test-runner: Add TestsComplete message

At the end of the test-runner app, right before we exit boot services,
send a TestsComplete message to the host. If the host doesn't receive
this message, the tests will be marked as failed.

Author: nicholasbishop

uefi-test-runner/src/main.rs

@@ -76,10 +76,23 @@ fn check_revision(rev: uefi::table::Revision) {
     );
 }
 
-/// Send the `request` string to the host via the `serial` device, then
-/// wait up to 10 seconds to receive a reply. Returns an error if the
-/// reply is not `"OK\n"`.
-fn send_request_helper(serial: &mut Serial, request: &str) -> Result {
+#[derive(Clone, Copy, Debug)]
+enum HostRequest {
+    /// Tell the host to take a screenshot and compare against the
+    /// golden image.
+    Screenshot(&'static str),
+
+    /// Tell the host that tests are complete. The host will consider
+    /// the tests failed if this message is not received.
+    TestsComplete,
+}
+
+fn send_request_helper(serial: &mut Serial, request: HostRequest) -> Result {
+    let request = match request {
+        HostRequest::Screenshot(name) => format!("SCREENSHOT: {name}\n"),
+        HostRequest::TestsComplete => "TESTS_COMPLETE\n".to_string(),
+    };
+
     // Set a 10 second timeout for the read and write operations.
     let mut io_mode = *serial.io_mode();
     io_mode.timeout = 10_000_000;
@@ -99,10 +112,10 @@ fn send_request_helper(serial: &mut Serial, request: &str) -> Result {
     }
 }
 
-/// Ask the test runner to check the current screen output against a reference.
-fn check_screenshot(bt: &BootServices, name: &str) {
-    let request = format!("SCREENSHOT: {name}\n");
-
+/// Send the `request` string to the host via the `serial` device, then
+/// wait up to 10 seconds to receive a reply. Returns an error if the
+/// reply is not `"OK\n"`.
+fn send_request_to_host(bt: &BootServices, request: HostRequest) {
     let serial_handle = bt
         .get_handle_for_protocol::<Serial>()
         .expect("Failed to get serial handle");
@@ -124,7 +137,7 @@ fn check_screenshot(bt: &BootServices, name: &str) {
 
     // Send the request, but don't check the result yet so that first
     // we can reconnect the console output for the logger.
-    let res = send_request_helper(&mut serial, &request);
+    let res = send_request_helper(&mut serial, request);
 
     // Release the serial device and reconnect all controllers to the
     // serial handle. This is necessary to restore the connection
@@ -135,11 +148,7 @@ fn check_screenshot(bt: &BootServices, name: &str) {
     let _ = bt.connect_controller(serial_handle, None, None, true);
 
     if let Err(err) = res {
-        panic!(
-            "request failed: \"{}\": {:?}",
-            request.trim_end(),
-            err.status()
-        );
+        panic!("request failed: \"{request:?}\": {:?}", err.status());
     }
 }
 
@@ -149,6 +158,11 @@ fn shutdown(image: uefi::Handle, mut st: SystemTable<Boot>) -> ! {
 
     info!("Testing complete, shutting down...");
 
+    // Tell the host that tests are done. We are about to exit boot
+    // services, so we can't easily communicate with the host any later
+    // than this.
+    send_request_to_host(st.boot_services(), HostRequest::TestsComplete);
+
     // Exit boot services as a proof that it works :)
     let sizes = st.boot_services().memory_map_size();
     let max_mmap_size = sizes.map_size + 2 * sizes.entry_size;

uefi-test-runner/src/proto/console/gop.rs

@@ -1,3 +1,4 @@
+use crate::{send_request_to_host, HostRequest};
 use uefi::prelude::*;
 use uefi::proto::console::gop::{BltOp, BltPixel, FrameBuffer, GraphicsOutput, PixelFormat};
 use uefi::table::boot::{BootServices, OpenProtocolAttributes, OpenProtocolParams};
@@ -23,7 +24,7 @@ pub unsafe fn test(image: Handle, bt: &BootServices) {
         fill_color(gop);
         draw_fb(gop);
 
-        crate::check_screenshot(bt, "gop_test");
+        send_request_to_host(bt, HostRequest::Screenshot("gop_test"));
     } else {
         // No tests can be run.
         warn!("UEFI Graphics Output Protocol is not supported");

xtask/src/qemu.rs

@@ -282,6 +282,8 @@ impl Io {
 }
 
 fn process_qemu_io(mut monitor_io: Io, mut serial_io: Io, tmp_dir: &Path) -> Result<()> {
+    let mut tests_complete = false;
+
     // This regex is used to detect and strip ANSI escape codes. These
     // escapes are added by the console output protocol when writing to
     // the serial device.
@@ -298,6 +300,9 @@ fn process_qemu_io(mut monitor_io: Io, mut serial_io: Io, tmp_dir: &Path) -> Res
         let line = ansi_escape.replace_all(line.as_bytes(), &b""[..]);
         let line = String::from_utf8(line.into()).expect("line is not utf8");
 
+        // Send an "OK" response to the app.
+        let mut reply_ok = || serial_io.write_all("OK\n");
+
         // If the app requests a screenshot, take it.
         if let Some(reference_name) = line.strip_prefix("SCREENSHOT: ") {
             let screenshot_path = tmp_dir.join("screenshot.ppm");
@@ -316,7 +321,7 @@ fn process_qemu_io(mut monitor_io: Io, mut serial_io: Io, tmp_dir: &Path) -> Res
             assert_eq!(reply, json!({"return": {}}));
 
             // Tell the VM that the screenshot was taken
-            serial_io.write_all("OK\n")?;
+            reply_ok()?;
 
             // Compare screenshot to the reference file specified by the user.
             // TODO: Add an operating mode where the reference is created if it doesn't exist.
@@ -330,11 +335,23 @@ fn process_qemu_io(mut monitor_io: Io, mut serial_io: Io, tmp_dir: &Path) -> Res
                 expected == actual,
                 "screenshot does not match reference image"
             )
+        } else if line == "TESTS_COMPLETE" {
+            // The app sends this command after running its tests to
+            // indicate it actually got to the end. If the tests failed
+            // earlier with a panic, this command will never be
+            // received.
+            tests_complete = true;
+
+            reply_ok()?;
         } else {
             println!("{line}");
         }
     }
 
+    if !tests_complete {
+        bail!("tests did not complete successfully");
+    }
+
     Ok(())
 }