Hi, in the last days I reused my work on L4RTEMS to do a quick and dirty test of the new virtualization layer.
The implementation -which isn't working yet- showed, that we the i386/virtualpok BSP is a very good point to start, but the vCPU interface of L4Re brings it's own dependencies which must be added to include/ and in Makefile.am. I also had to extend the virtualizationalyerbsp.h file with these includes and a structure shared between L4Re and RTEMS. This struct accommodates a vCPU and console capability and a pointer to the vCPU state. They are filled in at start up by L4Re and can then be used by RTEMS. The take away are two things: First, we might end up with an own BSP for each hypervisor. Second, as far as I can see now, they only differ in aspects of the layer, not in the drivers using the layer. The code isn't on github yet, as I am short on time and have to sort things out first. The obstacle at the moment is to create a library in L4Re, which includes all L4Re dependencies and has only a few undefined references, which can be resolved by RTEMS. Cheers Philipp On 09/20/2013 09:22 AM, Philipp Eppelt wrote: > Hi, > > what did I do in my project? > > I designed and implemented a virtualization layer, which should ease the > virtualization of RTEMS across different hypervisors. > To test the layer and because of the ARINC 653 compliance POK was chosen > as a proof-of-concept host OS. > > The project was a partial success. The layer is designed, implemented > and a BSP is using it, and it is at least partially working. > I didn't succeed in changing POK so it can forward interrupts to > partitions reliably. But this is an POK related issue, which I think > won't be an issue on a host OS providing a vCPU abstraction. Also > implementing this for other architectures might be easier than for x86. > > A console is printing hello World and sometimes under some circumstances > the base_sp sample printed output, too. But the latter is not reliable. > > I have documented my efforts, including implementation issues, GDB traps > and where I left off on the wiki page [0]. > Also explanations on how to port the i386/virtualpok BSP to other > hypervisors and how to port this approach to other architectures can be > found there. The latter is pretty abstract, as I don't know much about > the other architectures(arm, ppc, sparc). > > I provide two patches: > * Split of the i386 CPU between score/cpu and libcpu. The interrupt > handling was moved to libcpu and two new CPU variants were introduced > there: Native and virtual. The native one works like before but the > virtual one calls the virtualization layer instead of executing cli,sti > or hlt. The list of affected functions is documented in the wiki[0]. > BUT: This patch won't be merged, as includes in cpukit from libcpu > aren't allowed (but it works). But before the discussion about a new > configuration option isn't finished and the option is implemented there > is no other way to achieve this. > > * A new i386 BSP is introduced: virtualpok. It is the corresponding BSP > to the virtual i386 CPU model and brings along the virtualization layer > as two header files in it's include/ directory. A console driver, clock > driver and IRQ management is implemented and as far as possible tested > on POK. > > > If you have questions on the work, I'd be happy to answer them. > > Cheers, > Philipp > > [0] > http://wiki.rtems.org/wiki/index.php/GSOC_2013_-_Paravirtualization_of_RTEMS > _______________________________________________ > rtems-devel mailing list > [email protected] > http://www.rtems.org/mailman/listinfo/rtems-devel > _______________________________________________ rtems-devel mailing list [email protected] http://www.rtems.org/mailman/listinfo/rtems-devel
