* Jeremy Fitzhardinge (jeremy@xxxxxxxx) wrote: > Chris Wright wrote: > > Consistently wrap paravirt ops callsites > > "ugh" - mingo > > Had a thought. What if we do a kind of reverse/two-way module linkage? > Somehow compile each pv-op implementation like a module, and then link > the appropriate one in at boot time. This is very similar to something Steve was chatting with me about this morning. The idea he was tossing around was something a bit like an initrd that a load_module analog could link up. In a sense, it's similar to the VMI ROM, with the exceptions that the ABI is just created by the compiler from a normal mutable kernel API and it's linkage with symbols available on both sides. > Tricky parts: it would need two-way unresolved references between kernel > and module, and it would need to be able to run very early in the > kernel's life. This is the tricky part, and where Steve and I left off. > It would also limit us to plain old calls rather than > any inlining (though that could be done separately). > > On the upside, it removes pv_ops, and it might simplify the question of > how normal module exports work, since by that time they would just be > normal kernel functions. All the calls would be normal direct calls > rather than indirect. And it would allow us to free the memory for the > unused pv-ops backends. I suspect we could free the unused backends already. It also has one negative side-effect, which is promoting external module code that links with the kernel. IOW, there's much less incentive to get code merged if it's just a matter of linking. thanks, -chris _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
