Nicholas Piggin <npig...@gmail.com> writes:
> From: Glenn Miles <mil...@linux.vnet.ibm.com>
>
> Reviewed-by: Nicholas Piggin <npig...@gmail.com>
> Signed-off-by: Glenn Miles <mil...@linux.vnet.ibm.com>
> Signed-off-by: Nicholas Piggin <npig...@gmail.com>
> ---
> target/ppc/machine.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/target/ppc/machine.c b/target/ppc/machine.c
> index 6b6c31d903..731dd8df35 100644
> --- a/target/ppc/machine.c
> +++ b/target/ppc/machine.c
> @@ -711,6 +711,26 @@ static const VMStateDescription vmstate_reservation = {
> }
> };
>
> +#ifdef TARGET_PPC64
> +static bool bhrb_needed(void *opaque)
> +{
> + PowerPCCPU *cpu = opaque;
> + return (cpu->env.flags & POWERPC_FLAG_BHRB) != 0;
> +}
> +
> +static const VMStateDescription vmstate_bhrb = {
> + .name = "cpu/bhrb",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .needed = bhrb_needed,
> + .fields = (VMStateField[]) {
> + VMSTATE_UINTTL(env.bhrb_offset, PowerPCCPU),
> + VMSTATE_UINT64_ARRAY(env.bhrb, PowerPCCPU, BHRB_MAX_NUM_ENTRIES),
> + VMSTATE_END_OF_LIST()
> + }
> +};
> +#endif
> +
> const VMStateDescription vmstate_ppc_cpu = {
> .name = "cpu",
> .version_id = 5,
> @@ -756,6 +776,7 @@ const VMStateDescription vmstate_ppc_cpu = {
> #ifdef TARGET_PPC64
> &vmstate_tm,
> &vmstate_slb,
> + &vmstate_bhrb,
Running some tests now that Nick re-enabled ppc for migration tests, I
see that this new state breaks backward migrations:
$ QTEST_TRACE="vmstate_*" \
QTEST_QEMU_BINARY_DST=../build-previous/qemu-system-ppc64 \
QTEST_QEMU_BINARY=./qemu-system-ppc64 \
./tests/qtest/migration-test -p /ppc64/migration/precopy/tcp/plain
...
vmstate_load_state_field cpu/slb:env.slb
vmstate_n_elems env.slb: 64
vmstate_subsection_load cpu/slb
vmstate_subsection_load_bad cpu/slb: cpu/bhrb/(prefix)
vmstate_load_state_end cpu/slb end/0
vmstate_subsection_load_bad cpu: cpu/bhrb/(lookup)
qemu-system-ppc64: error while loading state for instance 0x0 of device 'cpu'
vmstate_downtime_checkpoint dst-precopy-loadvm-completed
qemu-system-ppc64: load of migration failed: No such file or directory
If you want to support backwards migration, then this needs to be
fixed. Otherwise we can ignore it.
