[PATCH v4 11/16] vfio: ccw: realize VFIO_DEVICE_G(S)ET_IRQ_INFO ioctls

Dong Jia Shi
2017-03-17T05:11:41Z

Realize VFIO_DEVICE_GET_IRQ_INFO ioctl to retrieve
VFIO_CCW_IO_IRQ information.

Realize VFIO_DEVICE_SET_IRQS ioctl to set an eventfd fd for
VFIO_CCW_IO_IRQ. Once a write operation to the ccw_io_region
was performed, trigger a signal on this fd.

Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
---
drivers/s390/cio/vfio_ccw_ops.c | 123 +++++++++++++++++++++++++++++++++++-
drivers/s390/cio/vfio_ccw_private.h | 4 ++
include/uapi/linux/vfio.h | 10 ++-
3 files changed, 134 insertions(+), 3 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 125818c..1294c53 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -202,6 +202,9 @@ static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev,
if (region->ret_code != 0)
return region->ret_code;

+ if (private->io_trigger)
+ eventfd_signal(private->io_trigger, 1);
+
return count;
}

@@ -209,7 +212,7 @@ static int vfio_ccw_mdev_get_device_info(struct vfio_device_info *info)
{
info->flags = VFIO_DEVICE_FLAGS_CCW | VFIO_DEVICE_FLAGS_RESET;
info->num_regions = VFIO_CCW_NUM_REGIONS;
- info->num_irqs = 0;
+ info->num_irqs = VFIO_CCW_NUM_IRQS;

return 0;
}
@@ -230,6 +233,83 @@ static int vfio_ccw_mdev_get_region_info(struct vfio_region_info *info,
}
}

+int vfio_ccw_mdev_get_irq_info(struct vfio_irq_info *info)
+{
+ if (info->index != VFIO_CCW_IO_IRQ_INDEX)
+ return -EINVAL;
+
+ info->count = 1;
+ info->flags = VFIO_IRQ_INFO_EVENTFD;
+
+ return 0;
+}
+
+static int vfio_ccw_mdev_set_irqs(struct mdev_device *mdev,
+ uint32_t flags,
+ void __user *data)
+{
+ struct vfio_ccw_private *private;
+ struct eventfd_ctx **ctx;
+
+ if (!(flags & VFIO_IRQ_SET_ACTION_TRIGGER))
+ return -EINVAL;
+
+ private = dev_get_drvdata(mdev_parent_dev(mdev));
+ if (!private)
+ return -ENODEV;
+
+ ctx = &private->io_trigger;
+
+ switch (flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
+ case VFIO_IRQ_SET_DATA_NONE:
+ {
+ if (*ctx)
+ eventfd_signal(*ctx, 1);
+ return 0;
+ }
+ case VFIO_IRQ_SET_DATA_BOOL:
+ {
+ uint8_t trigger;
+
+ if (get_user(trigger, (uint8_t __user *)data))
+ return -EFAULT;
+
+ if (trigger && *ctx)
+ eventfd_signal(*ctx, 1);
+ return 0;
+ }
+ case VFIO_IRQ_SET_DATA_EVENTFD:
+ {
+ int32_t fd;
+
+ if (get_user(fd, (int32_t __user *)data))
+ return -EFAULT;
+
+ if (fd == -1) {
+ if (*ctx)
+ eventfd_ctx_put(*ctx);
+ *ctx = NULL;
+ } else if (fd >= 0) {
+ struct eventfd_ctx *efdctx;
+
+ efdctx = eventfd_ctx_fdget(fd);
+ if (IS_ERR(efdctx))
+ return PTR_ERR(efdctx);
+
+ if (*ctx)
+ eventfd_ctx_put(*ctx);
+
+ *ctx = efdctx;
+ } else
+ return -EINVAL;
+
+ return 0;
+ }
+ default:
+ return -EINVAL;
+ }
+}
+
static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
unsigned int cmd,
unsigned long arg)
@@ -277,6 +357,47 @@ static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,

return copy_to_user((void __user *)arg, &info, minsz);
}
+ case VFIO_DEVICE_GET_IRQ_INFO:
+ {
+ struct vfio_irq_info info;
+
+ minsz = offsetofend(struct vfio_irq_info, count);
+
+ if (copy_from_user(&info, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (info.argsz < minsz || info.index >= VFIO_CCW_NUM_IRQS)
+ return -EINVAL;
+
+ ret = vfio_ccw_mdev_get_irq_info(&info);
+ if (ret)
+ return ret;
+
+ if (info.count == -1)
+ return -EINVAL;
+
+ return copy_to_user((void __user *)arg, &info, minsz);
+ }
+ case VFIO_DEVICE_SET_IRQS:
+ {
+ struct vfio_irq_set hdr;
+ size_t data_size;
+ void __user *data;
+
+ minsz = offsetofend(struct vfio_irq_set, count);
+
+ if (copy_from_user(&hdr, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ ret = vfio_set_irqs_validate_and_prepare(&hdr, 1,
+ VFIO_CCW_NUM_IRQS,
+ &data_size);
+ if (ret)
+ return ret;
+
+ data = (void __user *)(arg + minsz);
+ return vfio_ccw_mdev_set_irqs(mdev, hdr.flags, data);
+ }
case VFIO_DEVICE_RESET:
return vfio_ccw_mdev_reset(mdev);
default:
diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h
index 79e5337..dddab52 100644
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -11,6 +11,7 @@
#define _VFIO_CCW_PRIVATE_H_

#include <linux/completion.h>
+#include <linux/eventfd.h>
#include <linux/vfio_ccw.h>

#include "css.h"
@@ -29,6 +30,7 @@
* @cp: channel program for the current I/O operation
* @irb: irb info received from interrupt
* @scsw: scsw info
+ * @io_trigger: eventfd ctx for signaling userspace I/O results
*/
struct vfio_ccw_private {
struct subchannel *sch;
@@ -43,6 +45,8 @@ struct vfio_ccw_private {
struct channel_program cp;
struct irb irb;
union scsw scsw;
+
+ struct eventfd_ctx *io_trigger;
} __aligned(8);

extern int vfio_ccw_mdev_reg(struct subchannel *sch);
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 3fd70ff..ae46105 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -449,8 +449,9 @@ enum {
};

/*
- * The vfio-ccw bus driver makes use of the following fixed region.
- * Unimplemented regions return a size of zero.
+ * The vfio-ccw bus driver makes use of the following fixed region and
+ * IRQ index mapping. Unimplemented regions return a size of zero.
+ * Unimplemented IRQ types return a count of zero.
*/

enum {
@@ -458,6 +459,11 @@ enum {
VFIO_CCW_NUM_REGIONS
};

+enum {
+ VFIO_CCW_IO_IRQ_INDEX,
+ VFIO_CCW_NUM_IRQS
+};
+
/**
* VFIO_DEVICE_GET_PCI_HOT_RESET_INFO - _IORW(VFIO_TYPE, VFIO_BASE + 12,
* struct vfio_pci_hot_reset_info)
--
2.8.4