From: Farhan Ali <alifm@linux.ibm.com>
Subject: KVM: s390: device attrs to enable/disable AP interpretation
Patch-mainline: v4.20-rc1
Git-commit: 37940fb0b6a2c4bf101481365c42f250694ffd15
References: FATE#326370, LTC#169186, bsc#1113483

Summary:     kernel: AP Crypto Passthrough 
Description: This adds support for AP crypto passthrough for 
             kvm guests.

Upstream-Description:

             KVM: s390: device attrs to enable/disable AP interpretation

             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>
             Reviewed-by: Cornelia Huck <cohuck@redhat.com>
             Message-Id: <20180925231641.4954-25-akrowiak@linux.vnet.ibm.com>
             Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 arch/s390/include/uapi/asm/kvm.h |    2 ++
 arch/s390/kvm/kvm-s390.c         |   30 +++++++++++++++++++++++++++---
 2 files changed, 29 insertions(+), 3 deletions(-)

--- a/arch/s390/include/uapi/asm/kvm.h
+++ b/arch/s390/include/uapi/asm/kvm.h
@@ -163,6 +163,8 @@ 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
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -832,12 +832,11 @@ void kvm_s390_vcpu_crypto_reset_all(stru
 
 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));
@@ -845,6 +844,8 @@ static int kvm_s390_vm_set_crypto(struct
 		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));
@@ -852,17 +853,35 @@ static int kvm_s390_vm_set_crypto(struct
 		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:
+		if (!ap_instructions_available()) {
+			mutex_unlock(&kvm->lock);
+			return -EOPNOTSUPP;
+		}
+		kvm->arch.crypto.apie = 0;
+		break;
 	default:
 		mutex_unlock(&kvm->lock);
 		return -ENXIO;
@@ -1488,6 +1507,10 @@ static int kvm_s390_vm_has_attr(struct k
 		case KVM_S390_VM_CRYPTO_DISABLE_DEA_KW:
 			ret = 0;
 			break;
+		case KVM_S390_VM_CRYPTO_ENABLE_APIE:
+		case KVM_S390_VM_CRYPTO_DISABLE_APIE:
+			ret = ap_instructions_available() ? 0 : -ENXIO;
+			break;
 		default:
 			ret = -ENXIO;
 			break;
@@ -2511,6 +2534,7 @@ static void kvm_s390_vcpu_crypto_setup(s
 
 	vcpu->arch.sie_block->crycbd = vcpu->kvm->arch.crypto.crycbd;
 	vcpu->arch.sie_block->ecb3 &= ~(ECB3_AES | ECB3_DEA);
+	vcpu->arch.sie_block->eca &= ~ECA_APIE;
 
 	if (vcpu->kvm->arch.crypto.apie)
 		vcpu->arch.sie_block->eca |= ECA_APIE;