@@ -519,6 +519,60 @@ static void reset(DeviceState *d)
}
}
+static bool spapr_drc_needed(void *opaque)
+{
+ sPAPRDRConnector *drc = (sPAPRDRConnector *)opaque;
+ sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
+ bool rc = false;
+ sPAPRDREntitySense value;
+ drck->entity_sense(drc, &value);
+
+ /* If no dev is plugged in there is no need to migrate the DRC state */
+ if (value != SPAPR_DR_ENTITY_SENSE_PRESENT) {
+ return false;
+ }
+
+ /*
+ * If there is dev plugged in, we need to migrate the DRC state when
+ * it is different from cold-plugged state
+ */
+ switch (drc->type) {
+ case SPAPR_DR_CONNECTOR_TYPE_PCI:
+ rc = !((drc->isolation_state == SPAPR_DR_ISOLATION_STATE_UNISOLATED) &&
+ (drc->allocation_state == SPAPR_DR_ALLOCATION_STATE_USABLE) &&
+ drc->configured && drc->signalled && !drc->awaiting_release);
+ break;
+ case SPAPR_DR_CONNECTOR_TYPE_CPU:
+ case SPAPR_DR_CONNECTOR_TYPE_LMB:
+ rc = !((drc->isolation_state == SPAPR_DR_ISOLATION_STATE_ISOLATED) &&
+ (drc->allocation_state == SPAPR_DR_ALLOCATION_STATE_UNUSABLE) &&
+ drc->configured && drc->signalled && !drc->awaiting_release);
+ break;
+ case SPAPR_DR_CONNECTOR_TYPE_PHB:
+ case SPAPR_DR_CONNECTOR_TYPE_VIO:
+ default:
+ g_assert(false);
+ }
+ return rc;
+}
+
+static const VMStateDescription vmstate_spapr_drc = {
+ .name = "spapr_drc",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = spapr_drc_needed,
+ .fields = (VMStateField []) {
+ VMSTATE_UINT32(isolation_state, sPAPRDRConnector),
+ VMSTATE_UINT32(allocation_state, sPAPRDRConnector),
+ VMSTATE_UINT32(indicator_state, sPAPRDRConnector),
+ VMSTATE_BOOL(configured, sPAPRDRConnector),
+ VMSTATE_BOOL(awaiting_release, sPAPRDRConnector),
+ VMSTATE_BOOL(awaiting_allocation, sPAPRDRConnector),
+ VMSTATE_BOOL(signalled, sPAPRDRConnector),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
static void realize(DeviceState *d, Error **errp)
{
sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(d);
@@ -547,6 +601,8 @@ static void realize(DeviceState *d, Error **errp)
object_unref(OBJECT(drc));
}
g_free(child_name);
+ vmstate_register(DEVICE(drc), drck->get_index(drc), &vmstate_spapr_drc,
+ drc);
trace_spapr_drc_realize_complete(drck->get_index(drc));
}
In pseries, a firmware abstraction called Dynamic Reconfiguration Connector (DRC) is used to assign a particular dynamic resource to the guest and provide an interface to manage configuration/removal of the resource associated with it. In other words, DRC is the 'plugged state' of a device. Before this patch, DRC wasn't being migrated. This causes post-migration problems due to DRC state mismatch between source and target. The DRC state of a device X in the source might change, while in the target the DRC state of X is still fresh. When migrating the guest, X will not have the same hotplugged state as it did in the source. This means that we can't hot unplug X in the target after migration is completed because its DRC state is not consistent. https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1677552 is one bug that is caused by this DRC state mismatch between source and target. To migrate the DRC state, we defined the VMStateDescription struct for spapr_drc to enable the transmission of spapr_drc state in migration. Not all the elements in the DRC state are migrated - only those that can be modified by guest actions or device add/remove operations: - 'isolation_state', 'allocation_state' and 'indicator_state' are involved in the DR state transition diagram from PAPR+ 2.7, 13.4; - 'configured', 'signalled', 'awaiting_release' and 'awaiting_allocation' are needed in attaching and detaching devices; - 'indicator_state' provides users with hardware state information. These are the DRC elements that are migrated. In this patch the DRC state is migrated for PCI, LMB and CPU connector types. At this moment there is no support to migrate DRC for the PHB (PCI Host Bridge) type. In the 'realize' function the DRC is registered using vmstate_register, similar to what hw/ppc/spapr_iommu.c does in 'spapr_tce_table_realize'. This approach works because DRCs are bus-less and do not sit on a BusClass that implements bc->get_dev_path, so as a fallback the VMSD gets identified via "spapr_drc"/get_index(drc). Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com> --- hw/ppc/spapr_drc.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+)