Dor Laor wrote: >> On Tue, 2007-06-26 at 11:02 +0800, Dong, Eddie wrote: >>> Greg/Dor: >>> When thinking to merge APIC device model with PIC, a curious >>> question: Where does the code base come from? Xen or Qemu? I found >>> there are many diff from Xen (even excluding name difference). >>> Eddie >> >> I am fairly certain it originated in Xen (which might have >> originated in Qemu??) but there have been many many changes since >> then. I know Dor at least did all the porting to Linux (including >> the hrtimer work). I then ported it to the irqdevice model and >> reworked a good amount of the code. Between the two I am sure you >> will see lots of diffs from the original Xen code. >> >> -Greg > > As Greg mentioned, the base code (lapic.c) is Xen based. I also > stated it clearly in file header. > > Regarding merging it with mainline, if the AMD problems are over (as I > think they are) we can do it. There is one point regarding migration, > currently the apic state is not saved, it should be fixed. The irqdev > state should be also serialized.
Like we discussed in the PIC patch thread, we need to use the new user/kernel I/Fs which fixed the ABI holes in V09. We discussed part of the irq injection path, the basic conclusion so far is that we should not use push_back mechanism which makes an architecture hole in PIC/APIC state when an irq is pushed back. But yes they are not difficult to fix. But I just think why we need the irqdevice which occupy half of the patch in size and make life not very easy? (Yes it has the advantage to provide a good abstraction.) So I have 2 choices: 1: Port PIC to APIC patch which will use irqdevice abstraction layer and V09 irq injection path + bug fix mentioned above. 2: Port APIC to PIC patch (have above mentioned issue fixed) which eliminates irqdevice abstraction layer. We can discuss the abstraction layer in future if we want, but we can start from simple. IMO #2 is a little bit easier from effort point of view, but I am not sure what is the decision and up to the community. Or if somebody else are willing to do the merge, I will be very happy to dig other problems. > Avi should say his final word and he is lecturing in the OLS > convention. > > Oh, I just discovered old code of mine that handles apic save/restore. > I'm attaching the patch, its old and won't apply on the current > sources but it worked in the old days... > > Btw, you guys are doing fantastic, important job. Kudos ;) ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
