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

Jason Wang
2019-10-17T10:51:24Z

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