On 30.08.2017 18:36, Halil Pasic wrote: > If we detect that the internally manged state of the subchannel > is broken beyond repair while in do_subchannel_work in case of > virtual we just abort the operation and pretend all went well, > while in case of pass-through we honor the situation with -ENODEV > which results in cc 3 for the instruction whose handler triggered > the call. > > Let's be consistent on this and do the -ENODEV also for virtual > subchannels. > > Signed-off-by: Halil Pasic <pa...@linux.vnet.ibm.com> > Acked-by: Pierre Morel<pmo...@linux.vnet.ibm.com> > --- > hw/s390x/css.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/s390x/css.c b/hw/s390x/css.c > index 0822538cde..bc47bf5b20 100644 > --- a/hw/s390x/css.c > +++ b/hw/s390x/css.c > @@ -1078,7 +1078,7 @@ int do_subchannel_work_virtual(SubchDev *sch) > sch_handle_start_func_virtual(sch); > } else { > /* Cannot happen. */ > - return 0; > + return -ENODEV; > } > css_inject_io_interrupt(sch); > return 0;
First, I think ENODEV is not really a good choice here since there certainly was a device. So maybe use EINVAL or EBADR or something else instead? Second, while return an error code is certainly better than returning 0, I think most errors will still go unnoticed here, since most callers of do_subchannel_work() seem to ignore the return value ... so I wonder whether we rather want to have another way to recognize this condition. If the comment is right and this really can not happen, I think you should use an g_assert_notreached() here instead. Otherwise the comment should be changed and it's maybe a good idea to use a qemu_log_mask(LOG_GUEST_ERROR, "subchannel in bad state bla bla...") here. Thomas