Re: [Qemu-devel] [PATCH v2 1/5] vfio-ccw: make it safe to access channel programs

[Cornelia Huck]

On Tue, 22 Jan 2019 15:56:56 +0100
Halil Pasic <address@hidden> wrote:

> On Mon, 21 Jan 2019 12:03:50 +0100
> Cornelia Huck <address@hidden> wrote:
> 
> > When we get a solicited interrupt, the start function may have
> > been cleared by a csch, but we still have a channel program
> > structure allocated. Make it safe to call the cp accessors in
> > any case, so we can call them unconditionally.
> > 
> > Signed-off-by: Cornelia Huck <address@hidden>
> > ---
> >  drivers/s390/cio/vfio_ccw_cp.c | 3 +++
> >  drivers/s390/cio/vfio_ccw_cp.h | 2 ++
> >  2 files changed, 5 insertions(+)
> > 
> > diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
> > index 70a006ba4d05..714987ceea9a 100644
> > --- a/drivers/s390/cio/vfio_ccw_cp.c
> > +++ b/drivers/s390/cio/vfio_ccw_cp.c
> > @@ -335,6 +335,7 @@ static void cp_unpin_free(struct channel_program *cp)
> >     struct ccwchain *chain, *temp;
> >     int i;
> >  
> > +   cp->initialized = false;
> >     list_for_each_entry_safe(chain, temp, &cp->ccwchain_list, next) {
> >             for (i = 0; i < chain->ch_len; i++) {
> >                     pfn_array_table_unpin_free(chain->ch_pat + i,
> > @@ -701,6 +702,8 @@ int cp_init(struct channel_program *cp, struct device 
> > *mdev, union orb *orb)
> >      */
> >     cp->orb.cmd.c64 = 1;
> >  
> > +   cp->initialized = true;
> > +
> >     return ret;
> >  }
> >  
> > diff --git a/drivers/s390/cio/vfio_ccw_cp.h b/drivers/s390/cio/vfio_ccw_cp.h
> > index a4b74fb1aa57..3c20cd208da5 100644
> > --- a/drivers/s390/cio/vfio_ccw_cp.h
> > +++ b/drivers/s390/cio/vfio_ccw_cp.h
> > @@ -21,6 +21,7 @@
> >   * @ccwchain_list: list head of ccwchains
> >   * @orb: orb for the currently processed ssch request
> >   * @mdev: the mediated device to perform page pinning/unpinning
> > + * @initialized: whether this instance is actually initialized
> >   *
> >   * @ccwchain_list is the head of a ccwchain list, that contents the
> >   * translated result of the guest channel program that pointed out by
> > @@ -30,6 +31,7 @@ struct channel_program {
> >     struct list_head ccwchain_list;
> >     union orb orb;
> >     struct device *mdev;
> > +   bool initialized;
> >  };
> >  
> >  extern int cp_init(struct channel_program *cp, struct device *mdev,  
> 
> I fail to see how is this patch delivering on the promise made by it's
> title. I see only code that sets cp->initialized but none that reads it.
> The follow-up patches don't seem to care for cp->initialized either.

Grr, has been lost in the rebase. I'll redo this.