Messages in this thread | | | Subject | Re: [PATCH V4 4/6] mdev: introduce virtio device and its device ops | From | Jason Wang <> | Date | Fri, 18 Oct 2019 18:55:02 +0800 |
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On 2019/10/18 下午5:46, Cornelia Huck wrote: > On Thu, 17 Oct 2019 18:48:34 +0800 > Jason Wang <jasowang@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@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?)
Ok.
> >> +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/
Yes.
> >> + 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@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?
Yes, it is to and to be more obvious, I use the terminology from recent spec.
> >> + * @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/
Will fix.
> >> + * @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?
The vendor that provides this device. So something like this
I notice that MMIO also had this so it looks to me it's not pci specific.
> >> + * @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?
It's the API or mdev features other than virtio features. It could be used by driver to determine the capability of the mdev device. Besides _F_VERSION_1, we may add dirty page tracking etc which means we need new device ops.
> >> + * @get_generation: Get device generaton >> + * @mdev: mediated device >> + * Returns u32: device generation > Is that callback mandatory?
I think so, it's hard to emulate that completely in virtio-mdev transport.
Thanks
> >> + */ >> +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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