Hi,
I'm trying to use vSGA with a modified GTX 480 to Quadro 6000, the nvidia module gets loaded but xorg won't start 
I used this guide to softmod the GTX 480 into a Quadro 6000: http://www.davidgis.fr/blog/index.php?2013/09/18/969-xen-430-vga-passthrough-gtx-480-soft-moded-to-quadro-6000
This is my Xorg.log :
2013-12-29T04:34:57Z Xorg[35150]: unix:0
X.Org X Server 1.10.4
2013-12-29T04:34:57Z Xorg[35150]: unix:0
Release Date: 2011-08-19
2013-12-29T04:34:57Z Xorg[35150]: unix:0 X Protocol Version 11, Revision 0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 Build Operating System: Linux 2.6.18-308.8.1.el5 x86_64
2013-12-29T04:34:57Z Xorg[35150]: unix:0 Current Operating System: VMkernel esx.azar.pt 5.5.0 #1 SMP Release build-1331820 Sep 18 2013 23:08:31 x86_64
2013-12-29T04:34:57Z Xorg[35150]: unix:0 Build Date: 26 June 2013 12:34:22PM
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 Current version of pixman: 0.23.1
2013-12-29T04:34:57Z Xorg[35150]: unix:0 Before reporting problems, check http://wiki.x.org
to make sure that you have the latest version.
2013-12-29T04:34:57Z Xorg[35150]: unix:0 Markers:
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (--) probed,
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (**) from config file,
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (==) default setting,
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (++) from command line,
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (!!) notice,
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) informational,
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (WW) warning,
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (EE) error,
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (NI) not implemented,
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (??) unknown.
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (++) Using config file: "/etc/X11/xorg.conf.nvidia0"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (==) ServerLayout "VMware Configured"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (**) |-->Screen "Screen0" (0)
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (**) | |-->Monitor "Monitor0"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (**) | |-->Device "Card0"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (**) |-->Input Device "Mouse0"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (**) |-->Input Device "Keyboard0"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (==) Not automatically adding devices
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (==) Not automatically enabling devices
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (WW) xf86ReadBIOS: Failed to open /dev/mem (No such file or directory)
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (WW) The directory "/usr/share/fonts/X11/misc/" does not exist.
2013-12-29T04:34:57Z Xorg[35150]: unix:0 Entry deleted from font path.
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (WW) The directory "/usr/share/fonts/X11/TTF/" does not exist.
2013-12-29T04:34:57Z Xorg[35150]: unix:0 Entry deleted from font path.
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (WW) The directory "/usr/share/fonts/X11/OTF/" does not exist.
2013-12-29T04:34:57Z Xorg[35150]: unix:0 Entry deleted from font path.
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (WW) The directory "/usr/share/fonts/X11/Type1/" does not exist.
2013-12-29T04:34:57Z Xorg[35150]: unix:0 Entry deleted from font path.
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (WW) The directory "/usr/share/fonts/X11/100dpi/" does not exist.
2013-12-29T04:34:57Z Xorg[35150]: unix:0 Entry deleted from font path.
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (WW) The directory "/usr/share/fonts/X11/75dpi/" does not exist.
2013-12-29T04:34:57Z Xorg[35150]: unix:0 Entry deleted from font path.
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (==) FontPath set to:
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (**) ModulePath set to "/usr/lib/xorg/nvidia,/usr/lib/xorg/modules"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loader magic: 0x764250
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Module ABI versions:
2013-12-29T04:34:57Z Xorg[35150]: unix:0 X.Org ANSI C Emulation: 0.4
2013-12-29T04:34:57Z Xorg[35150]: unix:0 X.Org Video Driver: 10.0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 X.Org XInput driver : 12.2
2013-12-29T04:34:57Z Xorg[35150]: unix:0 X.Org Server Extension : 5.0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (--) PCI: (0:1:0:0) 10de:06d8:10de:075f
2013-12-29T04:34:57Z Xorg[35150]: unix:0 rev 163
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (--) PCI: (0:10:6:0) 1002:5c61:1002:0002
2013-12-29T04:34:57Z Xorg[35150]: unix:0 rev 1
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (WW) Open ACPI failed (/var/run/acpid.socket) (No such file or directory)
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) LoadModule: "extmod"
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading /usr/lib/xorg/modules/extensions/libextmod.so
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Module extmod: vendor="X.Org Foundation"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 compiled for 1.10.4
2013-12-29T04:34:57Z Xorg[35150]: unix:0 , module version = 1.0.0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 Module class: X.Org Server Extension
2013-12-29T04:34:57Z Xorg[35150]: unix:0 ABI class: X.Org Server Extension, version 5.0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading extension XVideo
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading extension XVideo-MotionCompensation
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading extension X-Resource
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) LoadModule: "glx"
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading /usr/lib/xorg/modules/extensions/libglx.so
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Module glx: vendor="NVIDIA Corporation"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 compiled for 4.0.2
2013-12-29T04:34:57Z Xorg[35150]: unix:0 , module version = 1.0.0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 Module class: X.Org Server Extension
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) NVIDIA GLX Module 319.65 Wed Oct 9 23:12:23 PDT 2013
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading extension GLX
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) LoadModule: "dri"
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading /usr/lib/xorg/modules/extensions/libdri.so
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Module dri: vendor="X.Org Foundation"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 compiled for 1.10.4
2013-12-29T04:34:57Z Xorg[35150]: unix:0 , module version = 1.0.0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 ABI class: X.Org Server Extension, version 5.0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading extension XFree86-DRI
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) LoadModule: "dri2"
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading /usr/lib/xorg/modules/extensions/libdri2.so
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Module dri2: vendor="X.Org Foundation"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 compiled for 1.10.4
2013-12-29T04:34:57Z Xorg[35150]: unix:0 , module version = 1.2.0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 ABI class: X.Org Server Extension, version 5.0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading extension DRI2
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) LoadModule: "gpu"
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading /usr/lib/xorg/modules/extensions/libgpu.so
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Module gpu: vendor="VMware, Inc."
2013-12-29T04:34:57Z Xorg[35150]: unix:0 compiled for 1.10.4
2013-12-29T04:34:57Z Xorg[35150]: unix:0 , module version = 0.4.0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 ABI class: X.Org Server Extension, version 5.0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading extension VMwareGPUResourceManager
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) LoadModule: "nvidia"
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading /usr/lib/xorg/modules/drivers/nvidia_drv.so
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Module nvidia: vendor="NVIDIA Corporation"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 compiled for 4.0.2
2013-12-29T04:34:57Z Xorg[35150]: unix:0 , module version = 1.0.0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 Module class: X.Org Video Driver
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) LoadModule: "void"
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading /usr/lib/xorg/modules/input/void_drv.so
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Module void: vendor="X.Org Foundation"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 compiled for 1.10.4
2013-12-29T04:34:57Z Xorg[35150]: unix:0 , module version = 1.4.0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 Module class: X.Org XInput Driver
2013-12-29T04:34:57Z Xorg[35150]: unix:0 ABI class: X.Org XInput driver, version 12.2
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) NVIDIA dlloader X Driver 319.65 Wed Oct 9 22:53:25 PDT 2013
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) NVIDIA Unified Driver for all Supported NVIDIA GPUs
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (++) using VT number 1
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading sub module "fb"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) LoadModule: "fb"
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading /usr/lib/xorg/modules/libfb.so
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Module fb: vendor="X.Org Foundation"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 compiled for 1.10.4
2013-12-29T04:34:57Z Xorg[35150]: unix:0 , module version = 1.0.0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 ABI class: X.Org ANSI C Emulation, version 0.4
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading sub module "wfb"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) LoadModule: "wfb"
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading /usr/lib/xorg/modules/libwfb.so
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Module wfb: vendor="X.Org Foundation"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 compiled for 1.10.4
2013-12-29T04:34:57Z Xorg[35150]: unix:0 , module version = 1.0.0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 ABI class: X.Org ANSI C Emulation, version 0.4
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading sub module "shadow"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) LoadModule: "shadow"
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (WW) Warning, couldn't open module shadow
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) UnloadModule: "shadow"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Unloading shadow
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (EE) Failed to load module "shadow" (module does not exist, 0)
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (WW) NVIDIA: Failed to load the shadow module, NoAccel mode will fallback to using fb mode
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading sub module "ramdac"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) LoadModule: "ramdac"
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Module "ramdac" already built-in
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading /usr/lib/xorg/modules/drivers/nvidia_drv.so
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading /usr/lib/xorg/modules/libwfb.so
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (II) Loading /usr/lib/xorg/modules/libfb.so
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (WW) VGA arbiter: cannot open kernel arbiter, no multi-card support
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (==) NVIDIA(0): Depth 24,
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (==) framebuffer bpp 32
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (==) NVIDIA(0): RGB weight 888
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (==) NVIDIA(0): Default visual is TrueColor
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (==) NVIDIA(0): Using gamma correction (1.0, 1.0, 1.0)
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (**) NVIDIA(0): Option "RegistryDwords"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 "MachineCacheLimit=1024"
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (**) NVIDIA(0): Option "IndirectMemoryAccess"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 "FALSE"
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (**) NVIDIA(0): Option "UseDisplayDevice"
2013-12-29T04:34:57Z Xorg[35150]: unix:0 "none"
2013-12-29T04:34:57Z Xorg[35150]: unix:0
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (**) NVIDIA(0): Enabling 2D acceleration
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (**) NVIDIA(0): Option "UseDisplayDevice" set to "none"; enabling NoScanout
2013-12-29T04:34:57Z Xorg[35150]: unix:0 (**) NVIDIA(0): mode
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (II) NVIDIA(0): NVIDIA GPU Quadro 6000 (GF100GL) at PCI:1:0:0 (GPU-0)
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) NVIDIA(0): Memory: 1572864 kBytes
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) NVIDIA(0): VideoBIOS: 70.00.21.00.02
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (II) NVIDIA(0): Detected PCI Express Link width: 16X
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) NVIDIA(0): Valid display device(s) on Quadro 6000 at PCI:1:0:0
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) NVIDIA(0): CRT-0
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) NVIDIA(0): CRT-1
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) NVIDIA(0): DFP-0
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) NVIDIA(0): DFP-1
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) NVIDIA(0): DFP-2
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) NVIDIA(0): CRT-0: 400.0 MHz maximum pixel clock
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) NVIDIA(0): CRT-1: 400.0 MHz maximum pixel clock
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) NVIDIA(0): DFP-0: 330.0 MHz maximum pixel clock
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) NVIDIA(0): DFP-0: Internal Single Link TMDS
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) NVIDIA(0): DFP-1: 165.0 MHz maximum pixel clock
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) NVIDIA(0): DFP-1: Internal Single Link TMDS
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) NVIDIA(0): DFP-2: 330.0 MHz maximum pixel clock
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) NVIDIA(0): DFP-2: Internal Single Link TMDS
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (II) NVIDIA(0): Validated MetaModes:
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (II) NVIDIA(0): "nvidia-auto-select"
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (II) NVIDIA(0): Virtual screen size determined to be 640 x 480
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (WW) NVIDIA(0): Unable to get display device for DPI computation.
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (==) NVIDIA(0): DPI set to (75, 75); computed from built-in default
2013-12-29T04:34:58Z Xorg[35150]: unix:0 (--) Depth 24 pixmap format is 32 bpp
2013-12-29T04:35:01Z Xorg[35150]: unix:0 (EE) NVIDIA(GPU-0): Failed to initialize DMA.
2013-12-29T04:35:01Z Xorg[35150]: unix:0 (EE) *** Aborting ***
2013-12-29T04:35:01Z Xorg[35150]: unix:0
Fatal server error:
2013-12-29T04:35:01Z Xorg[35150]: unix:0 AddScreen/ScreenInit failed for driver 0
2013-12-29T04:35:01Z Xorg[35150]: unix:0
2013-12-29T04:35:01Z Xorg[35150]: unix:0
Please contact VMware for support regarding this error.
Anyone has any idea?