Commit cf632463 authored by Bharata B Rao's avatar Bharata B Rao Committed by David Gibson
Browse files

spapr: Memory hot-unplug support 



Add support to hot remove pc-dimm memory devices.

Since we're introducing a machine-level unplug_request hook, we also
had handling for CPU unplug there as well to ensure CPU unplug
continues to work as it did before.

Signed-off-by: default avatarBharata B Rao <bharata@linux.vnet.ibm.com>
* add hooks to CAS/cmdline enablement of hotplug ACR support
* add hook for CPU unplug
Signed-off-by: default avatarMichael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
parent 79b78a6b

hw/ppc/spapr.c

+118 −1
Original line number Diff line number Diff line
@@ -2281,6 +2281,90 @@ out: 
    error_propagate(errp, local_err);

}



typedef struct sPAPRDIMMState {

    uint32_t nr_lmbs;

} sPAPRDIMMState;



static void spapr_lmb_release(DeviceState *dev, void *opaque)

{

    sPAPRDIMMState *ds = (sPAPRDIMMState *)opaque;

    HotplugHandler *hotplug_ctrl;



    if (--ds->nr_lmbs) {

        return;

    }



    g_free(ds);



    /*

     * Now that all the LMBs have been removed by the guest, call the

     * pc-dimm unplug handler to cleanup up the pc-dimm device.

     */

    hotplug_ctrl = qdev_get_hotplug_handler(dev);

    hotplug_handler_unplug(hotplug_ctrl, dev, &error_abort);

}



static void spapr_del_lmbs(DeviceState *dev, uint64_t addr_start, uint64_t size,

                           Error **errp)

{

    sPAPRDRConnector *drc;

    sPAPRDRConnectorClass *drck;

    uint32_t nr_lmbs = size / SPAPR_MEMORY_BLOCK_SIZE;

    int i;

    sPAPRDIMMState *ds = g_malloc0(sizeof(sPAPRDIMMState));

    uint64_t addr = addr_start;



    ds->nr_lmbs = nr_lmbs;

    for (i = 0; i < nr_lmbs; i++) {

        drc = spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_LMB,

                addr / SPAPR_MEMORY_BLOCK_SIZE);

        g_assert(drc);



        drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);

        drck->detach(drc, dev, spapr_lmb_release, ds, errp);

        addr += SPAPR_MEMORY_BLOCK_SIZE;

    }



    drc = spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_LMB,

                                   addr_start / SPAPR_MEMORY_BLOCK_SIZE);

    drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);

    spapr_hotplug_req_remove_by_count_indexed(SPAPR_DR_CONNECTOR_TYPE_LMB,

                                              nr_lmbs,

                                              drck->get_index(drc));

}



static void spapr_memory_unplug(HotplugHandler *hotplug_dev, DeviceState *dev,

                                Error **errp)

{

    sPAPRMachineState *ms = SPAPR_MACHINE(hotplug_dev);

    PCDIMMDevice *dimm = PC_DIMM(dev);

    PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);

    MemoryRegion *mr = ddc->get_memory_region(dimm);



    pc_dimm_memory_unplug(dev, &ms->hotplug_memory, mr);

    object_unparent(OBJECT(dev));

}



static void spapr_memory_unplug_request(HotplugHandler *hotplug_dev,

                                        DeviceState *dev, Error **errp)

{

    Error *local_err = NULL;

    PCDIMMDevice *dimm = PC_DIMM(dev);

    PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);

    MemoryRegion *mr = ddc->get_memory_region(dimm);

    uint64_t size = memory_region_size(mr);

    uint64_t addr;



    addr = object_property_get_int(OBJECT(dimm), PC_DIMM_ADDR_PROP, &local_err);

    if (local_err) {

        goto out;

    }



    spapr_del_lmbs(dev, addr, size, &error_abort);

out:

    error_propagate(errp, local_err);

}



void *spapr_populate_hotplug_cpu_dt(CPUState *cs, int *fdt_offset,

                                    sPAPRMachineState *spapr)

{
@@ -2354,10 +2438,42 @@ static void spapr_machine_device_plug(HotplugHandler *hotplug_dev, 
static void spapr_machine_device_unplug(HotplugHandler *hotplug_dev,

                                      DeviceState *dev, Error **errp)

{

    sPAPRMachineState *sms = SPAPR_MACHINE(qdev_get_machine());

    MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());



    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {

        if (spapr_ovec_test(sms->ov5_cas, OV5_HP_EVT)) {

            spapr_memory_unplug(hotplug_dev, dev, errp);

        } else {

            error_setg(errp, "Memory hot unplug not supported for this guest");

        }

    } else if (object_dynamic_cast(OBJECT(dev), TYPE_SPAPR_CPU_CORE)) {

        if (!mc->query_hotpluggable_cpus) {

            error_setg(errp, "CPU hot unplug not supported on this machine");

            return;

        }

        spapr_core_unplug(hotplug_dev, dev, errp);

    }

}



static void spapr_machine_device_unplug_request(HotplugHandler *hotplug_dev,

                                                DeviceState *dev, Error **errp)

{

    sPAPRMachineState *sms = SPAPR_MACHINE(qdev_get_machine());

    MachineClass *mc = 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");

        if (spapr_ovec_test(sms->ov5_cas, OV5_HP_EVT)) {

            spapr_memory_unplug_request(hotplug_dev, dev, errp);

        } else {

            /* NOTE: this means there is a window after guest reset, prior to

             * CAS negotiation, where unplug requests will fail due to the

             * capability not being detected yet. This is a bit different than

             * the case with PCI unplug, where the events will be queued and

             * eventually handled by the guest after boot

             */

            error_setg(errp, "Memory hot unplug not supported for this guest");

        }

    } else if (object_dynamic_cast(OBJECT(dev), TYPE_SPAPR_CPU_CORE)) {

        if (!mc->query_hotpluggable_cpus) {

            error_setg(errp, "CPU hot unplug not supported on this machine");
@@ -2503,6 +2619,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data) 
    hc->plug = spapr_machine_device_plug;

    hc->unplug = spapr_machine_device_unplug;

    mc->cpu_index_to_socket_id = spapr_cpu_index_to_socket_id;

    hc->unplug_request = spapr_machine_device_unplug_request;



    smc->dr_lmb_enabled = true;

    smc->tcg_default_cpu = "POWER8";

hw/ppc/spapr_drc.c

+17 −0
Original line number Diff line number Diff line
@@ -68,6 +68,23 @@ static uint32_t set_isolation_state(sPAPRDRConnector *drc, 
        }

    }



    /*

     * Fail any requests to ISOLATE the LMB DRC if this LMB doesn't

     * belong to a DIMM device that is marked for removal.

     *

     * Currently the guest userspace tool drmgr that drives the memory

     * hotplug/unplug will just try to remove a set of 'removable' LMBs

     * in response to a hot unplug request that is based on drc-count.

     * If the LMB being removed doesn't belong to a DIMM device that is

     * actually being unplugged, fail the isolation request here.

     */

    if (drc->type == SPAPR_DR_CONNECTOR_TYPE_LMB) {

        if ((state == SPAPR_DR_ISOLATION_STATE_ISOLATED) &&

             !drc->awaiting_release) {

            return RTAS_OUT_HW_ERROR;

        }

    }



    drc->isolation_state = state;



    if (drc->isolation_state == SPAPR_DR_ISOLATION_STATE_ISOLATED) {