Thread (13 messages) 13 messages, 4 authors, 2019-11-04

RE: [PATCH V6 3/6] mdev: introduce device specific ops

From: Parav Pandit <hidden>
Date: 2019-11-01 20:11:39
Also in: dri-devel, intel-gfx, kvm, linux-s390, lkml

-----Original Message-----
From: Jason Wang <jasowang@redhat.com>
Sent: Wednesday, October 30, 2019 1:45 AM
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Subject: [PATCH V6 3/6] mdev: introduce device specific ops

Currently, except for the create and remove, the rest of mdev_parent_ops is
designed for vfio-mdev driver only and may not help for kernel mdev driver.
With the help of class id, this patch introduces device specific callbacks inside
mdev_device structure. This allows different set of callback to be used by vfio-
mdev and virtio-mdev.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
[ ..]
quoted hunk ↗ jump to hunk
diff --git a/include/linux/vfio_mdev_ops.h b/include/linux/vfio_mdev_ops.h
new file mode 100644 index 000000000000..3907c5371c2b
--- /dev/null
+++ b/include/linux/vfio_mdev_ops.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * VFIO Mediated device definition
+ */
+
+#ifndef VFIO_MDEV_H
+#define VFIO_MDEV_H
+
I should have noticed this before. :-(
APIs exposed are by the mdev module and named with mdev_ prefix.
And file name is _ops.h,

We should name this file as mdev_vfio_ops.h

And #define should be MDEV_VFIO_OPS_H
+#include <linux/mdev.h>
+
+/**
+ * struct vfio_mdev_device_ops - Structure to be registered for each
s/vfio_mdev_device_ops/mdev_vfio_device_ops/

Similarly for virtio in future patches.
quoted hunk ↗ jump to hunk
+ * mdev device to register the device to vfio-mdev module.
+ *
+ * @open:		Open mediated device.
+ *			@mdev: mediated device.
+ *			Returns integer: success (0) or error (< 0)
+ * @release:		release mediated device
+ *			@mdev: mediated device.
+ * @read:		Read emulation callback
+ *			@mdev: mediated device structure
+ *			@buf: read buffer
+ *			@count: number of bytes to read
+ *			@ppos: address.
+ *			Retuns number on bytes read on success or error.
+ * @write:		Write emulation callback
+ *			@mdev: mediated device structure
+ *			@buf: write buffer
+ *			@count: number of bytes to be written
+ *			@ppos: address.
+ *			Retuns number on bytes written on success or error.
+ * @ioctl:		IOCTL callback
+ *			@mdev: mediated device structure
+ *			@cmd: ioctl command
+ *			@arg: arguments to ioctl
+ * @mmap:		mmap callback
+ *			@mdev: mediated device structure
+ *			@vma: vma structure
+ */
+struct vfio_mdev_device_ops {
+	int     (*open)(struct mdev_device *mdev);
+	void    (*release)(struct mdev_device *mdev);
+	ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
+			size_t count, loff_t *ppos);
+	ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
+			 size_t count, loff_t *ppos);
+	long	(*ioctl)(struct mdev_device *mdev, unsigned int cmd,
+			 unsigned long arg);
+	int	(*mmap)(struct mdev_device *mdev, struct vm_area_struct
*vma);
+};
+
+#endif
diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c index
115bc5074656..1afec20bf0c5 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -30,6 +30,7 @@
 #include <linux/iommu.h>
 #include <linux/sysfs.h>
 #include <linux/mdev.h>
+#include <linux/vfio_mdev_ops.h>
 #include <linux/pci.h>
 #include <linux/dma-buf.h>
 #include <linux/highmem.h>
@@ -516,6 +517,8 @@ static int mbochs_reset(struct mdev_device *mdev)
 	return 0;
 }

+static const struct vfio_mdev_device_ops vfio_mdev_ops;
+
 static int mbochs_create(struct kobject *kobj, struct mdev_device *mdev)  {
 	const struct mbochs_type *type = mbochs_find_type(kobj); @@ -561,7
+564,7 @@ static int mbochs_create(struct kobject *kobj, struct mdev_device
*mdev)
 	mbochs_reset(mdev);

 	mbochs_used_mbytes += type->mbytes;
-	mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+	mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
 	return 0;

 err_mem:
@@ -1419,12 +1422,7 @@ static struct attribute_group *mdev_type_groups[]
= {
 	NULL,
 };

-static const struct mdev_parent_ops mdev_fops = {
-	.owner			= THIS_MODULE,
-	.mdev_attr_groups	= mdev_dev_groups,
-	.supported_type_groups	= mdev_type_groups,
-	.create			= mbochs_create,
-	.remove			= mbochs_remove,
+static const struct vfio_mdev_device_ops vfio_mdev_ops = {
 	.open			= mbochs_open,
 	.release		= mbochs_close,
 	.read			= mbochs_read,
@@ -1433,6 +1431,14 @@ static const struct mdev_parent_ops mdev_fops = {
 	.mmap			= mbochs_mmap,
 };

+static const struct mdev_parent_ops mdev_fops = {
+	.owner			= THIS_MODULE,
+	.mdev_attr_groups	= mdev_dev_groups,
+	.supported_type_groups	= mdev_type_groups,
+	.create			= mbochs_create,
+	.remove			= mbochs_remove,
+};
+
 static const struct file_operations vd_fops = {
 	.owner		= THIS_MODULE,
 };
diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c index
665614574d50..d571fb65f50f 100644
--- a/samples/vfio-mdev/mdpy.c
+++ b/samples/vfio-mdev/mdpy.c
@@ -26,6 +26,7 @@
 #include <linux/iommu.h>
 #include <linux/sysfs.h>
 #include <linux/mdev.h>
+#include <linux/vfio_mdev_ops.h>
 #include <linux/pci.h>
 #include <drm/drm_fourcc.h>
 #include "mdpy-defs.h"
@@ -226,6 +227,8 @@ static int mdpy_reset(struct mdev_device *mdev)
 	return 0;
 }

+static const struct vfio_mdev_device_ops vfio_mdev_ops;
+
 static int mdpy_create(struct kobject *kobj, struct mdev_device *mdev)  {
 	const struct mdpy_type *type = mdpy_find_type(kobj); @@ -269,7
+272,7 @@ static int mdpy_create(struct kobject *kobj, struct mdev_device
*mdev)
 	mdpy_reset(mdev);

 	mdpy_count++;
-	mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+	mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
 	return 0;
 }
@@ -726,12 +729,7 @@ static struct attribute_group *mdev_type_groups[] = {
 	NULL,
 };

-static const struct mdev_parent_ops mdev_fops = {
-	.owner			= THIS_MODULE,
-	.mdev_attr_groups	= mdev_dev_groups,
-	.supported_type_groups	= mdev_type_groups,
-	.create			= mdpy_create,
-	.remove			= mdpy_remove,
+static const struct vfio_mdev_device_ops vfio_mdev_ops = {
 	.open			= mdpy_open,
 	.release		= mdpy_close,
 	.read			= mdpy_read,
@@ -740,6 +738,14 @@ static const struct mdev_parent_ops mdev_fops = {
 	.mmap			= mdpy_mmap,
 };

+static const struct mdev_parent_ops mdev_fops = {
+	.owner			= THIS_MODULE,
+	.mdev_attr_groups	= mdev_dev_groups,
+	.supported_type_groups	= mdev_type_groups,
+	.create			= mdpy_create,
+	.remove			= mdpy_remove,
+};
+
 static const struct file_operations vd_fops = {
 	.owner		= THIS_MODULE,
 };
diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c index
90da12ff7fd9..4048b242c636 100644
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -27,6 +27,7 @@
 #include <linux/ctype.h>
 #include <linux/file.h>
 #include <linux/mdev.h>
+#include <linux/vfio_mdev_ops.h>
 #include <linux/pci.h>
 #include <linux/serial.h>
 #include <uapi/linux/serial_reg.h>
@@ -708,6 +709,8 @@ static ssize_t mdev_access(struct mdev_device *mdev,
u8 *buf, size_t count,
 	return ret;
 }

+static const struct vfio_mdev_device_ops vfio_dev_ops;
+
 static int mtty_create(struct kobject *kobj, struct mdev_device *mdev)  {
 	struct mdev_state *mdev_state;
@@ -755,7 +758,7 @@ static int mtty_create(struct kobject *kobj, struct
mdev_device *mdev)
 	list_add(&mdev_state->next, &mdev_devices_list);
 	mutex_unlock(&mdev_list_lock);

-	mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+	mdev_set_vfio_ops(mdev, &vfio_dev_ops);
 	return 0;
 }
@@ -1388,6 +1391,14 @@ static struct attribute_group *mdev_type_groups[]
= {
 	NULL,
 };

+static const struct vfio_mdev_device_ops vfio_dev_ops = {
+	.open		= mtty_open,
+	.release	= mtty_close,
+	.read		= mtty_read,
+	.write		= mtty_write,
+	.ioctl		= mtty_ioctl,
+};
+
 static const struct mdev_parent_ops mdev_fops = {
 	.owner                  = THIS_MODULE,
 	.dev_attr_groups        = mtty_dev_groups,
@@ -1395,11 +1406,6 @@ static const struct mdev_parent_ops mdev_fops = {
 	.supported_type_groups  = mdev_type_groups,
 	.create                 = mtty_create,
 	.remove			= mtty_remove,
-	.open                   = mtty_open,
-	.release                = mtty_close,
-	.read                   = mtty_read,
-	.write                  = mtty_write,
-	.ioctl		        = mtty_ioctl,
 };

 static void mtty_device_release(struct device *dev)
--
2.19.1
With above small nit changes to rename the fields and file,

Reviewed-by: Parav Pandit <redacted>
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