cmdlib.sh: feed /dev/zero as qemu stdin

src/cmdlib.sh

@@ -733,9 +733,6 @@ runvm() {
     # and include all GPG keys
     find /etc/pki/rpm-gpg/ -type f >> "${vmpreparedir}/hostfiles"
 
-    local cmdoutput
-    cmdoutput=${tmp_builddir}/cmd-output.txt
-
     # the reason we do a heredoc here is so that the var substition takes
     # place immediately instead of having to proxy them through to the VM
     cat > "${vmpreparedir}/init" <<EOF
@@ -755,7 +752,7 @@ rc=0
 # - Use a subshell because otherwise init will use workdir as its cwd and we won't
 #   be able to unmount the virtiofs mount cleanly. This leads to consistency issues.
 if [ -z "${RUNVM_SHELL:-}" ]; then
-  (cd ${workdir}; bash ${tmp_builddir}/cmd.sh |& tee ${cmdoutput}) || rc=\$?
+  (cd ${workdir}; bash ${tmp_builddir}/cmd.sh |& tee /dev/virtio-ports/cosa-cmdout) || rc=\$?
 else
   (cd ${workdir}; bash)
 fi
@@ -789,9 +786,7 @@ EOF
         printf '%q ' "$arg" >> "${tmp_builddir}"/cmd.sh
     done
 
-    touch "${runvm_console}" "${cmdoutput}"
-    setpriv --pdeathsig SIGTERM -- tail -qF "${cmdoutput}" --pid $$ &
-    local tail_pid=$!
+    touch "${runvm_console}"
 
     # There seems to be some false positives in shellcheck
     # https://github.com/koalaman/shellcheck/issues/2217
@@ -826,7 +821,9 @@ EOF
 
     if [ -z "${RUNVM_SHELL:-}" ]; then
         if ! "${kola_args[@]}" -- "${base_qemu_args[@]}" \
-            "${qemu_args[@]}"; then
+            -device virtserialport,chardev=virtioserial0,name=cosa-cmdout \
+            -chardev stdio,id=virtioserial0 \
+            "${qemu_args[@]}" < /dev/zero; then # qemu hangs if it has nothing to read on stdin
                 cat "${runvm_console}"
                 fatal "Failed to run 'kola qemuexec'"
         fi
@@ -845,13 +842,6 @@ EOF
     fi
     rc="$(cat "${rc_file}")"
 
-    # XXX: this is for debugging temporarily
-    if [ -n "${TAIL_SLEEP:-}" ]; then
-        sleep "${TAIL_SLEEP}"
-    fi
-    # cleanup tail before nuking dir containing file it's following
-    kill "$tail_pid"
-
     if [ -n "${cleanup_tmpdir:-}" ]; then
         rm -rf "${tmp_builddir}"
         unset tmp_builddir

src/secex-genprotimgvm-scripts/runvm.sh

@@ -56,7 +56,7 @@ else
 fi
 
 if ! "${kola_args[@]}" -- "${base_qemu_args[@]}" \
-    "${qemu_args[@]}" <&-; then # the <&- here closes stdin otherwise qemu waits forever
+    "${qemu_args[@]}" < /dev/zero; then # qemu hangs if it has nothing to read on stdin
     cat "${runvm_console}"
     echo "Failed to run 'kola qemuexec'"
     exit 1