What you are essentially trying to do is create a PV interface to access the x86 emulator. Why not use a simple hypercall (VMCALL) to accomplish this instead of inventing yet another PV method? Something like “KVM_HC_EMULATE_NEXT_INSTRUCTION” in kvm_emulate_hypercall should do the trick (however it needs to be placed before the check for CPL>0 so that user mode code can test the emulator too). Nikita > On 27 Mar 2018, at 11:26, Liran Alon <liran.alon@xxxxxxxxxx> wrote: > > > ----- pbonzini@xxxxxxxxxx wrote: > >> On 27/03/2018 09:52, Liran Alon wrote: >>> In addition, I think this module parameter should be in kvm module >>> (not kvm_intel) and you should add similar logic to kvm_amd module >> (SVM) >> >> If you can move handle_ud to x86.c, then it makes sense to have the >> module parameter in the kvm module. I haven't checked. > > I don't see a reason why you couldn't do that. > >> >> Otherwise you would have to EXPORT_SYMBOL_GPL the variable; in the > > This is what I did for enable_vmware_backdoor module parameter. > I think this is what should be done in this case as-well. > >> end >> it's just a debugging tool, so it'd be simpler to just add it >> separately >> to kvm_intel and kvm_amd. > > I agree it's just a debugging tool. But no reason for it to be used differently > when running tests on Intel CPU vs. AMD CPU. > I think the effort to fix this is low. > >> >> Paolo > >
