desktop-packages team mailing list archive

[Michael DePaulo <mikedep333@xxxxxxxxx>]

On Sat, Sep 27, 2014 at 6:54 PM, Chris Good <chris.good@xxxxxxxxxxxxxx> wrote:
> Would someone please explain what the problem is in simple terms?
> I thought it was that Unity in Ubuntu 14.04 requires 3D acceleration but if so, why does Unity work when run in VirtualBox without 3D acceleration, and also when run in a VMware VM in a vSphere console?

On Fri, Oct 3, 2014 at 1:33 AM, Eugene San <eugenesan@xxxxxxxxx> wrote:
> chris-good:
> I might be wrong but by 3D acceleration, VM hypervizors usually mean H/W 3D offloading to host GPU.
> Also usually VM para-virtualized drivers support direct rendering and all most X11 extensions which can be used by Mesa (pure software or LLVM-pipe) to simulate 3D.
> Regarding Unity, it uses Compiz which also supports Mesa simulated 3D (at least in recent versions).
> Environments like NX/VNC/RDP and etc, usually lack direct rendering and most X11 extensions therefor 3D simulation is broken.
> It's sad that this fact is ignored by distributions and desktop environments developers and we are enforced to deal with it here :-(

Greetings from an X2Go developer,

This isn't a simple explanation, but it is as simple as I could make
it without losing important details.

On recent Linux distros, llvmpipe can provide software 3D rendering.
However, in order for 3D rendering to work with GNOME3 (and with many
other 3d programs), you *also* need an X server with good enough
support for the GLX extension. The X server needs to support the GLX
extension in the 1st place, and it needs to support a new enough
version of the GLX extension.

The current version of GLX is 1.4. I just checked: Both Ubuntu 12.04
and 14.04 have GLX 1.4 support in their X.org server.

X2Go (whose X server is nxagent 3.5.0.x) only supports GLX 1.2, You
can verify this by running the "glxinfo" command under X2Go. GLX 1.2
is not new enough for GNOME3, and thus X2Go is affected by this bug.

TightVNC 1.3.9-6.4ubuntu1 (in Ubuntu 14.04) is also affected because
it does not support GLX at all. You can verify this by running the
"glxinfo" command under a TightVNC server.

TigerVNC 1.3.0 (in Fedora 20) does support GLX 1.4. Therefore, it is
not affected; you can run GNOME3 under TigerVNC 1.3.0 (and possibly
prior versions.) I just tested this on both a physical Fedora 20
machine with 3D graphics hardware, and on a Fedora 20 VM whose
hypervisor does not provide 3D support.

When you running Ubuntu 12.04 or 14.4 under the VMware vSphere
console, the regular X.org X server is running, and that X server
supports GLX 1.4. VMware vSphere (ESXi) can provide 3D hardware
acceleration under certain setups, but in the absence of 3D, the guest
OS simply uses llvmpipe. In either case, the guest OS thinks the
vSphere console is its "local display".

The composite extension is also a limitation of many X servers. I am
not sure if the version needs to be new enough, or if the extension
simply needs to be present.

-Mike

-- 
You received this bug notification because you are a member of Desktop
Packages, which is subscribed to gnome-session in Ubuntu.
https://bugs.launchpad.net/bugs/1251281

Title:
  gnome-session-flashback fails to start without hardware acceleration
  in cloud/remote environments (Forwarded-X/XRDP/VNC/NX/X2GO/Chromoting)

Status in The GNOME 2 Session Manager:
  New
Status in “gnome-session” package in Ubuntu:
  Triaged

Bug description:
  This bug will cause static grey or black screen instead of openning
  remote session using Forwarded-X/XRDP/VNC/NX/X2GO/Chromoting from
  x2goclient, rdpclient(reminna/vinagre/mstsc), SSH, VNC, NOMACHINE and
  etc.

  1) lsb_release -rd
  Description:	Ubuntu 14.04 LTS
  Release:	14.04

  2) apt-cache policy gnome-session
  gnome-session:
    Installed: 3.9.90-0ubuntu12
    Candidate: 3.9.90-0ubuntu12
    Version table:
   *** 3.9.90-0ubuntu12 0
          500 http://us.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
          100 /var/lib/dpkg/status

  apt-cache policy gnome-session-fallback
  gnome-session-fallback:
    Installed: 1:3.8.0-1ubuntu12.1
    Candidate: 1:3.8.0-1ubuntu12.1
    Version table:
   *** 1:3.8.0-1ubuntu12.1 0
          500 http://us.archive.ubuntu.com/ubuntu/ trusty-updates/universe amd64 Packages
          100 /var/lib/dpkg/status
       1:3.8.0-1ubuntu11 0
          500 http://us.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages

  apt-cache policy xrdp
  xrdp:
    Installed: 0.6.0-1
    Candidate: 0.6.0-1
    Version table:
   *** 0.6.0-1 0
          500 http://us.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages
          100 /var/lib/dpkg/status

  apt-cache policy remmina
  remmina:
    Installed: 1.0.0-4ubuntu3
    Candidate: 1.0.0-4ubuntu3
    Version table:
   *** 1.0.0-4ubuntu3 0
          500 http://us.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
          100 /var/lib/dpkg/status

  apt-cache policy vinagre
  vinagre:
    Installed: 3.10.2-0ubuntu1
    Candidate: 3.10.2-0ubuntu1
    Version table:
   *** 3.10.2-0ubuntu1 0
          500 http://us.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages
          100 /var/lib/dpkg/status

  3) What is expected to happen is when one installs xrdp on the host
  and attempts to use remmina or vinagre on a Ubuntu 14.04 client to RDP
  in, it works.

  4) What happens instead is it shows a gray static screen as per attached screenshot. This would appear an issue with gnome-session as per client log:
  cat .xsession-errors.old
  Script for ibus started at run_im.
  Script for auto started at run_im.
  Script for default started at run_im.
  init: indicator-application main process ended, respawning
  init: indicator-application main process ended, respawning
  init: indicator-application respawning too fast, stopped
  Xsession: X session started for  at Sun Jul 20 15:25:59 CDT 2014
  X Error of failed request:  BadValue (integer parameter out of range for operation)
    Major opcode of failed request:  109 (X_ChangeHosts)
    Value in failed request:  0x5
    Serial number of failed request:  6
    Current serial number in output stream:  8
  localuser:moniker being added to access control list
  X Error of failed request:  BadValue (integer parameter out of range for operation)
    Major opcode of failed request:  109 (X_ChangeHosts)
    Value in failed request:  0x5
    Serial number of failed request:  6
    Current serial number in output stream:  8
  Script for ibus started at run_im.
  Script for auto started at run_im.
  Script for default started at run_im.
  Script for ibus started at run_im.
  Script for auto started at run_im.
  Script for default started at run_im.
  gnome-session-is-accelerated: No composite extension.
  gnome-session-check-accelerated: Helper exited with code 256
  gnome-session-is-accelerated: No composite extension.
  gnome-session-check-accelerated: Helper exited with code 256

  ** (process:2565): WARNING **: software acceleration check failed:
  Child process exited with code 1

  ** (x-session-manager:2565): CRITICAL **: We failed, but the fail
  whale is dead. Sorry....

  The following is not a WORKAROUND, create /etc/xorg.conf :
  Section "Device"
     Identifier  "Intel Graphics"
     Driver      "Intel"
     Option      "DRI" "False"
  EndSection

  ProblemType: Bug
  DistroRelease: Ubuntu 14.04
  Package: gnome-session 3.9.90-0ubuntu12
  ProcVersionSignature: Ubuntu 3.13.0-32.57-generic 3.13.11.4
  Uname: Linux 3.13.0-32-generic x86_64
  ApportVersion: 2.14.1-0ubuntu3.2
  Architecture: amd64
  CurrentDesktop: Unity
  Date: Sun Jul 20 15:35:23 2014
  InstallationDate: Installed on 2014-06-22 (28 days ago)
  InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
  PackageArchitecture: all
  SourcePackage: gnome-session
  UpgradeStatus: No upgrade log present (probably fresh install)

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