Commit 84cd8fc4 authored by Dong Jia Shi's avatar Dong Jia Shi Committed by Cornelia Huck

vfio: ccw: register vfio_ccw to the mediated device framework

To make vfio support subchannel devices, we need to leverage the
mediated device framework to create a mediated device for the
subchannel device.

This registers the subchannel device to the mediated device
framework during probe to enable mediated device creation.
Reviewed-by: default avatarPierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: default avatarDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170317031743.40128-7-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
parent 0a19e61e
......@@ -675,7 +675,7 @@ config EADM_SCH
config VFIO_CCW
def_tristate n
prompt "Support for VFIO-CCW subchannels"
depends on S390_CCW_IOMMU && VFIO
depends on S390_CCW_IOMMU && VFIO_MDEV
help
This driver allows usage of I/O subchannels via VFIO-CCW.
......
......@@ -18,5 +18,5 @@ obj-$(CONFIG_CCWGROUP) += ccwgroup.o
qdio-objs := qdio_main.o qdio_thinint.o qdio_debug.o qdio_setup.o
obj-$(CONFIG_QDIO) += qdio.o
vfio_ccw-objs += vfio_ccw_drv.o vfio_ccw_cp.o
vfio_ccw-objs += vfio_ccw_drv.o vfio_ccw_cp.o vfio_ccw_ops.o
obj-$(CONFIG_VFIO_CCW) += vfio_ccw.o
......@@ -19,7 +19,7 @@
/*
* Helpers
*/
static int vfio_ccw_sch_quiesce(struct subchannel *sch)
int vfio_ccw_sch_quiesce(struct subchannel *sch)
{
struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
DECLARE_COMPLETION_ONSTACK(completion);
......@@ -152,8 +152,16 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
if (ret)
goto out_disable;
ret = vfio_ccw_mdev_reg(sch);
if (ret)
goto out_rm_group;
atomic_set(&private->avail, 1);
return 0;
out_rm_group:
sysfs_remove_group(&sch->dev.kobj, &vfio_subchannel_attr_group);
out_disable:
cio_disable_subchannel(sch);
out_free:
......@@ -168,6 +176,8 @@ static int vfio_ccw_sch_remove(struct subchannel *sch)
vfio_ccw_sch_quiesce(sch);
vfio_ccw_mdev_unreg(sch);
sysfs_remove_group(&sch->dev.kobj, &vfio_subchannel_attr_group);
dev_set_drvdata(&sch->dev, NULL);
......
/*
* Physical device callbacks for vfio_ccw
*
* Copyright IBM Corp. 2017
*
* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
* Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
*/
#include <linux/vfio.h>
#include <linux/mdev.h>
#include "vfio_ccw_private.h"
static int vfio_ccw_mdev_notifier(struct notifier_block *nb,
unsigned long action,
void *data)
{
struct vfio_ccw_private *private =
container_of(nb, struct vfio_ccw_private, nb);
if (!private)
return NOTIFY_STOP;
/*
* TODO:
* Vendor drivers MUST unpin pages in response to an
* invalidation.
*/
if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP)
return NOTIFY_BAD;
return NOTIFY_DONE;
}
static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf)
{
return sprintf(buf, "I/O subchannel (Non-QDIO)\n");
}
MDEV_TYPE_ATTR_RO(name);
static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
char *buf)
{
return sprintf(buf, "%s\n", VFIO_DEVICE_API_CCW_STRING);
}
MDEV_TYPE_ATTR_RO(device_api);
static ssize_t available_instances_show(struct kobject *kobj,
struct device *dev, char *buf)
{
struct vfio_ccw_private *private = dev_get_drvdata(dev);
return sprintf(buf, "%d\n", atomic_read(&private->avail));
}
MDEV_TYPE_ATTR_RO(available_instances);
static struct attribute *mdev_types_attrs[] = {
&mdev_type_attr_name.attr,
&mdev_type_attr_device_api.attr,
&mdev_type_attr_available_instances.attr,
NULL,
};
static struct attribute_group mdev_type_group = {
.name = "io",
.attrs = mdev_types_attrs,
};
struct attribute_group *mdev_type_groups[] = {
&mdev_type_group,
NULL,
};
static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
{
struct vfio_ccw_private *private =
dev_get_drvdata(mdev_parent_dev(mdev));
if (atomic_dec_if_positive(&private->avail) < 0)
return -EPERM;
private->mdev = mdev;
return 0;
}
static int vfio_ccw_mdev_remove(struct mdev_device *mdev)
{
struct vfio_ccw_private *private;
struct subchannel *sch;
int ret;
private = dev_get_drvdata(mdev_parent_dev(mdev));
sch = private->sch;
ret = vfio_ccw_sch_quiesce(sch);
if (ret)
return ret;
ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
if (ret)
return ret;
private->mdev = NULL;
atomic_inc(&private->avail);
return 0;
}
static int vfio_ccw_mdev_open(struct mdev_device *mdev)
{
struct vfio_ccw_private *private =
dev_get_drvdata(mdev_parent_dev(mdev));
unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
private->nb.notifier_call = vfio_ccw_mdev_notifier;
return vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
&events, &private->nb);
}
void vfio_ccw_mdev_release(struct mdev_device *mdev)
{
struct vfio_ccw_private *private =
dev_get_drvdata(mdev_parent_dev(mdev));
vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
&private->nb);
}
static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
.owner = THIS_MODULE,
.supported_type_groups = mdev_type_groups,
.create = vfio_ccw_mdev_create,
.remove = vfio_ccw_mdev_remove,
.open = vfio_ccw_mdev_open,
.release = vfio_ccw_mdev_release,
};
int vfio_ccw_mdev_reg(struct subchannel *sch)
{
return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
}
void vfio_ccw_mdev_unreg(struct subchannel *sch)
{
mdev_unregister_device(&sch->dev);
}
......@@ -16,10 +16,21 @@
* struct vfio_ccw_private
* @sch: pointer to the subchannel
* @completion: synchronization helper of the I/O completion
* @avail: available for creating a mediated device
* @mdev: pointer to the mediated device
* @nb: notifier for vfio events
*/
struct vfio_ccw_private {
struct subchannel *sch;
struct completion *completion;
atomic_t avail;
struct mdev_device *mdev;
struct notifier_block nb;
} __aligned(8);
extern int vfio_ccw_mdev_reg(struct subchannel *sch);
extern void vfio_ccw_mdev_unreg(struct subchannel *sch);
extern int vfio_ccw_sch_quiesce(struct subchannel *sch);
#endif
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