[Intel-gfx] [PATCH V4 4/6] mdev: introduce virtio device and its device ops
Cornelia Huck
cohuck at redhat.com
Fri Oct 18 09:46:14 UTC 2019
On Thu, 17 Oct 2019 18:48:34 +0800
Jason Wang <jasowang at redhat.com> wrote:
> This patch implements basic support for mdev driver that supports
> virtio transport for kernel virtio driver.
>
> Signed-off-by: Jason Wang <jasowang at 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.
> + */
Change this as for the vfio comment (last patch?)
> +void mdev_set_virtio_ops(struct mdev_device *mdev,
> + const struct virtio_mdev_device_ops *virtio_ops)
> +{
> + BUG_ON(mdev->class_id);
s/BUG_ON/WARN_ON/
> + 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/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 at 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)
Probably dumb question (have not read the next patches yet): Is this
agnostic regarding split or packed queues?
> + * @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
s/get_features/set_features/
> + * @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
How is the vendor id defined? As for normal virtio-pci devices?
> + * @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.
What kind of 'features' are supposed to go in there? Are these bits,
like you defined for VIRTIO_MDEV_F_VERSION_1 above?
> + * @get_generation: Get device generaton
> + * @mdev: mediated device
> + * Returns u32: device generation
Is that callback mandatory?
> + */
> +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
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