[Qemu-devel] [PATCH 04/11] global_state: Make section optional

[Juan Quintela <quintela@redhat.com>]

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 <quintela@redhat.com>
---
 hw/i386/pc_piix.c             |  1 +
 hw/i386/pc_q35.c              |  1 +
 include/migration/migration.h |  1 +
 migration/migration.c         | 30 +++++++++++++++++++++++++++++-
 4 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index e142f75..735fb22 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -307,6 +307,7 @@ static void pc_init1(MachineState *machine)
 static void pc_compat_2_3(MachineState *machine)
 {
     savevm_skip_section_footers();
+    global_state_set_optional();
 }

 static void pc_compat_2_2(MachineState *machine)
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index b68263d..0523ecc 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -291,6 +291,7 @@ static void pc_q35_init(MachineState *machine)
 static void pc_compat_2_3(MachineState *machine)
 {
     savevm_skip_section_footers();
+    global_state_set_optional();
 }

 static void pc_compat_2_2(MachineState *machine)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 1280193..bb53d93 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -198,4 +198,5 @@ size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
 void ram_mig_init(void);
 void savevm_skip_section_footers(void);
 void register_global_state(void);
+void global_state_set_optional(void);
 #endif
diff --git a/migration/migration.c b/migration/migration.c
index 01bb90d..f1ecf76 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -99,6 +99,7 @@ void migration_incoming_state_destroy(void)


 typedef struct {
+    bool optional;
     int32_t size;
     uint8_t runstate[100];
 } GlobalState;
@@ -119,6 +120,33 @@ static 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;
@@ -149,7 +177,6 @@ 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);
 }

 static const VMStateDescription vmstate_globalstate = {
@@ -158,6 +185,7 @@ 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),
-- 
2.4.3