On 27/03/2018 11:05, Nikita Leshenko wrote: > 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? Because hypercalls force you to use %rax for the hypercall number. Paolo > 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