On Fri, 24 Apr 2015 12:17:34 +0530
Bharata B Rao <bhar...@linux.vnet.ibm.com> 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 <bhar...@linux.vnet.ibm.com>
> ---
> 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
[...]
> +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;
> + }
> +
> + 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;
Cosmetic nit: Superfluous return statement
> +}
> +
[...]
> 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)) {
Functions pointers are sometimes still confusing to me, but can't you
simplify that to:
if (!pcc->interrupts_big_endian(fcpu)) {
?
> + cpu->env.spr[SPR_LPCR] |= LPCR_ILE;
> + }
> +}
Thomas
