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vfio: ccw: realize VFIO_DEVICE_RESET ioctl 

Introduce VFIO_DEVICE_RESET ioctl for vfio-ccw to make it possible
to hot-reset the device.

We try to achieve a reset by first disabling the subchannel and
then enabling it again: this should clear all state at the subchannel.

Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170317031743.40128-11-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
This commit is contained in:
Dong Jia Shi 2017-03-17 04:17:37 +01:00 committed by Cornelia Huck
parent e01bcdd613
commit 83d1193a96
1 changed files with 33 additions and 14 deletions
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47
drivers/s390/cio/vfio_ccw_ops.c
View File

@ -12,6 +12,32 @@
#include "vfio_ccw_private.h"
static int vfio_ccw_mdev_reset(struct mdev_device *mdev)
{
struct vfio_ccw_private *private;
struct subchannel *sch;
int ret;
private = dev_get_drvdata(mdev_parent_dev(mdev));
if (!private)
return -ENODEV;
sch = private->sch;
/*
* TODO:
* In the cureent stage, some things like "no I/O running" and "no
* interrupt pending" are clear, but we are not sure what other state
* we need to care about.
* There are still a lot more instructions need to be handled. We
* should come back here later.
*/
ret = vfio_ccw_sch_quiesce(sch);
if (ret)
return ret;
return cio_enable_subchannel(sch, (u32)(unsigned long)sch);
}
static int vfio_ccw_mdev_notifier(struct notifier_block *nb,
unsigned long action,
void *data)
@ -28,15 +54,11 @@ static int vfio_ccw_mdev_notifier(struct notifier_block *nb,
*/
if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {
struct vfio_iommu_type1_dma_unmap *unmap = data;
struct subchannel *sch = private->sch;
if (!cp_iova_pinned(&private->cp, unmap->iova))
return NOTIFY_OK;
if (vfio_ccw_sch_quiesce(sch))
return NOTIFY_BAD;
if (cio_enable_subchannel(sch, (u32)(unsigned long)sch))
if (vfio_ccw_mdev_reset(private->mdev))
return NOTIFY_BAD;
cp_free(&private->cp);
@ -100,16 +122,11 @@ static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
static int vfio_ccw_mdev_remove(struct mdev_device *mdev)
{
struct vfio_ccw_private *private;
struct subchannel *sch;
struct vfio_ccw_private *private =
dev_get_drvdata(mdev_parent_dev(mdev));
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);
ret = vfio_ccw_mdev_reset(mdev);
if (ret)
return ret;
@ -190,7 +207,7 @@ static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev,
static int vfio_ccw_mdev_get_device_info(struct vfio_device_info *info)
{
info->flags = VFIO_DEVICE_FLAGS_CCW;
info->flags = VFIO_DEVICE_FLAGS_CCW | VFIO_DEVICE_FLAGS_RESET;
info->num_regions = VFIO_CCW_NUM_REGIONS;
info->num_irqs = 0;
@ -260,6 +277,8 @@ static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
return copy_to_user((void __user *)arg, &info, minsz);
}
case VFIO_DEVICE_RESET:
return vfio_ccw_mdev_reset(mdev);
default:
return -ENOTTY;
}