGE 02/29] migration: dump vmstate info as a json file for static

 analysis

To: rhvirt-patches@redhat.com,

    jen@redhat.com

RH-Author: Amit Shah <amit.shah@redhat.com>

Message-id: <024e1bc4c9618850da0624d2d2bbe0bc106cee45.1405072585.git.amit.shah@redhat.com>

Patchwork-id: 59782

O-Subject: [RHEL7.1 qemu-kvm PATCH 01/18] migration: dump vmstate info as a json file for static analysis

Bugzilla: 1118707

RH-Acked-by: Juan Quintela <quintela@redhat.com>

RH-Acked-by: Laszlo Ersek <lersek@redhat.com>

RH-Acked-by: Dr. David Alan Gilbert (git) <dgilbert@redhat.com>

This commit adds a new command, '-dump-vmstate', that takes a filename

as an argument.  When executed, QEMU will dump the vmstate information

for the machine type it's invoked with to the file, and quit.

The JSON-format output can then be used to compare the vmstate info for

different QEMU versions, specifically to test whether live migration

would break due to changes in the vmstate data.

A Python script that compares the output of such JSON dumps is included

in the following commit.

Signed-off-by: Amit Shah <amit.shah@redhat.com>

Reviewed-by: Juan Quintela <quintela@redhat.com>

Signed-off-by: Juan Quintela <quintela@redhat.com>

(cherry picked from commit abfd9ce341ec66eb2e63756b9da43f77c054788e)

Signed-off-by: Amit Shah <amit.shah@redhat.com>

Signed-off-by: jen <jen@redhat.com>

Conflicts:

	include/migration/vmstate.h

	vl.c

Signed-off-by: jen <jen@redhat.com>

---

 include/migration/vmstate.h |   2 +

 qemu-options.hx             |  14 +++++

 savevm.c                    | 135 ++++++++++++++++++++++++++++++++++++++++++++

 vl.c                        |  14 +++++

 4 files changed, 165 insertions(+)

diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h

index f2652e6..cae26d0 100644

--- a/include/migration/vmstate.h

+++ b/include/migration/vmstate.h

@@ -747,4 +747,6 @@ void vmstate_register_ram(struct MemoryRegion *memory, DeviceState *dev);

 void vmstate_unregister_ram(struct MemoryRegion *memory, DeviceState *dev);

 void vmstate_register_ram_global(struct MemoryRegion *memory);

+void dump_vmstate_json_to_file(FILE *out_fp);

+

 #endif

diff --git a/qemu-options.hx b/qemu-options.hx

index 1f2bb57..5d0f2cd 100644

--- a/qemu-options.hx

+++ b/qemu-options.hx

@@ -3098,6 +3098,20 @@ STEXI

 prepend a timestamp to each log message.(default:on)

 ETEXI

+DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,

+    "-dump-vmstate <file>\n"

+    "                Output vmstate information in JSON format to file.\n"

+    "                Use the scripts/vmstate-static-checker.py file to\n"

+    "                check for possible regressions in migration code\n"

+    "                by comparing two such vmstate dumps.",

+    QEMU_ARCH_ALL)

+STEXI

+@item -dump-vmstate @var{file}

+@findex -dump-vmstate

+Dump json-encoded vmstate information for current machine type to file

+in @var{file}

+ETEXI

+

 HXCOMM This is the last statement. Insert new options before this line!

 STEXI

 @end table

diff --git a/savevm.c b/savevm.c

index 94512dd..963dc7d 100644

--- a/savevm.c

+++ b/savevm.c

@@ -24,6 +24,7 @@

 #include "config-host.h"

 #include "qemu-common.h"

+#include "hw/boards.h"

 #include "hw/hw.h"

 #include "hw/qdev.h"

 #include "net/net.h"

@@ -1484,6 +1485,140 @@ 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)

+{

+    fprintf(out_file, "  \"vmschkmachine\": {\n");

+    fprintf(out_file, "    \"Name\": \"%s\"\n", current_machine->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;

diff --git a/vl.c b/vl.c

index a0099f6..ca3d498 100644

--- a/vl.c

+++ b/vl.c

@@ -2838,6 +2838,7 @@ int main(int argc, char **argv, char **envp)

     };

     const char *trace_events = NULL;

     const char *trace_file = NULL;

+    FILE *vmstate_dump_file = NULL;

     atexit(qemu_run_exit_notifiers);

     error_set_progname(argv[0]);

@@ -3794,6 +3795,13 @@ int main(int argc, char **argv, char **envp)

                 }

                 configure_msg(opts);

                 break;

+            case QEMU_OPTION_dump_vmstate:

+                vmstate_dump_file = fopen(optarg, "w");

+                if (vmstate_dump_file == NULL) {

+                    fprintf(stderr, "open %s: %s\n", optarg, strerror(errno));

+                    exit(1);

+                }

+                break;

             default:

                 os_parse_cmd_args(popt->index, optarg);

             }

@@ -4346,6 +4354,12 @@ int main(int argc, char **argv, char **envp)

         }

     }

+    if (vmstate_dump_file) {

+        /* dump and exit */

+        dump_vmstate_json_to_file(vmstate_dump_file);

+        return 0;

+    }

+

     if (incoming) {

         Error *local_err = NULL;

         qemu_start_incoming_migration(incoming, &local_err);

-- 

1.9.3