Commit 8149e299 authored Apr 02, 2017 by David Gibson

pseries: Enforce homogeneous threads-per-core



For reasons that may be useful in future, CPU core objects, as used on the
pseries machine type have their own nr-threads property, potentially
allowing cores with different numbers of threads in the same system.

If the user/management uses the values specified in query-hotpluggable-cpus
as they're expected to do, this will never matter in pratice.  But that's
not actually enforced - it's possible to manually specify a core with
a different number of threads from that in -smp.  That will confuse the
platform - most immediately, this can be used to create a CPU thread with
index above max_cpus which leads to an assertion failure in
spapr_cpu_core_realize().

For now, enforce that all cores must have the same, standard, number of
threads.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Bharata B Rao <bharata@linux.vnet.ibm.com>

parent 95b31d70

hw/ppc/spapr.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -2790,6 +2790,12 @@ static void spapr_core_pre_plug(HotplugHandler hotplug_dev, DeviceState dev,
		goto out;
		}

		if (cc->nr_threads != smp_threads) {
		error_setg(errp, "invalid nr-threads %d, must be %d",
		cc->nr_threads, smp_threads);
		return;
		}

		core_slot = spapr_find_cpu_slot(MACHINE(hotplug_dev), cc->core_id, &index);
		if (!core_slot) {
		error_setg(&local_err, "core id %d out of range", cc->core_id);