[PATCH 1/9] KVM: selftests: Return the target CPU from pin_task_to_random_cpu()

[Sean Christopherson]

When pinning a task to a random CPU, return which CPU the task was pinned
to so that the caller can do things like avoid running other tasks on the
target CPU.

Signed-off-by: Sean Christopherson <seanjc at google.com>
---
 tools/testing/selftests/kvm/include/kvm_util.h | 2 +-
 tools/testing/selftests/kvm/lib/kvm_util.c     | 5 +++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index b39e713c30a4..61d72e1e7601 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -1094,7 +1094,7 @@ static inline void pin_task_to_cpu(pthread_t task, int cpu)
 	TEST_ASSERT(!r, "Failed to set thread affinity to pCPU '%u'", cpu);
 }
 
-void pin_task_to_random_cpu(pthread_t task, cpu_set_t *possible_cpus);
+int pin_task_to_random_cpu(pthread_t task, cpu_set_t *possible_cpus);
 
 static inline int pin_task_to_any_cpu(pthread_t task)
 {
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 3794575d2ca0..af2bad0553f9 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -668,7 +668,7 @@ void kvm_print_vcpu_pinning_help(void)
 	       "     (default: no pinning)\n", name, name);
 }
 
-void pin_task_to_random_cpu(pthread_t task, cpu_set_t *possible_cpus)
+int pin_task_to_random_cpu(pthread_t task, cpu_set_t *possible_cpus)
 {
 	int target_idx;
 	int nr_cpus;
@@ -682,11 +682,12 @@ void pin_task_to_random_cpu(pthread_t task, cpu_set_t *possible_cpus)
 	for (cpu = 0; cpu < CPU_SETSIZE; cpu++) {
 		if (CPU_ISSET(cpu, possible_cpus) && target_idx-- == 0) {
 			pin_task_to_cpu(task, cpu);
-			return;
+			return cpu;
 		}
 	}
 
 	TEST_FAIL("Failed to find random CPU in possible_cpus");
+	return -1;
 }
 
 void kvm_parse_vcpu_pinning(const char *pcpus_string, u32 vcpu_to_pcpu[],
-- 
2.55.0.508.g3f0d502094-goog