> -----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 ? -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
