On Wed, 11 Oct 2017 04:38:21 +0200 Dong Jia Shi <[email protected]> wrote:
> We currently returns the same error code (-EFAULT) to indicate two s/returns/return/ > different error cases: > 1. a bug in vfio-ccw implementation has been found. > 2. a buggy channel program has been detected. > > This brings difficulty for userland program (specifically Qemu) to > handle. > > Let's use -EFAULT to only indicate the first case. For the second > case, we simply hand over the ccws to lower level for further > handling. > > Notice: > Once a bad idaw address is detected, the current behavior is to > suppress the ssch. With this fix, the channel program will be > accepted, and partial of the channel program (the part ahead of s/partial/part/ > the bad idaw) could possibly be executed by the device before > I/O conclusion. That actually sounds more sensible than the current behaviour. I'll fix up the typos when applying. > > Suggested-by: Halil Pasic <[email protected]> > Reviewed-by: Pierre Morel <[email protected]> > Signed-off-by: Dong Jia Shi <[email protected]> > --- > drivers/s390/cio/vfio_ccw_cp.c | 4 ---- > 1 file changed, 4 deletions(-) > > diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c > index 5ccfdc80d0ec..722f8b8c7273 100644 > --- a/drivers/s390/cio/vfio_ccw_cp.c > +++ b/drivers/s390/cio/vfio_ccw_cp.c > @@ -569,10 +569,6 @@ static int ccwchain_fetch_idal(struct ccwchain *chain, > > for (i = 0; i < idaw_nr; i++) { > idaw_iova = *(idaws + i); > - if (IS_ERR_VALUE(idaw_iova)) { > - ret = -EFAULT; > - goto out_free_idaws; > - } > > ret = pfn_array_alloc_pin(pat->pat_pa + i, cp->mdev, > idaw_iova, 1);
