On Wed, 17 Mar 2021 at 04:44, Gavin Shan <gs...@redhat.com> wrote:
>
> There is a added clock to trace buad rate change since v5.2.0 by
> commit aac63e0e6ea3 ("hw/char/pl011: add a clock input"). The added
> clock causes migration failure. For example, migration from v5.2.0
> to v5.1.0 can fail with the following error messages:
>
> qemu-system-aarch64: error while loading state for instance 0x0 \
> of device 'pl011'
> qemu-system-aarch64: load of migration failed: No such file or \
> directory
>
> This fixes the issue by reporting the baud rate change at post load
> time so that the clock won't be migrated by sub-section to avoid the
> migration failure.
>
> Cc: qemu-sta...@nongnu.org
> Fixes: aac63e0e6ea3 ("hw/char/pl011: add a clock input")
> Signed-off-by: Gavin Shan <gs...@redhat.com>
> ---
> hw/char/pl011.c | 22 +++++++++-------------
> 1 file changed, 9 insertions(+), 13 deletions(-)
>
> diff --git a/hw/char/pl011.c b/hw/char/pl011.c
> index c5621a195f..401bd28536 100644
> --- a/hw/char/pl011.c
> +++ b/hw/char/pl011.c
> @@ -322,20 +322,20 @@ static const MemoryRegionOps pl011_ops = {
> .endianness = DEVICE_NATIVE_ENDIAN,
> };
>
> -static const VMStateDescription vmstate_pl011_clock = {
> - .name = "pl011/clock",
> - .version_id = 1,
> - .minimum_version_id = 1,
> - .fields = (VMStateField[]) {
> - VMSTATE_CLOCK(clk, PL011State),
> - VMSTATE_END_OF_LIST()
> - }
> -};
> +static int pl011_post_load(void *opaque, int version_id)
> +{
> + PL011State *s = PL011(opaque);
> +
> + pl011_trace_baudrate_change(s);
> +
> + return 0;
> +}
>
> static const VMStateDescription vmstate_pl011 = {
> .name = "pl011",
> .version_id = 2,
> .minimum_version_id = 2,
> + .post_load = pl011_post_load,
> .fields = (VMStateField[]) {
> VMSTATE_UINT32(readbuff, PL011State),
> VMSTATE_UINT32(flags, PL011State),
> @@ -355,10 +355,6 @@ static const VMStateDescription vmstate_pl011 = {
> VMSTATE_INT32(read_trigger, PL011State),
> VMSTATE_END_OF_LIST()
> },
> - .subsections = (const VMStateDescription * []) {
> - &vmstate_pl011_clock,
> - NULL
> - }
> };
Doesn't dropping the subsection break migration compat ?
thanks
-- PMM
