3 files changed, 19 insertions, 1 deletions
diff --git a/tools/virtio/ringtest/main.c b/tools/virtio/ringtest/main.c
index f31353fac541..453ca3c21193 100644
--- a/tools/virtio/ringtest/main.c
+++ b/tools/virtio/ringtest/main.c
@@ -20,6 +20,7 @@
 int runcycles = 10000000;
 int max_outstanding = INT_MAX;
 int batch = 1;
+int param = 0;
 
 bool do_sleep = false;
 bool do_relax = false;
@@ -86,7 +87,7 @@ void set_affinity(const char *arg)
 	cpu = strtol(arg, &endptr, 0);
 	assert(!*endptr);
 
-	assert(cpu >= 0 || cpu < CPU_SETSIZE);
+	assert(cpu >= 0 && cpu < CPU_SETSIZE);
 
 	self = pthread_self();
 	CPU_ZERO(&cpuset);
@@ -247,6 +248,11 @@ static const struct option longopts[] = {
 		.val = 'b',
 	},
 	{
+		.name = "param",
+		.has_arg = required_argument,
+		.val = 'p',
+	},
+	{
 		.name = "sleep",
 		.has_arg = no_argument,
 		.val = 's',
@@ -274,6 +280,7 @@ static void help(void)
 		" [--run-cycles C (default: %d)]"
 		" [--batch b]"
 		" [--outstanding o]"
+		" [--param p]"
 		" [--sleep]"
 		" [--relax]"
 		" [--exit]"
@@ -328,6 +335,12 @@ int main(int argc, char **argv)
 			assert(c > 0 && c < INT_MAX);
 			max_outstanding = c;
 			break;
+		case 'p':
+			c = strtol(optarg, &endptr, 0);
+			assert(!*endptr);
+			assert(c > 0 && c < INT_MAX);
+			param = c;
+			break;
 		case 'b':
 			c = strtol(optarg, &endptr, 0);
 			assert(!*endptr);
diff --git a/tools/virtio/ringtest/main.h b/tools/virtio/ringtest/main.h
index 14142faf040b..90b0133004e1 100644
--- a/tools/virtio/ringtest/main.h
+++ b/tools/virtio/ringtest/main.h
@@ -10,6 +10,8 @@
 
 #include <stdbool.h>
 
+extern int param;
+
 extern bool do_exit;
 
 #if defined(__x86_64__) || defined(__i386__)
diff --git a/tools/virtio/ringtest/ptr_ring.c b/tools/virtio/ringtest/ptr_ring.c
index 635b07b4fdd3..7b22f1b20652 100644
--- a/tools/virtio/ringtest/ptr_ring.c
+++ b/tools/virtio/ringtest/ptr_ring.c
@@ -97,6 +97,9 @@ void alloc_ring(void)
 {
 	int ret = ptr_ring_init(&array, ring_size, 0);
 	assert(!ret);
+	/* Hacky way to poke at ring internals. Useful for testing though. */
+	if (param)
+		array.batch = param;
 }
 
 /* guest side */