[Qemu-devel] [PATCH 6/7] global_state: Make section optional

[Juan Quintela]

This section would be sent:

a- for all new machine types
b- for old achine types if section state is different form {running,paused}
   that were the only giving us troubles.

So, in new qemus: it is alwasy there.  In old qemus: they are only
there if it an error has happened, basically stoping on target.

Signed-off-by: Juan Quintela <quint...@redhat.com>
---
 hw/i386/pc_piix.c             |  2 ++
 include/migration/migration.h |  2 +-
 migration.c                   | 31 ++++++++++++++++++++++++++++++-
 3 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 4384633..078fbfb 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -52,6 +52,7 @@
 #ifdef CONFIG_XEN
 #  include <xen/hvm/hvm_info_table.h>
 #endif
+#include "migration/migration.h"

 #define MAX_IDE_BUS 2

@@ -323,6 +324,7 @@ static void pc_compat_2_0(MachineState *machine)
     legacy_acpi_table_size = 6652;
     smbios_legacy_mode = true;
     has_reserved_memory = false;
+    global_state_set_optional();
     pc_set_legacy_acpi_data_size();
 }

diff --git a/include/migration/migration.h b/include/migration/migration.h
index bc1069b..475ed48 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -177,5 +177,5 @@ size_t ram_control_save_page(QEMUFile *f, ram_addr_t 
block_offset,
 void register_global_state(void);
 void global_state_store(void);
 char *global_state_get_runstate(void);
-
+void global_state_set_optional(void);
 #endif
diff --git a/migration.c b/migration.c
index 6f7e50e..7379073 100644
--- a/migration.c
+++ b/migration.c
@@ -712,6 +712,7 @@ void migrate_fd_connect(MigrationState *s)
 }

 typedef struct {
+    bool optional;
     int32_t size;
     uint8_t runstate[100];
 } GlobalState;
@@ -732,6 +733,33 @@ char *global_state_get_runstate(void)
     return (char *)global_state.runstate;
 }

+void global_state_set_optional(void)
+{
+    global_state.optional = true;
+}
+
+static bool global_state_needed(void *opaque)
+{
+    GlobalState *s = opaque;
+    char *runstate = (char*)s->runstate;
+
+    /* If it is not optional, it is mandatory */
+
+    if (s->optional == false) {
+        return true;
+    }
+
+    /* If state is running or paused, it is not needed */
+
+    if (strcmp(runstate, "running") == 0 ||
+        strcmp(runstate, "paused") == 0) {
+        return false;
+    }
+
+    /* for any other state it is needed */
+    return true;
+}
+
 static int global_state_post_load(void *opaque, int version_id)
 {
     GlobalState *s = opaque;
@@ -759,7 +787,7 @@ static void global_state_pre_save(void *opaque)
     GlobalState *s = opaque;

     s->size = strlen((char*)s->runstate) + 1;
-    printf("saved state: %s\n", s->runstate);
+    printf("saved state: %s optional (%d)\n", s->runstate, s->optional);
 }

 static const VMStateDescription vmstate_globalstate = {
@@ -768,6 +796,7 @@ static const VMStateDescription vmstate_globalstate = {
     .minimum_version_id = 1,
     .post_load = global_state_post_load,
     .pre_save = global_state_pre_save,
+    .needed = global_state_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT32(size, GlobalState),
         VMSTATE_BUFFER(runstate, GlobalState),
-- 
2.1.0