[PATCH RFC 14/15] KVM: selftests: Add "-c" parameter to dirty log test

[Peter Xu]

It's only used to override the existing dirty ring size/count.  If
with a bigger ring count, we test async of dirty ring.  If with a
smaller ring count, we test ring full code path.

It has no use for non-dirty-ring tests.

Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
---
 tools/testing/selftests/kvm/dirty_log_test.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index 4799db91e919..c9db136a1f12 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -157,6 +157,7 @@ enum log_mode_t {
 /* Mode of logging.  Default is LOG_MODE_DIRTY_LOG */
 static enum log_mode_t host_log_mode;
 pthread_t vcpu_thread;
+static uint32_t test_dirty_ring_count = TEST_DIRTY_RING_COUNT;
 
 /* Only way to pass this to the signal handler */
 struct kvm_vm *current_vm;
@@ -216,7 +217,7 @@ static void dirty_ring_create_vm_done(struct kvm_vm *vm)
 	 * Switch to dirty ring mode after VM creation but before any
 	 * of the vcpu creation.
 	 */
-	vm_enable_dirty_ring(vm, TEST_DIRTY_RING_COUNT *
+	vm_enable_dirty_ring(vm, test_dirty_ring_count *
 			     sizeof(struct kvm_dirty_gfn));
 }
 
@@ -658,6 +659,9 @@ static void help(char *name)
 	printf("usage: %s [-h] [-i iterations] [-I interval] "
 	       "[-p offset] [-m mode]\n", name);
 	puts("");
+	printf(" -c: specify dirty ring size, in number of entries\n");
+	printf("     (only useful for dirty-ring test; default: %"PRIu32")\n",
+	       TEST_DIRTY_RING_COUNT);
 	printf(" -i: specify iteration counts (default: %"PRIu64")\n",
 	       TEST_HOST_LOOP_N);
 	printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n",
@@ -713,8 +717,11 @@ int main(int argc, char *argv[])
 	vm_guest_mode_params_init(VM_MODE_P40V48_4K, true, true);
 #endif
 
-	while ((opt = getopt(argc, argv, "hi:I:p:m:M:")) != -1) {
+	while ((opt = getopt(argc, argv, "c:hi:I:p:m:M:")) != -1) {
 		switch (opt) {
+		case 'c':
+			test_dirty_ring_count = strtol(optarg, NULL, 10);
+			break;
 		case 'i':
 			iterations = strtol(optarg, NULL, 10);
 			break;
-- 
2.21.0