[PULL 0/6] vfio-ccw updates for 4.18

[PULL 0/6] vfio-ccw updates for 4.18

[Cornelia Huck]

The following changes since commit 3376d98021e915196f4894d835325a884e635a04:

  s390/archrandom: Rework arch random implementation. (2018-05-25 08:12:58 +0200)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw.git tags/vfio-ccw-20180529

for you to fetch changes up to 3cd90214b70f7f971496bffc3c34d23b2141feb3:

  vfio: ccw: add tracepoints for interesting error paths (2018-05-29 09:27:42 +0200)

----------------------------------------------------------------
Various fixes and improvements in vfio-ccw, including a first stab
at adding tracepoints.

----------------------------------------------------------------

Dong Jia Shi (4):
  vfio: ccw: fix error return in vfio_ccw_sch_event
  vfio: ccw: shorten kernel doc description for pfn_array_pin()
  vfio: ccw: refactor and improve pfn_array_alloc_pin()
  vfio: ccw: set ccw->cda to NULL defensively

Halil Pasic (2):
  vfio: ccw: push down unsupported IDA check
  vfio: ccw: add tracepoints for interesting error paths

 drivers/s390/cio/Makefile         |   1 +
 drivers/s390/cio/vfio_ccw_cp.c    | 140 ++++++++++++++++++++------------------
 drivers/s390/cio/vfio_ccw_drv.c   |   5 +-
 drivers/s390/cio/vfio_ccw_fsm.c   |  17 ++++-
 drivers/s390/cio/vfio_ccw_trace.h |  54 +++++++++++++++
 5 files changed, 150 insertions(+), 67 deletions(-)
 create mode 100644 drivers/s390/cio/vfio_ccw_trace.h

-- 
2.14.3

[PULL 1/6] vfio: ccw: fix error return in vfio_ccw_sch_event

[Cornelia Huck]

From: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>

If the device has not been registered, or there is work pending,
we should reschedule a sch_event call again.

Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20180502072559.50691-1-bjsdjshi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
 drivers/s390/cio/vfio_ccw_drv.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index ea6a2d0b2894..770fa9cfc310 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -177,6 +177,7 @@ static int vfio_ccw_sch_event(struct subchannel *sch, int process)
 {
 	struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
 	unsigned long flags;
+	int rc = -EAGAIN;
 
 	spin_lock_irqsave(sch->lock, flags);
 	if (!device_is_registered(&sch->dev))
@@ -187,6 +188,7 @@ static int vfio_ccw_sch_event(struct subchannel *sch, int process)
 
 	if (cio_update_schib(sch)) {
 		vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER);
+		rc = 0;
 		goto out_unlock;
 	}
 
@@ -195,11 +197,12 @@ static int vfio_ccw_sch_event(struct subchannel *sch, int process)
 		private->state = private->mdev ? VFIO_CCW_STATE_IDLE :
 				 VFIO_CCW_STATE_STANDBY;
 	}
+	rc = 0;
 
 out_unlock:
 	spin_unlock_irqrestore(sch->lock, flags);
 
-	return 0;
+	return rc;
 }
 
 static struct css_device_id vfio_ccw_sch_ids[] = {
-- 
2.14.3

[PULL 2/6] vfio: ccw: push down unsupported IDA check

[Cornelia Huck]

From: Halil Pasic <pasic@linux.ibm.com>

There is at least one relevant guest OS that doesn't set the IDA flags in
the ORB as we would like them, but never uses any IDA. So instead of
saying -EOPNOTSUPP when observing an ORB, such that a channel program
specified by it could be a not supported one, let us say -EOPNOTSUPP only
if the channel program is a not supported one.

Of course, the real solution would be doing proper translation for all
IDA. This is possible, but given the current code not straight forward.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Tested-by: Jason J. Herne <jjherne@linux.ibm.com>
Message-Id: <20180516173342.15174-1-pasic@linux.ibm.com>
Reviewed-by: Dong Jia Shi <bjsdjshi@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
 drivers/s390/cio/vfio_ccw_cp.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
index dce92b2a895d..9a2a39df1056 100644
--- a/drivers/s390/cio/vfio_ccw_cp.c
+++ b/drivers/s390/cio/vfio_ccw_cp.c
@@ -365,6 +365,9 @@ static void cp_unpin_free(struct channel_program *cp)
  * This is the chain length not considering any TICs.
  * You need to do a new round for each TIC target.
  *
+ * The program is also validated for absence of not yet supported
+ * indirect data addressing scenarios.
+ *
  * Returns: the length of the ccw chain or -errno.
  */
 static int ccwchain_calc_length(u64 iova, struct channel_program *cp)
@@ -391,6 +394,14 @@ static int ccwchain_calc_length(u64 iova, struct channel_program *cp)
 	do {
 		cnt++;
 
+		/*
+		 * As we don't want to fail direct addressing even if the
+		 * orb specified one of the unsupported formats, we defer
+		 * checking for IDAWs in unsupported formats to here.
+		 */
+		if ((!cp->orb.cmd.c64 || cp->orb.cmd.i2k) && ccw_is_idal(ccw))
+			return -EOPNOTSUPP;
+
 		if ((!ccw_is_chain(ccw)) && (!ccw_is_tic(ccw)))
 			break;
 
@@ -656,10 +667,8 @@ int cp_init(struct channel_program *cp, struct device *mdev, union orb *orb)
 	/*
 	 * XXX:
 	 * Only support prefetch enable mode now.
-	 * Only support 64bit addressing idal.
-	 * Only support 4k IDAW.
 	 */
-	if (!orb->cmd.pfch || !orb->cmd.c64 || orb->cmd.i2k)
+	if (!orb->cmd.pfch)
 		return -EOPNOTSUPP;
 
 	INIT_LIST_HEAD(&cp->ccwchain_list);
@@ -688,6 +697,10 @@ int cp_init(struct channel_program *cp, struct device *mdev, union orb *orb)
 	ret = ccwchain_loop_tic(chain, cp);
 	if (ret)
 		cp_unpin_free(cp);
+	/* It is safe to force: if not set but idals used
+	 * ccwchain_calc_length returns an error.
+	 */
+	cp->orb.cmd.c64 = 1;
 
 	return ret;
 }
-- 
2.14.3

[PULL 3/6] vfio: ccw: shorten kernel doc description for pfn_array_pin()

[Cornelia Huck]

From: Dong Jia Shi <bjsdjshi@linux.ibm.com>

The kernel doc description for usage of the struct pfn_array in
pfn_array_pin() is unnecessary long. Let's shorten it by describing
the contents of the struct pfn_array fields at the struct's definition
instead.

Suggested-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.ibm.com>
Message-Id: <20180523025645.8978-2-bjsdjshi@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
 drivers/s390/cio/vfio_ccw_cp.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
index 9a2a39df1056..c532939c1c3f 100644
--- a/drivers/s390/cio/vfio_ccw_cp.c
+++ b/drivers/s390/cio/vfio_ccw_cp.c
@@ -23,9 +23,13 @@
 #define CCWCHAIN_LEN_MAX	256
 
 struct pfn_array {
+	/* Starting guest physical I/O address. */
 	unsigned long		pa_iova;
+	/* Array that stores PFNs of the pages need to pin. */
 	unsigned long		*pa_iova_pfn;
+	/* Array that receives PFNs of the pages pinned. */
 	unsigned long		*pa_pfn;
+	/* Number of pages to pin/pinned from @pa_iova. */
 	int			pa_nr;
 };
 
@@ -53,14 +57,8 @@ struct ccwchain {
  * Attempt to pin user pages in memory.
  *
  * Usage of pfn_array:
- * @pa->pa_iova     starting guest physical I/O address. Assigned by caller.
- * @pa->pa_iova_pfn array that stores PFNs of the pages need to pin. Allocated
- *                  by caller.
- * @pa->pa_pfn      array that receives PFNs of the pages pinned. Allocated by
- *                  caller.
- * @pa->pa_nr       number of pages from @pa->pa_iova to pin. Assigned by
- *                  caller.
- *                  number of pages pinned. Assigned by callee.
+ * Any field in this structure should be initialized by caller.
+ * We expect @pa->pa_nr > 0, and its value will be assigned by callee.
  *
  * Returns:
  *   Number of pages pinned on success.
-- 
2.14.3

[PULL 4/6] vfio: ccw: refactor and improve pfn_array_alloc_pin()

[Cornelia Huck]

From: Dong Jia Shi <bjsdjshi@linux.ibm.com>

This refactors pfn_array_alloc_pin() and also improves it by adding
defensive code in error handling so that calling pfn_array_unpin_free()
after error return won't lead to problem. This mainly does:
1. Merge pfn_array_pin() into pfn_array_alloc_pin(), since there is no
   other user of pfn_array_pin(). As a result, also remove kernel-doc
   for pfn_array_pin() and add/update kernel-doc for pfn_array_alloc_pin()
   and struct pfn_array.
2. For a vfio_pin_pages() failure, set pa->pa_nr to zero to indicate
   zero pages were pinned.
3. Set pa->pa_iova_pfn to NULL right after it was freed.

Suggested-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.ibm.com>
Message-Id: <20180523025645.8978-3-bjsdjshi@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
 drivers/s390/cio/vfio_ccw_cp.c | 82 +++++++++++++++++++-----------------------
 1 file changed, 36 insertions(+), 46 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
index c532939c1c3f..b0f20230fc72 100644
--- a/drivers/s390/cio/vfio_ccw_cp.c
+++ b/drivers/s390/cio/vfio_ccw_cp.c
@@ -29,7 +29,7 @@ struct pfn_array {
 	unsigned long		*pa_iova_pfn;
 	/* Array that receives PFNs of the pages pinned. */
 	unsigned long		*pa_pfn;
-	/* Number of pages to pin/pinned from @pa_iova. */
+	/* Number of pages pinned from @pa_iova. */
 	int			pa_nr;
 };
 
@@ -50,64 +50,33 @@ struct ccwchain {
 };
 
 /*
- * pfn_array_pin() - pin user pages in memory
+ * pfn_array_alloc_pin() - alloc memory for PFNs, then pin user pages in memory
  * @pa: pfn_array on which to perform the operation
  * @mdev: the mediated device to perform pin/unpin operations
+ * @iova: target guest physical address
+ * @len: number of bytes that should be pinned from @iova
  *
- * Attempt to pin user pages in memory.
+ * Attempt to allocate memory for PFNs, and pin user pages in memory.
  *
  * Usage of pfn_array:
- * Any field in this structure should be initialized by caller.
- * We expect @pa->pa_nr > 0, and its value will be assigned by callee.
+ * We expect (pa_nr == 0) and (pa_iova_pfn == NULL), any field in
+ * this structure will be filled in by this function.
  *
  * Returns:
  *   Number of pages pinned on success.
- *   If @pa->pa_nr is 0 or negative, returns 0.
+ *   If @pa->pa_nr is not 0, or @pa->pa_iova_pfn is not NULL initially,
+ *   returns -EINVAL.
  *   If no pages were pinned, returns -errno.
  */
-static int pfn_array_pin(struct pfn_array *pa, struct device *mdev)
-{
-	int i, ret;
-
-	if (pa->pa_nr <= 0) {
-		pa->pa_nr = 0;
-		return 0;
-	}
-
-	pa->pa_iova_pfn[0] = pa->pa_iova >> PAGE_SHIFT;
-	for (i = 1; i < pa->pa_nr; i++)
-		pa->pa_iova_pfn[i] = pa->pa_iova_pfn[i - 1] + 1;
-
-	ret = vfio_pin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr,
-			     IOMMU_READ | IOMMU_WRITE, pa->pa_pfn);
-
-	if (ret > 0 && ret != pa->pa_nr) {
-		vfio_unpin_pages(mdev, pa->pa_iova_pfn, ret);
-		pa->pa_nr = 0;
-		return 0;
-	}
-
-	return ret;
-}
-
-/* Unpin the pages before releasing the memory. */
-static void pfn_array_unpin_free(struct pfn_array *pa, struct device *mdev)
-{
-	vfio_unpin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr);
-	pa->pa_nr = 0;
-	kfree(pa->pa_iova_pfn);
-}
-
-/* Alloc memory for PFNs, then pin pages with them. */
 static int pfn_array_alloc_pin(struct pfn_array *pa, struct device *mdev,
 			       u64 iova, unsigned int len)
 {
-	int ret = 0;
+	int i, ret = 0;
 
 	if (!len)
 		return 0;
 
-	if (pa->pa_nr)
+	if (pa->pa_nr || pa->pa_iova_pfn)
 		return -EINVAL;
 
 	pa->pa_iova = iova;
@@ -124,18 +93,39 @@ static int pfn_array_alloc_pin(struct pfn_array *pa, struct device *mdev,
 		return -ENOMEM;
 	pa->pa_pfn = pa->pa_iova_pfn + pa->pa_nr;
 
-	ret = pfn_array_pin(pa, mdev);
+	pa->pa_iova_pfn[0] = pa->pa_iova >> PAGE_SHIFT;
+	for (i = 1; i < pa->pa_nr; i++)
+		pa->pa_iova_pfn[i] = pa->pa_iova_pfn[i - 1] + 1;
+
+	ret = vfio_pin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr,
+			     IOMMU_READ | IOMMU_WRITE, pa->pa_pfn);
 
-	if (ret > 0)
-		return ret;
-	else if (!ret)
+	if (ret < 0) {
+		goto err_out;
+	} else if (ret > 0 && ret != pa->pa_nr) {
+		vfio_unpin_pages(mdev, pa->pa_iova_pfn, ret);
 		ret = -EINVAL;
+		goto err_out;
+	}
+
+	return ret;
 
+err_out:
+	pa->pa_nr = 0;
 	kfree(pa->pa_iova_pfn);
+	pa->pa_iova_pfn = NULL;
 
 	return ret;
 }
 
+/* Unpin the pages before releasing the memory. */
+static void pfn_array_unpin_free(struct pfn_array *pa, struct device *mdev)
+{
+	vfio_unpin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr);
+	pa->pa_nr = 0;
+	kfree(pa->pa_iova_pfn);
+}
+
 static int pfn_array_table_init(struct pfn_array_table *pat, int nr)
 {
 	pat->pat_pa = kcalloc(nr, sizeof(*pat->pat_pa), GFP_KERNEL);
-- 
2.14.3

[PULL 5/6] vfio: ccw: set ccw->cda to NULL defensively

[Cornelia Huck]

From: Dong Jia Shi <bjsdjshi@linux.ibm.com>

Let's avoid free on ccw->cda that points to a guest address
or an already freed memory area by setting it to NULL if memory
allocation didn't happen or failed.

Signed-off-by: Dong Jia Shi <bjsdjshi@linux.ibm.com>
Message-Id: <20180523025645.8978-4-bjsdjshi@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
 drivers/s390/cio/vfio_ccw_cp.c | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
index b0f20230fc72..dbe7c7ac9ac8 100644
--- a/drivers/s390/cio/vfio_ccw_cp.c
+++ b/drivers/s390/cio/vfio_ccw_cp.c
@@ -502,7 +502,7 @@ static int ccwchain_fetch_direct(struct ccwchain *chain,
 	struct ccw1 *ccw;
 	struct pfn_array_table *pat;
 	unsigned long *idaws;
-	int idaw_nr;
+	int ret;
 
 	ccw = chain->ch_ccw + idx;
 
@@ -522,18 +522,19 @@ static int ccwchain_fetch_direct(struct ccwchain *chain,
 	 * needed when translating a direct ccw to a idal ccw.
 	 */
 	pat = chain->ch_pat + idx;
-	if (pfn_array_table_init(pat, 1))
-		return -ENOMEM;
-	idaw_nr = pfn_array_alloc_pin(pat->pat_pa, cp->mdev,
-				      ccw->cda, ccw->count);
-	if (idaw_nr < 0)
-		return idaw_nr;
+	ret = pfn_array_table_init(pat, 1);
+	if (ret)
+		goto out_init;
+
+	ret = pfn_array_alloc_pin(pat->pat_pa, cp->mdev, ccw->cda, ccw->count);
+	if (ret < 0)
+		goto out_init;
 
 	/* Translate this direct ccw to a idal ccw. */
-	idaws = kcalloc(idaw_nr, sizeof(*idaws), GFP_DMA | GFP_KERNEL);
+	idaws = kcalloc(ret, sizeof(*idaws), GFP_DMA | GFP_KERNEL);
 	if (!idaws) {
-		pfn_array_table_unpin_free(pat, cp->mdev);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto out_unpin;
 	}
 	ccw->cda = (__u32) virt_to_phys(idaws);
 	ccw->flags |= CCW_FLAG_IDA;
@@ -541,6 +542,12 @@ static int ccwchain_fetch_direct(struct ccwchain *chain,
 	pfn_array_table_idal_create_words(pat, idaws);
 
 	return 0;
+
+out_unpin:
+	pfn_array_table_unpin_free(pat, cp->mdev);
+out_init:
+	ccw->cda = 0;
+	return ret;
 }
 
 static int ccwchain_fetch_idal(struct ccwchain *chain,
@@ -570,7 +577,7 @@ static int ccwchain_fetch_idal(struct ccwchain *chain,
 	pat = chain->ch_pat + idx;
 	ret = pfn_array_table_init(pat, idaw_nr);
 	if (ret)
-		return ret;
+		goto out_init;
 
 	/* Translate idal ccw to use new allocated idaws. */
 	idaws = kzalloc(idaw_len, GFP_DMA | GFP_KERNEL);
@@ -602,6 +609,8 @@ static int ccwchain_fetch_idal(struct ccwchain *chain,
 	kfree(idaws);
 out_unpin:
 	pfn_array_table_unpin_free(pat, cp->mdev);
+out_init:
+	ccw->cda = 0;
 	return ret;
 }
 
-- 
2.14.3

[PULL 6/6] vfio: ccw: add tracepoints for interesting error paths

[Cornelia Huck]

From: Halil Pasic <pasic@linux.ibm.com>

Add some tracepoints so we can inspect what is not working as is should.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.ibm.com>
Message-Id: <20180523025645.8978-5-bjsdjshi@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
 drivers/s390/cio/Makefile         |  1 +
 drivers/s390/cio/vfio_ccw_fsm.c   | 17 +++++++++++-
 drivers/s390/cio/vfio_ccw_trace.h | 54 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 71 insertions(+), 1 deletion(-)
 create mode 100644 drivers/s390/cio/vfio_ccw_trace.h

diff --git a/drivers/s390/cio/Makefile b/drivers/s390/cio/Makefile
index a070ef0efe65..f230516abb96 100644
--- a/drivers/s390/cio/Makefile
+++ b/drivers/s390/cio/Makefile
@@ -5,6 +5,7 @@
 
 # The following is required for define_trace.h to find ./trace.h
 CFLAGS_trace.o := -I$(src)
+CFLAGS_vfio_ccw_fsm.o := -I$(src)
 
 obj-y += airq.o blacklist.o chsc.o cio.o css.o chp.o idset.o isc.o \
 	fcx.o itcw.o crw.o ccwreq.o trace.o ioasm.o
diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c
index 3c800642134e..797a82731159 100644
--- a/drivers/s390/cio/vfio_ccw_fsm.c
+++ b/drivers/s390/cio/vfio_ccw_fsm.c
@@ -13,6 +13,9 @@
 #include "ioasm.h"
 #include "vfio_ccw_private.h"
 
+#define CREATE_TRACE_POINTS
+#include "vfio_ccw_trace.h"
+
 static int fsm_io_helper(struct vfio_ccw_private *private)
 {
 	struct subchannel *sch;
@@ -110,6 +113,10 @@ static void fsm_disabled_irq(struct vfio_ccw_private *private,
 	 */
 	cio_disable_subchannel(sch);
 }
+inline struct subchannel_id get_schid(struct vfio_ccw_private *p)
+{
+	return p->sch->schid;
+}
 
 /*
  * Deal with the ccw command request from the userspace.
@@ -121,6 +128,7 @@ static void fsm_io_request(struct vfio_ccw_private *private,
 	union scsw *scsw = &private->scsw;
 	struct ccw_io_region *io_region = &private->io_region;
 	struct mdev_device *mdev = private->mdev;
+	char *errstr = "request";
 
 	private->state = VFIO_CCW_STATE_BOXED;
 
@@ -132,15 +140,19 @@ static void fsm_io_request(struct vfio_ccw_private *private,
 		/* Don't try to build a cp if transport mode is specified. */
 		if (orb->tm.b) {
 			io_region->ret_code = -EOPNOTSUPP;
+			errstr = "transport mode";
 			goto err_out;
 		}
 		io_region->ret_code = cp_init(&private->cp, mdev_dev(mdev),
 					      orb);
-		if (io_region->ret_code)
+		if (io_region->ret_code) {
+			errstr = "cp init";
 			goto err_out;
+		}
 
 		io_region->ret_code = cp_prefetch(&private->cp);
 		if (io_region->ret_code) {
+			errstr = "cp prefetch";
 			cp_free(&private->cp);
 			goto err_out;
 		}
@@ -148,6 +160,7 @@ static void fsm_io_request(struct vfio_ccw_private *private,
 		/* Start channel program and wait for I/O interrupt. */
 		io_region->ret_code = fsm_io_helper(private);
 		if (io_region->ret_code) {
+			errstr = "cp fsm_io_helper";
 			cp_free(&private->cp);
 			goto err_out;
 		}
@@ -164,6 +177,8 @@ static void fsm_io_request(struct vfio_ccw_private *private,
 
 err_out:
 	private->state = VFIO_CCW_STATE_IDLE;
+	trace_vfio_ccw_io_fctl(scsw->cmd.fctl, get_schid(private),
+			       io_region->ret_code, errstr);
 }
 
 /*
diff --git a/drivers/s390/cio/vfio_ccw_trace.h b/drivers/s390/cio/vfio_ccw_trace.h
new file mode 100644
index 000000000000..b1da53ddec1f
--- /dev/null
+++ b/drivers/s390/cio/vfio_ccw_trace.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0
+ * Tracepoints for vfio_ccw driver
+ *
+ * Copyright IBM Corp. 2018
+ *
+ * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
+ *            Halil Pasic <pasic@linux.vnet.ibm.com>
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM vfio_ccw
+
+#if !defined(_VFIO_CCW_TRACE_) || defined(TRACE_HEADER_MULTI_READ)
+#define _VFIO_CCW_TRACE_
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(vfio_ccw_io_fctl,
+	TP_PROTO(int fctl, struct subchannel_id schid, int errno, char *errstr),
+	TP_ARGS(fctl, schid, errno, errstr),
+
+	TP_STRUCT__entry(
+		__field(int, fctl)
+		__field_struct(struct subchannel_id, schid)
+		__field(int, errno)
+		__field(char*, errstr)
+	),
+
+	TP_fast_assign(
+		__entry->fctl = fctl;
+		__entry->schid = schid;
+		__entry->errno = errno;
+		__entry->errstr = errstr;
+	),
+
+	TP_printk("schid=%x.%x.%04x fctl=%x errno=%d info=%s",
+		  __entry->schid.cssid,
+		  __entry->schid.ssid,
+		  __entry->schid.sch_no,
+		  __entry->fctl,
+		  __entry->errno,
+		  __entry->errstr)
+);
+
+#endif /* _VFIO_CCW_TRACE_ */
+
+/* This part must be outside protection */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE vfio_ccw_trace
+
+#include <trace/define_trace.h>
-- 
2.14.3

Re: [PULL 0/6] vfio-ccw updates for 4.18

[Cornelia Huck]

On Tue, 29 May 2018 14:35:06 +0200
Cornelia Huck <cohuck@redhat.com> wrote:

Ping.

> The following changes since commit 3376d98021e915196f4894d835325a884e635a04:
> 
>   s390/archrandom: Rework arch random implementation. (2018-05-25 08:12:58 +0200)
> 
> are available in the Git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw.git tags/vfio-ccw-20180529
> 
> for you to fetch changes up to 3cd90214b70f7f971496bffc3c34d23b2141feb3:
> 
>   vfio: ccw: add tracepoints for interesting error paths (2018-05-29 09:27:42 +0200)
> 
> ----------------------------------------------------------------
> Various fixes and improvements in vfio-ccw, including a first stab
> at adding tracepoints.
> 
> ----------------------------------------------------------------
> 
> Dong Jia Shi (4):
>   vfio: ccw: fix error return in vfio_ccw_sch_event
>   vfio: ccw: shorten kernel doc description for pfn_array_pin()
>   vfio: ccw: refactor and improve pfn_array_alloc_pin()
>   vfio: ccw: set ccw->cda to NULL defensively
> 
> Halil Pasic (2):
>   vfio: ccw: push down unsupported IDA check
>   vfio: ccw: add tracepoints for interesting error paths
> 
>  drivers/s390/cio/Makefile         |   1 +
>  drivers/s390/cio/vfio_ccw_cp.c    | 140 ++++++++++++++++++++------------------
>  drivers/s390/cio/vfio_ccw_drv.c   |   5 +-
>  drivers/s390/cio/vfio_ccw_fsm.c   |  17 ++++-
>  drivers/s390/cio/vfio_ccw_trace.h |  54 +++++++++++++++
>  5 files changed, 150 insertions(+), 67 deletions(-)
>  create mode 100644 drivers/s390/cio/vfio_ccw_trace.h
>