Messages in this thread | | | Subject | Re: [PATCH v4 05/15] KVM: s390: enable/disable AP interpretive execution | From | Pierre Morel <> | Date | Mon, 16 Apr 2018 12:51:46 +0200 |
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On 15/04/2018 23:22, Tony Krowiak wrote: > The VFIO AP device model exploits interpretive execution of AP > instructions (APIE) to provide guests passthrough access to AP > devices. This patch introduces a new interface to enable and > disable APIE. > > Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com> > --- > arch/s390/include/asm/kvm-ap.h | 16 ++++++++++++++++ > arch/s390/include/asm/kvm_host.h | 1 + > arch/s390/kvm/kvm-ap.c | 20 ++++++++++++++++++++ > arch/s390/kvm/kvm-s390.c | 9 +++++++++ > 4 files changed, 46 insertions(+), 0 deletions(-) > > diff --git a/arch/s390/include/asm/kvm-ap.h b/arch/s390/include/asm/kvm-ap.h > index 736e93e..a6c092e 100644 > --- a/arch/s390/include/asm/kvm-ap.h > +++ b/arch/s390/include/asm/kvm-ap.h > @@ -35,4 +35,20 @@ > */ > void kvm_ap_build_crycbd(struct kvm *kvm); > > +/** > + * kvm_ap_interpret_instructions > + * > + * Indicate whether AP instructions shall be interpreted. If they are not > + * interpreted, all AP instructions will be intercepted and routed back to > + * userspace. > + * > + * @kvm: the virtual machine attributes > + * @enable: indicates whether AP instructions are to be interpreted (true) or > + * or not (false). > + * > + * Returns 0 if completed successfully; otherwise, returns -EOPNOTSUPP > + * indicating that AP instructions are not installed on the guest. > + */ > +int kvm_ap_interpret_instructions(struct kvm *kvm, bool enable); > + > #endif /* _ASM_KVM_AP */ > diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h > index 3162783..5470685 100644 > --- a/arch/s390/include/asm/kvm_host.h > +++ b/arch/s390/include/asm/kvm_host.h > @@ -715,6 +715,7 @@ struct kvm_s390_crypto { > __u32 crycbd; > __u8 aes_kw; > __u8 dea_kw; > + __u8 apie; > }; > > #define APCB0_MASK_SIZE 1 > diff --git a/arch/s390/kvm/kvm-ap.c b/arch/s390/kvm/kvm-ap.c > index 991bae4..55d11b5 100644 > --- a/arch/s390/kvm/kvm-ap.c > +++ b/arch/s390/kvm/kvm-ap.c > @@ -58,3 +58,23 @@ void kvm_ap_build_crycbd(struct kvm *kvm) > } > } > EXPORT_SYMBOL(kvm_ap_build_crycbd); > + > +int kvm_ap_interpret_instructions(struct kvm *kvm, bool enable) > +{ > + int ret = 0; > + > + mutex_lock(&kvm->lock); > + > + if (!test_kvm_cpu_feat(kvm, KVM_S390_VM_CPU_FEAT_AP)) {
Do we really need to test CPU_FEAT_AP?
I understand that KVM_S390_VM_CPU_FEAT_AP means AP instructions are interpreted. shouldn't we add this information in the name? like KVM_S390_VM_CPU_FEAT_APIE
> + ret = -EOPNOTSUPP; > + goto done; > + } > + > + kvm->arch.crypto.apie = enable; > + kvm_s390_vcpu_crypto_reset_all(kvm); > + > +done: > + mutex_unlock(&kvm->lock); > + return ret; > +} > +EXPORT_SYMBOL(kvm_ap_interpret_instructions); > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index 55cd897..1dc8566 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -1901,6 +1901,9 @@ static void kvm_s390_crypto_init(struct kvm *kvm) > kvm->arch.crypto.crycb = &kvm->arch.sie_page2->crycb; > kvm_ap_build_crycbd(kvm); > > + /* Default setting indicating SIE shall interpret AP instructions */ > + kvm->arch.crypto.apie = 1; > + > if (!test_kvm_facility(kvm, 76)) > return; > > @@ -2434,6 +2437,12 @@ static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu *vcpu) > { > vcpu->arch.sie_block->crycbd = vcpu->kvm->arch.crypto.crycbd; > > + vcpu->arch.sie_block->eca &= ~ECA_APIE; > + if (vcpu->kvm->arch.crypto.apie && > + test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_AP))
Do we call xxx_crypto_setup() if KVM does not support AP interpretation?
> + vcpu->arch.sie_block->eca |= ECA_APIE; > + > + > if (!test_kvm_facility(vcpu->kvm, 76)) > return; >
-- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany
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