diff options
| author | David Gibson <david@gibson.dropbear.id.au> | 2017-05-23 16:33:06 +1000 |
|---|---|---|
| committer | David Gibson <david@gibson.dropbear.id.au> | 2017-05-24 11:39:53 +1000 |
| commit | 459264ef24cf2d409b8baf2047fa86e697d6e9ab (patch) | |
| tree | eac8ed3d2b70ca2179f6a022a90f6400f9d8b058 /hw/ppc | |
| parent | 80c33d343f068012348869e16e579375c8911a04 (diff) | |
| download | qemu-459264ef24cf2d409b8baf2047fa86e697d6e9ab.tar.gz | |
pseries: Restore support for total vcpus not a multiple of threads-per-core for old machine types
As of pseries-2.7 and later, we require the total number of guest vcpus to
be a multiple of the threads-per-core. pseries-2.6 and earlier machine
types, however, are supposed to allow this for the sake of migration from
old qemu versions which allowed this.
Unfortunately, 8149e29 "pseries: Enforce homogeneous threads-per-core"
broke this by not considering the old machine type case. This fixes it by
only applying the check when the machine type supports hotpluggable cpus.
By not-entirely-coincidence, that corresponds to the same time when we
started enforcing total threads being a multiple of threads-per-core.
Fixes: 8149e2992f7811355cc34721b79d69d1a3a667dd
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Greg Kurz <groug@kaod.org>
Diffstat (limited to 'hw/ppc')
| -rw-r--r-- | hw/ppc/spapr.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index c92d269027..bcb0e184a0 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -2863,7 +2863,13 @@ static void spapr_core_pre_plug(HotplugHandler *hotplug_dev, DeviceState *dev, goto out; } - if (cc->nr_threads != smp_threads) { + /* + * In general we should have homogeneous threads-per-core, but old + * (pre hotplug support) machine types allow the last core to have + * reduced threads as a compatibility hack for when we allowed + * total vcpus not a multiple of threads-per-core. + */ + if (mc->has_hotpluggable_cpus && (cc->nr_threads != smp_threads)) { error_setg(errp, "invalid nr-threads %d, must be %d", cc->nr_threads, smp_threads); return; |