On Fri, Apr 24, 2015 at 12:17:34PM +0530, Bharata B Rao wrote: > Support CPU hotplug via device-add command. Set up device tree > entries for the hotplugged CPU core and use the exising EPOW event > infrastructure to send CPU hotplug notification to the guest. > > Also support cold plugged CPUs that are specified by -device option > on cmdline. > > Signed-off-by: Bharata B Rao <[email protected]> > --- > hw/ppc/spapr.c | 129 > ++++++++++++++++++++++++++++++++++++++++++++++++++ > hw/ppc/spapr_events.c | 8 ++-- > hw/ppc/spapr_rtas.c | 11 +++++ > 3 files changed, 145 insertions(+), 3 deletions(-) > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index b526b7d..9b0701c 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -33,6 +33,7 @@ > #include "sysemu/block-backend.h" > #include "sysemu/cpus.h" > #include "sysemu/kvm.h" > +#include "sysemu/device_tree.h" > #include "kvm_ppc.h" > #include "mmu-hash64.h" > #include "qom/cpu.h" > @@ -662,6 +663,17 @@ static void spapr_populate_cpu_dt(CPUState *cs, void > *fdt, int offset) > unsigned sockets = opts ? qemu_opt_get_number(opts, "sockets", 0) : 0; > uint32_t cpus_per_socket = sockets ? (smp_cpus / sockets) : 1; > uint32_t pft_size_prop[] = {0, cpu_to_be32(spapr->htab_shift)}; > + sPAPRDRConnector *drc; > + sPAPRDRConnectorClass *drck; > + int drc_index; > + > + if (spapr->dr_cpu_enabled) { > + drc = spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_CPU, index); > + g_assert(drc); > + drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc); > + drc_index = drck->get_index(drc); > + _FDT((fdt_setprop_cell(fdt, offset, "ibm,my-drc-index", drc_index))); > + } > > _FDT((fdt_setprop_cell(fdt, offset, "reg", index))); > _FDT((fdt_setprop_string(fdt, offset, "device_type", "cpu"))); > @@ -1850,6 +1862,114 @@ static void spapr_nmi(NMIState *n, int cpu_index, > Error **errp) > } > } > > +static void *spapr_populate_hotplug_cpu_dt(DeviceState *dev, CPUState *cs, > + int *fdt_offset) > +{ > + PowerPCCPU *cpu = POWERPC_CPU(cs); > + DeviceClass *dc = DEVICE_GET_CLASS(cs); > + int id = ppc_get_vcpu_dt_id(cpu); > + void *fdt; > + int offset, fdt_size; > + char *nodename; > + > + fdt = create_device_tree(&fdt_size); > + nodename = g_strdup_printf("%s@%x", dc->fw_name, id); > + offset = fdt_add_subnode(fdt, 0, nodename); > + > + spapr_populate_cpu_dt(cs, fdt, offset); > + g_free(nodename); > + > + *fdt_offset = offset; > + return fdt; > +} > + > +static void spapr_cpu_plug(HotplugHandler *hotplug_dev, DeviceState *dev, > + Error **errp) > +{ > + CPUState *cs = CPU(dev); > + PowerPCCPU *cpu = POWERPC_CPU(cs); > + int id = ppc_get_vcpu_dt_id(cpu); > + sPAPRDRConnector *drc = > + spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_CPU, id); > + sPAPRDRConnectorClass *drck; > + int smt = kvmppc_smt_threads(); > + Error *local_err = NULL; > + void *fdt = NULL; > + int i, fdt_offset = 0; > + > + /* Set NUMA node for the added CPUs */ > + for (i = 0; i < nb_numa_nodes; i++) { > + if (test_bit(cs->cpu_index, numa_info[i].node_cpu)) { > + cs->numa_node = i; > + break; > + } > + } > + > + /* > + * SMT threads return from here, only main thread (core) will > + * continue and signal hotplug event to the guest. > + */ > + if ((id % smt) != 0) { > + return; > + }
Couldn't you avoid this by attaching this call to the core device,
rather than the individual vcpu thread objects?
> + if (!spapr->dr_cpu_enabled) {
> + /*
> + * This is a cold plugged CPU but the machine doesn't support
> + * DR. So skip the hotplug path ensuring that the CPU is brought
> + * up online with out an associated DR connector.
> + */
> + return;
> + }
> +
> + g_assert(drc);
> +
> + /*
> + * Setup CPU DT entries only for hotplugged CPUs. For boot time or
> + * coldplugged CPUs DT entries are setup in spapr_finalize_fdt().
> + */
> + if (dev->hotplugged) {
> + fdt = spapr_populate_hotplug_cpu_dt(dev, cs, &fdt_offset);
> + }
> +
> + drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
> + drck->attach(drc, dev, fdt, fdt_offset, !dev->hotplugged, &local_err);
> + if (local_err) {
> + g_free(fdt);
> + error_propagate(errp, local_err);
> + return;
> + }
> +
> + /*
> + * We send hotplug notification interrupt to the guest only in case
> + * of hotplugged CPUs.
> + */
> + if (dev->hotplugged) {
> + spapr_hotplug_req_add_event(drc);
> + } else {
> + /*
> + * HACK to support removal of hotplugged CPU after VM migration:
> + *
> + * Since we want to be able to hot-remove those coldplugged CPUs
> + * started at boot time using -device option at the target VM, we set
> + * the right allocation_state and isolation_state for them, which for
> + * the hotplugged CPUs would be set via RTAS calls done from the
> + * guest during hotplug.
> + *
> + * This allows the coldplugged CPUs started using -device option to
> + * have the right isolation and allocation states as expected by the
> + * CPU hot removal code.
> + *
> + * This hack will be removed once we have DRC states migrated as part
> + * of VM migration.
> + */
> + drck->set_allocation_state(drc, SPAPR_DR_ALLOCATION_STATE_USABLE);
> + drck->set_isolation_state(drc, SPAPR_DR_ISOLATION_STATE_UNISOLATED);
> + }
> +
> + return;
> +}
> +
> static void spapr_machine_device_plug(HotplugHandler *hotplug_dev,
> DeviceState *dev, Error **errp)
> {
> @@ -1858,6 +1978,15 @@ static void spapr_machine_device_plug(HotplugHandler
> *hotplug_dev,
> PowerPCCPU *cpu = POWERPC_CPU(cs);
>
> spapr_cpu_init(cpu);
> + spapr_cpu_reset(cpu);
I'm a little surprised these get called here, rather than in the
creation / realize path of the core qdev.
> + /*
> + * Fail hotplug on machines where CPU DR isn't enabled.
> + */
> + if (!spapr->dr_cpu_enabled && dev->hotplugged) {
> + return;
> + }
> + spapr_cpu_plug(hotplug_dev, dev, errp);
> }
> }
>
> diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c
> index be82815..4ae818a 100644
> --- a/hw/ppc/spapr_events.c
> +++ b/hw/ppc/spapr_events.c
> @@ -421,14 +421,16 @@ static void spapr_hotplug_req_event(sPAPRDRConnector
> *drc, uint8_t hp_action)
> hp->hdr.section_length = cpu_to_be16(sizeof(*hp));
> hp->hdr.section_version = 1; /* includes extended modifier */
> hp->hotplug_action = hp_action;
> -
> + hp->drc.index = cpu_to_be32(drck->get_index(drc));
> + hp->hotplug_identifier = RTAS_LOG_V6_HP_ID_DRC_INDEX;
>
> switch (drc_type) {
> case SPAPR_DR_CONNECTOR_TYPE_PCI:
> - hp->drc.index = cpu_to_be32(drck->get_index(drc));
> - hp->hotplug_identifier = RTAS_LOG_V6_HP_ID_DRC_INDEX;
> hp->hotplug_type = RTAS_LOG_V6_HP_TYPE_PCI;
> break;
> + case SPAPR_DR_CONNECTOR_TYPE_CPU:
> + hp->hotplug_type = RTAS_LOG_V6_HP_TYPE_CPU;
> + break;
> default:
> /* we shouldn't be signaling hotplug events for resources
> * that don't support them
> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> index 57ec97a..48aeb86 100644
> --- a/hw/ppc/spapr_rtas.c
> +++ b/hw/ppc/spapr_rtas.c
> @@ -121,6 +121,16 @@ static void rtas_query_cpu_stopped_state(PowerPCCPU
> *cpu_,
> rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
> }
>
> +static void spapr_cpu_set_endianness(PowerPCCPU *cpu)
> +{
> + PowerPCCPU *fcpu = POWERPC_CPU(first_cpu);
> + PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(fcpu);
> +
> + if (!(*pcc->interrupts_big_endian)(fcpu)) {
> + cpu->env.spr[SPR_LPCR] |= LPCR_ILE;
> + }
> +}
> +
> static void rtas_start_cpu(PowerPCCPU *cpu_, sPAPREnvironment *spapr,
> uint32_t token, uint32_t nargs,
> target_ulong args,
> @@ -157,6 +167,7 @@ static void rtas_start_cpu(PowerPCCPU *cpu_,
> sPAPREnvironment *spapr,
> env->nip = start;
> env->gpr[3] = r3;
> cs->halted = 0;
> + spapr_cpu_set_endianness(cpu);
>
> qemu_cpu_kick(cs);
>
--
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
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