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Commit 4e149e43 authored by Dong Jia Shi's avatar Dong Jia Shi Committed by Cornelia Huck
Browse files

vfio: ccw: handle ccw command request 



We implement the basic ccw command handling infrastructure
here:
1. Translate the ccw commands.
2. Issue the translated ccw commands to the device.
3. Once we get the execution result, update the guest SCSW
   with it.

Acked-by: default avatarPierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: default avatarDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170317031743.40128-9-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
parent 060d2b5a

drivers/s390/cio/vfio_ccw_drv.c

+114 −0
Original line number Diff line number Diff line
@@ -11,9 +11,13 @@ 
#include <linux/init.h>

#include <linux/device.h>

#include <linux/slab.h>

#include <linux/uuid.h>

#include <linux/mdev.h>



#include <asm/isc.h>



#include "ioasm.h"

#include "css.h"

#include "vfio_ccw_private.h"



/*
@@ -59,6 +63,109 @@ int vfio_ccw_sch_quiesce(struct subchannel *sch) 
	return ret;

}



static int doing_io(struct vfio_ccw_private *private, u32 intparm)

{

	return (private->intparm == intparm);

}



static int vfio_ccw_sch_io_helper(struct vfio_ccw_private *private)

{

	struct subchannel *sch;

	union orb *orb;

	int ccode;

	__u8 lpm;

	u32 intparm;



	sch = private->sch;



	orb = cp_get_orb(&private->cp, (u32)(addr_t)sch, sch->lpm);



	/* Issue "Start Subchannel" */

	ccode = ssch(sch->schid, orb);



	switch (ccode) {

	case 0:

		/*

		 * Initialize device status information

		 */

		sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;

		break;

	case 1:		/* Status pending */

	case 2:		/* Busy */

		return -EBUSY;

	case 3:		/* Device/path not operational */

	{

		lpm = orb->cmd.lpm;

		if (lpm != 0)

			sch->lpm &= ~lpm;

		else

			sch->lpm = 0;



		if (cio_update_schib(sch))

			return -ENODEV;



		return sch->lpm ? -EACCES : -ENODEV;

	}

	default:

		return ccode;

	}



	intparm = (u32)(addr_t)sch;

	private->intparm = 0;

	wait_event(private->wait_q, doing_io(private, intparm));



	if (scsw_is_solicited(&private->irb.scsw))

		cp_update_scsw(&private->cp, &private->irb.scsw);



	return 0;

}



/* Deal with the ccw command request from the userspace. */

int vfio_ccw_sch_cmd_request(struct vfio_ccw_private *private)

{

	struct mdev_device *mdev = private->mdev;

	union orb *orb;

	union scsw *scsw = &private->scsw;

	struct irb *irb = &private->irb;

	struct ccw_io_region *io_region = &private->io_region;

	int ret;



	memcpy(scsw, io_region->scsw_area, sizeof(*scsw));



	if (scsw->cmd.fctl & SCSW_FCTL_START_FUNC) {

		orb = (union orb *)io_region->orb_area;



		ret = cp_init(&private->cp, mdev_dev(mdev), orb);

		if (ret)

			return ret;



		ret = cp_prefetch(&private->cp);

		if (ret) {

			cp_free(&private->cp);

			return ret;

		}



		/* Start channel program and wait for I/O interrupt. */

		ret = vfio_ccw_sch_io_helper(private);

		if (!ret) {

			/* Get irb info and copy it to irb_area. */

			memcpy(io_region->irb_area, irb, sizeof(*irb));

		}



		cp_free(&private->cp);

	} else if (scsw->cmd.fctl & SCSW_FCTL_HALT_FUNC) {

		/* XXX: Handle halt. */

		ret = -EOPNOTSUPP;

	} else if (scsw->cmd.fctl & SCSW_FCTL_CLEAR_FUNC) {

		/* XXX: Handle clear. */

		ret = -EOPNOTSUPP;

	} else {

		ret = -EOPNOTSUPP;

	}



	return ret;

}



/*

 * Sysfs interfaces

 */
@@ -113,12 +220,18 @@ static struct attribute_group vfio_subchannel_attr_group = { 
static void vfio_ccw_sch_irq(struct subchannel *sch)

{

	struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);

	struct irb *irb;



	inc_irq_stat(IRQIO_CIO);



	if (!private)

		return;



	irb = this_cpu_ptr(&cio_irb);

	memcpy(&private->irb, irb, sizeof(*irb));

	private->intparm = (u32)(addr_t)sch;

	wake_up(&private->wait_q);



	if (private->completion)

		complete(private->completion);

}
@@ -156,6 +269,7 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) 
	if (ret)

		goto out_rm_group;



	init_waitqueue_head(&private->wait_q);

	atomic_set(&private->avail, 1);



	return 0;

drivers/s390/cio/vfio_ccw_ops.c

+20 −4
Original line number Diff line number Diff line
@@ -23,13 +23,26 @@ static int vfio_ccw_mdev_notifier(struct notifier_block *nb, 
		return NOTIFY_STOP;



	/*

	 * TODO:

	 * Vendor drivers MUST unpin pages in response to an

	 * invalidation.

	 */

	if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP)

	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))

			return NOTIFY_BAD;



		cp_free(&private->cp);

		return NOTIFY_OK;

	}



	return NOTIFY_DONE;

}
@@ -167,7 +180,10 @@ static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev, 
	region = &private->io_region;

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

		return -EFAULT;

	region->ret_code = 0;



	region->ret_code = vfio_ccw_sch_cmd_request(private);

	if (region->ret_code != 0)

		return region->ret_code;



	return count;

}

drivers/s390/cio/vfio_ccw_private.h

+14 −0
Original line number Diff line number Diff line
@@ -10,9 +10,11 @@ 
#ifndef _VFIO_CCW_PRIVATE_H_

#define _VFIO_CCW_PRIVATE_H_



#include <linux/completion.h>

#include <linux/vfio_ccw.h>



#include "css.h"

#include "vfio_ccw_cp.h"



/**

 * struct vfio_ccw_private
@@ -22,6 +24,11 @@ 
 * @mdev: pointer to the mediated device

 * @nb: notifier for vfio events

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

 * @wait_q: wait for interrupt

 * @intparm: record current interrupt parameter, used for wait interrupt

 * @cp: channel program for the current I/O operation

 * @irb: irb info received from interrupt

 * @scsw: scsw info

 */

struct vfio_ccw_private {

	struct subchannel	*sch;
@@ -30,11 +37,18 @@ struct vfio_ccw_private { 
	struct mdev_device	*mdev;

	struct notifier_block	nb;

	struct ccw_io_region	io_region;



	wait_queue_head_t	wait_q;

	u32			intparm;

	struct channel_program	cp;

	struct irb		irb;

	union scsw		scsw;

} __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);

extern int vfio_ccw_sch_cmd_request(struct vfio_ccw_private *private);



#endif