On Sat, Aug 16, 2014 at 11:51:46PM -0700, Philip Guenther wrote: > On Wed, Jul 9, 2014 at 12:26 PM, Stefan Fritsch <[email protected]> wrote: > > > On Tuesday 08 July 2014 23:53:21, Mark Kettenis wrote: > > > ... > > > > If we're serious about supporting OpenBSD on (KVM) hypervisors, > > > something like this makes sense. We tend to try and have a single > > > kernel that runs on the widest range of hardware that is possible. > > > For example the OpenBSD/sparc64 kernel runs on both sun4u and sun4v > > > hardware, and the sun4v platforms has written paravirtualization all > > > over it. There I successfully made use of code patching > > > techniques. That might help on x86 as well. > > > > Yes, code patching may be useful. I haven't noticed it used in openbsd > > before, but I will take a look at sparc64. > > > > Code patching is used currently on i386 and amd64 for the SMAP support. > Grep for _copyin_stac, for example.
Now if only Intel would actually release a processor with SMAP... sparc also does patching for "fast" v8 mul/div/rem, search for ireplace in sys/arch/sparc/sparc/cpu.c
