[PATCH V4 4/6] mdev: introduce virtio device and its device ops

From: Jason Wang <jasowang@redhat.com>
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	stefanha@redhat.com, Jason Wang <jasowang@redhat.com>
Subject: [PATCH V4 4/6] mdev: introduce virtio device and its device ops
Date: Thu, 17 Oct 2019 18:48:34 +0800	[thread overview]
Message-ID: <20191017104836.32464-5-jasowang@redhat.com> (raw)
In-Reply-To: <20191017104836.32464-1-jasowang@redhat.com>

This patch implements basic support for mdev driver that supports
virtio transport for kernel virtio driver.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/vfio/mdev/mdev_core.c |  12 +++
 include/linux/mdev.h          |   4 +
 include/linux/virtio_mdev.h   | 151 ++++++++++++++++++++++++++++++++++
 3 files changed, 167 insertions(+)
 create mode 100644 include/linux/virtio_mdev.h

diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index d0f3113c8071..5834f6b7c7a5 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -57,6 +57,18 @@ void mdev_set_vfio_ops(struct mdev_device *mdev,
 }
 EXPORT_SYMBOL(mdev_set_vfio_ops);
 
+/* Specify the virtio device ops for the mdev device, this
+ * must be called during create() callback for virtio mdev device.
+ */
+void mdev_set_virtio_ops(struct mdev_device *mdev,
+			 const struct virtio_mdev_device_ops *virtio_ops)
+{
+	BUG_ON(mdev->class_id);
+	mdev->class_id = MDEV_CLASS_ID_VIRTIO;
+	mdev->device_ops = virtio_ops;
+}
+EXPORT_SYMBOL(mdev_set_virtio_ops);
+
 const void *mdev_get_dev_ops(struct mdev_device *mdev)
 {
 	return mdev->device_ops;
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index 3d29e09e20c9..13e045e09d3b 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -17,6 +17,7 @@
 
 struct mdev_device;
 struct vfio_mdev_device_ops;
+struct virtio_mdev_device_ops;
 
 /*
  * Called by the parent device driver to set the device which represents
@@ -111,6 +112,8 @@ void mdev_set_drvdata(struct mdev_device *mdev, void *data);
 const guid_t *mdev_uuid(struct mdev_device *mdev);
 void mdev_set_vfio_ops(struct mdev_device *mdev,
 		       const struct vfio_mdev_device_ops *vfio_ops);
+void mdev_set_virtio_ops(struct mdev_device *mdev,
+                         const struct virtio_mdev_device_ops *virtio_ops);
 const void *mdev_get_dev_ops(struct mdev_device *mdev);
 
 extern struct bus_type mdev_bus_type;
@@ -127,6 +130,7 @@ struct mdev_device *mdev_from_dev(struct device *dev);
 
 enum {
 	MDEV_CLASS_ID_VFIO = 1,
+	MDEV_CLASS_ID_VIRTIO = 2,
 	/* New entries must be added here */
 };
 
diff --git a/include/linux/virtio_mdev.h b/include/linux/virtio_mdev.h
new file mode 100644
index 000000000000..b965b50f9b24
--- /dev/null
+++ b/include/linux/virtio_mdev.h
@@ -0,0 +1,151 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Virtio mediated device driver
+ *
+ * Copyright 2019, Red Hat Corp.
+ *     Author: Jason Wang <jasowang@redhat.com>
+ */
+#ifndef _LINUX_VIRTIO_MDEV_H
+#define _LINUX_VIRTIO_MDEV_H
+
+#include <linux/interrupt.h>
+#include <linux/mdev.h>
+#include <uapi/linux/vhost.h>
+
+#define VIRTIO_MDEV_DEVICE_API_STRING		"virtio-mdev"
+#define VIRTIO_MDEV_F_VERSION_1 0x1
+
+struct virtio_mdev_callback {
+	irqreturn_t (*callback)(void *data);
+	void *private;
+};
+
+/**
+ * struct vfio_mdev_device_ops - Structure to be registered for each
+ * mdev device to register the device to virtio-mdev module.
+ *
+ * @set_vq_address:		Set the address of virtqueue
+ *				@mdev: mediated device
+ *				@idx: virtqueue index
+ *				@desc_area: address of desc area
+ *				@driver_area: address of driver area
+ *				@device_area: address of device area
+ *				Returns integer: success (0) or error (< 0)
+ * @set_vq_num:		Set the size of virtqueue
+ *				@mdev: mediated device
+ *				@idx: virtqueue index
+ *				@num: the size of virtqueue
+ * @kick_vq:			Kick the virtqueue
+ *				@mdev: mediated device
+ *				@idx: virtqueue index
+ * @set_vq_cb:			Set the interrupt callback function for
+ *				a virtqueue
+ *				@mdev: mediated device
+ *				@idx: virtqueue index
+ *				@cb: virtio-mdev interrupt callback structure
+ * @set_vq_ready:		Set ready status for a virtqueue
+ *				@mdev: mediated device
+ *				@idx: virtqueue index
+ *				@ready: ready (true) not ready(false)
+ * @get_vq_ready:		Get ready status for a virtqueue
+ *				@mdev: mediated device
+ *				@idx: virtqueue index
+ *				Returns boolean: ready (true) or not (false)
+ * @set_vq_state:		Set the state for a virtqueue
+ *				@mdev: mediated device
+ *				@idx: virtqueue index
+ *				@state: virtqueue state (last_avail_idx)
+ *				Returns integer: success (0) or error (< 0)
+ * @get_vq_state:		Get the state for a virtqueue
+ *				@mdev: mediated device
+ *				@idx: virtqueue index
+ *				Returns virtqueue state (last_avail_idx)
+ * @get_vq_align:		Get the virtqueue align requirement
+ *				for the device
+ *				@mdev: mediated device
+ *				Returns virtqueue algin requirement
+ * @get_features:		Get virtio features supported by the device
+ *				@mdev: mediated device
+ *				Returns the virtio features support by the
+ *				device
+ * @get_features:		Set virtio features supported by the driver
+ *				@mdev: mediated device
+ *				@features: feature support by the driver
+ *				Returns integer: success (0) or error (< 0)
+ * @set_config_cb:		Set the config interrupt callback
+ *				@mdev: mediated device
+ *				@cb: virtio-mdev interrupt callback structure
+ * @get_vq_num_max:		Get the max size of virtqueue
+ *				@mdev: mediated device
+ *				Returns u16: max size of virtqueue
+ * @get_device_id:		Get virtio device id
+ *				@mdev: mediated device
+ *				Returns u32: virtio device id
+ * @get_vendor_id:		Get virtio vendor id
+ *				@mdev: mediated device
+ *				Returns u32: virtio vendor id
+ * @get_status: 		Get the device status
+ *				@mdev: mediated device
+ *				Returns u8: virtio device status
+ * @set_status: 		Set the device status
+ *				@mdev: mediated device
+ *				@status: virtio device status
+ * @get_config: 		Read from device specific configuration space
+ *				@mdev: mediated device
+ *				@offset: offset from the beginning of
+ *				configuration space
+ *				@buf: buffer used to read to
+ *				@len: the length to read from
+ *				configration space
+ * @set_config: 		Write to device specific configuration space
+ *				@mdev: mediated device
+ *				@offset: offset from the beginning of
+ *				configuration space
+ *				@buf: buffer used to write from
+ *				@len: the length to write to
+ *				configration space
+ * @get_mdev_features:		Get the feature of virtio mdev device
+ *				@mdev: mediated device
+ *				Returns the mdev features (API) support by
+ *				the device.
+ * @get_generation:		Get device generaton
+ *				@mdev: mediated device
+ *				Returns u32: device generation
+ */
+struct virtio_mdev_device_ops {
+	/* Virtqueue ops */
+	int (*set_vq_address)(struct mdev_device *mdev,
+			      u16 idx, u64 desc_area, u64 driver_area,
+			      u64 device_area);
+	void (*set_vq_num)(struct mdev_device *mdev, u16 idx, u32 num);
+	void (*kick_vq)(struct mdev_device *mdev, u16 idx);
+	void (*set_vq_cb)(struct mdev_device *mdev, u16 idx,
+			  struct virtio_mdev_callback *cb);
+	void (*set_vq_ready)(struct mdev_device *mdev, u16 idx, bool ready);
+	bool (*get_vq_ready)(struct mdev_device *mdev, u16 idx);
+	int (*set_vq_state)(struct mdev_device *mdev, u16 idx, u64 state);
+	u64 (*get_vq_state)(struct mdev_device *mdev, u16 idx);
+
+	/* Device ops */
+	u16 (*get_vq_align)(struct mdev_device *mdev);
+	u64 (*get_features)(struct mdev_device *mdev);
+	int (*set_features)(struct mdev_device *mdev, u64 features);
+	void (*set_config_cb)(struct mdev_device *mdev,
+			      struct virtio_mdev_callback *cb);
+	u16 (*get_vq_num_max)(struct mdev_device *mdev);
+	u32 (*get_device_id)(struct mdev_device *mdev);
+	u32 (*get_vendor_id)(struct mdev_device *mdev);
+	u8 (*get_status)(struct mdev_device *mdev);
+	void (*set_status)(struct mdev_device *mdev, u8 status);
+	void (*get_config)(struct mdev_device *mdev, unsigned int offset,
+			   void *buf, unsigned int len);
+	void (*set_config)(struct mdev_device *mdev, unsigned int offset,
+			   const void *buf, unsigned int len);
+	u64 (*get_mdev_features)(struct mdev_device *mdev);
+	u32 (*get_generation)(struct mdev_device *mdev);
+};
+
+void mdev_set_virtio_ops(struct mdev_device *mdev,
+			 const struct virtio_mdev_device_ops *virtio_ops);
+
+#endif
-- 
2.19.1

