Merge tag 'kvm-s390-next-4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into next

KVM: s390: : Feature and fix for kvm/next (4.8) part 4

1. Provide an exit to userspace for the invalid opcode 0 (used for
   software breakpoints)
2. "Fix" (by returning condition code 3) some unhandled PTFF subcodes

4 files changed, 37 insertions, 2 deletions

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 946fc86202fd..183b01727de4 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -43,6 +43,7 @@
 /* s390-specific vcpu->requests bit members */
 #define KVM_REQ_ENABLE_IBS         8
 #define KVM_REQ_DISABLE_IBS        9
+#define KVM_REQ_ICPT_OPEREXC       10
 
 #define SIGP_CTRL_C		0x80
 #define SIGP_CTRL_SCN_MASK	0x3f
@@ -666,6 +667,7 @@ struct kvm_arch{
 	int user_cpu_state_ctrl;
 	int user_sigp;
 	int user_stsi;
+	int user_instr0;
 	struct s390_io_adapter *adapters[MAX_S390_IO_ADAPTERS];
 	wait_queue_head_t ipte_wq;
 	int ipte_lock_count;
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index 850be47c4cc9..7a2f1551bc39 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -359,6 +359,9 @@ static int handle_operexc(struct kvm_vcpu *vcpu)
 	    test_kvm_facility(vcpu->kvm, 74))
 		return handle_sthyi(vcpu);
 
+	if (vcpu->arch.sie_block->ipa == 0 && vcpu->kvm->arch.user_instr0)
+		return -EOPNOTSUPP;
+
 	return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
 }
 
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index d42428c11794..63ac7c1641a7 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -364,6 +364,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_S390_USER_STSI:
 	case KVM_CAP_S390_SKEYS:
 	case KVM_CAP_S390_IRQ_STATE:
+	case KVM_CAP_S390_USER_INSTR0:
 		r = 1;
 		break;
 	case KVM_CAP_S390_MEM_OP:
@@ -456,6 +457,16 @@ out:
 	return r;
 }
 
+static void icpt_operexc_on_all_vcpus(struct kvm *kvm)
+{
+	unsigned int i;
+	struct kvm_vcpu *vcpu;
+
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		kvm_s390_sync_request(KVM_REQ_ICPT_OPEREXC, vcpu);
+	}
+}
+
 static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap)
 {
 	int r;
@@ -507,6 +518,12 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap)
 		kvm->arch.user_stsi = 1;
 		r = 0;
 		break;
+	case KVM_CAP_S390_USER_INSTR0:
+		VM_EVENT(kvm, 3, "%s", "ENABLE: CAP_S390_USER_INSTR0");
+		kvm->arch.user_instr0 = 1;
+		icpt_operexc_on_all_vcpus(kvm);
+		r = 0;
+		break;
 	default:
 		r = -EINVAL;
 		break;
@@ -1836,6 +1853,8 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
 		vcpu->arch.gmap = vcpu->kvm->arch.gmap;
 		sca_add_vcpu(vcpu);
 	}
+	if (test_kvm_facility(vcpu->kvm, 74) || vcpu->kvm->arch.user_instr0)
+		vcpu->arch.sie_block->ictl |= ICTL_OPEREXC;
 	/* make vcpu_load load the right gmap on the first trigger */
 	vcpu->arch.enabled_gmap = vcpu->arch.gmap;
 }
@@ -1923,8 +1942,6 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
 	}
 	vcpu->arch.sie_block->riccbd = (unsigned long) &vcpu->run->s.regs.riccb;
 	vcpu->arch.sie_block->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
-	if (test_kvm_facility(vcpu->kvm, 74))
-		vcpu->arch.sie_block->ictl |= ICTL_OPEREXC;
 
 	if (vcpu->kvm->arch.use_cmma) {
 		rc = kvm_s390_vcpu_setup_cmma(vcpu);
@@ -2369,6 +2386,11 @@ retry:
 		goto retry;
 	}
 
+	if (kvm_check_request(KVM_REQ_ICPT_OPEREXC, vcpu)) {
+		vcpu->arch.sie_block->ictl |= ICTL_OPEREXC;
+		goto retry;
+	}
+
 	/* nothing to do, just clear the request */
 	clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
 
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index c77ad2dc334f..46160388e996 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -1185,7 +1185,15 @@ static int handle_sckpf(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
+static int handle_ptff(struct kvm_vcpu *vcpu)
+{
+	/* we don't emulate any control instructions yet */
+	kvm_s390_set_psw_cc(vcpu, 3);
+	return 0;
+}
+
 static const intercept_handler_t x01_handlers[256] = {
+	[0x04] = handle_ptff,
 	[0x07] = handle_sckpf,
 };