KVM: PPC: Book3S HV: Fix preempted vcore list locking

When a vcore gets preempted, we put it on the preempted vcore list for
the current CPU.  The runner task then calls schedule() and comes back
some time later and takes itself off the list.  We need to be careful
to lock the list that it was put onto, which may not be the list for the
current CPU since the runner task may have moved to another CPU.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 6e3ef308b4c5d6f2f99fb13832293c26fa58ae3c..3d022766294aaba5d398724ee02c9f4fc50f99b6 100644 (file)
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1962,10 +1962,11 @@ static void kvmppc_vcore_preempt(struct kvmppc_vcore *vc)
 
 static void kvmppc_vcore_end_preempt(struct kvmppc_vcore *vc)
 {
-       struct preempted_vcore_list *lp = this_cpu_ptr(&preempted_vcores);
+       struct preempted_vcore_list *lp;
 
        kvmppc_core_end_stolen(vc);
        if (!list_empty(&vc->preempt_list)) {
+               lp = &per_cpu(preempted_vcores, vc->pcpu);
                spin_lock(&lp->lock);
                list_del_init(&vc->preempt_list);
                spin_unlock(&lp->lock);