[PATCH 1/3] vfio-ccw: add capabilities chain

Cornelia Huck
2018-11-22T16:54:30Z

Allow to extend the regions used by vfio-ccw. The first user will be
handling of halt and clear subchannel.

Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
drivers/s390/cio/vfio_ccw_ops.c | 182 ++++++++++++++++++++++++----
drivers/s390/cio/vfio_ccw_private.h | 38 ++++++
include/uapi/linux/vfio.h | 1 +
3 files changed, 195 insertions(+), 26 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index f673e106c041..a5d731ed2a39 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -3,9 +3,11 @@
* Physical device callbacks for vfio_ccw
*
* Copyright IBM Corp. 2017
+ * Copyright Red Hat, Inc. 2018
*
* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
* Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
+ * Cornelia Huck <cohuck@redhat.com>
*/

#include <linux/vfio.h>
@@ -157,47 +159,76 @@ static void vfio_ccw_mdev_release(struct mdev_device *mdev)
{
struct vfio_ccw_private *private =
dev_get_drvdata(mdev_parent_dev(mdev));
+ int i;

vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
&private->nb);
+
+ for (i = 0; i < private->num_regions; i++)
+ private->region[i].ops->release(private, &private->region[i]);
+
+ private->num_regions = 0;
+ kfree(private->region);
+ private->region = NULL;
}

-static ssize_t vfio_ccw_mdev_read(struct mdev_device *mdev,
- char __user *buf,
- size_t count,
- loff_t *ppos)
+static ssize_t vfio_ccw_mdev_read_io_region(struct vfio_ccw_private *private,
+ char __user *buf, size_t count,
+ loff_t *ppos)
{
- struct vfio_ccw_private *private;
+ loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
struct ccw_io_region *region;

- if (*ppos + count > sizeof(*region))
+ if (pos + count > sizeof(*region))
return -EINVAL;

- private = dev_get_drvdata(mdev_parent_dev(mdev));
region = private->io_region;
- if (copy_to_user(buf, (void *)region + *ppos, count))
+ if (copy_to_user(buf, (void *)region + pos, count))
return -EFAULT;

return count;
}

-static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev,
- const char __user *buf,
- size_t count,
- loff_t *ppos)
+static ssize_t vfio_ccw_mdev_read(struct mdev_device *mdev,
+ char __user *buf,
+ size_t count,
+ loff_t *ppos)
{
+ unsigned int index = VFIO_CCW_OFFSET_TO_INDEX(*ppos);
struct vfio_ccw_private *private;
+
+ private = dev_get_drvdata(mdev_parent_dev(mdev));
+
+ if (index >= VFIO_CCW_NUM_REGIONS + private->num_regions)
+ return -EINVAL;
+
+ switch (index) {
+ case VFIO_CCW_CONFIG_REGION_INDEX:
+ return vfio_ccw_mdev_read_io_region(private, buf, count, ppos);
+ default:
+ index -= VFIO_CCW_NUM_REGIONS;
+ return private->region[index].ops->read(private, buf, count,
+ ppos);
+ }
+
+ return -EINVAL;
+}
+
+static ssize_t vfio_ccw_mdev_write_io_region(struct vfio_ccw_private *private,
+ const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
struct ccw_io_region *region;

- if (*ppos + count > sizeof(*region))
+ if (pos + count > sizeof(*region))
return -EINVAL;

- private = dev_get_drvdata(mdev_parent_dev(mdev));
if (private->state != VFIO_CCW_STATE_IDLE)
return -EACCES;

region = private->io_region;
- if (copy_from_user((void *)region + *ppos, buf, count))
+ if (copy_from_user((void *)region + pos, buf, count))
return -EFAULT;

vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_IO_REQ);
@@ -207,21 +238,55 @@ static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev,
}

return count;
+
}

-static int vfio_ccw_mdev_get_device_info(struct vfio_device_info *info)
+static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev,
+ const char __user *buf,
+ size_t count,
+ loff_t *ppos)
{
+ unsigned int index = VFIO_CCW_OFFSET_TO_INDEX(*ppos);
+ struct vfio_ccw_private *private;
+
+ private = dev_get_drvdata(mdev_parent_dev(mdev));
+
+ if (index >= VFIO_CCW_NUM_REGIONS + private->num_regions)
+ return -EINVAL;
+
+ switch (index) {
+ case VFIO_CCW_CONFIG_REGION_INDEX:
+ return vfio_ccw_mdev_write_io_region(private, buf, count, ppos);
+ default:
+ index -= VFIO_CCW_NUM_REGIONS;
+ return private->region[index].ops->write(private, buf, count,
+ ppos);
+ }
+
+ return -EINVAL;
+}
+
+static int vfio_ccw_mdev_get_device_info(struct vfio_device_info *info,
+ struct mdev_device *mdev)
+{
+ struct vfio_ccw_private *private;
+
+ private = dev_get_drvdata(mdev_parent_dev(mdev));
info->flags = VFIO_DEVICE_FLAGS_CCW | VFIO_DEVICE_FLAGS_RESET;
- info->num_regions = VFIO_CCW_NUM_REGIONS;
+ info->num_regions = VFIO_CCW_NUM_REGIONS + private->num_regions;
info->num_irqs = VFIO_CCW_NUM_IRQS;

return 0;
}

static int vfio_ccw_mdev_get_region_info(struct vfio_region_info *info,
- u16 *cap_type_id,
- void **cap_type)
+ struct mdev_device *mdev,
+ unsigned long arg)
{
+ struct vfio_ccw_private *private;
+ int i;
+
+ private = dev_get_drvdata(mdev_parent_dev(mdev));
switch (info->index) {
case VFIO_CCW_CONFIG_REGION_INDEX:
info->offset = 0;
@@ -229,9 +294,51 @@ static int vfio_ccw_mdev_get_region_info(struct vfio_region_info *info,
info->flags = VFIO_REGION_INFO_FLAG_READ
| VFIO_REGION_INFO_FLAG_WRITE;
return 0;
- default:
- return -EINVAL;
+ default: /* all other regions are handled via capability chain */
+ {
+ struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
+ struct vfio_region_info_cap_type cap_type = {
+ .header.id = VFIO_REGION_INFO_CAP_TYPE,
+ .header.version = 1 };
+ int ret;
+
+ if (info->index >=
+ VFIO_CCW_NUM_REGIONS + private->num_regions)
+ return -EINVAL;
+
+ i = info->index - VFIO_CCW_NUM_REGIONS;
+
+ info->offset = VFIO_CCW_INDEX_TO_OFFSET(info->index);
+ info->size = private->region[i].size;
+ info->flags = private->region[i].flags;
+
+ cap_type.type = private->region[i].type;
+ cap_type.subtype = private->region[i].subtype;
+
+ ret = vfio_info_add_capability(&caps, &cap_type.header,
+ sizeof(cap_type));
+ if (ret)
+ return ret;
+
+ info->flags |= VFIO_REGION_INFO_FLAG_CAPS;
+ if (info->argsz < sizeof(*info) + caps.size) {
+ info->argsz = sizeof(*info) + caps.size;
+ info->cap_offset = 0;
+ } else {
+ vfio_info_cap_shift(&caps, sizeof(*info));
+ if (copy_to_user((void __user *)arg + sizeof(*info),
+ caps.buf, caps.size)) {
+ kfree(caps.buf);
+ return -EFAULT;
+ }
+ info->cap_offset = sizeof(*info);
+ }
+
+ kfree(caps.buf);
+
+ }
}
+ return 0;
}

static int vfio_ccw_mdev_get_irq_info(struct vfio_irq_info *info)
@@ -308,6 +415,32 @@ static int vfio_ccw_mdev_set_irqs(struct mdev_device *mdev,
}
}

+int vfio_ccw_register_dev_region(struct vfio_ccw_private *private,
+ unsigned int subtype,
+ const struct vfio_ccw_regops *ops,
+ size_t size, u32 flags, void *data)
+{
+ struct vfio_ccw_region *region;
+
+ region = krealloc(private->region,
+ (private->num_regions + 1) * sizeof(*region),
+ GFP_KERNEL);
+ if (!region)
+ return -ENOMEM;
+
+ private->region = region;
+ private->region[private->num_regions].type = VFIO_REGION_TYPE_CCW;
+ private->region[private->num_regions].subtype = subtype;
+ private->region[private->num_regions].ops = ops;
+ private->region[private->num_regions].size = size;
+ private->region[private->num_regions].flags = flags;
+ private->region[private->num_regions].data = data;
+
+ private->num_regions++;
+
+ return 0;
+}
+
static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
unsigned int cmd,
unsigned long arg)
@@ -328,7 +461,7 @@ static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
if (info.argsz < minsz)
return -EINVAL;

- ret = vfio_ccw_mdev_get_device_info(&info);
+ ret = vfio_ccw_mdev_get_device_info(&info, mdev);
if (ret)
return ret;

@@ -337,8 +470,6 @@ static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
case VFIO_DEVICE_GET_REGION_INFO:
{
struct vfio_region_info info;
- u16 cap_type_id = 0;
- void *cap_type = NULL;

minsz = offsetofend(struct vfio_region_info, offset);

@@ -348,8 +479,7 @@ static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
if (info.argsz < minsz)
return -EINVAL;

- ret = vfio_ccw_mdev_get_region_info(&info, &cap_type_id,
- &cap_type);
+ ret = vfio_ccw_mdev_get_region_info(&info, mdev, arg);
if (ret)
return ret;

diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h
index 078e46f9623d..a6f9f84526e2 100644
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -3,9 +3,11 @@
* Private stuff for vfio_ccw driver
*
* Copyright IBM Corp. 2017
+ * Copyright Red Hat, Inc. 2018
*
* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
* Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
+ * Cornelia Huck <cohuck@redhat.com>
*/

#ifndef _VFIO_CCW_PRIVATE_H_
@@ -19,6 +21,38 @@
#include "css.h"
#include "vfio_ccw_cp.h"

+#define VFIO_CCW_OFFSET_SHIFT 40
+#define VFIO_CCW_OFFSET_TO_INDEX(off) (off >> VFIO_CCW_OFFSET_SHIFT)
+#define VFIO_CCW_INDEX_TO_OFFSET(index) ((u64)(index) << VFIO_CCW_OFFSET_SHIFT)
+#define VFIO_CCW_OFFSET_MASK (((u64)(1) << VFIO_CCW_OFFSET_SHIFT) - 1)
+
+/* capability chain handling similar to vfio-pci */
+struct vfio_ccw_private;
+struct vfio_ccw_region;
+
+struct vfio_ccw_regops {
+ size_t (*read)(struct vfio_ccw_private *private, char __user *buf,
+ size_t count, loff_t *ppos);
+ size_t (*write)(struct vfio_ccw_private *private,
+ const char __user *buf, size_t count, loff_t *ppos);
+ void (*release)(struct vfio_ccw_private *private,
+ struct vfio_ccw_region *region);
+};
+
+struct vfio_ccw_region {
+ u32 type;
+ u32 subtype;
+ const struct vfio_ccw_regops *ops;
+ void *data;
+ size_t size;
+ u32 flags;
+};
+
+int vfio_ccw_register_dev_region(struct vfio_ccw_private *private,
+ unsigned int subtype,
+ const struct vfio_ccw_regops *ops,
+ size_t size, u32 flags, void *data);
+
/**
* struct vfio_ccw_private
* @sch: pointer to the subchannel
@@ -28,6 +62,8 @@
* @mdev: pointer to the mediated device
* @nb: notifier for vfio events
* @io_region: MMIO region to input/output I/O arguments/results
+ * @region: additional regions for other subchannel operations
+ * @num_regions: number of additional regions
* @cp: channel program for the current I/O operation
* @irb: irb info received from interrupt
* @scsw: scsw info
@@ -42,6 +78,8 @@ struct vfio_ccw_private {
struct mdev_device *mdev;
struct notifier_block nb;
struct ccw_io_region *io_region;
+ struct vfio_ccw_region *region;
+ int num_regions;

struct channel_program cp;
struct irb irb;
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 813102810f53..565669f95534 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -297,6 +297,7 @@ struct vfio_region_info_cap_type {

#define VFIO_REGION_TYPE_PCI_VENDOR_TYPE (1 << 31)
#define VFIO_REGION_TYPE_PCI_VENDOR_MASK (0xffff)
+#define VFIO_REGION_TYPE_CCW (1 << 30)

/* 8086 Vendor sub-types */
#define VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION (1)
--
2.17.2