Messages in this thread | | | Subject | Re: [PATCH v10 24/26] KVM: s390: device attrs to enable/disable AP interpretation | From | Tony Krowiak <> | Date | Fri, 21 Sep 2018 19:40:36 -0400 |
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On 09/17/2018 04:51 AM, David Hildenbrand wrote: > Am 12.09.18 um 21:43 schrieb Tony Krowiak: >> From: Tony Krowiak <akrowiak@linux.ibm.com> >> >> Introduces two new VM crypto device attributes (KVM_S390_VM_CRYPTO) >> to enable or disable AP instruction interpretation from userspace >> via the KVM_SET_DEVICE_ATTR ioctl: >> >> * The KVM_S390_VM_CRYPTO_ENABLE_APIE attribute enables hardware >> interpretation of AP instructions executed on the guest. >> >> * The KVM_S390_VM_CRYPTO_DISABLE_APIE attribute disables hardware >> interpretation of AP instructions executed on the guest. In this >> case the instructions will be intercepted and pass through to >> the guest. >> >> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com> >> --- >> arch/s390/include/asm/kvm_host.h | 1 + >> arch/s390/include/uapi/asm/kvm.h | 2 ++ >> arch/s390/kvm/kvm-s390.c | 27 +++++++++++++++++++++++---- >> 3 files changed, 26 insertions(+), 4 deletions(-) >> >> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h >> index b32bd1b..36d3531 100644 >> --- a/arch/s390/include/asm/kvm_host.h >> +++ b/arch/s390/include/asm/kvm_host.h >> @@ -719,6 +719,7 @@ struct kvm_s390_crypto { >> __u32 crycbd; >> __u8 aes_kw; >> __u8 dea_kw; >> + __u8 apie; >> }; >> >> #define APCB0_MASK_SIZE 1 >> diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h >> index 8c23afc..a8dbd90 100644 >> --- a/arch/s390/include/uapi/asm/kvm.h >> +++ b/arch/s390/include/uapi/asm/kvm.h >> @@ -161,6 +161,8 @@ struct kvm_s390_vm_cpu_subfunc { >> #define KVM_S390_VM_CRYPTO_ENABLE_DEA_KW 1 >> #define KVM_S390_VM_CRYPTO_DISABLE_AES_KW 2 >> #define KVM_S390_VM_CRYPTO_DISABLE_DEA_KW 3 >> +#define KVM_S390_VM_CRYPTO_ENABLE_APIE 4 >> +#define KVM_S390_VM_CRYPTO_DISABLE_APIE 5 >> >> /* kvm attributes for migration mode */ >> #define KVM_S390_VM_MIGRATION_STOP 0 >> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >> index 2cdd980..286c2e0 100644 >> --- a/arch/s390/kvm/kvm-s390.c >> +++ b/arch/s390/kvm/kvm-s390.c >> @@ -856,12 +856,11 @@ void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm) >> >> static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr) >> { >> - if (!test_kvm_facility(kvm, 76)) >> - return -EINVAL; >> - >> mutex_lock(&kvm->lock); >> switch (attr->attr) { >> case KVM_S390_VM_CRYPTO_ENABLE_AES_KW: >> + if (!test_kvm_facility(kvm, 76)) >> + return -EINVAL; >> get_random_bytes( >> kvm->arch.crypto.crycb->aes_wrapping_key_mask, >> sizeof(kvm->arch.crypto.crycb->aes_wrapping_key_mask)); >> @@ -869,6 +868,8 @@ static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr) >> VM_EVENT(kvm, 3, "%s", "ENABLE: AES keywrapping support"); >> break; >> case KVM_S390_VM_CRYPTO_ENABLE_DEA_KW: >> + if (!test_kvm_facility(kvm, 76)) >> + return -EINVAL; >> get_random_bytes( >> kvm->arch.crypto.crycb->dea_wrapping_key_mask, >> sizeof(kvm->arch.crypto.crycb->dea_wrapping_key_mask)); >> @@ -876,17 +877,31 @@ static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr) >> VM_EVENT(kvm, 3, "%s", "ENABLE: DEA keywrapping support"); >> break; >> case KVM_S390_VM_CRYPTO_DISABLE_AES_KW: >> + if (!test_kvm_facility(kvm, 76)) >> + return -EINVAL; >> kvm->arch.crypto.aes_kw = 0; >> memset(kvm->arch.crypto.crycb->aes_wrapping_key_mask, 0, >> sizeof(kvm->arch.crypto.crycb->aes_wrapping_key_mask)); >> VM_EVENT(kvm, 3, "%s", "DISABLE: AES keywrapping support"); >> break; >> case KVM_S390_VM_CRYPTO_DISABLE_DEA_KW: >> + if (!test_kvm_facility(kvm, 76)) >> + return -EINVAL; >> kvm->arch.crypto.dea_kw = 0; >> memset(kvm->arch.crypto.crycb->dea_wrapping_key_mask, 0, >> sizeof(kvm->arch.crypto.crycb->dea_wrapping_key_mask)); >> VM_EVENT(kvm, 3, "%s", "DISABLE: DEA keywrapping support"); >> break; >> + case KVM_S390_VM_CRYPTO_ENABLE_APIE: >> + if (!ap_instructions_available()) { >> + mutex_unlock(&kvm->lock); >> + return -EOPNOTSUPP; >> + } >> + kvm->arch.crypto.apie = 1; >> + break; >> + case KVM_S390_VM_CRYPTO_DISABLE_APIE: >> + kvm->arch.crypto.apie = 0; >> + break; >> default: >> mutex_unlock(&kvm->lock); >> return -ENXIO; >> @@ -1493,6 +1508,8 @@ static int kvm_s390_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr) >> case KVM_S390_VM_CRYPTO_ENABLE_DEA_KW: >> case KVM_S390_VM_CRYPTO_DISABLE_AES_KW: >> case KVM_S390_VM_CRYPTO_DISABLE_DEA_KW: >> + case KVM_S390_VM_CRYPTO_ENABLE_APIE: >> + case KVM_S390_VM_CRYPTO_DISABLE_APIE: > > As also replied to the QEMU series, could we indicate > KVM_S390_VM_CRYPTO_ENABLE_APIE (and maybe > KVM_S390_VM_CRYPTO_DISABLE_APIE) only with ap_instructions_available(), > so we can avoid the additional KVM_S390_VM_CPU_FEAT_AP? > > KVM_S390_VM_CPU_FEAT_AP is right now completely unused in KVM otherwise > (never checked, we only care about apie).
After much discussion with Halil and a few exchanges with you, we decided to go ahead and accept your suggestion to get rid of KVM_S390_VM_CPU_FEAT and keep the VM device attributes to enable/disable apie.
To that end, I responded to patches 03/26, 11/26 and 25/26 with fixup! patches that show the KVM/kernel changes that will be necessary to get rid of KVM_S390_VM_CPU_FEAT and use apie to control ECA.28. I did that to generate discussion in v10 rather than waiting until v11 for comments. I make no guarantees that those fixup! patches will successfully apply should you have a v10 branch generated from this patch series you want to update.
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