Subject: bug#30505: marionette/virtio-console issues lead to test failures

From: [email-masked] (Ludovic Courtès)
Date: Sun, 18 Feb 2018 01:01:31 +0100

Hello,

On core-updates (or is it master now?), “make check-system TESTS=basic”
fails with:

--8<---------------cut here---------------start------------->8---
Test begin:
  test-name: "/run/current-system is a GC root"
  source-file: "/gnu/store/irm2375f5p7nzyqqllwjfaby3ywhi5wq-basic-builder"
  source-line: 2
  source-form: (test-eq "/run/current-system is a GC root" (quote success!) (marionette-eval (quote (begin (add-to-load-path "/gnu/store/pn333fnrdazadmzvkbyzby8cfr176yrh-guix-0.14.0-8.bc880f9/share/guile/site/2.2") (use-modules (srfi srfi-34) (guix store)) (let ((system (readlink "/run/current-system"))) (guard (c ((nix-protocol-error? c) (and (file-exists? system) (quote success!)))) (with-store store (delete-paths store (list system)) #f))))) marionette))
Test end:
  result-kind: fail
  actual-value: #{\x1b;%G\x1b;%G\x1b;%G\x1b;%G\x1b;%G\x1b;%Gsuccess!}#
  expected-value: success!
--8<---------------cut here---------------end--------------->8---

We see similar issues with other system tests.

The “\x1b;%G” sequences correspond to the “select UTF-8” console code
(see console_codes(4)).  We’re receiving this as if we were a console,
but in fact all we want is to exchange raw bytes between the host and
the guest; we don’t want to be a full-fledged console.

I thought that using virtserialport instead of virtio-console might help
(see patch below), but the problem persists.  I’m not sure if it’s the
kernel that decides to send these codes or what.  Also unclear as to why
this happens on ‘core-updates’ and not ‘master’.

What am I missing?

Ludo’.

diff --git a/gnu/build/marionette.scm b/gnu/build/marionette.scm
index 7554a710a..173a67cef 100644
--- a/gnu/build/marionette.scm
+++ b/gnu/build/marionette.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2016, 2017 Ludovic Courtès <[email-masked]>
+;;; Copyright © 2016, 2017, 2018 Ludovic Courtès <[email-masked]>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -97,8 +97,11 @@ QEMU monitor and to the guest's backdoor REPL."
           "-monitor" (string-append "unix:" socket-directory "/monitor")
           "-chardev" (string-append "socket,id=repl,path=" socket-directory
                                     "/repl")
+
+          ;; See
+          ;; <http://www.linux-kvm.org/page/VMchannel_Requirements#Invocation>.
           "-device" "virtio-serial"
-          "-device" "virtconsole,chardev=repl"))
+          "-device" "virtserialport,chardev=repl,name=org.gnu.guix.port.0"))
 
   (define (accept* port)
     (match (select (list port) '() (list port) timeout)
diff --git a/gnu/tests.scm b/gnu/tests.scm
index 3e4c3d4e3..31249f0be 100644
--- a/gnu/tests.scm
+++ b/gnu/tests.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2016, 2017 Ludovic Courtès <[email-masked]>
+;;; Copyright © 2016, 2017, 2018 Ludovic Courtès <[email-masked]>
 ;;; Copyright © 2017 Mathieu Othacehe <[email-masked]>
 ;;; Copyright © 2017 Tobias Geerinckx-Rice <[email-masked]>
 ;;;
@@ -69,7 +69,7 @@
   marionette-configuration make-marionette-configuration
   marionette-configuration?
   (device           marionette-configuration-device ;string
-                    (default "/dev/hvc0"))
+                    (default "/dev/virtio-ports/org.gnu.guix.port.0"))
   (imported-modules marionette-configuration-imported-modules
                     (default '()))
   (requirements     marionette-configuration-requirements ;list of symbols
@@ -87,17 +87,10 @@
 
             (modules '((ice-9 match)
                        (srfi srfi-9 gnu)
-                       (guix build syscalls)
                        (rnrs bytevectors)))
             (start
-             (with-imported-modules `((guix build syscalls)
-                                      ,@imported-modules)
+             (with-imported-modules imported-modules
                #~(lambda ()
-                   (define (clear-echo termios)
-                     (set-field termios (termios-local-flags)
-                                (logand (lognot (local-flags ECHO))
-                                        (termios-local-flags termios))))
-
                    (define (self-quoting? x)
                      (letrec-syntax ((one-of (syntax-rules ()
                                                ((_) #f)
@@ -112,20 +105,7 @@
                       (dynamic-wind
                         (const #t)
                         (lambda ()
-                          (let* ((repl    (open-file #$device "r+0"))
-                                 (termios (tcgetattr (fileno repl)))
-                                 (console (open-file "/dev/console" "r+0")))
-                            ;; Don't echo input back.
-                            (tcsetattr (fileno repl) (tcsetattr-action TCSANOW)
-                                       (clear-echo termios))
-
-                            ;; Redirect output to the console.
-                            (close-fdes 1)
-                            (close-fdes 2)
-                            (dup2 (fileno console) 1)
-                            (dup2 (fileno console) 2)
-                            (close-port console)
-
+                          (let ((repl (open-file #$device "r+0")))
                             (display 'ready repl)
                             (let loop ()
                               (newline repl)
diff --git a/gnu/tests/base.scm b/gnu/tests/base.scm
index 1bc7a7027..64332000a 100644
--- a/gnu/tests/base.scm
+++ b/gnu/tests/base.scm
@@ -323,11 +323,6 @@ info --version")
             'success!
             (marionette-eval '(begin
                                 ;; Make sure the (guix …) modules are found.
-                                ;;
-                                ;; XXX: Currently shepherd and marionette run
-                                ;; on Guile 2.0 whereas Guix is on 2.2.  Yet
-                                ;; we should be able to load the 2.0 Scheme
-                                ;; files since it's pure Scheme.
                                 (add-to-load-path
                                  #+(file-append guix "/share/guile/site/2.2"))
 
@@ -337,9 +332,12 @@ info --version")
                                   (guard (c ((nix-protocol-error? c)
                                              (and (file-exists? system)
                                                   'success!)))
-                                    (with-store store
-                                      (delete-paths store (list system))
-                                      #f))))
+                                    (parameterize ((current-build-output-port
+                                                    (open-file "/dev/console"
+                                                               "r+0")))
+                                     (with-store store
+                                       (delete-paths store (list system))
+                                       #f)))))
                              marionette))
 
           ;; This symlink is currently unused, but better have it point to the