VirtIO-GPU 3D OpenGL Hardware Acceleration for VMs
randrianasulu at gmail.com
Wed Feb 17 07:10:32 UTC 2016
I tried to test virtGL on nouveau, and found few surprizes.
First, new quemu (commit commit a5af12871fd4601c44f08d9e49131e9ca13ef102, Merge
remote-tracking branch 'remotes/sstabellini/tags/xen-2016-02-12' into staging)
failed to link wih gcc 4.9 if I specified -march=i486, switching to -march=i686
fixed this. I found this solution while search for specific error message:
error message in my case was "undefined reference to `__atomic_load_8' "
Second, I found my Xserver (1.12.4 patched with some patches from later
Xservers, excluding most of glx stuff) was too old, for host side. Qemu just
crashed at the moment guest loaded drm driver. Upgrading to 1.18.1 fixed this,
but I assume anything from 1.13.0 should be minimally enough ? (due to
GLX_ARB_create_context, GLX_ARB_create_context_profile stuff)
Next, I found even 1.18.1 by default builds without glamor support. There was
configure swicth --enable-glamor, but it was, unlike dri3 stuff, off by
default. Switching it on allowed guest to finally have 3d as in working
glxinfo. glxgears still segfaulted. making /dev/shm user (ok, world-) writable
fixed this. Found by strace-ing glxgears, and launching glxgears from root,
where it worked. DRI3 stuff on host, where I also tried it, segfaulted
similary, but I can live with DRI2/EXA here, especially because nouveau still
have issues with glamor/modesetting, on both nv50, and nvc0, as I was told on
I also tried few MESA debug environment variables in attttempt to get rid of
artefacts inside VM, but sadly they remained there.
ESA_EXTENSION_MAX_YEAR=2001 ./x86_64-softmmu/qemu-system-x86_64 -cdrom /home/admin/slaxdvd-4.5.0-x64-test.iso -m
512 -display sdl,gl=on -enable-kvm -soundhw es1370 -usb -vga virtio -usbdevice
mouse -cpu host
for example not resulted in any improvements.
MESA_GL_VERSION_OVERRIDE=3.0 and any version below (on host) resulted, like with
old X server, in crashed qemu:
gl_version 0 - compat profile
WARNING: running without ARB robustness in place may crash
qemu-system-x86_64: Couldn't find current GLX or EGL context.
(note gl_version 0 thing - libepoxy bug? I use 1.3.1)
So, I assume right now host 3D driver must support OpenGL 3.1 or up?
#nouveau log from 16-02-2016:
I hope it will help someone!
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