On Tue, 2 May 2017 10:15:19 +0800
Dong Jia Shi <bjsdjshi@xxxxxxxxxxxxxxxxxx> wrote:
> * Auger Eric <eric.auger@xxxxxxxxxx> [2017-05-01 19:28:23 +0200]:
> > > static void vfio_ccw_io_notifier_handler(void *opaque)
> > > {
> > > VFIOCCWDevice *vcdev = opaque;
> > > + struct ccw_io_region *region = vcdev->io_region;
> > > + S390CCWDevice *cdev = S390_CCW_DEVICE(vcdev);
> > > + CcwDevice *ccw_dev = CCW_DEVICE(cdev);
> > > + SubchDev *sch = ccw_dev->sch;
> > > + SCSW *s = &sch->curr_status.scsw;
> > > + IRB irb;
> > >
> > > if (!event_notifier_test_and_clear(&vcdev->io_notifier)) {
> > > return;
> > > }
> > > +
> > > + if (pread(vcdev->vdev.fd, region,
> > > + vcdev->io_region_size, vcdev->io_region_offset) == -1) {
> > is it possible to read less bytes than requested?
> Currently, impossible. The kernel side returns either the full region,
> or an error.
> But we surely could make it more friendly for a partial return. I will
> add a check for that case, and generate a channel program check for it.
I think a channel-control check would be more appropriate here.
