[Qemu-devel] [RFC PATCH] Allow building without graphics support

[Scott Wood]

QEMU is sometimes used in embedded contexts, where graphical support
is unnecessary.  The ability to turn off graphics support not only
saves some space, but it eliminates the dependency on pixman.

Signed-off-by: Scott Wood <address@hidden>
---
There are undoubtedly some rough edges that need to be cleaned up and
other parts of graphics code that could be compiled out -- this is mainly
meant to see what people think of the concept.

My immediate motivation was that the QEMU-supplied pixman was being a
pain to cross compile (especially without hacking up the generated QEMU
makefiles to pass additional things to pixman's configure), and in
general it would be nice to not have to carry around graphical baggage
when running on hardware that doesn't even have a display (so I was more
inclined to do this than to spend effort fixing the pixman build).
---
 Makefile.objs    |    7 +++++--
 configure        |   26 +++++++++++++++++++++++++-
 console.h        |    4 ++++
 hw/Makefile.objs |    4 ++++
 no-console.c     |    8 ++++++++
 qemu-char.c      |    2 ++
 qemu-pixman.c    |    1 +
 qemu-pixman.h    |    4 ++++
 ui/Makefile.objs |    2 ++
 ui/vnc.h         |    4 ++++
 vl.c             |   14 ++++++++++++--
 11 files changed, 71 insertions(+), 5 deletions(-)
 create mode 100644 no-console.c

diff --git a/Makefile.objs b/Makefile.objs
index 3c7abca..360500d 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -68,8 +68,11 @@ endif
 common-obj-y = $(block-obj-y) blockdev.o blockdev-nbd.o block/
 common-obj-y += net.o net/
 common-obj-y += qom/
-common-obj-y += readline.o console.o cursor.o
-common-obj-y += qemu-pixman.o
+common-obj-y += readline.o
+common-obj-$(CONFIG_GRAPHICS) += console.o cursor.o qemu-pixman.o
+ifneq ($(CONFIG_GRAPHICS),y)
+common-obj-y += no-console.o
+endif
 common-obj-y += $(oslib-obj-y)
 common-obj-$(CONFIG_WIN32) += os-win32.o
 common-obj-$(CONFIG_POSIX) += os-posix.o
diff --git a/configure b/configure
index 38b1cc6..6cb73e6 100755
--- a/configure
+++ b/configure
@@ -223,6 +223,7 @@ libiscsi=""
 coroutine=""
 seccomp=""
 glusterfs=""
+graphics="yes"
 
 # parse CC options first
 for opt do
@@ -880,6 +881,14 @@ for opt do
   ;;
   --enable-glusterfs) glusterfs="yes"
   ;;
+  --disable-graphics)
+    graphics="no"
+    vnc="no"
+    spice="no"
+    curses="no"
+  ;;
+  --enable-graphics) graphics="yes"
+  ;;
   *) echo "ERROR: unknown option $opt"; show_help="yes"
   ;;
   esac
@@ -1128,6 +1137,8 @@ echo "  --with-coroutine=BACKEND coroutine backend. 
Supported options:"
 echo "                           gthread, ucontext, sigaltstack, windows"
 echo "  --enable-glusterfs       enable GlusterFS backend"
 echo "  --disable-glusterfs      disable GlusterFS backend"
+echo "  --enable-graphics        enable graphics support (default)"
+echo "  --disable-graphics       disable graphics support"
 echo ""
 echo "NOTE: The object files are built at the place where configure is 
launched"
 exit 1
@@ -2126,6 +2137,14 @@ fi
 ##########################################
 # pixman support probe
 
+if test "$graphics" = "no"; then
+  pixman="not needed"
+  if test "$vnc" = "yes" -o "$spice" = "yes"; then
+    echo "ERROR: graphics disabled but vnc or spice enabled"
+    exit 1
+  fi
+fi
+
 if test "$pixman" = ""; then
   if $pkg_config --atleast-version=0.18.4 pixman-1 > /dev/null 2>&1; then
     pixman="system"
@@ -2136,7 +2155,7 @@ fi
 if test "$pixman" = "system"; then
   pixman_cflags=`$pkg_config --cflags pixman-1 2>/dev/null`
   pixman_libs=`$pkg_config --libs pixman-1 2>/dev/null`
-else
+elif test "$pixman" != "not needed"; then
   if test ! -d ${source_path}/pixman/pixman; then
     echo "ERROR: pixman not present (or older than 0.18.4). Your options:"
     echo "  (1) Preferred: Install the pixman devel package (any recent"
@@ -3257,6 +3276,7 @@ echo "build guest agent $guest_agent"
 echo "seccomp support   $seccomp"
 echo "coroutine backend $coroutine_backend"
 echo "GlusterFS support $glusterfs"
+echo "graphics          $graphics"
 
 if test "$sdl_too_old" = "yes"; then
 echo "-> Your SDL version is too old - please upgrade to have SDL support"
@@ -3603,6 +3623,10 @@ if test "$glusterfs" = "yes" ; then
   echo "CONFIG_GLUSTERFS=y" >> $config_host_mak
 fi
 
+if test "$graphics" = "yes" ; then
+  echo "CONFIG_GRAPHICS=y" >> $config_host_mak
+fi
+
 # USB host support
 case "$usb" in
 linux)
diff --git a/console.h b/console.h
index 50a0512..49d8469 100644
--- a/console.h
+++ b/console.h
@@ -120,8 +120,10 @@ struct PixelFormat {
 };
 
 struct DisplaySurface {
+#ifdef CONFIG_GRAPHICS
     pixman_format_code_t format;
     pixman_image_t *image;
+#endif
     uint8_t flags;
 
     struct PixelFormat pf;
@@ -340,6 +342,7 @@ static inline bool dpy_cursor_define_supported(struct 
DisplayState *s)
     return false;
 }
 
+#ifdef CONFIG_GRAPHICS
 static inline int ds_get_linesize(DisplayState *ds)
 {
     return pixman_image_get_stride(ds->surface->image);
@@ -401,6 +404,7 @@ static inline int ds_get_bmask(DisplayState *ds)
 {
     return ds->surface->pf.bmask;
 }
+#endif
 
 #ifdef CONFIG_CURSES
 #include <curses.h>
diff --git a/hw/Makefile.objs b/hw/Makefile.objs
index d581d8d..6297759 100644
--- a/hw/Makefile.objs
+++ b/hw/Makefile.objs
@@ -127,12 +127,14 @@ common-obj-y += sysbus.o isa-bus.o
 common-obj-y += qdev-addr.o
 
 # VGA
+ifeq ($(CONFIG_GRAPHICS), y)
 common-obj-$(CONFIG_VGA_PCI) += vga-pci.o
 common-obj-$(CONFIG_VGA_ISA) += vga-isa.o
 common-obj-$(CONFIG_VGA_ISA_MM) += vga-isa-mm.o
 common-obj-$(CONFIG_VMWARE_VGA) += vmware_vga.o
 common-obj-$(CONFIG_VMMOUSE) += vmmouse.o
 common-obj-$(CONFIG_VGA_CIRRUS) += cirrus_vga.o
+endif
 
 common-obj-$(CONFIG_RC4030) += rc4030.o
 common-obj-$(CONFIG_DP8393X) += dp8393x.o
@@ -200,7 +202,9 @@ obj-$(CONFIG_SOFTMMU) += vhost_net.o
 obj-$(CONFIG_VHOST_NET) += vhost.o
 obj-$(CONFIG_REALLY_VIRTFS) += 9pfs/
 obj-$(CONFIG_NO_PCI) += pci-stub.o
+ifeq ($(CONFIG_GRAPHICS), y)
 obj-$(CONFIG_VGA) += vga.o
+endif
 obj-$(CONFIG_SOFTMMU) += device-hotplug.o
 obj-$(CONFIG_XEN) += xen_domainbuild.o xen_machine_pv.o
 
diff --git a/no-console.c b/no-console.c
new file mode 100644
index 0000000..f4e418f
--- /dev/null
+++ b/no-console.c
@@ -0,0 +1,8 @@
+#include "qemu-common.h"
+#include "error.h"
+#include "qmp-commands.h"
+
+void qmp_screendump(const char *filename, Error **errp)
+{
+  error_setg(errp, "device doesn't support screendump\n");
+}
diff --git a/qemu-char.c b/qemu-char.c
index 242b799..e488e2c 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -2735,7 +2735,9 @@ static const struct {
     { .name = "socket",    .open = qemu_chr_open_socket },
     { .name = "udp",       .open = qemu_chr_open_udp },
     { .name = "msmouse",   .open = qemu_chr_open_msmouse },
+#ifdef CONFIG_GRAPHICS
     { .name = "vc",        .open = text_console_init },
+#endif
 #ifdef _WIN32
     { .name = "file",      .open = qemu_chr_open_win_file_out },
     { .name = "pipe",      .open = qemu_chr_open_win_pipe },
diff --git a/qemu-pixman.c b/qemu-pixman.c
index e46e180..821a525 100644
--- a/qemu-pixman.c
+++ b/qemu-pixman.c
@@ -3,6 +3,7 @@
  * See the COPYING file in the top-level directory.
  */
 
+#include "qemu-common.h"
 #include "qemu-pixman.h"
 
 int qemu_pixman_get_type(int rshift, int gshift, int bshift)
diff --git a/qemu-pixman.h b/qemu-pixman.h
index bee55eb..0844816 100644
--- a/qemu-pixman.h
+++ b/qemu-pixman.h
@@ -6,6 +6,8 @@
 #ifndef QEMU_PIXMAN_H
 #define QEMU_PIXMAN_H
 
+#ifdef CONFIG_GRAPHICS
+
 #include <pixman.h>
 
 #include "console.h"
@@ -36,4 +38,6 @@ pixman_image_t 
*qemu_pixman_mirror_create(pixman_format_code_t format,
                                           pixman_image_t *image);
 void qemu_pixman_image_unref(pixman_image_t *image);
 
+#endif /* CONFIG_GRAPHICS */
+
 #endif /* QEMU_PIXMAN_H */
diff --git a/ui/Makefile.objs b/ui/Makefile.objs
index adc07be..91cca0b 100644
--- a/ui/Makefile.objs
+++ b/ui/Makefile.objs
@@ -8,7 +8,9 @@ vnc-obj-y += vnc-jobs.o
 
 common-obj-y += keymaps.o
 common-obj-$(CONFIG_SPICE) += spice-core.o spice-input.o spice-display.o
+ifeq ($(CONFIG_GRAPHICS),y)
 common-obj-$(CONFIG_SDL) += sdl.o sdl_zoom.o x_keymap.o
+endif
 common-obj-$(CONFIG_COCOA) += cocoa.o
 common-obj-$(CONFIG_CURSES) += curses.o
 common-obj-$(CONFIG_VNC) += $(vnc-obj-y)
diff --git a/ui/vnc.h b/ui/vnc.h
index 6141e88..60b19cd 100644
--- a/ui/vnc.h
+++ b/ui/vnc.h
@@ -41,6 +41,8 @@
 #include "vnc-palette.h"
 #include "vnc-enc-zrle.h"
 
+#ifdef CONFIG_VNC
+
 // #define _VNC_DEBUG 1
 
 #ifdef _VNC_DEBUG
@@ -560,4 +562,6 @@ int vnc_zrle_send_framebuffer_update(VncState *vs, int x, 
int y, int w, int h);
 int vnc_zywrle_send_framebuffer_update(VncState *vs, int x, int y, int w, int 
h);
 void vnc_zrle_clear(VncState *vs);
 
+#endif
+
 #endif /* __QEMU_VNC_H */
diff --git a/vl.c b/vl.c
index a3ab384..5679db3 100644
--- a/vl.c
+++ b/vl.c
@@ -180,8 +180,14 @@ int main(int argc, char **argv)
 static const char *data_dir;
 const char *bios_name = NULL;
 enum vga_retrace_method vga_retrace_method = VGA_RETRACE_DUMB;
+
+#ifdef CONFIG_GRAPHICS
 DisplayType display_type = DT_DEFAULT;
 static int display_remote;
+#else
+DisplayType display_type = DT_NOGRAPHIC;
+#endif
+
 const char* keyboard_layout = NULL;
 ram_addr_t ram_size;
 const char *mem_path = NULL;
@@ -2532,7 +2538,9 @@ int main(int argc, char **argv, char **envp)
     const char *initrd_filename;
     const char *kernel_filename, *kernel_cmdline;
     char boot_devices[33] = "cad"; /* default to HD->floppy->CD-ROM */
+#ifdef CONFIG_GRAPHICS
     DisplayState *ds;
+#endif
     int cyls, heads, secs, translation;
     QemuOpts *hda_opts = NULL, *opts, *machine_opts;
     QemuOptsList *olist;
@@ -3887,6 +3895,7 @@ int main(int argc, char **argv, char **envp)
 
     net_check_clients();
 
+#ifdef CONFIG_GRAPHICS
     /* just use the first displaystate for the moment */
     ds = get_displaystate();
 
@@ -3927,7 +3936,7 @@ int main(int argc, char **argv, char **envp)
     default:
         break;
     }
-
+#endif /* CONFIG_GRAPHICS */
     /* must be after terminal init, SDL library changes signal handlers */
     os_setup_signal_handling();
 
@@ -3954,9 +3963,10 @@ int main(int argc, char **argv, char **envp)
         qemu_spice_display_init(ds);
     }
 #endif
-
+#ifdef CONFIG_GRAPHICS
     /* display setup */
     text_consoles_set_display(ds);
+#endif
 
     if (foreach_device_config(DEV_GDB, gdbserver_start) < 0) {
         exit(1);
-- 
1.7.9.5