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Date:   Fri, 28 Oct 2022 14:52:26 -0400
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Subject: Re: [PATCH v1 3/7] vfio/ccw: move private initialization to callback
Content-Language: en-US
To:     Eric Farman <farman@linux.ibm.com>,
        Alex Williamson <alex.williamson@redhat.com>,
        Cornelia Huck <cohuck@redhat.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Kevin Tian <kevin.tian@intel.com>, Yi Liu <yi.l.liu@intel.com>
Cc:     Zhenyu Wang <zhenyuw@linux.intel.com>,
        Zhi Wang <zhi.a.wang@intel.com>,
        Jani Nikula <jani.nikula@linux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@intel.com>,
        Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Halil Pasic <pasic@linux.ibm.com>,
        Vineeth Vijayan <vneethv@linux.ibm.com>,
        Peter Oberparleiter <oberpar@linux.ibm.com>,
        Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        Christian Borntraeger <borntraeger@linux.ibm.com>,
        Sven Schnelle <svens@linux.ibm.com>,
        Tony Krowiak <akrowiak@linux.ibm.com>,
        Jason Herne <jjherne@linux.ibm.com>,
        Harald Freudenberger <freude@linux.ibm.com>,
        Diana Craciun <diana.craciun@oss.nxp.com>,
        Eric Auger <eric.auger@redhat.com>,
        Kirti Wankhede <kwankhede@nvidia.com>,
        Abhishek Sahu <abhsahu@nvidia.com>,
        Yishai Hadas <yishaih@nvidia.com>,
        intel-gvt-dev@lists.freedesktop.org,
        intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,
        kvm@vger.kernel.org
References: <20221019162135.798901-1-farman@linux.ibm.com>
 <20221019162135.798901-4-farman@linux.ibm.com>
From:   Matthew Rosato <mjrosato@linux.ibm.com>
In-Reply-To: <20221019162135.798901-4-farman@linux.ibm.com>
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Precedence: bulk

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.

> 
> 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()

Either way:

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


>  
> -	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;