On Tuesday 12 August 2014 04:49 PM, Alexander Graf wrote: > > On 12.08.14 07:17, Madhavan Srinivasan wrote: >> On Monday 11 August 2014 02:45 PM, Alexander Graf wrote: >>> On 11.08.14 10:51, Benjamin Herrenschmidt wrote: >>>> On Mon, 2014-08-11 at 09:26 +0200, Alexander Graf wrote: >>>>>> diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c >>>>>> index da86d9b..d95014e 100644 >>>>>> --- a/arch/powerpc/kvm/emulate.c >>>>>> +++ b/arch/powerpc/kvm/emulate.c >>>>> This should be book3s_emulate.c. >>>> Any reason we can't make that 00dddd00 opcode as breakpoint common to >>>> all powerpc variants ? >>> I can't think of a good reason. We use a hypercall on booke (which traps >>> into an illegal instruction for pr) today, but I don't think it has to >>> be that way. >>> >>> Given that the user space API allows us to change it dynamically, there >>> should be nothing blocking us from going with 00dddd00 always. >>> >> Kindly correct me if i am wrong. So we can still have a common code in >> emulate.c to set the env for both HV and pr incase of illegal >> instruction (i will rebase latest src). But suggestion here to use >> 00dddd00, in that case current path in embed is kvmppc_handle_exit >> (booke.c) -> BOOKE_INTERRUPT_HV_PRIV -> emulation_exit -> >> kvmppc_emulate_instruction, will change to kvmppc_handle_exit (booke.c) >> -> BOOKE_INTERRUPT_PROGRAM -> if debug instr call emulation_exit else >> send to guest? > > I can't follow your description above. > My bad. > With the latest git version HV KVM does not include emulate.c anymore. > > Also, it would make a lot of sense of have the same soft breakpoint > instruction across all ppc targets, so it would make sense to change it > to 0x00dddd00 for booke as well. > Got it. Was describing the current control flow with respect to booke and where changes needed (for same software breakpoint inst). This is for my understanding and wanted verify. kvmppc_handle_exit(booke.c) -> BOOKE_INTERRUPT_HV_PRIV -> emulation_exit ->kvmppc_emulate_instruction Incase of using the same software breakpoint instruction (0x00dddd00), then we need to add code in booke something like this kvmppc_handle_exit (booke.c) -> BOOKE_INTERRUPT_PROGRAM -> if debug instr ->emulation_exit else ->send to guest? > Basically you would have handling code in emulate.c and book3s_hv.c at > the end of the day. > Yes. Will resend the patch with updated code. > > Alex > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
