Quoting Daniel Henrique Barboza (2017-05-19 09:27:50)
> From: Jianjun Duan <du...@linux.vnet.ibm.com>
>
> In racing situations between hotplug events and migration operation,
> a rtas hotplug event could have not yet be delivered to the source
> guest when migration is started. In this case the pending_events of
> spapr state need be transmitted to the target so that the hotplug
> event can be finished on the target.
>
> All the different fields of the events are encoded as defined by
> PAPR. We can migrate them as a binary stream inside VBUFFER without
> any concerns about data padding or endianess.
>
> pending_events is put in a subsection in the spapr state VMSD to make
> sure migration across different versions is not broken.
>
> Signed-off-by: Jianjun Duan <du...@linux.vnet.ibm.com>
> Signed-off-by: Daniel Henrique Barboza <danie...@linux.vnet.ibm.com>
Reviewed-by: Michael Roth <mdr...@linux.vnet.ibm.com>
> ---
> hw/ppc/spapr.c | 32 ++++++++++++++++++++++++++++++++
> hw/ppc/spapr_events.c | 12 ++++++++++++
> include/hw/ppc/spapr.h | 3 ++-
> 3 files changed, 46 insertions(+), 1 deletion(-)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 0980d73..5afd328 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1444,6 +1444,37 @@ static bool version_before_3(void *opaque, int
> version_id)
> return version_id < 3;
> }
>
> +static bool spapr_pending_events_needed(void *opaque)
> +{
> + sPAPRMachineState *spapr = (sPAPRMachineState *)opaque;
> + return !QTAILQ_EMPTY(&spapr->pending_events);
> +}
> +
> +static const VMStateDescription vmstate_spapr_event_entry = {
> + .name = "spapr_event_log_entry",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .fields = (VMStateField[]) {
> + VMSTATE_INT32(log_type, sPAPREventLogEntry),
> + VMSTATE_UINT32(data_size, sPAPREventLogEntry),
> + VMSTATE_VBUFFER_ALLOC_UINT32(data, sPAPREventLogEntry, 0,
> + NULL, data_size),
> + VMSTATE_END_OF_LIST()
> + },
> +};
> +
> +static const VMStateDescription vmstate_spapr_pending_events = {
> + .name = "spapr_pending_events",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .needed = spapr_pending_events_needed,
> + .fields = (VMStateField[]) {
> + VMSTATE_QTAILQ_V(pending_events, sPAPRMachineState, 1,
> + vmstate_spapr_event_entry, sPAPREventLogEntry,
> next),
> + VMSTATE_END_OF_LIST()
> + },
> +};
> +
> static bool spapr_ov5_cas_needed(void *opaque)
> {
> sPAPRMachineState *spapr = opaque;
> @@ -1542,6 +1573,7 @@ static const VMStateDescription vmstate_spapr = {
> .subsections = (const VMStateDescription*[]) {
> &vmstate_spapr_ov5_cas,
> &vmstate_spapr_patb_entry,
> + &vmstate_spapr_pending_events,
> NULL
> }
> };
> diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c
> index 73e2a18..a509c46 100644
> --- a/hw/ppc/spapr_events.c
> +++ b/hw/ppc/spapr_events.c
> @@ -350,6 +350,18 @@ static void rtas_event_log_queue(int log_type, void
> *data)
> g_assert(data);
> entry->log_type = log_type;
> entry->data = data;
> +
> + switch (log_type) {
> + case RTAS_LOG_TYPE_EPOW:
> + entry->data_size = sizeof(struct epow_log_full);
> + break;
> + case RTAS_LOG_TYPE_HOTPLUG:
> + entry->data_size = sizeof(struct hp_log_full);
> + break;
> + default:
> + g_assert(false);
> + }
> +
> QTAILQ_INSERT_TAIL(&spapr->pending_events, entry, next);
> }
>
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index 02239a5..0554e11 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -597,8 +597,9 @@ struct sPAPRTCETable {
> sPAPRTCETable *spapr_tce_find_by_liobn(target_ulong liobn);
>
> struct sPAPREventLogEntry {
> - int log_type;
> + int32_t log_type;
> void *data;
> + uint32_t data_size;
> QTAILQ_ENTRY(sPAPREventLogEntry) next;
> };
>
> --
> 2.9.4
>
