On Mon, Apr 06, 2020 at 03:09:51PM -0400, Vivek Goyal wrote: > On Mon, Mar 09, 2020 at 09:22:15PM +0100, Peter Zijlstra wrote: > > On Mon, Mar 09, 2020 at 08:05:18PM +0100, Thomas Gleixner wrote: > > > Andy Lutomirski <luto@xxxxxxxxxx> writes: > > > > > > I'm okay with the save/restore dance, I guess. It's just yet more > > > > entry crud to deal with architecture nastiness, except that this > > > > nastiness is 100% software and isn't Intel/AMD's fault. > > > > > > And we can do it in C and don't have to fiddle with it in the ASM > > > maze. > > > > Right; I'd still love to kill KVM_ASYNC_PF_SEND_ALWAYS though, even if > > we do the save/restore in do_nmi(). That is some wild brain melt. Also, > > AFAIK none of the distros are actually shipping a PREEMPT=y kernel > > anyway, so killing it shouldn't matter much. > > It will be nice if we can retain KVM_ASYNC_PF_SEND_ALWAYS. I have another > use case outside CONFIG_PREEMPT. > > I am trying to extend async pf interface to also report page fault errors > to the guest. Then please start over and design a sane ParaVirt Fault interface. The current one is utter crap.
