diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c index 8b13f7098c61..59920f96ebc0 100644 --- a/arch/s390/kvm/intercept.c +++ b/arch/s390/kvm/intercept.c @@ -361,6 +361,9 @@ static int handle_partial_execution(struct kvm_vcpu *vcpu) static int handle_operexc(struct kvm_vcpu *vcpu) { + psw_t oldpsw, newpsw; + int rc; + vcpu->stat.exit_operation_exception++; trace_kvm_s390_handle_operexc(vcpu, vcpu->arch.sie_block->ipa, vcpu->arch.sie_block->ipb); @@ -371,6 +374,24 @@ static int handle_operexc(struct kvm_vcpu *vcpu) if (vcpu->arch.sie_block->ipa == 0 && vcpu->kvm->arch.user_instr0) return -EOPNOTSUPP; + rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &newpsw, sizeof(psw_t)); + if (rc) + return rc; + /* + * Avoid endless loops of operation exceptions, if the pgm new + * PSW will cause a new operation exception. + * The heuristic checks if the pgm new psw is within 6 bytes before + * the faulting psw address (with same DAT, AS settings) and the + * new psw is not a wait psw and the fault was not triggered by + * problem state. + */ + oldpsw = vcpu->arch.sie_block->gpsw; + if (oldpsw.addr - newpsw.addr <= 6 && + !(newpsw.mask & PSW_MASK_WAIT) && + !(oldpsw.mask & PSW_MASK_PSTATE) && + (newpsw.mask & PSW_MASK_ASC) == (oldpsw.mask & PSW_MASK_ASC) && + (newpsw.mask & PSW_MASK_DAT) == (oldpsw.mask & PSW_MASK_DAT)) + return -EOPNOTSUPP; return kvm_s390_inject_program_int(vcpu, PGM_OPERATION); }