Re: [Qemu-devel] [PATCH] timer/aspeed: fix vmstate version id

[Peter Maydell]

On 23 April 2018 at 07:40, Cédric Le Goater <address@hidden> wrote:
> commit 1d3e65aa7ac5 ("hw/timer: Add value matching support to
> aspeed_timer") increased the vmstate version of the timers array but
> doing so, it broke migration. To fix, we also need to change the
> vmstate version of the aspeed timer controller model.
>
> Signed-off-by: Cédric Le Goater <address@hidden>
> ---
>
>  To test on a 'palmetto-bmc' board, download the latest built OpenBMC
>  flash image :
>
>    wget 
> https://openpower.xyz/job/openbmc-build/distro=ubuntu,target=palmetto/lastSuccessfulBuild/artifact/deploy/images/palmetto/flash-palmetto
>
>  start two instances of QEMU with :
>
>    qemu-system-arm -m 512 -M palmetto-bmc -drive 
> file=./flash-palmetto,format=raw,if=mtd -serial mon:stdio -nographic 
> -nodefaults
>
>  and :
>
>    qemu-system-arm -m 512 -M palmetto-bmc -drive 
> file=./flash-palmetto,format=raw,if=mtd -serial mon:stdio -nographic 
> -nodefaults -incoming tcp::1234
>
>  then, run migrate from the monitor:
>
>    (qemu) migrate tcp:localhost:1234
>
>  hw/timer/aspeed_timer.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/hw/timer/aspeed_timer.c b/hw/timer/aspeed_timer.c
> index 50acbf530a3a..7df19bd9df91 100644
> --- a/hw/timer/aspeed_timer.c
> +++ b/hw/timer/aspeed_timer.c
> @@ -498,8 +498,8 @@ static const VMStateDescription vmstate_aspeed_timer = {
>
>  static const VMStateDescription vmstate_aspeed_timer_state = {
>      .name = "aspeed.timerctrl",
> -    .version_id = 1,
> -    .minimum_version_id = 1,
> +    .version_id = 2,
> +    .minimum_version_id = 2,
>      .fields = (VMStateField[]) {
>          VMSTATE_UINT32(ctrl, AspeedTimerCtrlState),
>          VMSTATE_UINT32(ctrl2, AspeedTimerCtrlState),

Wouldn't it be simpler to just fix the incorrect value in
the VMSTATE_STRUCT_ARRAY(timers, AspeedTimerCtrlState,
line ?

thanks
-- PMM