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Commit 060d2b5a authored by Dong Jia Shi's avatar Dong Jia Shi Committed by Cornelia Huck
Browse files

vfio: ccw: introduce ccw_io_region 



To provide user-space a set of interfaces to:
1. pass in a ccw program to perform an I/O operation.
2. read back I/O results of the completed I/O operations.
We introduce an MMIO region for the vfio-ccw device here.

This region is defined to content:
1. areas to store arguments that an ssch required.
2. areas to store the I/O results.

Using pwrite/pread to the device on this region, a user-space program
could write/read data to/from the vfio-ccw device.

Reviewed-by: default avatarPierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: default avatarDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170317031743.40128-8-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
parent 84cd8fc4

drivers/s390/cio/vfio_ccw_ops.c

+47 −0
Original line number Diff line number Diff line
@@ -127,6 +127,51 @@ void vfio_ccw_mdev_release(struct mdev_device *mdev) 
				 &private->nb);

}



static ssize_t vfio_ccw_mdev_read(struct mdev_device *mdev,

				  char __user *buf,

				  size_t count,

				  loff_t *ppos)

{

	struct vfio_ccw_private *private;

	struct ccw_io_region *region;



	if (*ppos + count > sizeof(*region))

		return -EINVAL;



	private = dev_get_drvdata(mdev_parent_dev(mdev));

	if (!private)

		return -ENODEV;



	region = &private->io_region;

	if (copy_to_user(buf, (void *)region + *ppos, count))

		return -EFAULT;



	return count;

}



static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev,

				   const char __user *buf,

				   size_t count,

				   loff_t *ppos)

{

	struct vfio_ccw_private *private;

	struct ccw_io_region *region;



	if (*ppos + count > sizeof(*region))

		return -EINVAL;



	private = dev_get_drvdata(mdev_parent_dev(mdev));

	if (!private)

		return -ENODEV;



	region = &private->io_region;

	if (copy_from_user((void *)region + *ppos, buf, count))

		return -EFAULT;

	region->ret_code = 0;



	return count;

}



static const struct mdev_parent_ops vfio_ccw_mdev_ops = {

	.owner			= THIS_MODULE,

	.supported_type_groups  = mdev_type_groups,
@@ -134,6 +179,8 @@ static const struct mdev_parent_ops vfio_ccw_mdev_ops = { 
	.remove			= vfio_ccw_mdev_remove,

	.open			= vfio_ccw_mdev_open,

	.release		= vfio_ccw_mdev_release,

	.read			= vfio_ccw_mdev_read,

	.write			= vfio_ccw_mdev_write,

};



int vfio_ccw_mdev_reg(struct subchannel *sch)

drivers/s390/cio/vfio_ccw_private.h

+4 −0
Original line number Diff line number Diff line
@@ -10,6 +10,8 @@ 
#ifndef _VFIO_CCW_PRIVATE_H_

#define _VFIO_CCW_PRIVATE_H_



#include <linux/vfio_ccw.h>



#include "css.h"



/**
@@ -19,6 +21,7 @@ 
 * @avail: available for creating a mediated device

 * @mdev: pointer to the mediated device

 * @nb: notifier for vfio events

 * @io_region: MMIO region to input/output I/O arguments/results

 */

struct vfio_ccw_private {

	struct subchannel	*sch;
@@ -26,6 +29,7 @@ struct vfio_ccw_private { 
	atomic_t		avail;

	struct mdev_device	*mdev;

	struct notifier_block	nb;

	struct ccw_io_region	io_region;

} __aligned(8);



extern int vfio_ccw_mdev_reg(struct subchannel *sch);

include/uapi/linux/vfio_ccw.h

0 → 100644
+24 −0
Original line number Diff line number Diff line 
/*

 * Interfaces for vfio-ccw

 *

 * Copyright IBM Corp. 2017

 *

 * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>

 */



#ifndef _VFIO_CCW_H_

#define _VFIO_CCW_H_



#include <linux/types.h>



struct ccw_io_region {

#define ORB_AREA_SIZE 12

	__u8	orb_area[ORB_AREA_SIZE];

#define SCSW_AREA_SIZE 12

	__u8	scsw_area[SCSW_AREA_SIZE];

#define IRB_AREA_SIZE 96

	__u8	irb_area[IRB_AREA_SIZE];

	__u32	ret_code;

} __packed;



#endif