| Message ID | 20191118061703.8669-6-jasowang@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mdev based hardware virtio offloading support | expand |
On Mon, Nov 18, 2019 at 02:17:02PM +0800, Jason Wang wrote: > This patch introduces a new mdev transport for virtio. This is used to > use kernel virtio driver to drive the mediated device that is capable > of populating virtqueue directly. > > A new virtio-mdev driver will be registered to the mdev bus, when a > new virtio-mdev device is probed, it will register the device with > mdev based config ops. This means it is a software transport between > mdev driver and mdev device. The transport was implemented through > bus_ops of mdev parent. > > Signed-off-by: Jason Wang <jasowang@redhat.com> > --- > drivers/virtio/Kconfig | 13 ++ > drivers/virtio/Makefile | 1 + > drivers/virtio/virtio_mdev.c | 409 +++++++++++++++++++++++++++++++++++ > include/linux/mdev_virtio.h | 5 + > 4 files changed, 428 insertions(+) > create mode 100644 drivers/virtio/virtio_mdev.c > > diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig > index 078615cf2afc..6a89b3de97d3 100644 > --- a/drivers/virtio/Kconfig > +++ b/drivers/virtio/Kconfig > @@ -43,6 +43,19 @@ config VIRTIO_PCI_LEGACY > > If unsure, say Y. > > +config VIRTIO_MDEV > + tristate "MDEV driver for virtio devices" > + depends on MDEV_VIRTIO > + default n > + help > + This driver provides support for virtio based paravirtual > + device driver over MDEV bus. For this to be useful, you need > + an appropriate virtio mdev device implementation that > + operates on a physical device to allow the datapath of virtio > + to be offloaded to hardware. > + > + If unsure, say M. > + > config VIRTIO_PMEM > tristate "Support for virtio pmem driver" > depends on VIRTIO > diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile > index 3a2b5c5dcf46..f2997b6c812f 100644 > --- a/drivers/virtio/Makefile > +++ b/drivers/virtio/Makefile > @@ -6,3 +6,4 @@ virtio_pci-y := virtio_pci_modern.o virtio_pci_common.o > virtio_pci-$(CONFIG_VIRTIO_PCI_LEGACY) += virtio_pci_legacy.o > obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o > obj-$(CONFIG_VIRTIO_INPUT) += virtio_input.o > +obj-$(CONFIG_VIRTIO_MDEV) += virtio_mdev.o > diff --git a/drivers/virtio/virtio_mdev.c b/drivers/virtio/virtio_mdev.c > new file mode 100644 > index 000000000000..7fdb42f055df > --- /dev/null > +++ b/drivers/virtio/virtio_mdev.c > @@ -0,0 +1,409 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * VIRTIO based driver for Mediated device > + * > + * Copyright (c) 2019, 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/mdev_virtio.h> > +#include <linux/virtio_config.h> > +#include <linux/virtio_ring.h> > + > +#define DRIVER_VERSION "0.1" > +#define DRIVER_AUTHOR "Red Hat Corporation" > +#define DRIVER_DESC "VIRTIO based driver for Mediated device" > + > +#define to_virtio_mdev_device(dev) \ > + container_of(dev, struct virtio_mdev_device, vdev) > + > +struct virtio_mdev_device { > + struct virtio_device vdev; > + struct mdev_device *mdev; > + u64 features; > + > + /* The lock to protect virtqueue list */ > + spinlock_t lock; > + /* List of virtio_mdev_vq_info */ > + struct list_head virtqueues; > +}; > + > +struct virtio_mdev_vq_info { > + /* the actual virtqueue */ > + struct virtqueue *vq; > + > + /* the list node for the virtqueues list */ > + struct list_head node; > +}; > + > +static struct mdev_device *vm_get_mdev(struct virtio_device *vdev) > +{ > + struct virtio_mdev_device *vm_dev = to_virtio_mdev_device(vdev); > + struct mdev_device *mdev = vm_dev->mdev; > + > + return mdev; > +} > + > +static void virtio_mdev_get(struct virtio_device *vdev, unsigned offset, > + void *buf, unsigned len) > +{ > + struct mdev_device *mdev = vm_get_mdev(vdev); > + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); > + > + ops->get_config(mdev, offset, buf, len); > +} > + > +static void virtio_mdev_set(struct virtio_device *vdev, unsigned offset, > + const void *buf, unsigned len) > +{ > + struct mdev_device *mdev = vm_get_mdev(vdev); > + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); > + > + ops->set_config(mdev, offset, buf, len); > +} > + > +static u32 virtio_mdev_generation(struct virtio_device *vdev) > +{ > + struct mdev_device *mdev = vm_get_mdev(vdev); > + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); > + > + > + if (ops->get_generation) > + return ops->get_generation(mdev); > + > + return 0; > +} > + > +static u8 virtio_mdev_get_status(struct virtio_device *vdev) > +{ > + struct mdev_device *mdev = vm_get_mdev(vdev); > + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); > + > + return ops->get_status(mdev); > +} > + > +static void virtio_mdev_set_status(struct virtio_device *vdev, u8 status) > +{ > + struct mdev_device *mdev = vm_get_mdev(vdev); > + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); > + > + return ops->set_status(mdev, status); > +} > + > +static void virtio_mdev_reset(struct virtio_device *vdev) > +{ > + struct mdev_device *mdev = vm_get_mdev(vdev); > + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); > + > + return ops->set_status(mdev, 0); > +} > + > +static bool virtio_mdev_notify(struct virtqueue *vq) > +{ > + struct mdev_device *mdev = vm_get_mdev(vq->vdev); > + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); > + > + ops->kick_vq(mdev, vq->index); > + > + return true; > +} > + > +static irqreturn_t virtio_mdev_config_cb(void *private) > +{ > + struct virtio_mdev_device *vm_dev = private; > + > + virtio_config_changed(&vm_dev->vdev); > + > + return IRQ_HANDLED; > +} > + > +static irqreturn_t virtio_mdev_virtqueue_cb(void *private) > +{ > + struct virtio_mdev_vq_info *info = private; > + > + return vring_interrupt(0, info->vq); > +} > + > +static struct virtqueue * > +virtio_mdev_setup_vq(struct virtio_device *vdev, unsigned int index, > + void (*callback)(struct virtqueue *vq), > + const char *name, bool ctx) > +{ > + struct virtio_mdev_device *vm_dev = to_virtio_mdev_device(vdev); > + struct mdev_device *mdev = vm_get_mdev(vdev); > + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); > + struct virtio_mdev_vq_info *info; > + struct virtio_mdev_callback cb; > + struct virtqueue *vq; > + u64 desc_addr, driver_addr, device_addr; > + unsigned long flags; > + u32 align, num; > + int err; > + > + if (!name) > + return NULL; > + > + /* Queue shouldn't already be set up. */ > + if (ops->get_vq_ready(mdev, 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); > + > + num = ops->get_vq_num_max(mdev); > + if (num == 0) { > + err = -ENOENT; > + goto error_new_virtqueue; > + } > + > + /* Create the vring */ > + align = ops->get_vq_align(mdev); > + vq = vring_create_virtqueue(index, num, align, vdev, > + true, true, ctx, > + virtio_mdev_notify, callback, name); > + if (!vq) { > + err = -ENOMEM; > + goto error_new_virtqueue; > + } > + > + /* Setup virtqueue callback */ > + cb.callback = virtio_mdev_virtqueue_cb; > + cb.private = info; > + ops->set_vq_cb(mdev, index, &cb); > + ops->set_vq_num(mdev, 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(mdev, index, > + desc_addr, driver_addr, > + device_addr)) { > + err = -EINVAL; > + goto err_vq; > + } > + > + ops->set_vq_ready(mdev, index, 1); > + > + vq->priv = info; > + info->vq = vq; > + > + spin_lock_irqsave(&vm_dev->lock, flags); > + list_add(&info->node, &vm_dev->virtqueues); > + spin_unlock_irqrestore(&vm_dev->lock, flags); > + > + return vq; > + > +err_vq: > + vring_del_virtqueue(vq); > +error_new_virtqueue: > + ops->set_vq_ready(mdev, index, 0); > + WARN_ON(ops->get_vq_ready(mdev, index)); > + kfree(info); > + return ERR_PTR(err); > +} > + > +static void virtio_mdev_del_vq(struct virtqueue *vq) > +{ > + struct virtio_mdev_device *vm_dev = to_virtio_mdev_device(vq->vdev); > + struct mdev_device *mdev = vm_dev->mdev; > + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); > + struct virtio_mdev_vq_info *info = vq->priv; > + unsigned int index = vq->index; > + unsigned long flags; > + > + spin_lock_irqsave(&vm_dev->lock, flags); > + list_del(&info->node); > + spin_unlock_irqrestore(&vm_dev->lock, flags); > + > + /* Select and deactivate the queue */ > + ops->set_vq_ready(mdev, index, 0); > + WARN_ON(ops->get_vq_ready(mdev, index)); > + > + vring_del_virtqueue(vq); > + > + kfree(info); > +} > + > +static void virtio_mdev_del_vqs(struct virtio_device *vdev) > +{ > + struct virtqueue *vq, *n; > + > + list_for_each_entry_safe(vq, n, &vdev->vqs, list) > + virtio_mdev_del_vq(vq); > +} > + > +static int virtio_mdev_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_mdev_device *vm_dev = to_virtio_mdev_device(vdev); > + struct mdev_device *mdev = vm_get_mdev(vdev); > + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); > + struct virtio_mdev_callback cb; > + int i, err, queue_idx = 0; > + > + for (i = 0; i < nvqs; ++i) { > + if (!names[i]) { > + vqs[i] = NULL; > + continue; > + } > + > + vqs[i] = virtio_mdev_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_mdev_config_cb; > + cb.private = vm_dev; > + ops->set_config_cb(mdev, &cb); > + > + return 0; > + > +err_setup_vq: > + virtio_mdev_del_vqs(vdev); > + return err; > +} > + > +static u64 virtio_mdev_get_features(struct virtio_device *vdev) > +{ > + struct mdev_device *mdev = vm_get_mdev(vdev); > + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); > + > + return ops->get_features(mdev); > +} > + > +static int virtio_mdev_finalize_features(struct virtio_device *vdev) > +{ > + struct mdev_device *mdev = vm_get_mdev(vdev); > + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); > + > + /* Give virtio_ring a chance to accept features. */ > + vring_transport_features(vdev); > + > + return ops->set_features(mdev, vdev->features); > +} > + > +static const char *virtio_mdev_bus_name(struct virtio_device *vdev) > +{ > + struct virtio_mdev_device *vm_dev = to_virtio_mdev_device(vdev); > + struct mdev_device *mdev = vm_dev->mdev; > + > + return dev_name(mdev_dev(mdev)); > +} > + > +static const struct virtio_config_ops virtio_mdev_config_ops = { > + .get = virtio_mdev_get, > + .set = virtio_mdev_set, > + .generation = virtio_mdev_generation, > + .get_status = virtio_mdev_get_status, > + .set_status = virtio_mdev_set_status, > + .reset = virtio_mdev_reset, > + .find_vqs = virtio_mdev_find_vqs, > + .del_vqs = virtio_mdev_del_vqs, > + .get_features = virtio_mdev_get_features, > + .finalize_features = virtio_mdev_finalize_features, > + .bus_name = virtio_mdev_bus_name, > +}; > + > +static void virtio_mdev_release_dev(struct device *_d) > +{ > + struct virtio_device *vdev = > + container_of(_d, struct virtio_device, dev); > + struct virtio_mdev_device *vm_dev = > + container_of(vdev, struct virtio_mdev_device, vdev); > + struct mdev_device *mdev = vm_dev->mdev; > + > + devm_kfree(mdev_dev(mdev), vm_dev); > +} > + > +static int virtio_mdev_probe(struct device *dev) > +{ > + struct mdev_device *mdev = mdev_virtio_from_dev(dev); > + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); > + struct virtio_mdev_device *vm_dev; > + int rc; > + > + vm_dev = devm_kzalloc(dev, sizeof(*vm_dev), GFP_KERNEL); > + if (!vm_dev) > + return -ENOMEM; > + > + vm_dev->vdev.dev.parent = dev; > + vm_dev->vdev.dev.release = virtio_mdev_release_dev; > + vm_dev->vdev.config = &virtio_mdev_config_ops; > + vm_dev->mdev = mdev; > + INIT_LIST_HEAD(&vm_dev->virtqueues); > + spin_lock_init(&vm_dev->lock); > + > + vm_dev->vdev.id.device = ops->get_device_id(mdev); > + if (vm_dev->vdev.id.device == 0) > + return -ENODEV; > + > + vm_dev->vdev.id.vendor = ops->get_vendor_id(mdev); > + rc = register_virtio_device(&vm_dev->vdev); > + if (rc) > + put_device(dev); > + else > + dev_set_drvdata(dev, vm_dev); > + > + return rc; > +} > + > +static void virtio_mdev_remove(struct device *dev) > +{ > + struct virtio_mdev_device *vm_dev = dev_get_drvdata(dev); > + > + unregister_virtio_device(&vm_dev->vdev); > +} > + > +static const struct mdev_virtio_class_id virtio_id_table[] = { > + { MDEV_VIRTIO_CLASS_ID_VIRTIO }, > + { 0 }, > +}; > + Do we still need the class ID? It's a virtio mdev bus, do we need a virtio class as well? > +MODULE_DEVICE_TABLE(mdev_virtio, virtio_id_table); > + > +static struct mdev_virtio_driver virtio_mdev_driver = { > + .drv = { > + .name = "virtio_mdev", > + .probe = virtio_mdev_probe, > + .remove = virtio_mdev_remove, > + }, > + .id_table = virtio_id_table, > +}; > + > +static int __init virtio_mdev_init(void) > +{ > + return mdev_register_driver(&virtio_mdev_driver.drv, THIS_MODULE, > + &mdev_virtio_bus_type); > +} > + > +static void __exit virtio_mdev_exit(void) > +{ > + mdev_unregister_driver(&virtio_mdev_driver.drv); > +} > + > +module_init(virtio_mdev_init) > +module_exit(virtio_mdev_exit) > + > +MODULE_VERSION(DRIVER_VERSION); > +MODULE_LICENSE("GPL v2"); > +MODULE_AUTHOR(DRIVER_AUTHOR); > +MODULE_DESCRIPTION(DRIVER_DESC); > diff --git a/include/linux/mdev_virtio.h b/include/linux/mdev_virtio.h > index ef2dbb6c383a..5f75f3cf59e1 100644 > --- a/include/linux/mdev_virtio.h > +++ b/include/linux/mdev_virtio.h > @@ -25,6 +25,11 @@ struct virtio_mdev_callback { > void *private; > }; > > +enum { > + MDEV_VIRTIO_CLASS_ID_VIRTIO = 1, > + /* New entries must be added here */ > +}; > + > /** > * struct mdev_virtio_device_ops - Structure to be registered for each > * mdev device to register the device for virtio/vhost drivers. > -- > 2.19.1
On 2019/11/18 下午6:44, Michael S. Tsirkin wrote: >> +static const struct mdev_virtio_class_id virtio_id_table[] = { >> + { MDEV_VIRTIO_CLASS_ID_VIRTIO }, >> + { 0 }, >> +}; >> + > Do we still need the class ID? It's a virtio mdev bus, > do we need a virtio class as well? > If we want to have auto match between vhost-mdev driver and vhost-mdev device, we need this. Otherwise, user need to manually probe or bind driver to the device. Thanks
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index 078615cf2afc..6a89b3de97d3 100644 --- a/drivers/virtio/Kconfig +++ b/drivers/virtio/Kconfig @@ -43,6 +43,19 @@ config VIRTIO_PCI_LEGACY If unsure, say Y. +config VIRTIO_MDEV + tristate "MDEV driver for virtio devices" + depends on MDEV_VIRTIO + default n + help + This driver provides support for virtio based paravirtual + device driver over MDEV bus. For this to be useful, you need + an appropriate virtio mdev device implementation that + operates on a physical device to allow the datapath of virtio + to be offloaded to hardware. + + If unsure, say M. + config VIRTIO_PMEM tristate "Support for virtio pmem driver" depends on VIRTIO diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile index 3a2b5c5dcf46..f2997b6c812f 100644 --- a/drivers/virtio/Makefile +++ b/drivers/virtio/Makefile @@ -6,3 +6,4 @@ virtio_pci-y := virtio_pci_modern.o virtio_pci_common.o virtio_pci-$(CONFIG_VIRTIO_PCI_LEGACY) += virtio_pci_legacy.o obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o obj-$(CONFIG_VIRTIO_INPUT) += virtio_input.o +obj-$(CONFIG_VIRTIO_MDEV) += virtio_mdev.o diff --git a/drivers/virtio/virtio_mdev.c b/drivers/virtio/virtio_mdev.c new file mode 100644 index 000000000000..7fdb42f055df --- /dev/null +++ b/drivers/virtio/virtio_mdev.c @@ -0,0 +1,409 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * VIRTIO based driver for Mediated device + * + * Copyright (c) 2019, 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/mdev_virtio.h> +#include <linux/virtio_config.h> +#include <linux/virtio_ring.h> + +#define DRIVER_VERSION "0.1" +#define DRIVER_AUTHOR "Red Hat Corporation" +#define DRIVER_DESC "VIRTIO based driver for Mediated device" + +#define to_virtio_mdev_device(dev) \ + container_of(dev, struct virtio_mdev_device, vdev) + +struct virtio_mdev_device { + struct virtio_device vdev; + struct mdev_device *mdev; + u64 features; + + /* The lock to protect virtqueue list */ + spinlock_t lock; + /* List of virtio_mdev_vq_info */ + struct list_head virtqueues; +}; + +struct virtio_mdev_vq_info { + /* the actual virtqueue */ + struct virtqueue *vq; + + /* the list node for the virtqueues list */ + struct list_head node; +}; + +static struct mdev_device *vm_get_mdev(struct virtio_device *vdev) +{ + struct virtio_mdev_device *vm_dev = to_virtio_mdev_device(vdev); + struct mdev_device *mdev = vm_dev->mdev; + + return mdev; +} + +static void virtio_mdev_get(struct virtio_device *vdev, unsigned offset, + void *buf, unsigned len) +{ + struct mdev_device *mdev = vm_get_mdev(vdev); + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); + + ops->get_config(mdev, offset, buf, len); +} + +static void virtio_mdev_set(struct virtio_device *vdev, unsigned offset, + const void *buf, unsigned len) +{ + struct mdev_device *mdev = vm_get_mdev(vdev); + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); + + ops->set_config(mdev, offset, buf, len); +} + +static u32 virtio_mdev_generation(struct virtio_device *vdev) +{ + struct mdev_device *mdev = vm_get_mdev(vdev); + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); + + + if (ops->get_generation) + return ops->get_generation(mdev); + + return 0; +} + +static u8 virtio_mdev_get_status(struct virtio_device *vdev) +{ + struct mdev_device *mdev = vm_get_mdev(vdev); + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); + + return ops->get_status(mdev); +} + +static void virtio_mdev_set_status(struct virtio_device *vdev, u8 status) +{ + struct mdev_device *mdev = vm_get_mdev(vdev); + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); + + return ops->set_status(mdev, status); +} + +static void virtio_mdev_reset(struct virtio_device *vdev) +{ + struct mdev_device *mdev = vm_get_mdev(vdev); + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); + + return ops->set_status(mdev, 0); +} + +static bool virtio_mdev_notify(struct virtqueue *vq) +{ + struct mdev_device *mdev = vm_get_mdev(vq->vdev); + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); + + ops->kick_vq(mdev, vq->index); + + return true; +} + +static irqreturn_t virtio_mdev_config_cb(void *private) +{ + struct virtio_mdev_device *vm_dev = private; + + virtio_config_changed(&vm_dev->vdev); + + return IRQ_HANDLED; +} + +static irqreturn_t virtio_mdev_virtqueue_cb(void *private) +{ + struct virtio_mdev_vq_info *info = private; + + return vring_interrupt(0, info->vq); +} + +static struct virtqueue * +virtio_mdev_setup_vq(struct virtio_device *vdev, unsigned int index, + void (*callback)(struct virtqueue *vq), + const char *name, bool ctx) +{ + struct virtio_mdev_device *vm_dev = to_virtio_mdev_device(vdev); + struct mdev_device *mdev = vm_get_mdev(vdev); + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); + struct virtio_mdev_vq_info *info; + struct virtio_mdev_callback cb; + struct virtqueue *vq; + u64 desc_addr, driver_addr, device_addr; + unsigned long flags; + u32 align, num; + int err; + + if (!name) + return NULL; + + /* Queue shouldn't already be set up. */ + if (ops->get_vq_ready(mdev, 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); + + num = ops->get_vq_num_max(mdev); + if (num == 0) { + err = -ENOENT; + goto error_new_virtqueue; + } + + /* Create the vring */ + align = ops->get_vq_align(mdev); + vq = vring_create_virtqueue(index, num, align, vdev, + true, true, ctx, + virtio_mdev_notify, callback, name); + if (!vq) { + err = -ENOMEM; + goto error_new_virtqueue; + } + + /* Setup virtqueue callback */ + cb.callback = virtio_mdev_virtqueue_cb; + cb.private = info; + ops->set_vq_cb(mdev, index, &cb); + ops->set_vq_num(mdev, 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(mdev, index, + desc_addr, driver_addr, + device_addr)) { + err = -EINVAL; + goto err_vq; + } + + ops->set_vq_ready(mdev, index, 1); + + vq->priv = info; + info->vq = vq; + + spin_lock_irqsave(&vm_dev->lock, flags); + list_add(&info->node, &vm_dev->virtqueues); + spin_unlock_irqrestore(&vm_dev->lock, flags); + + return vq; + +err_vq: + vring_del_virtqueue(vq); +error_new_virtqueue: + ops->set_vq_ready(mdev, index, 0); + WARN_ON(ops->get_vq_ready(mdev, index)); + kfree(info); + return ERR_PTR(err); +} + +static void virtio_mdev_del_vq(struct virtqueue *vq) +{ + struct virtio_mdev_device *vm_dev = to_virtio_mdev_device(vq->vdev); + struct mdev_device *mdev = vm_dev->mdev; + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); + struct virtio_mdev_vq_info *info = vq->priv; + unsigned int index = vq->index; + unsigned long flags; + + spin_lock_irqsave(&vm_dev->lock, flags); + list_del(&info->node); + spin_unlock_irqrestore(&vm_dev->lock, flags); + + /* Select and deactivate the queue */ + ops->set_vq_ready(mdev, index, 0); + WARN_ON(ops->get_vq_ready(mdev, index)); + + vring_del_virtqueue(vq); + + kfree(info); +} + +static void virtio_mdev_del_vqs(struct virtio_device *vdev) +{ + struct virtqueue *vq, *n; + + list_for_each_entry_safe(vq, n, &vdev->vqs, list) + virtio_mdev_del_vq(vq); +} + +static int virtio_mdev_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_mdev_device *vm_dev = to_virtio_mdev_device(vdev); + struct mdev_device *mdev = vm_get_mdev(vdev); + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); + struct virtio_mdev_callback cb; + int i, err, queue_idx = 0; + + for (i = 0; i < nvqs; ++i) { + if (!names[i]) { + vqs[i] = NULL; + continue; + } + + vqs[i] = virtio_mdev_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_mdev_config_cb; + cb.private = vm_dev; + ops->set_config_cb(mdev, &cb); + + return 0; + +err_setup_vq: + virtio_mdev_del_vqs(vdev); + return err; +} + +static u64 virtio_mdev_get_features(struct virtio_device *vdev) +{ + struct mdev_device *mdev = vm_get_mdev(vdev); + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); + + return ops->get_features(mdev); +} + +static int virtio_mdev_finalize_features(struct virtio_device *vdev) +{ + struct mdev_device *mdev = vm_get_mdev(vdev); + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); + + /* Give virtio_ring a chance to accept features. */ + vring_transport_features(vdev); + + return ops->set_features(mdev, vdev->features); +} + +static const char *virtio_mdev_bus_name(struct virtio_device *vdev) +{ + struct virtio_mdev_device *vm_dev = to_virtio_mdev_device(vdev); + struct mdev_device *mdev = vm_dev->mdev; + + return dev_name(mdev_dev(mdev)); +} + +static const struct virtio_config_ops virtio_mdev_config_ops = { + .get = virtio_mdev_get, + .set = virtio_mdev_set, + .generation = virtio_mdev_generation, + .get_status = virtio_mdev_get_status, + .set_status = virtio_mdev_set_status, + .reset = virtio_mdev_reset, + .find_vqs = virtio_mdev_find_vqs, + .del_vqs = virtio_mdev_del_vqs, + .get_features = virtio_mdev_get_features, + .finalize_features = virtio_mdev_finalize_features, + .bus_name = virtio_mdev_bus_name, +}; + +static void virtio_mdev_release_dev(struct device *_d) +{ + struct virtio_device *vdev = + container_of(_d, struct virtio_device, dev); + struct virtio_mdev_device *vm_dev = + container_of(vdev, struct virtio_mdev_device, vdev); + struct mdev_device *mdev = vm_dev->mdev; + + devm_kfree(mdev_dev(mdev), vm_dev); +} + +static int virtio_mdev_probe(struct device *dev) +{ + struct mdev_device *mdev = mdev_virtio_from_dev(dev); + const struct mdev_virtio_ops *ops = mdev_virtio_get_ops(mdev); + struct virtio_mdev_device *vm_dev; + int rc; + + vm_dev = devm_kzalloc(dev, sizeof(*vm_dev), GFP_KERNEL); + if (!vm_dev) + return -ENOMEM; + + vm_dev->vdev.dev.parent = dev; + vm_dev->vdev.dev.release = virtio_mdev_release_dev; + vm_dev->vdev.config = &virtio_mdev_config_ops; + vm_dev->mdev = mdev; + INIT_LIST_HEAD(&vm_dev->virtqueues); + spin_lock_init(&vm_dev->lock); + + vm_dev->vdev.id.device = ops->get_device_id(mdev); + if (vm_dev->vdev.id.device == 0) + return -ENODEV; + + vm_dev->vdev.id.vendor = ops->get_vendor_id(mdev); + rc = register_virtio_device(&vm_dev->vdev); + if (rc) + put_device(dev); + else + dev_set_drvdata(dev, vm_dev); + + return rc; +} + +static void virtio_mdev_remove(struct device *dev) +{ + struct virtio_mdev_device *vm_dev = dev_get_drvdata(dev); + + unregister_virtio_device(&vm_dev->vdev); +} + +static const struct mdev_virtio_class_id virtio_id_table[] = { + { MDEV_VIRTIO_CLASS_ID_VIRTIO }, + { 0 }, +}; + +MODULE_DEVICE_TABLE(mdev_virtio, virtio_id_table); + +static struct mdev_virtio_driver virtio_mdev_driver = { + .drv = { + .name = "virtio_mdev", + .probe = virtio_mdev_probe, + .remove = virtio_mdev_remove, + }, + .id_table = virtio_id_table, +}; + +static int __init virtio_mdev_init(void) +{ + return mdev_register_driver(&virtio_mdev_driver.drv, THIS_MODULE, + &mdev_virtio_bus_type); +} + +static void __exit virtio_mdev_exit(void) +{ + mdev_unregister_driver(&virtio_mdev_driver.drv); +} + +module_init(virtio_mdev_init) +module_exit(virtio_mdev_exit) + +MODULE_VERSION(DRIVER_VERSION); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR(DRIVER_AUTHOR); +MODULE_DESCRIPTION(DRIVER_DESC); diff --git a/include/linux/mdev_virtio.h b/include/linux/mdev_virtio.h index ef2dbb6c383a..5f75f3cf59e1 100644 --- a/include/linux/mdev_virtio.h +++ b/include/linux/mdev_virtio.h @@ -25,6 +25,11 @@ struct virtio_mdev_callback { void *private; }; +enum { + MDEV_VIRTIO_CLASS_ID_VIRTIO = 1, + /* New entries must be added here */ +}; + /** * struct mdev_virtio_device_ops - Structure to be registered for each * mdev device to register the device for virtio/vhost drivers.
This patch introduces a new mdev transport for virtio. This is used to use kernel virtio driver to drive the mediated device that is capable of populating virtqueue directly. A new virtio-mdev driver will be registered to the mdev bus, when a new virtio-mdev device is probed, it will register the device with mdev based config ops. This means it is a software transport between mdev driver and mdev device. The transport was implemented through bus_ops of mdev parent. Signed-off-by: Jason Wang <jasowang@redhat.com> --- drivers/virtio/Kconfig | 13 ++ drivers/virtio/Makefile | 1 + drivers/virtio/virtio_mdev.c | 409 +++++++++++++++++++++++++++++++++++ include/linux/mdev_virtio.h | 5 + 4 files changed, 428 insertions(+) create mode 100644 drivers/virtio/virtio_mdev.c