Messages in this thread Patch in this message | | | Date | Fri, 17 Sep 2021 09:28:41 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v2 00/13] perf: KVM: Fix, optimize, and clean up callbacks |
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On Thu, Sep 16, 2021 at 09:37:43PM +0000, Sean Christopherson wrote: > On Sat, Aug 28, 2021, Peter Zijlstra wrote:
> Argh, sorry, I somehow managed to miss all of your replies. I'll get back to > this series next week. Thanks for the quick response! > > > Lets keep the whole intel_pt crud inside x86... > > In theory, I like the idea of burying intel_pt inside x86 (and even in > Intel+VMX code for the most part), but the actual implementation is a > bit gross. Because of the whole "KVM can be a module" thing,
ARGH!! we should really fix that. I've heard other archs have made much better choices here.
> either > the static call and __static_call_return0 would need to be exported, > or a new register/unregister pair would have to be exported.
So I don't mind exporting __static_call_return0, but exporting a raw static_call is much like exporting a function pointer :/
> The unregister path would also need its own synchronize_rcu(). In general, I > don't love duplicating the logic, but it's not the end of the world. > > Either way works for me. Paolo or Peter, do either of you have a preference?
Can we de-feature kvm as a module and only have this PT functionality when built-in? :-)
> > --- > > Index: linux-2.6/arch/x86/events/core.c > > =================================================================== > > --- linux-2.6.orig/arch/x86/events/core.c > > +++ linux-2.6/arch/x86/events/core.c > > @@ -92,7 +92,7 @@ DEFINE_STATIC_CALL_RET0(x86_pmu_guest_ge > > > > DEFINE_STATIC_CALL_RET0(x86_guest_state, *(perf_guest_cbs->state)); > > DEFINE_STATIC_CALL_RET0(x86_guest_get_ip, *(perf_guest_cbs->get_ip)); > > -DEFINE_STATIC_CALL_RET0(x86_guest_handle_intel_pt_intr, *(perf_guest_cbs->handle_intel_pt_intr)); > > +DEFINE_STATIC_CALL_RET0(x86_guest_handle_intel_pt_intr, unsigned int (*)(void)); > > FWIW, the param needs to be a raw function, not a function pointer.
Yeah, I keep making that mistake.. and I wrote the bloody thing :/
I have a 'fix' for that, but I need to finish that and also flag-day change :-(
https://lkml.kernel.org/r/YS+0eIeAJsRRArk4@hirez.programming.kicks-ass.net
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