Re: [PATCH v1 3/7] vfio/ccw: move private initialization to callback

[Eric Farman <farman@linux.ibm.com>]

On Fri, 2022-10-28 at 14:52 -0400, Matthew Rosato wrote:
> On 10/19/22 12:21 PM, Eric Farman wrote:
> > There's already a device initialization callback that is
> > used to initialize the release completion workaround.
> 
> As discussed off-list, maybe clarify what callback you're talking
> about here and/or reference the commit that added it.

Agreed. Will point out that it's private->release_comp, introduced with
commit ebb72b765fb49 ("vfio/ccw: Use the new device life cycle
helpers")

> 
> > 
> > Move the other elements of the vfio_ccw_private struct that
> > require distinct initialization over to that routine.
> > 
> > Signed-off-by: Eric Farman <farman@linux.ibm.com>
> > ---
> >  drivers/s390/cio/vfio_ccw_drv.c     | 57 +++----------------------
> > ----
> >  drivers/s390/cio/vfio_ccw_ops.c     | 43 ++++++++++++++++++++++
> >  drivers/s390/cio/vfio_ccw_private.h |  7 +++-
> >  3 files changed, 55 insertions(+), 52 deletions(-)
> > 
> > diff --git a/drivers/s390/cio/vfio_ccw_drv.c
> > b/drivers/s390/cio/vfio_ccw_drv.c
> > index 4ee953c8ae39..cc9ed2fd970f 100644
> > --- a/drivers/s390/cio/vfio_ccw_drv.c
> > +++ b/drivers/s390/cio/vfio_ccw_drv.c
> > @@ -24,10 +24,10 @@
> >  #include "vfio_ccw_private.h"
> >  
> >  struct workqueue_struct *vfio_ccw_work_q;
> > -static struct kmem_cache *vfio_ccw_io_region;
> > -static struct kmem_cache *vfio_ccw_cmd_region;
> > -static struct kmem_cache *vfio_ccw_schib_region;
> > -static struct kmem_cache *vfio_ccw_crw_region;
> > +struct kmem_cache *vfio_ccw_io_region;
> > +struct kmem_cache *vfio_ccw_cmd_region;
> > +struct kmem_cache *vfio_ccw_schib_region;
> > +struct kmem_cache *vfio_ccw_crw_region;
> >  
> >  debug_info_t *vfio_ccw_debug_msg_id;
> >  debug_info_t *vfio_ccw_debug_trace_id;
> > @@ -74,7 +74,7 @@ int vfio_ccw_sch_quiesce(struct subchannel *sch)
> >         return ret;
> >  }
> >  
> > -static void vfio_ccw_sch_io_todo(struct work_struct *work)
> > +void vfio_ccw_sch_io_todo(struct work_struct *work)
> >  {
> >         struct vfio_ccw_private *private;
> >         struct irb *irb;
> > @@ -110,7 +110,7 @@ static void vfio_ccw_sch_io_todo(struct
> > work_struct *work)
> >                 eventfd_signal(private->io_trigger, 1);
> >  }
> >  
> > -static void vfio_ccw_crw_todo(struct work_struct *work)
> > +void vfio_ccw_crw_todo(struct work_struct *work)
> >  {
> >         struct vfio_ccw_private *private;
> >  
> > @@ -154,52 +154,7 @@ static struct vfio_ccw_private
> > *vfio_ccw_alloc_private(struct subchannel *sch)
> >         if (!private)
> >                 return ERR_PTR(-ENOMEM);
> 
> Not sure we really still need vfio_ccw_alloc_private() now or whether
> you can just kzalloc() inline right in vfio_ccw_sch_probe()

Fair. It ends up ends up getting scrapped in patch 6 anyway, but that
might clean things up just a smidge more. Will give it a whirl.

> Either way:
> 
> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>

Thanks!

> 
> 
> >  
> > -       mutex_init(&private->io_mutex);
> > -       private->state = VFIO_CCW_STATE_STANDBY;
> > -       INIT_LIST_HEAD(&private->crw);
> > -       INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo);
> > -       INIT_WORK(&private->crw_work, vfio_ccw_crw_todo);
> > -
> > -       private->cp.guest_cp = kcalloc(CCWCHAIN_LEN_MAX,
> > sizeof(struct ccw1),
> > -                                      GFP_KERNEL);
> > -       if (!private->cp.guest_cp)
> > -               goto out_free_private;
> > -
> > -       private->io_region = kmem_cache_zalloc(vfio_ccw_io_region,
> > -                                              GFP_KERNEL |
> > GFP_DMA);
> > -       if (!private->io_region)
> > -               goto out_free_cp;
> > -
> > -       private->cmd_region =
> > kmem_cache_zalloc(vfio_ccw_cmd_region,
> > -                                               GFP_KERNEL |
> > GFP_DMA);
> > -       if (!private->cmd_region)
> > -               goto out_free_io;
> > -
> > -       private->schib_region =
> > kmem_cache_zalloc(vfio_ccw_schib_region,
> > -                                                 GFP_KERNEL |
> > GFP_DMA);
> > -
> > -       if (!private->schib_region)
> > -               goto out_free_cmd;
> > -
> > -       private->crw_region =
> > kmem_cache_zalloc(vfio_ccw_crw_region,
> > -                                               GFP_KERNEL |
> > GFP_DMA);
> > -
> > -       if (!private->crw_region)
> > -               goto out_free_schib;
> >         return private;
> > -
> > -out_free_schib:
> > -       kmem_cache_free(vfio_ccw_schib_region, private-
> > >schib_region);
> > -out_free_cmd:
> > -       kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region);
> > -out_free_io:
> > -       kmem_cache_free(vfio_ccw_io_region, private->io_region);
> > -out_free_cp:
> > -       kfree(private->cp.guest_cp);
> > -out_free_private:
> > -       mutex_destroy(&private->io_mutex);
> > -       kfree(private);
> > -       return ERR_PTR(-ENOMEM);
> >  }
> >  
> >  static void vfio_ccw_free_private(struct vfio_ccw_private
> > *private)
> > diff --git a/drivers/s390/cio/vfio_ccw_ops.c
> > b/drivers/s390/cio/vfio_ccw_ops.c
> > index cf383c729d53..626b8eb3507b 100644
> > --- a/drivers/s390/cio/vfio_ccw_ops.c
> > +++ b/drivers/s390/cio/vfio_ccw_ops.c
> > @@ -50,8 +50,51 @@ static int vfio_ccw_mdev_init_dev(struct
> > vfio_device *vdev)
> >         struct vfio_ccw_private *private =
> >                 container_of(vdev, struct vfio_ccw_private, vdev);
> >  
> > +       mutex_init(&private->io_mutex);
> > +       private->state = VFIO_CCW_STATE_STANDBY;
> > +       INIT_LIST_HEAD(&private->crw);
> > +       INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo);
> > +       INIT_WORK(&private->crw_work, vfio_ccw_crw_todo);
> >         init_completion(&private->release_comp);
> > +
> > +       private->cp.guest_cp = kcalloc(CCWCHAIN_LEN_MAX,
> > sizeof(struct ccw1),
> > +                                      GFP_KERNEL);
> > +       if (!private->cp.guest_cp)
> > +               goto out_free_private;
> > +
> > +       private->io_region = kmem_cache_zalloc(vfio_ccw_io_region,
> > +                                              GFP_KERNEL |
> > GFP_DMA);
> > +       if (!private->io_region)
> > +               goto out_free_cp;
> > +
> > +       private->cmd_region =
> > kmem_cache_zalloc(vfio_ccw_cmd_region,
> > +                                               GFP_KERNEL |
> > GFP_DMA);
> > +       if (!private->cmd_region)
> > +               goto out_free_io;
> > +
> > +       private->schib_region =
> > kmem_cache_zalloc(vfio_ccw_schib_region,
> > +                                                 GFP_KERNEL |
> > GFP_DMA);
> > +       if (!private->schib_region)
> > +               goto out_free_cmd;
> > +
> > +       private->crw_region =
> > kmem_cache_zalloc(vfio_ccw_crw_region,
> > +                                               GFP_KERNEL |
> > GFP_DMA);
> > +       if (!private->crw_region)
> > +               goto out_free_schib;
> > +
> >         return 0;
> > +
> > +out_free_schib:
> > +       kmem_cache_free(vfio_ccw_schib_region, private-
> > >schib_region);
> > +out_free_cmd:
> > +       kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region);
> > +out_free_io:
> > +       kmem_cache_free(vfio_ccw_io_region, private->io_region);
> > +out_free_cp:
> > +       kfree(private->cp.guest_cp);
> > +out_free_private:
> > +       mutex_destroy(&private->io_mutex);
> > +       return -ENOMEM;
> >  }
> >  
> >  static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
> > diff --git a/drivers/s390/cio/vfio_ccw_private.h
> > b/drivers/s390/cio/vfio_ccw_private.h
> > index 0fdff1435230..b35940057073 100644
> > --- a/drivers/s390/cio/vfio_ccw_private.h
> > +++ b/drivers/s390/cio/vfio_ccw_private.h
> > @@ -116,6 +116,8 @@ struct vfio_ccw_private {
> >  } __aligned(8);
> >  
> >  int vfio_ccw_sch_quiesce(struct subchannel *sch);
> > +void vfio_ccw_sch_io_todo(struct work_struct *work);
> > +void vfio_ccw_crw_todo(struct work_struct *work);
> >  
> >  extern struct mdev_driver vfio_ccw_mdev_driver;
> >  
> > @@ -163,7 +165,10 @@ static inline void vfio_ccw_fsm_event(struct
> > vfio_ccw_private *private,
> >  }
> >  
> >  extern struct workqueue_struct *vfio_ccw_work_q;
> > -
> > +extern struct kmem_cache *vfio_ccw_io_region;
> > +extern struct kmem_cache *vfio_ccw_cmd_region;
> > +extern struct kmem_cache *vfio_ccw_schib_region;
> > +extern struct kmem_cache *vfio_ccw_crw_region;
> >  
> >  /* s390 debug feature, similar to base cio */
> >  extern debug_info_t *vfio_ccw_debug_msg_id;
>