KVM: s390: Handle sthyi also for instruction intercept

Right now we handle the STHYI only via the operation exception intercept
(illegal instruction). If hardware ever decides to provide an
instruction intercept for STHYI, we should handle that as well.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

arch/s390/kvm/intercept.c

@@ -368,8 +368,7 @@ static int handle_operexc(struct kvm_vcpu *vcpu)
 	trace_kvm_s390_handle_operexc(vcpu, vcpu->arch.sie_block->ipa,
 				      vcpu->arch.sie_block->ipb);
 
-	if (vcpu->arch.sie_block->ipa == 0xb256 &&
-	    test_kvm_facility(vcpu->kvm, 74))
+	if (vcpu->arch.sie_block->ipa == 0xb256)
 		return handle_sthyi(vcpu);
 
 	if (vcpu->arch.sie_block->ipa == 0 && vcpu->kvm->arch.user_instr0)

arch/s390/kvm/priv.c

@@ -760,6 +760,7 @@ static const intercept_handler_t b2_handlers[256] = {
 	[0x3b] = handle_io_inst,
 	[0x3c] = handle_io_inst,
 	[0x50] = handle_ipte_interlock,
+	[0x56] = handle_sthyi,
 	[0x5f] = handle_io_inst,
 	[0x74] = handle_io_inst,
 	[0x76] = handle_io_inst,

arch/s390/kvm/sthyi.c

@@ -404,6 +404,9 @@ int handle_sthyi(struct kvm_vcpu *vcpu)
 	u64 code, addr, cc = 0;
 	struct sthyi_sctns *sctns = NULL;
 
+	if (!test_kvm_facility(vcpu->kvm, 74))
+		return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
+
 	/*
 	 * STHYI requires extensive locking in the higher hypervisors
 	 * and is very computational/memory expensive. Therefore we