On Thu, 2007-06-21 at 22:28 +0800, Dong, Eddie wrote: > > > I suppose, but it somewhat defeats the purpose IMO. Every pin in the > > 8259 that gets tickled implicitly means an IOAPIC pin was tickled > > also. Do we really want to go to userspace for that? Essentially > > User space can handle this, go to IOAPIC first and then decide to go to > in kernel PIC or not. Here the assumption is that an irq line is either > serviced > by PIC or IOAPIC, it will never be serviced by both. > > So no back to user space.
Yeah, I suppose if we adopt that optimization from Xen/Qemu that is true. The design in my head is trying to emulate the actual signal path in hardware so it gets dispatched to both models. I suppose you can get away with a shortcut like that here (though I don't really love the idea ;). I think it comes down to the decision, like you said. If we go with IOAPIC in the kernel, just route to both like I am thinking. If we leave it in userspace, optimize the context switch away for performance reasons. -Greg ------------------------------------------------------------------------- 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
