migration: Add configuration section

It needs to be the first one and it is not optional, that is the reason
why it is opencoded.  For new machine types, it is required that machine
type name is the same in both sides.

It is just done right now for pc's.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 3ee3b47cec02e1090381c67c850ccbd3edd1de7f..4c3cb40ce09fb3d48dc1f9ef8198e7b734c00c4c 100644 (file)
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -313,6 +313,7 @@ static void pc_compat_2_3(MachineState *machine)
         pcms->smm = ON_OFF_AUTO_OFF;
     }
     global_state_set_optional();
+    savevm_skip_configuration();
 }
 
 static void pc_compat_2_2(MachineState *machine)

diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 0dc4ab149a37b8092eff90cbe2794f6e176f1aad..43e6c18777cbcf0548b8dd1e621a462ffe80a17e 100644 (file)
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -296,6 +296,7 @@ static void pc_compat_2_3(MachineState *machine)
         pcms->smm = ON_OFF_AUTO_OFF;
     }
     global_state_set_optional();
+    savevm_skip_configuration();
 }
 
 static void pc_compat_2_2(MachineState *machine)

diff --git a/include/migration/migration.h b/include/migration/migration.h
index f153eba47acab371fcc84ff1ccdef11bf7e806d1..a308eccf186164d73cd044cd61adc03e4b2b1ea4 100644 (file)
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -34,6 +34,7 @@
 #define QEMU_VM_SECTION_FULL         0x04
 #define QEMU_VM_SUBSECTION           0x05
 #define QEMU_VM_VMDESCRIPTION        0x06
+#define QEMU_VM_CONFIGURATION        0x07
 #define QEMU_VM_SECTION_FOOTER       0x7e
 
 struct MigrationParams {
@@ -199,4 +200,5 @@ void ram_mig_init(void);
 void savevm_skip_section_footers(void);
 void register_global_state(void);
 void global_state_set_optional(void);
+void savevm_skip_configuration(void);
 #endif

diff --git a/migration/savevm.c b/migration/savevm.c
index e779c96ef954cd77c4d02852abb584831ebb221c..b28a2694adb9e35964d04dd58dff2f5a7c643b14 100644 (file)
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -246,11 +246,55 @@ typedef struct SaveStateEntry {
 typedef struct SaveState {
     QTAILQ_HEAD(, SaveStateEntry) handlers;
     int global_section_id;
+    bool skip_configuration;
+    uint32_t len;
+    const char *name;
 } SaveState;
 
 static SaveState savevm_state = {
     .handlers = QTAILQ_HEAD_INITIALIZER(savevm_state.handlers),
     .global_section_id = 0,
+    .skip_configuration = false,
+};
+
+void savevm_skip_configuration(void)
+{
+    savevm_state.skip_configuration = true;
+}
+
+
+static void configuration_pre_save(void *opaque)
+{
+    SaveState *state = opaque;
+    const char *current_name = MACHINE_GET_CLASS(current_machine)->name;
+
+    state->len = strlen(current_name);
+    state->name = current_name;
+}
+
+static int configuration_post_load(void *opaque, int version_id)
+{
+    SaveState *state = opaque;
+    const char *current_name = MACHINE_GET_CLASS(current_machine)->name;
+
+    if (strncmp(state->name, current_name, state->len) != 0) {
+        error_report("Machine type received is '%s' and local is '%s'",
+                     state->name, current_name);
+        return -EINVAL;
+    }
+    return 0;
+}
+
+static const VMStateDescription vmstate_configuration = {
+    .name = "configuration",
+    .version_id = 1,
+    .post_load = configuration_post_load,
+    .pre_save = configuration_pre_save,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(len, SaveState),
+        VMSTATE_VBUFFER_ALLOC_UINT32(name, SaveState, 0, NULL, 0, len),
+        VMSTATE_END_OF_LIST()
+    },
 };
 
 static void dump_vmstate_vmsd(FILE *out_file,
@@ -723,6 +767,11 @@ void qemu_savevm_state_begin(QEMUFile *f,
         se->ops->set_params(params, se->opaque);
     }
 
+    if (!savevm_state.skip_configuration) {
+        qemu_put_byte(f, QEMU_VM_CONFIGURATION);
+        vmstate_save_state(f, &vmstate_configuration, &savevm_state, 0);
+    }
+
     QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
         if (!se->ops || !se->ops->save_live_setup) {
             continue;
@@ -1037,6 +1086,18 @@ int qemu_loadvm_state(QEMUFile *f)
         return -ENOTSUP;
     }
 
+    if (!savevm_state.skip_configuration) {
+        if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
+            error_report("Configuration section missing");
+            return -EINVAL;
+        }
+        ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0);
+
+        if (ret) {
+            return ret;
+        }
+    }
+
     while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) {
         uint32_t instance_id, version_id, section_id;
         SaveStateEntry *se;