[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Qemu-devel] [PULL 1/1] pseries: Enforce homogeneous threads-per-core

From: David Gibson
Subject: [Qemu-devel] [PULL 1/1] pseries: Enforce homogeneous threads-per-core
Date: Mon, 3 Apr 2017 20:08:32 +1000

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

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

Signed-off-by: David Gibson <address@hidden>
Reviewed-by: Bharata B Rao <address@hidden>
 hw/ppc/spapr.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 44c26e4..35db949 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -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);

reply via email to

[Prev in Thread] Current Thread [Next in Thread]