Function test_rxq_event

virtio-devices/src/vsock/device.rs:778–844

()

    #[test]
    fn test_rxq_event() {
        // Test case:
        // - there is pending RX data in the backend; and
        // - the driver makes RX buffers available; and
        // - the backend successfully places its RX data into the queue.
        {
            let test_ctx = TestContext::new();
            let mut ctx = test_ctx.create_epoll_handler_context();

            ctx.handler.backend.write().unwrap().set_pending_rx(true);
            ctx.handler
                .backend
                .write()
                .unwrap()
                .set_rx_err(Some(VsockError::NoData));
            ctx.signal_rxq_event();

            // The available RX buffer should've been left untouched.
            assert_eq!(ctx.guest_rxvq.used.idx.get(), 0);
        }

        // Test case:
        // - there is pending RX data in the backend; and
        // - the driver makes RX buffers available; and
        // - the backend errors out, when attempting to receive data.
        {
            let test_ctx = TestContext::new();
            let mut ctx = test_ctx.create_epoll_handler_context();

            ctx.handler.backend.write().unwrap().set_pending_rx(true);
            ctx.signal_rxq_event();

            // The available RX buffer should have been used.
            assert_eq!(ctx.guest_rxvq.used.idx.get(), 1);
        }

        // Test case: the driver provided a malformed RX descriptor chain.
        {
            let test_ctx = TestContext::new();
            let mut ctx = test_ctx.create_epoll_handler_context();

            // Invalidate the packet header descriptor, by setting its length to 0.
            ctx.guest_rxvq.dtable[0].len.set(0);

            // The chain should've been processed, without employing the backend.
            ctx.handler.process_rx().unwrap();
            assert_eq!(ctx.guest_rxvq.used.idx.get(), 1);
            assert_eq!(ctx.handler.backend.read().unwrap().rx_ok_cnt, 0);
        }

        // Test case: spurious RXQ_EVENT.
        {
            let test_ctx = TestContext::new();
            let mut ctx = test_ctx.create_epoll_handler_context();
            ctx.handler.backend.write().unwrap().set_pending_rx(false);

            let events = epoll::Events::EPOLLIN;
            let event = epoll::Event::new(events, RX_QUEUE_EVENT as u64);