On 21.07.2016 15:46, Laurent Vivier wrote: > > > On 21/07/2016 15:16, Thomas Huth wrote: >> On 21.07.2016 12:12, Laurent Vivier wrote: >>> As userfaultfd syscall is available on powerpc, migration >>> postcopy can be used. >> >> Good idea to add this test for PPC, too! > > The idea comes from David Gilbert :) > Thanks David! > >> >>> This patch adds the support needed to test this on powerpc, >>> instead of using a bootsector to run code to modify memory, >>> we use a FORTH script in "boot-command" property. >>> >>> As spapr machine doesn't support "-prom-env" argument >>> (the nvram is initialized by SLOF and not by QEMU), >>> "boot-command" is provided to SLOF via a file mapped nvram >>> (with "-drive file=...,if=pflash") >> >> I wonder whether we could easily add support for the "-prom-env" >> parameter for the sPAPR machine, too, since the NVRAM layout seems to be >> pretty much the same as on the old CHRP Mac machines...? > > The only thing we need to have "-prom-env" is to initialize the nvram > partitions in QEMU if they don't exist. > > I didn't follow this way because this work is normally to be done by the > firmware not by QEMU. If we do it in QEMU, SLOF will do not, and we > can't be sure we are doing the things well, as SLOF does.
I'm slightly familiar with the NVRAM code in SLOF ... shouldn't be too hard to get a similar layout done with QEMU, especially if we can re-use some of the OpenBIOS NVRAM functions in QEMU. > On Mac, it is another history, originally, firmware was OpenHackware, > not OpenBIOS, and OH was only here to allow to boot the kernel nothing > more (it was really a hack: there was not forth interpreter [oh, my god!]). > So all the important stuffs were done by QEMU, like to initialize the > NVRAM, the PCI bus, ... and this allows to set values in the environment > variables. > > But if you think it is viable, it should be really easy to do (like > cut'n'paste from OpenBIOS ABI)... Having -prom-env for SLOF, too, would be really posh, so I think I'll have a try when I got some spare minutes ... hmm, my TODO list seems to keep rather growing than shrinking ... maybe I'm doing something wrong ;-) Thomas
