Re: [PATCH V2 6/8] mdev: introduce virtio device and its device ops

From: Jason Wang
Date: Wed Sep 25 2019 - 08:07:12 EST


On 2019/9/25 äå7:06, Alex Williamson wrote:
> On Tue, 24 Sep 2019 21:53:30 +0800
> Jason Wang <jasowang@xxxxxxxxxx> wrote:
>
>> This patch implements basic support for mdev driver that supports
>> virtio transport for kernel virtio driver.
>>
>> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
>> ---
>> include/linux/mdev.h | 2 +
>> include/linux/virtio_mdev.h | 145 ++++++++++++++++++++++++++++++++++++
>> 2 files changed, 147 insertions(+)
>> create mode 100644 include/linux/virtio_mdev.h
>>
>> diff --git a/include/linux/mdev.h b/include/linux/mdev.h
>> index 3414307311f1..73ac27b3b868 100644
>> --- a/include/linux/mdev.h
>> +++ b/include/linux/mdev.h
>> @@ -126,6 +126,8 @@ struct mdev_device *mdev_from_dev(struct device *dev);
>>
>> enum {
>> MDEV_ID_VFIO = 1,
>> + MDEV_ID_VIRTIO = 2,
>> + MDEV_ID_VHOST = 3,
> MDEV_ID_VHOST isn't used yet here.


Yes, just want to reserve one but it look too early to do that.


> Also, given the strong
> interdependence between the class_id and the ops structure, we might
> wand to define them in the same place. Thanks,
>
> Alex


Yes, as you suggest in patch 5/8.

Thanks


>
>> /* 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..d1a40a739266
>> --- /dev/null
>> +++ b/include/linux/virtio_mdev.h
>> @@ -0,0 +1,145 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Virtio mediated device driver
>> + *
>> + * Copyright 2019, Red Hat Corp.
>> + * Author: Jason Wang <jasowang@xxxxxxxxxx>
>> + */
>> +#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_VERSION 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 interrut calback 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 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_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 confiugration 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 confiugration 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_version: Get the version of virtio mdev device
>> + * @mdev: mediated device
>> + * Returns integer: version of 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_queue_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);
>> + int (*get_version)(struct mdev_device *mdev);
>> + u32 (*get_generation)(struct mdev_device *mdev);
>> +};
>> +
>> +#endif
>> +