Implement VNC GuiVM

We expose a new 'guivm' flavor. In order to enable this remote GuiVM,
one has to enable Qubes services:

- lightdm
- guivm
- guivm-vnc

This is similar to `sys-gui-gpu` setup but here, `guivm-vnc` service
add ExecStartPre and ExecStartPost to lightdm systemd service in order
to configure Xorg server with dummyqbs driver and x11vnc server.

Makefile

@@ -77,9 +77,7 @@ clean:
 
 install: install-rh-agent install-pulseaudio
 
-install-rh-agent: appvm install-common
-	install -m 0644 -D appvm-scripts/qubes-gui-agent.service \
-		$(DESTDIR)/$(SYSLIBDIR)/systemd/system/qubes-gui-agent.service
+install-rh-agent: appvm install-common install-systemd
 	install -m 0644 -D appvm-scripts/etc/sysconfig/desktop \
 		$(DESTDIR)/etc/sysconfig/desktop
 	install -D appvm-scripts/etc/X11/xinit/xinitrc.d/20qt-x11-no-mitshm.sh \
@@ -91,13 +89,11 @@ install-rh-agent: appvm install-common
 	install -D appvm-scripts/etc/X11/xinit/xinitrc.d/60xfce-desktop.sh \
 		$(DESTDIR)/etc/X11/xinit/xinitrc.d/60xfce-desktop.sh
 
-install-debian: appvm install-common install-pulseaudio
+install-debian: appvm install-common install-pulseaudio install-systemd
 	install -d $(DESTDIR)/etc/X11/Xsession.d
 	install -m 0644 appvm-scripts/etc/X11/Xsession.d/* $(DESTDIR)/etc/X11/Xsession.d/
 	install -d $(DESTDIR)/etc/xdg
 	install -m 0644 appvm-scripts/etc/xdg-debian/* $(DESTDIR)/etc/xdg
-	install -m 0644 -D appvm-scripts/qubes-gui-agent.service \
-		$(DESTDIR)/$(SYSLIBDIR)/systemd/system/qubes-gui-agent.service
 
 install-pulseaudio:
 	install -D pulse/start-pulseaudio-with-vchan \
@@ -116,6 +112,10 @@ endif
 	install -m 0644 -D appvm-scripts/etc/xdgautostart/qubes-pulseaudio.desktop \
 		$(DESTDIR)/etc/xdg/autostart/qubes-pulseaudio.desktop
 
+install-systemd:
+	install -m 0644 -D appvm-scripts/qubes-gui-agent.service \
+		$(DESTDIR)/$(SYSLIBDIR)/systemd/system/qubes-gui-agent.service
+
 install-common:
 	install -D gui-agent/qubes-gui $(DESTDIR)/usr/bin/qubes-gui
 	install -D gui-common/qubes-gui-runuser $(DESTDIR)/usr/bin/qubes-gui-runuser
@@ -130,6 +130,10 @@ install-common:
 		$(DESTDIR)/usr/bin/qubes-run-xephyr
 	install -D appvm-scripts/usrbin/qubes-start-xephyr \
 		$(DESTDIR)/usr/bin/qubes-start-xephyr
+	install -D appvm-scripts/usrbin/qubes-run-x11vnc-pre \
+		$(DESTDIR)/usr/bin/qubes-run-x11vnc-pre
+	install -D appvm-scripts/usrbin/qubes-run-x11vnc \
+		$(DESTDIR)/usr/bin/qubes-run-x11vnc
 	install -D appvm-scripts/usrbin/qubes-change-keyboard-layout \
 		$(DESTDIR)/usr/bin/qubes-change-keyboard-layout
 	install -D appvm-scripts/usrbin/qubes-set-monitor-layout \
@@ -142,6 +146,10 @@ install-common:
 		$(DESTDIR)$(LIBDIR)/xorg/modules/drivers/dummyqbs_drv.so
 	install -m 0644 -D appvm-scripts/etc/X11/xorg-qubes.conf.template \
 		$(DESTDIR)/etc/X11/xorg-qubes.conf.template
+	install -m 0644 -D appvm-scripts/etc/X11/xorg-qubes-x11vnc.conf.template \
+		$(DESTDIR)/etc/X11/xorg-qubes-x11vnc.conf.template
+	install -m 0644 -D appvm-scripts/etc/systemd/system/lightdm.service.d/qubes-guivm-vnc.conf \
+		$(DESTDIR)/etc/systemd/system/lightdm.service.d/qubes-guivm-vnc.conf
 	install -m 0644 -D appvm-scripts/etc/profile.d/qubes-gui.sh \
 		$(DESTDIR)/etc/profile.d/qubes-gui.sh
 	install -m 0644 -D appvm-scripts/etc/profile.d/qubes-gui.csh \

appvm-scripts/etc/X11/Xsession.d/50guivm-windows-prefix

@@ -7,6 +7,6 @@
 QUBES_VMNAME="$(qubesdb-read /guivm-windows-prefix)"
 
 # Set _QUBES_VMNAME atom for a window manager (e.g. xfwm4)
-if qsvc guivm-gui-agent; then
+if qsvc guivm; then
     xprop -root -f _QUBES_VMNAME 8s -set _QUBES_VMNAME "${QUBES_VMNAME:-GuiVM}"
-fi
+fi

appvm-scripts/etc/X11/Xsession.d/60xfce-desktop

@@ -3,7 +3,7 @@
 # shellcheck disable=SC1091
 . /usr/lib/qubes/init/functions
 
-if ! qsvc guivm-gui-agent; then
+if ! qsvc guivm; then
 
 XDG_MENU_PREFIX="xfce-"
 export XDG_MENU_PREFIX
@@ -27,4 +27,4 @@ fi
 export QT_QPA_PLATFORMTHEME=qt5ct
 
 xfsettingsd --replace&
-fi
+fi

appvm-scripts/etc/X11/xorg-qubes-x11vnc.conf.template

@@ -0,0 +1,34 @@
+Section "Module"
+    Load "fb"
+EndSection
+
+Section "ServerLayout"
+    Identifier      "Default Layout"
+    Screen          0 "Screen0" 0 0
+EndSection
+
+Section "Device"
+    Identifier      "Videocard0"
+    Driver          "dummyqbs"
+    VideoRam        %MEM%
+    Option          "GUIDomID" "%GUI_DOMID%"
+EndSection
+
+Section "Monitor"
+    Identifier      "Monitor0"
+    HorizSync       %MIN_MAX_HSYNC%
+    VertRefresh     %MIN_MAX_VSYNC%
+%MODELINES%
+    Option          "PreferredMode" "QB1024x768"
+EndSection
+
+Section "Screen"
+    Identifier      "Screen0"
+    Device          "Videocard0"
+	Monitor         "Monitor0"
+    DefaultDepth    %DEPTH%
+    SubSection "Display"
+        Viewport        0 0
+        Depth           %DEPTH%
+    EndSubSection
+EndSection

appvm-scripts/etc/systemd/system/lightdm.service.d/qubes-guivm-vnc.conf

@@ -0,0 +1,6 @@
+[Unit]
+ConditionPathExists=/var/run/qubes-service/lightdm
+
+[Service]
+ExecStartPre=/usr/bin/qubes-run-x11vnc-pre
+ExecStartPost=/usr/bin/qubes-run-x11vnc

appvm-scripts/usrbin/qubes-run-x11vnc

@@ -0,0 +1,26 @@
+#!/bin/sh
+#
+# The Qubes OS Project, http://www.qubes-os.org
+#
+# Copyright (C) 2021  Frédéric Pierret  <[email protected]>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+#
+X11VNC=/usr/bin/x11vnc
+# WIP: Ensure to have the good set of x11vnc options.
+OPTIONS_VNC="-display :0 -auth /var/run/lightdm/root/\:0 -noxrecord -noxfixes -noxdamage -loop"
+
+$X11VNC $OPTIONS_VNC &

appvm-scripts/usrbin/qubes-run-x11vnc-pre

@@ -0,0 +1,112 @@
+#!/bin/bash
+#
+# The Qubes OS Project, http://www.qubes-os.org
+#
+# Copyright (C) 2021  Frédéric Pierret  <[email protected]>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+#
+
+# Source Qubes library.
+# shellcheck disable=SC1091
+. /usr/lib/qubes/init/functions
+
+array_min_max() {
+    read -r -a array <<< "$@"
+    max=${array[0]}
+    min=${array[0]}
+
+    for i in ${array[*]}; do
+      (( i > max )) && max=$i
+      (( i < min )) && min=$i
+    done
+    echo "$min"-"$max"
+}
+
+if qsvc guivm-vnc; then
+    GUI_DOMID="$(qubesdb-read /qubes-gui-domain-xid 2>/dev/null)"
+    MEM_MIN="$(qubesdb-read /qubes-gui-videoram-min 2>/dev/null)"
+    MEM_OVERHEAD="$(qubesdb-read /qubes-gui-videoram-overhead 2>/dev/null)"
+    : "${MEM_MIN:=0}"
+    : "${MEM_OVERHEAD:=$((2560 * 1600 * 4 / 1024))}"
+
+    MEM=$((MEM + MEM_OVERHEAD))
+    if [ $MEM -lt $MEM_MIN ]; then
+        MEM=$MEM_MIN
+    fi
+
+    DUMMY_MAX_CLOCK=300
+    PREFERRED_HSYNC=50
+    DEPTH=24
+
+    HSYNC=()
+    VSYNC=()
+    MODELINES=()
+    RESOLUTIONS="320x240
+    640x480
+    800x600
+    1024x768
+    1152x864
+    1280x1024
+    1400x1050
+    1600x1200
+    2048x1536
+    800x480
+    1366x768
+    1440x900
+    1600x1024
+    1680x1050
+    1920x1200
+    2560x1600
+    1280x720
+    1920x1080"
+
+    for RES in ${RESOLUTIONS[*]};
+    do
+        W=${RES%x*}
+        H=${RES#*x}
+        HTOTAL=$((W+3))
+        VTOTAL=$((H+3))
+        CLOCK=$((PREFERRED_HSYNC*HTOTAL/1000))
+        if [ $CLOCK -gt $DUMMY_MAX_CLOCK ]; then CLOCK=$DUMMY_MAX_CLOCK ; fi
+        MODELINE="$CLOCK $W $((W+1)) $((W+2)) $HTOTAL $H $((H+1)) $((H+2)) $VTOTAL"
+
+        HSYNC_START=$((CLOCK*1000/HTOTAL))
+        HSYNC_END=$((HSYNC_START+1))
+
+        VREFR_START=$((CLOCK*1000000/HTOTAL/VTOTAL))
+        VREFR_END=$((VREFR_START+1))
+
+        HSYNC+=("$HSYNC_START" "$HSYNC_END")
+        VSYNC+=("$VREFR_START" "$VREFR_END")
+        MODELINES+=("    Modeline \"QB$RES\" $MODELINE")
+    done
+
+    ALL_MODELINES="$(printf '%s\\n' "${MODELINES[@]}")"
+    MIN_MAX_HSYNC="$(array_min_max "${HSYNC[@]}")"
+    MIN_MAX_VSYNC="$(array_min_max "${VSYNC[@]}")"
+
+    sed -e s/%MEM%/$MEM/ \
+        -e s/%GUI_DOMID%/"$GUI_DOMID"/ \
+        -e s/%DEPTH%/$DEPTH/ \
+        -e s/%MODELINES%/"$ALL_MODELINES"/ \
+        -e s/%MIN_MAX_HSYNC%/"$MIN_MAX_HSYNC"/ \
+        -e s/%MIN_MAX_VSYNC%/"$MIN_MAX_VSYNC"/ \
+        < /etc/X11/xorg-qubes-x11vnc.conf.template > /etc/X11/xorg.conf
+
+    # 2**30
+    echo 1073741824 > /sys/module/xen_gntalloc/parameters/limit
+fi

appvm-scripts/usrbin/qubes-run-xorg

@@ -24,6 +24,8 @@
 # shellcheck disable=SC1091
 . /usr/lib/qubes/init/functions
 
+## This script is triggered by qubes-gui-agent systemd service.
+
 #expects W, H, MEM and DEPTH env vars to be set by invoker
 DUMMY_MAX_CLOCK=300 #hardcoded in dummy_drv
 PREFERRED_HSYNC=50
@@ -107,7 +109,6 @@ fi
 
 if qsvc guivm-gui-agent; then
     DISPLAY_XORG=:1
-    DISPLAY_XEPHYR=:0
 
     # Create Xorg. Xephyr will be started using qubes-start-xephyr later.
     exec runuser -u "$DEFAULT_USER" -- /bin/sh -l -c "exec $XORG $DISPLAY_XORG -nolisten tcp vt07 -wr -config xorg-qubes.conf > ~/.xorg-errors 2>&1" &

debian/control

@@ -111,3 +111,12 @@ Depends:
     ${misc:Depends}
 Description: XFCE desktop support for Qubes VM
  XFCE desktop support for Qubes VM
+
+Package: qubes-gui-vnc
+Architecture: any
+Depends:
+    x11vnc
+    ${shlibs:Depends},
+    ${misc:Depends}
+Description: Remote GuiVM support using VNC
+ Remote GuiVM support using VNC

debian/qubes-gui-vnc.install

@@ -0,0 +1,4 @@
+usr/bin/qubes-run-x11vnc-pre
+usr/bin/qubes-run-x11vnc
+etc/X11/xorg-qubes-x11vnc.conf.template
+etc/systemd/system/lightdm.service.d/qubes-guivm-vnc.conf

rpm_spec/gui-agent.spec.in

@@ -94,6 +94,13 @@ Summary: XFCE desktop support for Qubes VM
 %description xfce
 XFCE desktop support for Qubes VM
 
+%package -n qubes-gui-vnc
+Summary: Remote GuiVM support using VNC
+Requires: x11vnc
+
+%description -n qubes-gui-vnc
+Remote GuiVM support using VNC
+
 %description
 The Qubes GUI agent that needs to be installed in VM in order to provide the
 Qubes fancy GUI.
@@ -198,5 +205,12 @@ rm -f %{name}-%{version}
 %files xfce
 /etc/X11/xinit/xinitrc.d/60xfce-desktop.sh
 
+%files -n qubes-gui-vnc
+#/lib/systemd/system/qubes-gui-vncserver.service
+%attr(0644,root,root) /etc/X11/xorg-qubes-x11vnc.conf.template
+%attr(0644,root,root) /etc/systemd/system/lightdm.service.d/qubes-guivm-vnc.conf
+/usr/bin/qubes-run-x11vnc-pre
+/usr/bin/qubes-run-x11vnc
+
 %changelog
 @CHANGELOG@