Computer Tech

Microsoft and its GPL Hyper-V drivers

Considering the lack of general attention this has received in the media, Nick asked me to blog on this topic and set a time-line. So here goes:

  • Microsoft first announced they were releasing the Hyper-V drivers as GPL code on the 20th of July 2009. Note this is an announcement and not the actual release. These drivers allow Linux guests running on top of Hyper-V to bypass emulation of I/O functions and talk to the hypervisor directly ( ie. paravirtualisation ), thereby increasing performance. There is some speculation that this move was as a result of possible GPL infringements in the LinuxIC code.
  • On the 5th of August, Thorsten Leemhuis from H-Online blogged that the LinuxIC drivers would be part of the upcoming 2.6.32 kernel release.
  • 10th Sept., the Hyper-V drivers are listed for inclusion in the kernel staging area. Greg Kroah-Hartman says that the staging area is not a dumping ground for dead code. “If no one steps up to maintain and work to get the code merged into the main portion of the kernel, the drivers will be removed”. A fly in the ointment for the Hyper-V drivers is that they may be removed in Linux 2.6.33, after a lack of response from the Microsoft developers concerning maintenance.
  • Microsoft responds to comments from Greg regarding the Hyper-V drivers, saying that work has not stopped on the drivers first released in July. Sam Ramji, Microsoft’s Open Source director, says that they are continuing to work hard on the drivers and that these are still scheduled for inclusion in the 2.6.32 kernel.
  • Thorsten blogs that the drivers are now part of the staging area as of 20th Sept. and that they are not likely to be removed as a result of Microsoft’s renewed vigour with regards to ongoing development of these.
  • The Hyper-V drivers remain in the staging area of 2.6.32 as of the 28th Sept. for further development.