ahci: Migrate IDEStatus

Amazingly, we weren't doing this before.

Make sure we migrate the IDEState structure that belongs to
the AHCIDevice.IDEBus structure during migrations.

No version numbering changes because AHCI is not officially
migratable (and we can all see with good reason why) so we
do not impact any official builds by altering the stream and
leaving it at version 1.

This fixes the rerror=stop/werror=stop test case where we wish
to migrate a halted job. Previously, the error code would not
migrate, so even if the job completed successfully, AHCI would
report an error because it would still have the placeholder
error code from initialization time.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 1424708286-16483-15-git-send-email-jsnow@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

hw/ide/ahci.c

@@ -1321,6 +1321,7 @@ static const VMStateDescription vmstate_ahci_device = {
     .version_id = 1,
     .fields = (VMStateField[]) {
         VMSTATE_IDE_BUS(port, AHCIDevice),
+        VMSTATE_IDE_DRIVE(port.ifs[0], AHCIDevice),
         VMSTATE_UINT32(port_state, AHCIDevice),
         VMSTATE_UINT32(finished, AHCIDevice),
         VMSTATE_UINT32(port_regs.lst_addr, AHCIDevice),

hw/ide/internal.h

@@ -526,6 +526,9 @@ extern const VMStateDescription vmstate_ide_drive;
 #define VMSTATE_IDE_DRIVES(_field, _state) \
     VMSTATE_STRUCT_ARRAY(_field, _state, 2, 3, vmstate_ide_drive, IDEState)
 
+#define VMSTATE_IDE_DRIVE(_field, _state) \
+    VMSTATE_STRUCT(_field, _state, 1, vmstate_ide_drive, IDEState)
+
 void ide_bus_reset(IDEBus *bus);
 int64_t ide_get_sector(IDEState *s);
 void ide_set_sector(IDEState *s, int64_t sector_num);