Merge tag 'vfio-ccw-20190621' of...

Merge tag 'vfio-ccw-20190621' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw into features

Refactoring of the vfio-ccw cp handling, simplifying the
code and avoiding unneeded allocating/copying.

* tag 'vfio-ccw-20190621' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw:
  vfio-ccw: Remove copy_ccw_from_iova()
  vfio-ccw: Factor out the ccw0-to-ccw1 transition
  vfio-ccw: Copy CCW data outside length calculation
  vfio-ccw: Skip second copy of guest cp to host
  vfio-ccw: Move guest_cp storage into common struct
  s390/cio: Combine direct and indirect CCW paths
  vfio-ccw: Rearrange IDAL allocation in direct CCW
  vfio-ccw: Remove pfn_array_table
  vfio-ccw: Adjust the first IDAW outside of the nested loops
  vfio-ccw: Rearrange pfn_array and pfn_array_table arrays
  s390/cio: Use generalized CCW handler in cp_init()
  s390/cio: Generalize the TIC handler
  s390/cio: Refactor the routine that handles TIC CCWs
  s390/cio: Squash cp_free() and cp_unpin_free()
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

drivers/s390/cio/vfio_ccw_cp.h

@@ -16,6 +16,12 @@
 
 #include "orb.h"
 
+/*
+ * Max length for ccw chain.
+ * XXX: Limit to 256, need to check more?
+ */
+#define CCWCHAIN_LEN_MAX	256
+
 /**
  * struct channel_program - manage information for channel program
  * @ccwchain_list: list head of ccwchains
@@ -32,6 +38,7 @@ struct channel_program {
 	union orb orb;
 	struct device *mdev;
 	bool initialized;
+	struct ccw1 *guest_cp;
 };
 
 extern int cp_init(struct channel_program *cp, struct device *mdev,

drivers/s390/cio/vfio_ccw_drv.c

@@ -129,6 +129,11 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
 	if (!private)
 		return -ENOMEM;
 
+	private->cp.guest_cp = kcalloc(CCWCHAIN_LEN_MAX, sizeof(struct ccw1),
+				       GFP_KERNEL);
+	if (!private->cp.guest_cp)
+		goto out_free;
+
 	private->io_region = kmem_cache_zalloc(vfio_ccw_io_region,
 					       GFP_KERNEL | GFP_DMA);
 	if (!private->io_region)
@@ -169,6 +174,7 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
 		kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region);
 	if (private->io_region)
 		kmem_cache_free(vfio_ccw_io_region, private->io_region);
+	kfree(private->cp.guest_cp);
 	kfree(private);
 	return ret;
 }
@@ -185,6 +191,7 @@ static int vfio_ccw_sch_remove(struct subchannel *sch)
 
 	kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region);
 	kmem_cache_free(vfio_ccw_io_region, private->io_region);
+	kfree(private->cp.guest_cp);
 	kfree(private);
 
 	return 0;