linux/drivers/virtio/virtio_vdpa.c
Parav Pandit 6dbb1f1687 vdpa: Introduce and use vdpa device get, set config helpers
Subsequent patches enable get and set configuration either
via management device or via vdpa device' config ops.

This requires synchronization between multiple callers to get and set
config callbacks. Features setting also influence the layout of the
configuration fields endianness.

To avoid exposing synchronization primitives to callers, introduce
helper for setting the configuration and use it.

Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20211026175519.87795-2-parav@nvidia.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-11-01 05:26:49 -04:00

416 lines
9.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* VIRTIO based driver for vDPA device
*
* Copyright (c) 2020, Red Hat. All rights reserved.
* Author: Jason Wang <jasowang@redhat.com>
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/uuid.h>
#include <linux/virtio.h>
#include <linux/vdpa.h>
#include <linux/virtio_config.h>
#include <linux/virtio_ring.h>
#define MOD_VERSION "0.1"
#define MOD_AUTHOR "Jason Wang <jasowang@redhat.com>"
#define MOD_DESC "vDPA bus driver for virtio devices"
#define MOD_LICENSE "GPL v2"
struct virtio_vdpa_device {
struct virtio_device vdev;
struct vdpa_device *vdpa;
u64 features;
/* The lock to protect virtqueue list */
spinlock_t lock;
/* List of virtio_vdpa_vq_info */
struct list_head virtqueues;
};
struct virtio_vdpa_vq_info {
/* the actual virtqueue */
struct virtqueue *vq;
/* the list node for the virtqueues list */
struct list_head node;
};
static inline struct virtio_vdpa_device *
to_virtio_vdpa_device(struct virtio_device *dev)
{
return container_of(dev, struct virtio_vdpa_device, vdev);
}
static struct vdpa_device *vd_get_vdpa(struct virtio_device *vdev)
{
return to_virtio_vdpa_device(vdev)->vdpa;
}
static void virtio_vdpa_get(struct virtio_device *vdev, unsigned offset,
void *buf, unsigned len)
{
struct vdpa_device *vdpa = vd_get_vdpa(vdev);
vdpa_get_config(vdpa, offset, buf, len);
}
static void virtio_vdpa_set(struct virtio_device *vdev, unsigned offset,
const void *buf, unsigned len)
{
struct vdpa_device *vdpa = vd_get_vdpa(vdev);
vdpa_set_config(vdpa, offset, buf, len);
}
static u32 virtio_vdpa_generation(struct virtio_device *vdev)
{
struct vdpa_device *vdpa = vd_get_vdpa(vdev);
const struct vdpa_config_ops *ops = vdpa->config;
if (ops->get_generation)
return ops->get_generation(vdpa);
return 0;
}
static u8 virtio_vdpa_get_status(struct virtio_device *vdev)
{
struct vdpa_device *vdpa = vd_get_vdpa(vdev);
const struct vdpa_config_ops *ops = vdpa->config;
return ops->get_status(vdpa);
}
static void virtio_vdpa_set_status(struct virtio_device *vdev, u8 status)
{
struct vdpa_device *vdpa = vd_get_vdpa(vdev);
const struct vdpa_config_ops *ops = vdpa->config;
return ops->set_status(vdpa, status);
}
static void virtio_vdpa_reset(struct virtio_device *vdev)
{
struct vdpa_device *vdpa = vd_get_vdpa(vdev);
vdpa_reset(vdpa);
}
static bool virtio_vdpa_notify(struct virtqueue *vq)
{
struct vdpa_device *vdpa = vd_get_vdpa(vq->vdev);
const struct vdpa_config_ops *ops = vdpa->config;
ops->kick_vq(vdpa, vq->index);
return true;
}
static irqreturn_t virtio_vdpa_config_cb(void *private)
{
struct virtio_vdpa_device *vd_dev = private;
virtio_config_changed(&vd_dev->vdev);
return IRQ_HANDLED;
}
static irqreturn_t virtio_vdpa_virtqueue_cb(void *private)
{
struct virtio_vdpa_vq_info *info = private;
return vring_interrupt(0, info->vq);
}
static struct virtqueue *
virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index,
void (*callback)(struct virtqueue *vq),
const char *name, bool ctx)
{
struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev);
struct vdpa_device *vdpa = vd_get_vdpa(vdev);
const struct vdpa_config_ops *ops = vdpa->config;
struct virtio_vdpa_vq_info *info;
struct vdpa_callback cb;
struct virtqueue *vq;
u64 desc_addr, driver_addr, device_addr;
/* Assume split virtqueue, switch to packed if necessary */
struct vdpa_vq_state state = {0};
unsigned long flags;
u32 align, max_num, min_num = 1;
bool may_reduce_num = true;
int err;
if (!name)
return NULL;
if (index >= vdpa->nvqs)
return ERR_PTR(-ENOENT);
/* Queue shouldn't already be set up. */
if (ops->get_vq_ready(vdpa, index))
return ERR_PTR(-ENOENT);
/* Allocate and fill out our active queue description */
info = kmalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return ERR_PTR(-ENOMEM);
max_num = ops->get_vq_num_max(vdpa);
if (max_num == 0) {
err = -ENOENT;
goto error_new_virtqueue;
}
if (ops->get_vq_num_min)
min_num = ops->get_vq_num_min(vdpa);
may_reduce_num = (max_num == min_num) ? false : true;
/* Create the vring */
align = ops->get_vq_align(vdpa);
vq = vring_create_virtqueue(index, max_num, align, vdev,
true, may_reduce_num, ctx,
virtio_vdpa_notify, callback, name);
if (!vq) {
err = -ENOMEM;
goto error_new_virtqueue;
}
/* Setup virtqueue callback */
cb.callback = virtio_vdpa_virtqueue_cb;
cb.private = info;
ops->set_vq_cb(vdpa, index, &cb);
ops->set_vq_num(vdpa, index, virtqueue_get_vring_size(vq));
desc_addr = virtqueue_get_desc_addr(vq);
driver_addr = virtqueue_get_avail_addr(vq);
device_addr = virtqueue_get_used_addr(vq);
if (ops->set_vq_address(vdpa, index,
desc_addr, driver_addr,
device_addr)) {
err = -EINVAL;
goto err_vq;
}
/* reset virtqueue state index */
if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
struct vdpa_vq_state_packed *s = &state.packed;
s->last_avail_counter = 1;
s->last_avail_idx = 0;
s->last_used_counter = 1;
s->last_used_idx = 0;
}
err = ops->set_vq_state(vdpa, index, &state);
if (err)
goto err_vq;
ops->set_vq_ready(vdpa, index, 1);
vq->priv = info;
info->vq = vq;
spin_lock_irqsave(&vd_dev->lock, flags);
list_add(&info->node, &vd_dev->virtqueues);
spin_unlock_irqrestore(&vd_dev->lock, flags);
return vq;
err_vq:
vring_del_virtqueue(vq);
error_new_virtqueue:
ops->set_vq_ready(vdpa, index, 0);
/* VDPA driver should make sure vq is stopeed here */
WARN_ON(ops->get_vq_ready(vdpa, index));
kfree(info);
return ERR_PTR(err);
}
static void virtio_vdpa_del_vq(struct virtqueue *vq)
{
struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vq->vdev);
struct vdpa_device *vdpa = vd_dev->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
struct virtio_vdpa_vq_info *info = vq->priv;
unsigned int index = vq->index;
unsigned long flags;
spin_lock_irqsave(&vd_dev->lock, flags);
list_del(&info->node);
spin_unlock_irqrestore(&vd_dev->lock, flags);
/* Select and deactivate the queue (best effort) */
ops->set_vq_ready(vdpa, index, 0);
vring_del_virtqueue(vq);
kfree(info);
}
static void virtio_vdpa_del_vqs(struct virtio_device *vdev)
{
struct virtqueue *vq, *n;
list_for_each_entry_safe(vq, n, &vdev->vqs, list)
virtio_vdpa_del_vq(vq);
}
static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned nvqs,
struct virtqueue *vqs[],
vq_callback_t *callbacks[],
const char * const names[],
const bool *ctx,
struct irq_affinity *desc)
{
struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev);
struct vdpa_device *vdpa = vd_get_vdpa(vdev);
const struct vdpa_config_ops *ops = vdpa->config;
struct vdpa_callback cb;
int i, err, queue_idx = 0;
for (i = 0; i < nvqs; ++i) {
if (!names[i]) {
vqs[i] = NULL;
continue;
}
vqs[i] = virtio_vdpa_setup_vq(vdev, queue_idx++,
callbacks[i], names[i], ctx ?
ctx[i] : false);
if (IS_ERR(vqs[i])) {
err = PTR_ERR(vqs[i]);
goto err_setup_vq;
}
}
cb.callback = virtio_vdpa_config_cb;
cb.private = vd_dev;
ops->set_config_cb(vdpa, &cb);
return 0;
err_setup_vq:
virtio_vdpa_del_vqs(vdev);
return err;
}
static u64 virtio_vdpa_get_features(struct virtio_device *vdev)
{
struct vdpa_device *vdpa = vd_get_vdpa(vdev);
const struct vdpa_config_ops *ops = vdpa->config;
return ops->get_features(vdpa);
}
static int virtio_vdpa_finalize_features(struct virtio_device *vdev)
{
struct vdpa_device *vdpa = vd_get_vdpa(vdev);
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
return vdpa_set_features(vdpa, vdev->features);
}
static const char *virtio_vdpa_bus_name(struct virtio_device *vdev)
{
struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev);
struct vdpa_device *vdpa = vd_dev->vdpa;
return dev_name(&vdpa->dev);
}
static const struct virtio_config_ops virtio_vdpa_config_ops = {
.get = virtio_vdpa_get,
.set = virtio_vdpa_set,
.generation = virtio_vdpa_generation,
.get_status = virtio_vdpa_get_status,
.set_status = virtio_vdpa_set_status,
.reset = virtio_vdpa_reset,
.find_vqs = virtio_vdpa_find_vqs,
.del_vqs = virtio_vdpa_del_vqs,
.get_features = virtio_vdpa_get_features,
.finalize_features = virtio_vdpa_finalize_features,
.bus_name = virtio_vdpa_bus_name,
};
static void virtio_vdpa_release_dev(struct device *_d)
{
struct virtio_device *vdev =
container_of(_d, struct virtio_device, dev);
struct virtio_vdpa_device *vd_dev =
container_of(vdev, struct virtio_vdpa_device, vdev);
kfree(vd_dev);
}
static int virtio_vdpa_probe(struct vdpa_device *vdpa)
{
const struct vdpa_config_ops *ops = vdpa->config;
struct virtio_vdpa_device *vd_dev, *reg_dev = NULL;
int ret = -EINVAL;
vd_dev = kzalloc(sizeof(*vd_dev), GFP_KERNEL);
if (!vd_dev)
return -ENOMEM;
vd_dev->vdev.dev.parent = vdpa_get_dma_dev(vdpa);
vd_dev->vdev.dev.release = virtio_vdpa_release_dev;
vd_dev->vdev.config = &virtio_vdpa_config_ops;
vd_dev->vdpa = vdpa;
INIT_LIST_HEAD(&vd_dev->virtqueues);
spin_lock_init(&vd_dev->lock);
vd_dev->vdev.id.device = ops->get_device_id(vdpa);
if (vd_dev->vdev.id.device == 0)
goto err;
vd_dev->vdev.id.vendor = ops->get_vendor_id(vdpa);
ret = register_virtio_device(&vd_dev->vdev);
reg_dev = vd_dev;
if (ret)
goto err;
vdpa_set_drvdata(vdpa, vd_dev);
return 0;
err:
if (reg_dev)
put_device(&vd_dev->vdev.dev);
else
kfree(vd_dev);
return ret;
}
static void virtio_vdpa_remove(struct vdpa_device *vdpa)
{
struct virtio_vdpa_device *vd_dev = vdpa_get_drvdata(vdpa);
unregister_virtio_device(&vd_dev->vdev);
}
static struct vdpa_driver virtio_vdpa_driver = {
.driver = {
.name = "virtio_vdpa",
},
.probe = virtio_vdpa_probe,
.remove = virtio_vdpa_remove,
};
module_vdpa_driver(virtio_vdpa_driver);
MODULE_VERSION(MOD_VERSION);
MODULE_LICENSE(MOD_LICENSE);
MODULE_AUTHOR(MOD_AUTHOR);
MODULE_DESCRIPTION(MOD_DESC);