Description: Can't start Xorg anymore.

Additional info:

extra/xf86-input-evdev 2.9.2-1
extra/xf86-video-fbdev 0.4.4-4
extra/xf86-video-vesa 2.3.2-6
extra/xorg-bdftopcf 1.0.5-1
extra/xorg-font-util 1.3.1-1
extra/xorg-font-utils 7.6-4
extra/xorg-fonts-100dpi 1.0.3-2
extra/xorg-fonts-75dpi 1.0.3-2
extra/xorg-fonts-alias 1.0.3-1
extra/xorg-fonts-encodings 1.0.4-4
extra/xorg-fonts-misc 1.0.3-3
extra/xorg-iceauth 1.0.7-1
extra/xorg-mkfontdir 1.0.7-2
extra/xorg-mkfontscale 1.1.2-1
extra/xorg-server 1.17.1-4
extra/xorg-server-common 1.17.1-4
extra/xorg-setxkbmap 1.3.0-2
extra/xorg-xauth 1.0.9-1
extra/xorg-xinit 1.3.4-2
extra/xorg-xkbcomp 1.3.0-1
extra/xorg-xrdb 1.1.0-1
extra/xorg-xset 1.2.3-1

Log file:

[ 776.947] X Protocol Version 11, Revision 0
[ 776.949] Build Operating System: Linux 3.18.6-1-ARCH i686
[ 776.951] Current Operating System: Linux mini32 3.19.2-1-ARCH #1 SMP PREEMPT Wed Mar 18 16:36:01 CET 2015 i686
[ 776.951] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-linux root=UUID=a652f9bf-304a-4b05-b8a7-e75e6b7cf4d3 rw
[ 776.955] Build Date: 14 March 2015 06:47:44PM
[ 776.957]
[ 776.959] Current version of pixman: 0.32.6
[ 776.962] Before reporting problems, check http://wiki.x.org
to make sure that you have the latest version.
[ 776.962] Markers: (--) probed, (**) from config file, (==) default setting,
(++) from command line, (!!) notice, (II) informational,
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[ 776.968] (==) Log file: "/home/davide/.local/share/xorg/Xorg.0.log", Time: Sun Mar 29 15:22:36 2015
[ 776.970] (==) Using system config directory "/usr/share/X11/xorg.conf.d"
[ 776.970] (==) No Layout section. Using the first Screen section.
[ 776.970] (==) No screen section available. Using defaults.
[ 776.970] (**) |-->Screen "Default Screen Section" (0)
[ 776.970] (**) | |-->Monitor "<default monitor>"
[ 776.970] (==) No monitor specified for screen "Default Screen Section".
Using a default monitor configuration.
[ 776.971] (==) Automatically adding devices
[ 776.971] (==) Automatically enabling devices
[ 776.971] (==) Automatically adding GPU devices
[ 776.971] (WW) `fonts.dir' not found (or not valid) in "/usr/share/fonts/OTF/".
[ 776.971] Entry deleted from font path.
[ 776.971] (Run 'mkfontdir' on "/usr/share/fonts/OTF/").
[ 776.971] (==) FontPath set to:
/usr/share/fonts/misc/,
/usr/share/fonts/TTF/,
/usr/share/fonts/Type1/,
/usr/share/fonts/100dpi/,
/usr/share/fonts/75dpi/
[ 776.971] (==) ModulePath set to "/usr/lib/xorg/modules"
[ 776.971] (II) The server relies on udev to provide the list of input devices.
If no devices become available, reconfigure udev or disable AutoAddDevices.
[ 776.971] (II) Loader magic: 0x829e700
[ 776.971] (II) Module ABI versions:
[ 776.971] X.Org ANSI C Emulation: 0.4
[ 776.971] X.Org Video Driver: 19.0
[ 776.971] X.Org XInput driver : 21.0
[ 776.971] X.Org Server Extension : 9.0
[ 776.973] (II) systemd-logind: took control of session /org/freedesktop/login1/session/c1
[ 776.973] (II) xfree86: Adding drm device (/dev/dri/card0)
[ 776.974] (II) systemd-logind: got fd for /dev/dri/card0 226:0 fd 8 paused 0
[ 776.977] (--) PCI:*(0:0:2:0) 1234:1111:1af4:1100 rev 0, Mem @ 0xfd000000/16777216, 0xfebd0000/4096, BIOS @ 0x????????/65536
[ 776.977] (WW) Open ACPI failed (/var/run/acpid.socket) (No such file or directory)
[ 776.977] (II) LoadModule: "glx"
[ 776.977] (II) Loading /usr/lib/xorg/modules/extensions/libglx.so
[ 776.979] (II) Module glx: vendor="X.Org Foundation"
[ 776.979] compiled for 1.17.1, module version = 1.0.0
[ 776.979] ABI class: X.Org Server Extension, version 9.0
[ 776.979] (==) AIGLX enabled
[ 776.979] (==) Matched modesetting as autoconfigured driver 0
[ 776.979] (==) Matched fbdev as autoconfigured driver 1
[ 776.979] (==) Matched vesa as autoconfigured driver 2
[ 776.979] (==) Assigned the driver to the xf86ConfigLayout
[ 776.979] (II) LoadModule: "modesetting"
[ 776.979] (II) Loading /usr/lib/xorg/modules/drivers/modesetting_drv.so
[ 776.979] (II) Module modesetting: vendor="X.Org Foundation"
[ 776.979] compiled for 1.17.1, module version = 1.17.1
[ 776.979] Module class: X.Org Video Driver
[ 776.979] ABI class: X.Org Video Driver, version 19.0
[ 776.979] (II) LoadModule: "fbdev"
[ 776.979] (II) Loading /usr/lib/xorg/modules/drivers/fbdev_drv.so
[ 776.979] (II) Module fbdev: vendor="X.Org Foundation"
[ 776.980] compiled for 1.17.0, module version = 0.4.4
[ 776.980] Module class: X.Org Video Driver
[ 776.980] ABI class: X.Org Video Driver, version 19.0
[ 776.980] (II) LoadModule: "vesa"
[ 776.980] (II) Loading /usr/lib/xorg/modules/drivers/vesa_drv.so
[ 776.980] (II) Module vesa: vendor="X.Org Foundation"
[ 776.980] compiled for 1.17.0, module version = 2.3.2
[ 776.980] Module class: X.Org Video Driver
[ 776.980] ABI class: X.Org Video Driver, version 19.0
[ 776.980] (II) modesetting: Driver for Modesetting Kernel Drivers: kms
[ 776.980] (II) FBDEV: driver for framebuffer: fbdev
[ 776.980] (II) VESA: driver for VESA chipsets: vesa
[ 776.980] (++) using VT number 1

[ 776.980] (--) controlling tty is VT number 1, auto-enabling KeepTty
[ 776.980] xf86EnableIOPorts: failed to set IOPL for I/O (Operation not permitted)
[ 776.980] (II) modeset(0): using drv /dev/dri/card0
[ 776.980] (WW) Falling back to old probe method for fbdev
[ 776.980] (II) Loading sub module "fbdevhw"
[ 776.980] (II) LoadModule: "fbdevhw"
[ 776.980] (II) Loading /usr/lib/xorg/modules/libfbdevhw.so
[ 776.981] (II) Module fbdevhw: vendor="X.Org Foundation"
[ 776.981] compiled for 1.17.1, module version = 0.0.2
[ 776.981] ABI class: X.Org Video Driver, version 19.0
[ 776.981] (WW) Falling back to old probe method for vesa
[ 776.981] (WW) VGA arbiter: cannot open kernel arbiter, no multi-card support
[ 776.981] (II) modeset(0): Creating default Display subsection in Screen section
"Default Screen Section" for depth/fbbpp 24/32
[ 776.981] (==) modeset(0): Depth 24, (==) framebuffer bpp 32
[ 776.981] (==) modeset(0): RGB weight 888
[ 776.981] (==) modeset(0): Default visual is TrueColor
[ 776.981] (II) Loading sub module "glamoregl"
[ 776.981] (II) LoadModule: "glamoregl"
[ 776.981] (II) Loading /usr/lib/xorg/modules/libglamoregl.so
[ 776.988] (II) Module glamoregl: vendor="X.Org Foundation"
[ 776.988] compiled for 1.17.1, module version = 1.0.0
[ 776.988] ABI class: X.Org ANSI C Emulation, version 0.4
[ 776.988] (II) glamor: OpenGL accelerated X.org driver based.
[ 777.031] (II) glamor: EGL version 1.4 (DRI2):
[ 777.031] EGL_MESA_drm_image required.
[ 777.031] (EE) modeset(0): glamor initialization failed
[ 777.031] (II) modeset(0): ShadowFB: preferred NO, enabled NO
[ 777.031] (II) modeset(0): Output Virtual-0 has no monitor section
[ 777.031] (II) modeset(0): EDID for output Virtual-0
[ 777.031] (II) modeset(0): Printing probed modes for output Virtual-0
[ 777.031] (II) modeset(0): Modeline "1024x768"x60.0 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync (48.4 kHz eP)
[ 777.031] (II) modeset(0): Modeline "1600x1200"x60.0 162.00 1600 1664 1856 2160 1200 1201 1204 1250 +hsync +vsync (75.0 kHz e)
[ 777.031] (II) modeset(0): Modeline "1680x1050"x60.0 146.25 1680 1784 1960 2240 1050 1053 1059 1089 -hsync +vsync (65.3 kHz e)
[ 777.031] (II) modeset(0): Modeline "1680x1050"x59.9 119.00 1680 1728 1760 1840 1050 1053 1059 1080 +hsync -vsync (64.7 kHz e)
[ 777.031] (II) modeset(0): Modeline "1400x1050"x60.0 121.75 1400 1488 1632 1864 1050 1053 1057 1089 -hsync +vsync (65.3 kHz e)
[ 777.031] (II) modeset(0): Modeline "1400x1050"x59.9 101.00 1400 1448 1480 1560 1050 1053 1057 1080 +hsync -vsync (64.7 kHz e)
[ 777.031] (II) modeset(0): Modeline "1280x1024"x60.0 108.00 1280 1328 1440 1688 1024 1025 1028 1066 +hsync +vsync (64.0 kHz e)
[ 777.031] (II) modeset(0): Modeline "1440x900"x59.9 106.50 1440 1520 1672 1904 900 903 909 934 -hsync +vsync (55.9 kHz e)
[ 777.031] (II) modeset(0): Modeline "1440x900"x59.9 88.75 1440 1488 1520 1600 900 903 909 926 +hsync -vsync (55.5 kHz e)
[ 777.031] (II) modeset(0): Modeline "1280x960"x60.0 108.00 1280 1376 1488 1800 960 961 964 1000 +hsync +vsync (60.0 kHz e)
[ 777.031] (II) modeset(0): Modeline "1360x768"x60.0 85.50 1360 1424 1536 1792 768 771 777 795 +hsync +vsync (47.7 kHz e)
[ 777.031] (II) modeset(0): Modeline "1280x800"x59.8 83.50 1280 1352 1480 1680 800 803 809 831 +hsync -vsync (49.7 kHz e)
[ 777.031] (II) modeset(0): Modeline "1280x800"x59.9 71.00 1280 1328 1360 1440 800 803 809 823 +hsync -vsync (49.3 kHz e)
[ 777.031] (II) modeset(0): Modeline "1280x768"x59.9 79.50 1280 1344 1472 1664 768 771 778 798 -hsync +vsync (47.8 kHz e)
[ 777.031] (II) modeset(0): Modeline "1280x768"x60.0 68.25 1280 1328 1360 1440 768 771 778 790 +hsync -vsync (47.4 kHz e)
[ 777.031] (II) modeset(0): Modeline "800x600"x60.3 40.00 800 840 968 1056 600 601 605 628 +hsync +vsync (37.9 kHz e)
[ 777.031] (II) modeset(0): Modeline "800x600"x56.2 36.00 800 824 896 1024 600 601 603 625 +hsync +vsync (35.2 kHz e)
[ 777.031] (II) modeset(0): Modeline "848x480"x60.0 33.75 848 864 976 1088 480 486 494 517 +hsync +vsync (31.0 kHz e)
[ 777.031] (II) modeset(0): Modeline "640x480"x59.9 25.18 640 656 752 800 480 489 492 525 -hsync -vsync (31.5 kHz e)
[ 777.031] (II) modeset(0): Output Virtual-0 connected
[ 777.031] (II) modeset(0): Using exact sizes for initial modes
[ 777.031] (II) modeset(0): Output Virtual-0 using initial mode 1024x768
[ 777.031] (II) modeset(0): Using default gamma of (1.0, 1.0, 1.0) unless otherwise stated.
[ 777.031] (==) modeset(0): DPI set to (96, 96)
[ 777.031] (II) Loading sub module "fb"
[ 777.031] (II) LoadModule: "fb"
[ 777.031] (II) Loading /usr/lib/xorg/modules/libfb.so
[ 777.032] (II) Module fb: vendor="X.Org Foundation"
[ 777.032] compiled for 1.17.1, module version = 1.0.0
[ 777.032] ABI class: X.Org ANSI C Emulation, version 0.4
[ 777.032] (II) UnloadModule: "fbdev"
[ 777.032] (II) Unloading fbdev
[ 777.032] (II) UnloadSubModule: "fbdevhw"
[ 777.032] (II) Unloading fbdevhw
[ 777.032] (II) UnloadModule: "vesa"
[ 777.032] (II) Unloading vesa
[ 777.032] (==) Depth 24 pixmap format is 32 bpp
[ 777.032] (==) modeset(0): Backing store enabled
[ 777.032] (==) modeset(0): Silken mouse enabled
[ 777.032] (II) modeset(0): RandR 1.2 enabled, ignore the following RandR disabled message.
[ 777.032] (==) modeset(0): DPMS enabled
[ 777.034] (--) RandR disabled
[ 777.041] (II) AIGLX: Screen 0 is not DRI2 capable
[ 777.041] (EE) AIGLX: reverting to software rendering
[ 777.042] (II) AIGLX: Loaded and initialized swrast
[ 777.042] (II) GLX: Initialized DRISWRAST GL provider for screen 0
[ 777.043] (EE)
Fatal server error:
[ 777.043] (EE) failed to create screen resources(EE)
[ 777.043] (EE)
Please consult the The X.Org Foundation support
at http://wiki.x.org
for help.
[ 777.043] (EE) Please also check the log file at "/home/persson/.local/share/xorg/Xorg.0.log" for additional information.
[ 777.043] (EE)
[ 777.047] (EE) Server terminated with error (1). Closing log file.

I have neither an xorg.conf file, nor fragments of it.
I'm not sure what broke it, since I upgraded lots of packages at once. Last time I used it (about two months ago) it was working.
This happens in a KVM virtual machine using the standard VGA virtual video adapter:

00:02.0 VGA compatible controller: Device 1234:1111 (prog-if 00 [VGA controller])
Subsystem: Red Hat, Inc Device 1100
Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
Latency: 0
Region 0: Memory at fd000000 (32-bit, prefetchable) [size=16M]
Region 2: Memory at febd0000 (32-bit, non-prefetchable) [size=4K]
Expansion ROM at febc0000 [disabled] [size=64K]
Kernel driver in use: bochs-drm
Kernel modules: bochs_drm

My user is member of all possible groups:

$ groups
tty disk mem kmem wheel log locate proc lock dbus network video audio optical storage scanner input power users polkitd colord systemd-journal systemd-network persson


Steps to reproduce:

startx