[Qemu-devel] [PATCH] migration: remove subsections in fdc and rtl8139 and bump versions

[Anthony Liguori <aliguori@us.ibm.com>]

As Paolo points out, the migration protocol is ambiguous when using subsections
today.  That means that even if we preserve subsections and change the protocol
accordingly, the old protocol w/subsections is still ambiguous.

Remove subsection usage and bump any device using subsections.  This effectively
eliminates the amiguouity and allows for a clean transition to a new protocol
with unambiguous subsections.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
 hw/fdc.c     |   37 ++++++-------------------------------
 hw/rtl8139.c |   34 +++-------------------------------
 2 files changed, 9 insertions(+), 62 deletions(-)

diff --git a/hw/fdc.c b/hw/fdc.c
index edf0360..d8d74c9 100644
--- a/hw/fdc.c
+++ b/hw/fdc.c
@@ -554,45 +554,20 @@ static int fdrive_media_changed_post_load(void *opaque, int version_id)
     return 0;
 }
 
-static bool fdrive_media_changed_needed(void *opaque)
-{
-    FDrive *drive = opaque;
-
-    return (drive->bs != NULL && drive->bs->media_changed != 1);
-}
-
-static const VMStateDescription vmstate_fdrive_media_changed = {
-    .name = "fdrive/media_changed",
-    .version_id = 1,
-    .minimum_version_id = 1,
-    .minimum_version_id_old = 1,
-    .pre_save = fdrive_media_changed_pre_save,
-    .post_load = fdrive_media_changed_post_load,
-    .fields      = (VMStateField[]) {
-        VMSTATE_UINT8(media_changed, FDrive),
-        VMSTATE_END_OF_LIST()
-    }
-};
-
 static const VMStateDescription vmstate_fdrive = {
     .name = "fdrive",
-    .version_id = 1,
-    .minimum_version_id = 1,
-    .minimum_version_id_old = 1,
+    .version_id = 2,
+    .minimum_version_id = 2,
+    .minimum_version_id_old = 2,
+    .pre_save = fdrive_media_changed_pre_save,
+    .post_load = fdrive_media_changed_post_load,
     .fields      = (VMStateField[]) {
         VMSTATE_UINT8(head, FDrive),
         VMSTATE_UINT8(track, FDrive),
         VMSTATE_UINT8(sect, FDrive),
+        VMSTATE_UINT8(media_changed, FDrive),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_fdrive_media_changed,
-            .needed = &fdrive_media_changed_needed,
-        } , {
-            /* empty */
-        }
-    }
 };
 
 static void fdc_pre_save(void *opaque)
diff --git a/hw/rtl8139.c b/hw/rtl8139.c
index 5214b8c..11951f2 100644
--- a/hw/rtl8139.c
+++ b/hw/rtl8139.c
@@ -505,9 +505,6 @@ typedef struct RTL8139State {
     /* PCI interrupt timer */
     QEMUTimer *timer;
     int64_t TimerExpire;
-
-    /* Support migration to/from old versions */
-    int rtl8139_mmio_io_addr_dummy;
 } RTL8139State;
 
 static void rtl8139_set_next_tctr_time(RTL8139State *s, int64_t current_time);
@@ -3259,21 +3256,6 @@ static int rtl8139_post_load(void *opaque, int version_id)
     return 0;
 }
 
-static bool rtl8139_hotplug_ready_needed(void *opaque)
-{
-    return qdev_machine_modified();
-}
-
-static const VMStateDescription vmstate_rtl8139_hotplug_ready ={
-    .name = "rtl8139/hotplug_ready",
-    .version_id = 1,
-    .minimum_version_id = 1,
-    .minimum_version_id_old = 1,
-    .fields      = (VMStateField []) {
-        VMSTATE_END_OF_LIST()
-    }
-};
-
 static void rtl8139_pre_save(void *opaque)
 {
     RTL8139State* s = opaque;
@@ -3283,14 +3265,13 @@ static void rtl8139_pre_save(void *opaque)
     rtl8139_set_next_tctr_time(s, current_time);
     s->TCTR = muldiv64(current_time - s->TCTR_base, PCI_FREQUENCY,
                        get_ticks_per_sec());
-    s->rtl8139_mmio_io_addr_dummy = s->rtl8139_mmio_io_addr;
 }
 
 static const VMStateDescription vmstate_rtl8139 = {
     .name = "rtl8139",
-    .version_id = 4,
-    .minimum_version_id = 3,
-    .minimum_version_id_old = 3,
+    .version_id = 5,
+    .minimum_version_id = 5,
+    .minimum_version_id_old = 5,
     .post_load = rtl8139_post_load,
     .pre_save  = rtl8139_pre_save,
     .fields      = (VMStateField []) {
@@ -3336,7 +3317,6 @@ static const VMStateDescription vmstate_rtl8139 = {
 
         VMSTATE_UNUSED(4),
         VMSTATE_MACADDR(conf.macaddr, RTL8139State),
-        VMSTATE_INT32(rtl8139_mmio_io_addr_dummy, RTL8139State),
 
         VMSTATE_UINT32(currTxDesc, RTL8139State),
         VMSTATE_UINT32(currCPlusRxDesc, RTL8139State),
@@ -3366,14 +3346,6 @@ static const VMStateDescription vmstate_rtl8139 = {
         VMSTATE_UINT32_V(cplus_enabled, RTL8139State, 4),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection []) {
-        {
-            .vmsd = &vmstate_rtl8139_hotplug_ready,
-            .needed = rtl8139_hotplug_ready_needed,
-        }, {
-            /* empty */
-        }
-    }
 };
 
 /***********************************************************/
-- 
1.7.4.1