On Mon, May 04, 2015 at 05:53:23PM +0200, Thomas Huth wrote:
> 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)) {
That should work too. Thanks.
Regards,
Bharata.
