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@xxxxxxxxxxxxxxxxxx> --- 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)) { + 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)) + vcpu->arch.sie_block->eca |= ECA_APIE; + + if (!test_kvm_facility(vcpu->kvm, 76)) return; -- 1.7.1