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

[Anthony Liguori <anthony@codemonkey.ws>]

On 08/02/2011 06:08 PM, Anthony Liguori wrote:
> 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>

And to clarify, I'm proposing we carry this for stable 0.15 and master.

Regards,

Anthony Liguori

> ---
>   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 */
> -        }
> -    }
>   };
>
>   /***********************************************************/