> -----Original Message----- > From: Alexander Graf [mailto:agraf@xxxxxxx] > Sent: Monday, July 15, 2013 8:59 PM > To: Bhushan Bharat-R65777 > Cc: kvm@xxxxxxxxxxxxxxx; kvm-ppc@xxxxxxxxxxxxxxx; Wood Scott-B07421; Yoder > Stuart-B08248 > Subject: Re: [PATCH 2/5] booke: exit to guest userspace for unimplemented hcalls > in kvm > > > On 15.07.2013, at 17:13, Bhushan Bharat-R65777 wrote: > > > > > > >> -----Original Message----- > >> From: Alexander Graf [mailto:agraf@xxxxxxx] > >> Sent: Monday, July 15, 2013 8:27 PM > >> To: Bhushan Bharat-R65777 > >> Cc: kvm@xxxxxxxxxxxxxxx; kvm-ppc@xxxxxxxxxxxxxxx; Wood Scott-B07421; > >> Yoder > >> Stuart-B08248 > >> Subject: Re: [PATCH 2/5] booke: exit to guest userspace for > >> unimplemented hcalls in kvm > >> > >> > >> On 15.07.2013, at 16:50, Bhushan Bharat-R65777 wrote: > >> > >>> > >>> > >>>> -----Original Message----- > >>>> From: Alexander Graf [mailto:agraf@xxxxxxx] > >>>> Sent: Monday, July 15, 2013 5:16 PM > >>>> To: Bhushan Bharat-R65777 > >>>> Cc: kvm@xxxxxxxxxxxxxxx; kvm-ppc@xxxxxxxxxxxxxxx; Wood > >>>> Scott-B07421; Yoder > >>>> Stuart-B08248 > >>>> Subject: Re: [PATCH 2/5] booke: exit to guest userspace for > >>>> unimplemented hcalls in kvm > >>>> > >>>> > >>>> On 15.07.2013, at 13:38, Bhushan Bharat-R65777 wrote: > >>>> > >>>>> > >>>>> > >>>>>> -----Original Message----- > >>>>>> From: Alexander Graf [mailto:agraf@xxxxxxx] > >>>>>> Sent: Monday, July 15, 2013 5:02 PM > >>>>>> To: Bhushan Bharat-R65777 > >>>>>> Cc: kvm@xxxxxxxxxxxxxxx; kvm-ppc@xxxxxxxxxxxxxxx; Wood > >>>>>> Scott-B07421; Yoder Stuart-B08248; Bhushan Bharat-R65777 > >>>>>> Subject: Re: [PATCH 2/5] booke: exit to guest userspace for > >>>>>> unimplemented hcalls in kvm > >>>>>> > >>>>>> > >>>>>> On 15.07.2013, at 13:11, Bharat Bhushan wrote: > >>>>>> > >>>>>>> Exit to guest user space if kvm does not implement the hcall. > >>>>>>> > >>>>>>> Signed-off-by: Bharat Bhushan <bharat.bhushan@xxxxxxxxxxxxx> > >>>>>>> --- > >>>>>>> arch/powerpc/kvm/booke.c | 47 +++++++++++++++++++++++++++++++++++++- > -- > >> -- > >>>> - > >>>>>>> arch/powerpc/kvm/powerpc.c | 1 + > >>>>>>> include/uapi/linux/kvm.h | 1 + > >>>>>>> 3 files changed, 42 insertions(+), 7 deletions(-) > >>>>>>> > >>>>>>> diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c > >>>>>>> index > >>>>>>> 17722d8..c8b41b4 100644 > >>>>>>> --- a/arch/powerpc/kvm/booke.c > >>>>>>> +++ b/arch/powerpc/kvm/booke.c > >>>>>>> @@ -1005,9 +1005,25 @@ int kvmppc_handle_exit(struct kvm_run > >>>>>>> *run, struct > >>>>>> kvm_vcpu *vcpu, > >>>>>>> break; > >>>>>>> > >>>>>>> #ifdef CONFIG_KVM_BOOKE_HV > >>>>>>> - case BOOKE_INTERRUPT_HV_SYSCALL: > >>>>>>> + case BOOKE_INTERRUPT_HV_SYSCALL: { > >>>>>> > >>>>>> This is getting large. Please extract hcall handling into its own > function. > >>>>>> Maybe you can merge the HV and non-HV case then too. > >>>>>> > >>>>>>> + int i; > >>>>>>> if (!(vcpu->arch.shared->msr & MSR_PR)) { > >>>>>>> - kvmppc_set_gpr(vcpu, 3, kvmppc_kvm_pv(vcpu)); > >>>>>>> + r = kvmppc_kvm_pv(vcpu); > >>>>>>> + if (r != EV_UNIMPLEMENTED) { > >>>>>>> + /* except unimplemented return to guest */ > >>>>>>> + kvmppc_set_gpr(vcpu, 3, r); > >>>>>>> + kvmppc_account_exit(vcpu, SYSCALL_EXITS); > >>>>>>> + r = RESUME_GUEST; > >>>>>>> + break; > >>>>>>> + } > >>>>>>> + /* Exit to userspace for unimplemented hcalls in kvm > >> */ > >>>>>>> + run->epapr_hcall.nr = kvmppc_get_gpr(vcpu, 11); > >>>>>>> + run->epapr_hcall.ret = 0; > >>>>>>> + for (i = 0; i < 8; i++) > >>>>>>> + run->epapr_hcall.args[i] = kvmppc_get_gpr(vcpu, > >> 3 + > >>>>>> i); > >>>>>>> + vcpu->arch.hcall_needed = 1; > >>>>>>> + kvmppc_account_exit(vcpu, SYSCALL_EXITS); > >>>>>>> + r = RESUME_HOST; > >>>>>>> } else { > >>>>>>> /* > >>>>>>> * hcall from guest userspace -- send privileged @@ - > 1016,22 > >>>>>>> +1032,39 @@ int kvmppc_handle_exit(struct kvm_run *run, struct > >>>>>>> +kvm_vcpu *vcpu, > >>>>>>> kvmppc_core_queue_program(vcpu, ESR_PPR); > >>>>>>> } > >>>>>>> > >>>>>>> - r = RESUME_GUEST; > >>>>>>> + run->exit_reason = KVM_EXIT_EPAPR_HCALL; > >>>>> > >>>>> > >>>>> Oops, what I have done, I wanted this to be > >>>>> kvmppc_account_exit(vcpu, SYSCALL_EXITS); > >>>>> > >>>>> s/ run->exit_reason = KVM_EXIT_EPAPR_HCALL;/ > >>>>> kvmppc_account_exit(vcpu, SYSCALL_EXITS); > >>>>> > >>>>> -Bharat > >>>>> > >>>>>> > >>>>>> This looks odd. Your exit reason only changes when you do the > >>>>>> hcall exiting, right? > >>>>>> > >>>>>> You also need to guard user space hcall exits with an ENABLE_CAP. > >>>>>> Otherwise older user space will break, as it doesn't know about > >>>>>> the exit type > >>>> yet. > >>>>> > >>>>> So the user space so make enable_cap also? > >>>> > >>>> User space needs to call enable_cap on this cap, yes. Otherwise a > >>>> guest can confuse user space with an hcall exit it can't handle. > >>> > >>> We do not have enable_cap for book3s, any specific reason why ? > >> > >> We do. If you enable PAPR, you get PAPR hcalls. If you enable OSI, > >> you get OSI hcalls. > > > > Oh, We check this on book3s_PR and book3s_HV. > > > >> KVM hcalls on book3s don't return to user space. > > > > It exits, is not it? "arch/powerpc/kvm/book3s_pr.c" exits with > KVM_EXIT_PAPR_HCALL. And same in book3s_pv. > > It doesn't even start handling the hcall if papr_enabled isn't set ;). On PR, not HV :-) -Bharat > > > 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
