David Gibson <da...@gibson.dropbear.id.au> writes: >> >> >> >> As smp_thread defaults to 1 in vl.c, similarly smp_cores also has the >> >> default value of 1 in vl.c. In powernv, we were setting nr-cores like >> >> this: >> >> >> >> object_property_set_int(chip, smp_cores, "nr-cores", >> >> &error_fatal); >> >> >> >> Even when there were multiple cpus (-smp 4), when the guest boots up, we >> >> just get one core (i.e. smp_cores was 1) with single thread(smp_threads >> >> was 1), which is wrong as per the command-line that was provided. >> > >> > Right, so, -smp 4 defaults to 4 sockets, each with 1 core of 1 >> > thread. If you can't supply 4 sockets you should error, but you >> > shouldn't go and change the number of cores per socket. >> >> OK, that makes sense now. And I do see that smp_cpus is 4 in the above >> case. Now looking more into it, i see that powernv has something called >> "num_chips", isnt this same as sockets ? Do we need num_chips separately? > > Ah, yes, I see. It's probably still reasonable to keep num_chips as > an internal variable, rather than using (smp_cpus / smp_cores / > smp_threads) everywhere. But we shouldn't have it as a direct > user-settable property, instead setting it from the -smp command line > option.
Something like the below works till num_chips=2, after that guest does not boot up. This might be some limitation within the OS, Cedric might have some clue. Otherwise, I see that multiple chips are created with single core having single thread. ppc/pnv: Use num_chips for multiple sockets When the user does not provide the cpu topology, e.g. "-smp 4", machine fails to initialize 4 cpus. QEMU assumes smp_threads and smp_cores both as 1. Make sure that we initialize multiple chips for this. Remove the user-settable property num_chips from machine command line option Signed-off-by: Nikunj A Dadhania <nik...@linux.vnet.ibm.com> diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c index 9724719..fa501f9 100644 --- a/hw/ppc/pnv.c +++ b/hw/ppc/pnv.c @@ -709,7 +709,17 @@ static void ppc_powernv_init(MachineState *machine) exit(1); } + pnv->num_chips = smp_cpus / (smp_cores * smp_threads); pnv->chips = g_new0(PnvChip *, pnv->num_chips); + + if (smp_cpus != (smp_threads * pnv->num_chips * smp_cores)) { + error_report("cpu topology not balanced: " + "chips (%u) * cores (%u) * threads (%u) != " + "number of cpus (%u)", + pnv->num_chips, smp_cores, smp_threads, smp_cpus); + exit(1); + } + for (i = 0; i < pnv->num_chips; i++) { char chip_name[32]; Object *chip = object_new(chip_typename); @@ -1255,53 +1265,12 @@ static void pnv_pic_print_info(InterruptStatsProvider *obj, } } -static void pnv_get_num_chips(Object *obj, Visitor *v, const char *name, - void *opaque, Error **errp) -{ - visit_type_uint32(v, name, &POWERNV_MACHINE(obj)->num_chips, errp); -} - -static void pnv_set_num_chips(Object *obj, Visitor *v, const char *name, - void *opaque, Error **errp) -{ - PnvMachineState *pnv = POWERNV_MACHINE(obj); - uint32_t num_chips; - Error *local_err = NULL; - - visit_type_uint32(v, name, &num_chips, &local_err); - if (local_err) { - error_propagate(errp, local_err); - return; - } - - /* - * TODO: should we decide on how many chips we can create based - * on #cores and Venice vs. Murano vs. Naples chip type etc..., - */ - if (!is_power_of_2(num_chips) || num_chips > 4) { - error_setg(errp, "invalid number of chips: '%d'", num_chips); - return; - } - - pnv->num_chips = num_chips; -} - static void powernv_machine_initfn(Object *obj) { PnvMachineState *pnv = POWERNV_MACHINE(obj); pnv->num_chips = 1; } -static void powernv_machine_class_props_init(ObjectClass *oc) -{ - object_class_property_add(oc, "num-chips", "uint32", - pnv_get_num_chips, pnv_set_num_chips, - NULL, NULL, NULL); - object_class_property_set_description(oc, "num-chips", - "Specifies the number of processor chips", - NULL); -} - static void powernv_machine_class_init(ObjectClass *oc, void *data) { MachineClass *mc = MACHINE_CLASS(oc); @@ -1321,8 +1290,6 @@ static void powernv_machine_class_init(ObjectClass *oc, void *data) xic->ics_get = pnv_ics_get; xic->ics_resend = pnv_ics_resend; ispc->print_info = pnv_pic_print_info; - - powernv_machine_class_props_init(oc); } static const TypeInfo powernv_machine_info = {