On Thu, May 12, 2016 at 09:18:22AM +0530, Bharata B Rao wrote: > Remove the CPU core device by removing the underlying CPU thread devices. > Hot removal of CPU for sPAPR guests is achieved by sending the hot unplug > notification to the guest. Release the vCPU object after CPU hot unplug so > that vCPU fd can be parked and reused. > > Signed-off-by: Bharata B Rao Reviewed-by: David Gibson Couple of suggestions for minor improvements below, though. > --- > hw/ppc/spapr.c | 16 ++++++++ > hw/ppc/spapr_cpu_core.c | 81 +++++++++++++++++++++++++++++++++++++++++ > include/hw/ppc/spapr.h | 1 + > include/hw/ppc/spapr_cpu_core.h | 11 ++++++ > 4 files changed, 109 insertions(+) > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 8c3100d..a8cd74d 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -2342,11 +2342,27 @@ static void spapr_machine_device_plug(HotplugHandler *hotplug_dev, > } > } > > +void spapr_cpu_destroy(PowerPCCPU *cpu) I think this would make more sense in spapr_cpu_core.c (where it could be static). > +{ > + sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine()); > + > + xics_cpu_destroy(spapr->icp, cpu); > + qemu_unregister_reset(spapr_cpu_reset, cpu); > +} > + > static void spapr_machine_device_unplug(HotplugHandler *hotplug_dev, > DeviceState *dev, Error **errp) > { > + sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(qdev_get_machine()); > + > if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) { > error_setg(errp, "Memory hot unplug not supported by sPAPR"); > + } else if (object_dynamic_cast(OBJECT(dev), TYPE_SPAPR_CPU_CORE)) { > + if (!smc->dr_cpu_enabled) { > + error_setg(errp, "CPU hot unplug not supported on this machine"); > + return; > + } > + spapr_core_unplug(hotplug_dev, dev, errp); > } > } > > diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c > index ed36beb..0b62456 100644 > --- a/hw/ppc/spapr_cpu_core.c > +++ b/hw/ppc/spapr_cpu_core.c > @@ -28,6 +28,87 @@ char *spapr_get_cpu_core_type(const char *model) > return g_strdup(core_type); > } > > +static void spapr_cpu_core_cleanup(struct sPAPRCPUUnplugList *unplug_list) > +{ > + sPAPRCPUUnplug *unplug, *next; > + Object *cpu; > + > + QLIST_FOREACH_SAFE(unplug, unplug_list, node, next) { > + cpu = unplug->cpu; > + object_unparent(cpu); > + QLIST_REMOVE(unplug, node); > + g_free(unplug); > + } > +} > + > +static void spapr_add_cpu_to_unplug_list(Object *cpu, > + struct sPAPRCPUUnplugList *unplug_list) > +{ > + sPAPRCPUUnplug *unplug = g_malloc(sizeof(*unplug)); > + > + unplug->cpu = cpu; > + QLIST_INSERT_HEAD(unplug_list, unplug, node); > +} > + > +static int spapr_cpu_release(Object *obj, void *opaque) > +{ > + DeviceState *dev = DEVICE(obj); > + CPUState *cs = CPU(dev); > + PowerPCCPU *cpu = POWERPC_CPU(cs); > + struct sPAPRCPUUnplugList *unplug_list = opaque; > + > + spapr_cpu_destroy(cpu); > + cpu_remove_sync(cs); > + > + /* > + * We are still walking the core object's children list, and > + * hence can't cleanup this CPU thread object just yet. Put > + * it on a list for later removal. > + */ > + spapr_add_cpu_to_unplug_list(obj, unplug_list); > + return 0; > +} > + > +static void spapr_core_release(DeviceState *dev, void *opaque) > +{ > + struct sPAPRCPUUnplugList unplug_list; > + sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine()); > + sPAPRCPUCore *core = SPAPR_CPU_CORE(OBJECT(dev)); > + CPUCore *cc = CPU_CORE(dev); > + int smt = kvmppc_smt_threads(); > + > + QLIST_INIT(&unplug_list); > + object_child_foreach(OBJECT(dev), spapr_cpu_release, &unplug_list); > + spapr_cpu_core_cleanup(&unplug_list); > + spapr->cores[cc->core / smt] = NULL; Could you avoid the awkwardness with the two phase release by stepping through the cc->threads array instead of using object_child_foreach()? > + > + g_free(core->threads); > + object_unparent(OBJECT(dev)); > +} > + > +void spapr_core_unplug(HotplugHandler *hotplug_dev, DeviceState *dev, > + Error **errp) > +{ > + sPAPRCPUCore *core = SPAPR_CPU_CORE(OBJECT(dev)); > + PowerPCCPU *cpu = &core->threads[0]; > + int id = ppc_get_vcpu_dt_id(cpu); > + sPAPRDRConnector *drc = > + spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_CPU, id); > + sPAPRDRConnectorClass *drck; > + Error *local_err = NULL; > + > + g_assert(drc); > + > + drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc); > + drck->detach(drc, dev, spapr_core_release, NULL, &local_err); > + if (local_err) { > + error_propagate(errp, local_err); > + return; > + } > + > + spapr_hotplug_req_remove_by_index(drc); > +} > + > void spapr_core_plug(HotplugHandler *hotplug_dev, DeviceState *dev, > Error **errp) > { > diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h > index ca4ae3e..a443693 100644 > --- a/include/hw/ppc/spapr.h > +++ b/include/hw/ppc/spapr.h > @@ -585,6 +585,7 @@ void spapr_hotplug_req_remove_by_count(sPAPRDRConnectorType drc_type, > void spapr_cpu_init(sPAPRMachineState *spapr, PowerPCCPU *cpu, Error **errp); > void *spapr_populate_hotplug_cpu_dt(CPUState *cs, int *fdt_offset, > sPAPRMachineState *spapr); > +void spapr_cpu_destroy(PowerPCCPU *cpu); > > /* rtas-configure-connector state */ > struct sPAPRConfigureConnectorState { > diff --git a/include/hw/ppc/spapr_cpu_core.h b/include/hw/ppc/spapr_cpu_core.h > index 4cd837e..3d8d6ac 100644 > --- a/include/hw/ppc/spapr_cpu_core.h > +++ b/include/hw/ppc/spapr_cpu_core.h > @@ -30,4 +30,15 @@ void spapr_core_pre_plug(HotplugHandler *hotplug_dev, DeviceState *dev, > char *spapr_get_cpu_core_type(const char *model); > void spapr_core_plug(HotplugHandler *hotplug_dev, DeviceState *dev, > Error **errp); > +void spapr_core_unplug(HotplugHandler *hotplug_dev, DeviceState *dev, > + Error **errp); > + > +/* List to store unplugged CPU objects for cleanup during unplug */ > +typedef struct sPAPRCPUUnplug { > + Object *cpu; > + QLIST_ENTRY(sPAPRCPUUnplug) node; > +} sPAPRCPUUnplug; > + > +QLIST_HEAD(sPAPRCPUUnplugList, sPAPRCPUUnplug); > + > #endif -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson