So, yes that (arbiter) line is present even when I remove xf86-video-qxl
and it still works. It also seems to use the modesetting driver:
[ 122.015] (==) Matched qxl as autoconfigured driver 0
[ 122.015] (==) Matched modesetting as autoconfigured driver 1
[ 122.015] (==) Matched fbdev as autoconfigured driver 2
[ 122.015] (==) Matched vesa as autoconfigured driver 3
[ 122.015] (==) Assigned the driver to the xf86ConfigLayout
[ 122.015] (II) LoadModule: "qxl"
[ 122.015] (WW) Warning, couldn't open module qxl
[ 122.015] (EE) Failed to load module "qxl" (module does not exist, 0)
[ 122.015] (II) LoadModule: "modesetting"
[ 122.015] (II) Loading /usr/lib/xorg/modules/drivers/modesetting_drv.so
[ 122.017] (II) Module modesetting: vendor="X.Org Foundation"
[ 122.017] compiled for 1.21.1.3, module version = 1.21.1
[ 122.017] Module class: X.Org Video Driver
[ 122.017] ABI class: X.Org Video Driver, version 25.2
[ 122.017] (II) LoadModule: "fbdev"
[ 122.017] (WW) Warning, couldn't open module fbdev
[ 122.017] (EE) Failed to load module "fbdev" (module does not exist, 0)
[ 122.017] (II) LoadModule: "vesa"
[ 122.017] (WW) Warning, couldn't open module vesa
[ 122.017] (EE) Failed to load module "vesa" (module does not exist, 0)
[ 122.017] (II) modesetting: Driver for Modesetting Kernel Drivers: kms
[ 122.017] (II) modeset(0): using drv /dev/dri/card0
[ 122.017] (WW) VGA arbiter: cannot open kernel arbiter, no multi-card support
[ 122.017] (II) modeset(0): Creating default Display subsection in Screen section
"Default Screen Section" for depth/fbbpp 24/32
[ 122.017] (==) modeset(0): Depth 24, (==) framebuffer bpp 32
[ 122.017] (==) modeset(0): RGB weight 888
[ 122.017] (==) modeset(0): Default visual is TrueColor
[ 122.017] (II) Loading sub module "glamoregl"
[ 122.017] (II) LoadModule: "glamoregl"
[ 122.017] (II) Loading /usr/lib/xorg/modules/libglamoregl.so
[ 122.020] (II) Module glamoregl: vendor="X.Org Foundation"
[ 122.020] compiled for 1.21.1.3, module version = 1.0.1
[ 122.020] ABI class: X.Org ANSI C Emulation, version 0.4
[ 122.036] (II) modeset(0): Refusing to try glamor on llvmpipe
[ 122.037] (II) modeset(0): glamor initialization failed
[ 122.037] (II) modeset(0): ShadowFB: preferred NO, enabled NO
[ 122.037] (II) modeset(0): Output Virtual-1 has no monitor section
[ 122.037] (II) modeset(0): Output Virtual-2 has no monitor section
[ 122.037] (II) modeset(0): Output Virtual-3 has no monitor section
[ 122.037] (II) modeset(0): Output Virtual-4 has no monitor section
[ 122.037] (II) modeset(0): EDID for output Virtual-1
[ 122.037] (II) modeset(0): Printing probed modes for output Virtual-1
[ 122.037] (II) modeset(0): Modeline "1024x768"x60.0 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync (48.4 kHz eP)
...