Spice performance HORRIBLE

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)
...