auto-test: Non-blocking write test

This new test puts a port in non-blocking mode in the guest and keeps
sending data till the host can't accept any more. In this case, the vq
is filled and the guest gets -EAGAIN on write. poll() should not return
POLLOUT.

Signed-off-by: Amit Shah <amit.shah@redhat.com>

1 files changed, 71 insertions, 0 deletions

diff --git a/auto-virtserial.c b/auto-virtserial.c
index e3f2a81..5777583 100644
--- a/auto-virtserial.c
+++ b/auto-virtserial.c
@@ -501,6 +501,64 @@ out:
 	return err;
 }
 
+static int test_blocking_write(int nr)
+{
+	return 0;
+}
+
+static int test_nonblocking_write(int nr)
+{
+	unsigned int i;
+	int err, ret;
+	bool test_done;
+
+	ret = guest_open_port(nr);
+	err = result(__func__, true, "guest open", ret, -1, -1, OP_GT, false);
+	if (err)
+		return err;
+
+	ret = guest_set_port_nonblocking(nr, true);
+	err = result(__func__, true, "blocking", ret, 0, 0, OP_EQ, false);
+	if (err)
+		goto out;
+
+	host_connect_chardev(nr);
+
+	test_done = false;
+	/*
+	 * We currently have 128 buffers in a virtqueue --
+	 * hw/virtio-serial-bus.c, so this while loop should stop when
+	 * i is 128.
+	 */
+	for (i = 0; i < 200 && !test_done; i++) {
+		ret = guest_poll(nr, 0);
+		if (i && ret == 0) {
+			/* vq full. Nonblocking IO and poll for that works. */
+
+			test_done = true;
+
+			/* Now try writing to the guest. That should fail too */
+		}
+		err = result(__func__, test_done, "guest poll", ret,
+			     0, POLLOUT, OP_EQ, false);
+		if (err)
+			goto out;
+
+		ret = guest_write(nr, BUF_LENGTH);
+		err = result(__func__, test_done, "guest write",
+			     ret, -EAGAIN, BUF_LENGTH, OP_EQ, false);
+		if (err)
+			goto out;
+	}
+
+out:
+	ret = guest_set_port_nonblocking(nr, false);
+	err = result(__func__, true, "blocking", ret, 0, 0, OP_EQ, true);
+	host_close_chardev(nr);
+	guest_close_port(nr);
+	return err;
+}
+
 static int test_poll(int nr)
 {
 	int err, ret;
@@ -1042,6 +1100,8 @@ enum {
 	TEST_READ_WO_HOST,
 	TEST_BLOCKING_READ,
 	TEST_NOBLOCK_READ,
+	TEST_BLOCKING_WRITE,
+	TEST_NONBLOCK_WRITE,
 	TEST_POLL,
 	TEST_G_THROTTLE,
 	TEST_H_THROTTLE,
@@ -1087,6 +1147,14 @@ static struct test_parameters {
 		.needs_guestok = true,
 	},
 	{
+		.test_function = test_blocking_write,
+		.needs_guestok = true,
+	},
+	{
+		.test_function = test_nonblocking_write,
+		.needs_guestok = true,
+	},
+	{
 		.test_function = test_poll,
 		.needs_guestok = true,
 	},
@@ -1182,6 +1250,9 @@ static int start_tests(void)
 	run_test(TEST_BLOCKING_READ, 2);
 	run_test(TEST_NOBLOCK_READ, 2);
 
+	run_test(TEST_BLOCKING_WRITE, 2);
+	run_test(TEST_NONBLOCK_WRITE, 2);
+
 	run_test(TEST_POLL, 2);
 
 #if 0