From 060d2b5afcc4f9e2d61e2b059e648f569b8dba9a Mon Sep 17 00:00:00 2001 From: Dong Jia Shi Date: Fri, 17 Mar 2017 04:17:34 +0100 Subject: 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: Pierre Morel Signed-off-by: Dong Jia Shi Message-Id: <20170317031743.40128-8-bjsdjshi@linux.vnet.ibm.com> Signed-off-by: Cornelia Huck --- drivers/s390/cio/vfio_ccw_ops.c | 47 +++++++++++++++++++++++++++++++++++++ drivers/s390/cio/vfio_ccw_private.h | 4 ++++ 2 files changed, 51 insertions(+) (limited to 'drivers/s390') diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c index b8a2fed58f02..6c06805839d8 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -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) diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h index 5afb3ba5c7b5..359e96ba9c6c 100644 --- a/drivers/s390/cio/vfio_ccw_private.h +++ b/drivers/s390/cio/vfio_ccw_private.h @@ -10,6 +10,8 @@ #ifndef _VFIO_CCW_PRIVATE_H_ #define _VFIO_CCW_PRIVATE_H_ +#include + #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); -- cgit v1.2.3-59-g8ed1b