Looks like Microsoft releases the Linux drivers to enable a Linux kernel running as a guest in a Hyper-V hypervisor to run in ‘enlightened mode’, which sounds pretty much like Xen‘s PV drivers for Windows, providing better IO performance, under the GPLv2 (which is the same open-source license as the Linux kernel itself). Quoting the Hyper-V Architecture and Feature Overview:
Enlightened I/O is a specialized virtualization-aware implementation of high level communication protocols (such as SCSI) that utilize the VMBus directly, bypassing any device emulation layer. This makes the communication more efficient but requires an enlightened guest that is hypervisor and VMBus aware.
The drivers seem to be developed by Novell, so I guess the Boycott Novell guys will have some more coverage^Wrants soon (Update: can’t find the reference on this anymore, so this might be a false statement, sorry. Thanks for pointing out RubenV)
Interesting times on the virtualization front… Although I for one do not plan to replace Xen, xVM or VirtualBox anytime soon.
Sources:
On a side note: Red Hat entered the Standard & Poor’s 500 index, which might show Linux is gaining more interest from enterprises and investors.
So those are kernel drivers, right? So tell me which other license they shall have chosen for kernel drivers? AFAIK usung another license but GPL (and maybe BSD – IANAL) is grey area and asking for trouble when it comes to kernel drivers.
Kernel drivers indeed. Non-GPL kernel drivers are written anyway, although being discouraged, obviously. That’s why the kernel has both EXPORT_SYMBOL and EXPORT_SYMBOL_GPL macros, check an LWN article related to this.
in your link from lkml we can read:
“(…) thank the following
people who made this possible:
– (…)
– Novell for sponsoring my work on the Linux Driver project, without
which, this would not have even been possible.
(…)”
I think Greg is the person that novell is sponsoring to develop kernel drivers “for free”, n resquest from vendors.
“This saga started when one of the user’s on the Vyatta forum inquired about supporting Hyper-V network driver in the Vyatta kernel. A little googling6 found the necessary drivers, but on closer examination there was a problem. The driver had both open-source components which were under GPL, and statically linked to several binary parts. The GPL does not permit mixing of closed and open source parts, so this was an obvious violation of the license. Rather than creating noise, my goal was to resolve the problem, so I turned to Greg Kroah-Hartman7. Since Novell has a (too) close association with Microsoft, my expectation was that Greg could prod the right people to get the issue resolved.”
From here:
http://linux-network-plumber.blogspot.com/2009/07/congratulations-microsoft.html
You should’ve looked at the patches, looks like MS couldn’t let go of its coding style conventions and follow the Linux kernel coding style