diff --git a/xen/common/schedule.c b/xen/common/schedule.c
index 8bea9a203e..343ab6306e 100644
--- a/xen/common/schedule.c
+++ b/xen/common/schedule.c
@@ -869,6 +869,11 @@ void sched_set_affinity(
         cpumask_copy(v->cpu_hard_affinity, hard);
     if ( soft )
         cpumask_copy(v->cpu_soft_affinity, soft);
+
+    v->soft_aff_effective = !cpumask_subset(v->cpu_hard_affinity,
+                                            v->cpu_soft_affinity) &&
+                            cpumask_intersects(v->cpu_soft_affinity,
+                                               v->cpu_hard_affinity);
 }
 
 static int vcpu_set_affinity(
diff --git a/xen/include/xen/sched-if.h b/xen/include/xen/sched-if.h
index 65b4538114..9596eae1e2 100644
--- a/xen/include/xen/sched-if.h
+++ b/xen/include/xen/sched-if.h
@@ -270,10 +270,9 @@ static inline cpumask_t* cpupool_domain_cpumask(struct domain *d)
  */
 static inline int has_soft_affinity(const struct vcpu *v)
 {
-    return !cpumask_subset(cpupool_domain_cpumask(v->domain),
-                           v->cpu_soft_affinity) &&
-           !cpumask_subset(v->cpu_hard_affinity, v->cpu_soft_affinity) &&
-           cpumask_intersects(v->cpu_soft_affinity, v->cpu_hard_affinity);
+    return v->soft_aff_effective &&
+           !cpumask_subset(cpupool_domain_cpumask(v->domain),
+                           v->cpu_soft_affinity);
 }
 
 /*
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index cbd50e9867..3303fd9803 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -210,6 +210,9 @@ struct vcpu
     bool             hcall_compat;
 #endif
 
+    /* Does soft affinity actually play a role (given hard affinity)? */
+    bool             soft_aff_effective;
+
     /* The CPU, if any, which is holding onto this VCPU's state. */
 #define VCPU_CPU_CLEAN (~0u)
     unsigned int     dirty_cpu;