Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 83d1193a authored by Dong Jia Shi's avatar Dong Jia Shi Committed by Cornelia Huck
Browse files

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: default avatarDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170317031743.40128-11-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
parent e01bcdd6

drivers/s390/cio/vfio_ccw_ops.c

+33 −14
Original line number Diff line number Diff line
@@ -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;

	}