In response to a Phoronix Forums thread about using VIA graphics under Linux on an old laptop, a Phoronix reader shared he had working VIA Linux graphics. The reported configuration was Lubuntu 12.10 with an ASRock PVR530 motherboard that boasts VX900 / Chrome 9 graphics.
As proof of his working VIA Linux graphics configuration, he posted a screenshot that showed the contents of his system details as detected by the Phoronix Test Suite. The system shows a VIA C7-D processor with the PVR530 motherboard and VIA VX900 (Chrome 9 HD) graphics running from Ubuntu 12.10 with the Linux 3.5 kernel and there's accelerated support. What's interesting is that the VIA 3D driver is provided by Mesa 7.11 and is Gallium3D-based!
After seeing this VIA Gallium3D driver mentioned in the forum thread and receiving an email about it, I checked it out. On the VIA Linux portal is a "Unified GFX driver" for Ubuntu 12.10 that supports VIA VX800 and VX900 hardware.
The driver is labelled, "Unified GFX Driver v92-006-75396_TTM_KMS_Xserver [x86 & x64] (13 Mar 2013) (21.4M)." When exploring this driver package from the middle of March, there's 32-bit and 64-bit binary blobs for Mesa 7.11 and Mesa 8.1 (what became known as Mesa 9.0). The driver package also includes the X.Org Server bits and builds upon earlier TTM+KMS work. VIA says that the driver supports X.Org 7.6, hardware video overlays with X-Video, 2D hardware acceleration by UXA, and can handle RandR 1.3.
The Mesa components are binary-only and consist of the libGL.so.1.2 and via_chrome9_dri.so along with the via_drv.so DDX file in the same directory. There's also "VIA Chrome 9 TTM" patches that are said to be able to be applied from Linux 3.4 to Linux 3.6 kernels. The kernel bits are the only open-source parts of the VIA driver package.
Next up was downloading the "126.96.36.199-006-75396-20130304" source package for the driver. The source bits for the X.Org Server include UXA and the VIA 2D driver bits. The TTM kernel bits have separate directories for the Linux 2.6.32, 2.6.37, and 3.4 to 3.6 kernels. There's also a simple VIA user guide bundled in. There isn't any source code pertaining to this VIA Gallium3D Chrome 9 driver.
So it seems since at least the middle of March there is a VIA Gallium3D driver that works on Ubuntu 12.10 as tested by a Phoronix reader, but this driver stack isn't open-source. Also don't expect VIA to proactively update the Mesa blob for newer releases. There isn't yet any re-build of the Chrome 9 driver for Mesa 9.1 or any Git snapshots and using VIA graphics on Linux will still likely result in much pain and suffering.