From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5A4BDCA9EAE for ; Tue, 29 Oct 2019 10:06:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1B0C120830 for ; Tue, 29 Oct 2019 10:06:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728457AbfJ2KGw (ORCPT ); Tue, 29 Oct 2019 06:06:52 -0400 Received: from mga07.intel.com ([134.134.136.100]:61266 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727578AbfJ2KGv (ORCPT ); Tue, 29 Oct 2019 06:06:51 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Oct 2019 03:06:50 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,243,1569308400"; d="scan'208";a="189894140" Received: from dpdk-virtio-tbie-2.sh.intel.com ([10.67.104.74]) by orsmga007.jf.intel.com with ESMTP; 29 Oct 2019 03:06:47 -0700 From: Tiwei Bie To: mst@redhat.com, jasowang@redhat.com, alex.williamson@redhat.com, maxime.coquelin@redhat.com Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, dan.daly@intel.com, cunming.liang@intel.com, zhihong.wang@intel.com, lingshan.zhu@intel.com, tiwei.bie@intel.com Subject: [PATCH v3] vhost: introduce mdev based hardware backend Date: Tue, 29 Oct 2019 18:07:34 +0800 Message-Id: <20191029100734.9861-1-tiwei.bie@intel.com> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch introduces a mdev based hardware vhost backend. This backend is built on top of the same abstraction used in virtio-mdev and provides a generic vhost interface for userspace to accelerate the virtio devices in guest. This backend is implemented as a mdev device driver on top of the same mdev device ops used in virtio-mdev but using a different mdev class id, and it will register the device as a VFIO device for userspace to use. Userspace can setup the IOMMU with the existing VFIO container/group APIs and then get the device fd with the device name. After getting the device fd of this device, userspace can use vhost ioctls to setup the backend. Signed-off-by: Tiwei Bie --- This patch depends on below series: https://lkml.org/lkml/2019/10/23/614 v2 -> v3: - Fix the return value (Jason); - Don't cache unnecessary information in vhost-mdev (Jason); - Get rid of the memset in open (Jason); - Add comments for VHOST_SET_MEM_TABLE, ... (Jason); - Filter out unsupported features in vhost-mdev (Jason); - Add _GET_DEVICE_ID ioctl (Jason); - Add _GET_CONFIG/_SET_CONFIG ioctls (Jason); - Drop _GET_QUEUE_NUM ioctl (Jason); - Fix the copy-paste errors in _IOW/_IOR usage; - Some minor fixes and improvements; v1 -> v2: - Replace _SET_STATE with _SET_STATUS (MST); - Check status bits at each step (MST); - Report the max ring size and max number of queues (MST); - Add missing MODULE_DEVICE_TABLE (Jason); - Only support the network backend w/o multiqueue for now; - Some minor fixes and improvements; - Rebase on top of virtio-mdev series v4; RFC v4 -> v1: - Implement vhost-mdev as a mdev device driver directly and connect it to VFIO container/group. (Jason); - Pass ring addresses as GPAs/IOVAs in vhost-mdev to avoid meaningless HVA->GPA translations (Jason); RFC v3 -> RFC v4: - Build vhost-mdev on top of the same abstraction used by virtio-mdev (Jason); - Introduce vhost fd and pass VFIO fd via SET_BACKEND ioctl (MST); RFC v2 -> RFC v3: - Reuse vhost's ioctls instead of inventing a VFIO regions/irqs based vhost protocol on top of vfio-mdev (Jason); RFC v1 -> RFC v2: - Introduce a new VFIO device type to build a vhost protocol on top of vfio-mdev; drivers/vfio/mdev/mdev_core.c | 20 ++ drivers/vfio/mdev/mdev_private.h | 1 + drivers/vhost/Kconfig | 12 + drivers/vhost/Makefile | 3 + drivers/vhost/mdev.c | 554 +++++++++++++++++++++++++++++++ include/linux/mdev.h | 5 + include/uapi/linux/vhost.h | 18 + include/uapi/linux/vhost_types.h | 8 + 8 files changed, 621 insertions(+) create mode 100644 drivers/vhost/mdev.c diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c index 9b00c3513120..3cfd787d605c 100644 --- a/drivers/vfio/mdev/mdev_core.c +++ b/drivers/vfio/mdev/mdev_core.c @@ -96,6 +96,26 @@ mdev_get_virtio_ops(struct mdev_device *mdev) } EXPORT_SYMBOL(mdev_get_virtio_ops); +/* Specify the vhost device ops for the mdev device, this + * must be called during create() callback for vhost mdev device. + */ +void mdev_set_vhost_ops(struct mdev_device *mdev, + const struct virtio_mdev_device_ops *vhost_ops) +{ + mdev_set_class(mdev, MDEV_CLASS_ID_VHOST); + mdev->vhost_ops = vhost_ops; +} +EXPORT_SYMBOL(mdev_set_vhost_ops); + +/* Get the vhost device ops for the mdev device. */ +const struct virtio_mdev_device_ops * +mdev_get_vhost_ops(struct mdev_device *mdev) +{ + WARN_ON(mdev->class_id != MDEV_CLASS_ID_VHOST); + return mdev->vhost_ops; +} +EXPORT_SYMBOL(mdev_get_vhost_ops); + struct device *mdev_dev(struct mdev_device *mdev) { return &mdev->dev; diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h index 7b47890c34e7..5597c846e52f 100644 --- a/drivers/vfio/mdev/mdev_private.h +++ b/drivers/vfio/mdev/mdev_private.h @@ -40,6 +40,7 @@ struct mdev_device { union { const struct vfio_mdev_device_ops *vfio_ops; const struct virtio_mdev_device_ops *virtio_ops; + const struct virtio_mdev_device_ops *vhost_ops; }; }; diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig index 3d03ccbd1adc..062cada28f89 100644 --- a/drivers/vhost/Kconfig +++ b/drivers/vhost/Kconfig @@ -34,6 +34,18 @@ config VHOST_VSOCK To compile this driver as a module, choose M here: the module will be called vhost_vsock. +config VHOST_MDEV + tristate "Vhost driver for Mediated devices" + depends on EVENTFD && VFIO && VFIO_MDEV + select VHOST + default n + ---help--- + This kernel module can be loaded in host kernel to accelerate + guest virtio devices with the mediated device based backends. + + To compile this driver as a module, choose M here: the module will + be called vhost_mdev. + config VHOST tristate ---help--- diff --git a/drivers/vhost/Makefile b/drivers/vhost/Makefile index 6c6df24f770c..ad9c0f8c6d8c 100644 --- a/drivers/vhost/Makefile +++ b/drivers/vhost/Makefile @@ -10,4 +10,7 @@ vhost_vsock-y := vsock.o obj-$(CONFIG_VHOST_RING) += vringh.o +obj-$(CONFIG_VHOST_MDEV) += vhost_mdev.o +vhost_mdev-y := mdev.o + obj-$(CONFIG_VHOST) += vhost.o diff --git a/drivers/vhost/mdev.c b/drivers/vhost/mdev.c new file mode 100644 index 000000000000..35b2fb33e686 --- /dev/null +++ b/drivers/vhost/mdev.c @@ -0,0 +1,554 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Vhost driver for mediated device based backends. + * + * Copyright (C) 2018-2019 Intel Corporation. + * + * Author: Tiwei Bie + * + * Thanks to Jason Wang and Michael S. Tsirkin for the valuable + * comments and suggestions. And thanks to Cunming Liang and + * Zhihong Wang for all their supports. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include "vhost.h" + +enum { + VHOST_MDEV_FEATURES = + (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | + (1ULL << VIRTIO_F_ANY_LAYOUT) | + (1ULL << VIRTIO_F_VERSION_1) | + (1ULL << VIRTIO_F_IOMMU_PLATFORM) | + (1ULL << VIRTIO_F_RING_PACKED) | + (1ULL << VIRTIO_F_ORDER_PLATFORM) | + (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | + (1ULL << VIRTIO_RING_F_EVENT_IDX), + + VHOST_MDEV_NET_FEATURES = VHOST_MDEV_FEATURES | + (1ULL << VIRTIO_NET_F_CSUM) | + (1ULL << VIRTIO_NET_F_GUEST_CSUM) | + (1ULL << VIRTIO_NET_F_MTU) | + (1ULL << VIRTIO_NET_F_MAC) | + (1ULL << VIRTIO_NET_F_GUEST_TSO4) | + (1ULL << VIRTIO_NET_F_GUEST_TSO6) | + (1ULL << VIRTIO_NET_F_GUEST_ECN) | + (1ULL << VIRTIO_NET_F_GUEST_UFO) | + (1ULL << VIRTIO_NET_F_HOST_TSO4) | + (1ULL << VIRTIO_NET_F_HOST_TSO6) | + (1ULL << VIRTIO_NET_F_HOST_ECN) | + (1ULL << VIRTIO_NET_F_HOST_UFO) | + (1ULL << VIRTIO_NET_F_MRG_RXBUF) | + (1ULL << VIRTIO_NET_F_STATUS) | + (1ULL << VIRTIO_NET_F_SPEED_DUPLEX), +}; + +/* Currently, only network backend w/o multiqueue is supported. */ +#define VHOST_MDEV_VQ_MAX 2 + +struct vhost_mdev { + /* The lock is to protect this structure. */ + struct mutex mutex; + struct vhost_dev dev; + struct vhost_virtqueue *vqs; + int nvqs; + int virtio_id; + bool opened; + struct mdev_device *mdev; +}; + +static const u64 vhost_mdev_features[] = { + [VIRTIO_ID_NET] = VHOST_MDEV_NET_FEATURES, +}; + +static void handle_vq_kick(struct vhost_work *work) +{ + struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, + poll.work); + struct vhost_mdev *m = container_of(vq->dev, struct vhost_mdev, dev); + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(m->mdev); + + ops->kick_vq(m->mdev, vq - m->vqs); +} + +static irqreturn_t vhost_mdev_virtqueue_cb(void *private) +{ + struct vhost_virtqueue *vq = private; + struct eventfd_ctx *call_ctx = vq->call_ctx; + + if (call_ctx) + eventfd_signal(call_ctx, 1); + + return IRQ_HANDLED; +} + +static void vhost_mdev_reset(struct vhost_mdev *m) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + + ops->set_status(mdev, 0); +} + +static long vhost_mdev_get_device_id(struct vhost_mdev *m, u8 __user *argp) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + u32 device_id; + + device_id = ops->get_device_id(mdev); + + if (copy_to_user(argp, &device_id, sizeof(device_id))) + return -EFAULT; + + return 0; +} + +static long vhost_mdev_get_status(struct vhost_mdev *m, u8 __user *statusp) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + u8 status; + + status = ops->get_status(mdev); + + if (copy_to_user(statusp, &status, sizeof(status))) + return -EFAULT; + + return 0; +} + +static long vhost_mdev_set_status(struct vhost_mdev *m, u8 __user *statusp) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + u8 status; + + if (copy_from_user(&status, statusp, sizeof(status))) + return -EFAULT; + + /* + * Userspace shouldn't remove status bits unless reset the + * status to 0. + */ + if (status != 0 && (ops->get_status(mdev) & ~status) != 0) + return -EINVAL; + + ops->set_status(mdev, status); + + return 0; +} + +static int vhost_mdev_config_validate(struct vhost_mdev *m, + struct vhost_mdev_config *c) +{ + long size = 0; + + switch (m->virtio_id) { + case VIRTIO_ID_NET: + size = sizeof(struct virtio_net_config); + break; + } + + if (c->len == 0) + return -EINVAL; + + if (c->off >= size || c->len > size || c->off + c->len > size) + return -E2BIG; + + return 0; +} + +static long vhost_mdev_get_config(struct vhost_mdev *m, + struct vhost_mdev_config __user *c) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + struct vhost_mdev_config config; + unsigned long size = offsetof(struct vhost_mdev_config, buf); + u8 *buf; + + if (copy_from_user(&config, c, size)) + return -EFAULT; + if (vhost_mdev_config_validate(m, &config)) + return -EINVAL; + buf = kvzalloc(config.len, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + ops->get_config(mdev, config.off, buf, config.len); + + if (copy_to_user(c->buf, buf, config.len)) { + kvfree(buf); + return -EFAULT; + } + + kvfree(buf); + return 0; +} + +static long vhost_mdev_set_config(struct vhost_mdev *m, + struct vhost_mdev_config __user *c) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + struct vhost_mdev_config config; + unsigned long size = offsetof(struct vhost_mdev_config, buf); + u8 *buf; + + if (copy_from_user(&config, c, size)) + return -EFAULT; + if (vhost_mdev_config_validate(m, &config)) + return -EINVAL; + buf = kvzalloc(config.len, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + if (copy_from_user(buf, c->buf, config.len)) { + kvfree(buf); + return -EFAULT; + } + + ops->set_config(mdev, config.off, buf, config.len); + + kvfree(buf); + return 0; +} + +static long vhost_mdev_get_features(struct vhost_mdev *m, u64 __user *featurep) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + u64 features; + + features = ops->get_features(mdev); + features &= vhost_mdev_features[m->virtio_id]; + + if (copy_to_user(featurep, &features, sizeof(features))) + return -EFAULT; + + return 0; +} + +static long vhost_mdev_set_features(struct vhost_mdev *m, u64 __user *featurep) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + u64 features; + + /* + * It's not allowed to change the features after they have + * been negotiated. + */ + if (ops->get_status(mdev) & VIRTIO_CONFIG_S_FEATURES_OK) + return -EBUSY; + + if (copy_from_user(&features, featurep, sizeof(features))) + return -EFAULT; + + if (features & ~vhost_mdev_features[m->virtio_id]) + return -EINVAL; + + if (ops->set_features(mdev, features)) + return -EINVAL; + + return 0; +} + +static long vhost_mdev_get_vring_num(struct vhost_mdev *m, u16 __user *argp) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + u16 num; + + num = ops->get_vq_num_max(mdev); + + if (copy_to_user(argp, &num, sizeof(num))) + return -EFAULT; + + return 0; +} + +static long vhost_mdev_vring_ioctl(struct vhost_mdev *m, unsigned int cmd, + void __user *argp) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + struct virtio_mdev_callback cb; + struct vhost_virtqueue *vq; + struct vhost_vring_state s; + u8 status; + u32 idx; + long r; + + r = get_user(idx, (u32 __user *)argp); + if (r < 0) + return r; + if (idx >= m->nvqs) + return -ENOBUFS; + + status = ops->get_status(mdev); + + /* + * It's not allowed to detect and program vqs before + * features negotiation or after enabling driver. + */ + if (!(status & VIRTIO_CONFIG_S_FEATURES_OK) || + (status & VIRTIO_CONFIG_S_DRIVER_OK)) + return -EBUSY; + + vq = &m->vqs[idx]; + + if (cmd == VHOST_MDEV_SET_VRING_ENABLE) { + if (copy_from_user(&s, argp, sizeof(s))) + return -EFAULT; + ops->set_vq_ready(mdev, idx, s.num); + return 0; + } + + /* + * It's not allowed to detect and program vqs with + * vqs enabled. + */ + if (ops->get_vq_ready(mdev, idx)) + return -EBUSY; + + if (cmd == VHOST_GET_VRING_BASE) + vq->last_avail_idx = ops->get_vq_state(m->mdev, idx); + + r = vhost_vring_ioctl(&m->dev, cmd, argp); + if (r) + return r; + + switch (cmd) { + case VHOST_SET_VRING_ADDR: + /* + * In vhost-mdev, the ring addresses set by userspace should + * be the DMA addresses within the VFIO container/group. + */ + if (ops->set_vq_address(mdev, idx, (u64)vq->desc, + (u64)vq->avail, (u64)vq->used)) + r = -ENODEV; + break; + + case VHOST_SET_VRING_BASE: + if (ops->set_vq_state(mdev, idx, vq->last_avail_idx)) + r = -ENODEV; + break; + + case VHOST_SET_VRING_CALL: + if (vq->call_ctx) { + cb.callback = vhost_mdev_virtqueue_cb; + cb.private = vq; + } else { + cb.callback = NULL; + cb.private = NULL; + } + ops->set_vq_cb(mdev, idx, &cb); + break; + + case VHOST_SET_VRING_NUM: + ops->set_vq_num(mdev, idx, vq->num); + break; + } + + return r; +} + +static int vhost_mdev_open(void *device_data) +{ + struct vhost_mdev *m = device_data; + struct vhost_dev *dev; + struct vhost_virtqueue **vqs; + int nvqs, i, r; + + if (!try_module_get(THIS_MODULE)) + return -ENODEV; + + mutex_lock(&m->mutex); + + if (m->opened) { + r = -EBUSY; + goto err; + } + + nvqs = m->nvqs; + vhost_mdev_reset(m); + + vqs = kmalloc_array(nvqs, sizeof(*vqs), GFP_KERNEL); + if (!vqs) { + r = -ENOMEM; + goto err; + } + + dev = &m->dev; + for (i = 0; i < nvqs; i++) { + vqs[i] = &m->vqs[i]; + vqs[i]->handle_kick = handle_vq_kick; + } + vhost_dev_init(dev, vqs, nvqs, 0, 0, 0); + m->opened = true; + mutex_unlock(&m->mutex); + + return 0; + +err: + mutex_unlock(&m->mutex); + module_put(THIS_MODULE); + return r; +} + +static void vhost_mdev_release(void *device_data) +{ + struct vhost_mdev *m = device_data; + + mutex_lock(&m->mutex); + vhost_mdev_reset(m); + vhost_dev_stop(&m->dev); + vhost_dev_cleanup(&m->dev); + + kfree(m->dev.vqs); + m->opened = false; + mutex_unlock(&m->mutex); + module_put(THIS_MODULE); +} + +static long vhost_mdev_unlocked_ioctl(void *device_data, + unsigned int cmd, unsigned long arg) +{ + struct vhost_mdev *m = device_data; + void __user *argp = (void __user *)arg; + long r; + + mutex_lock(&m->mutex); + + switch (cmd) { + case VHOST_MDEV_GET_DEVICE_ID: + r = vhost_mdev_get_device_id(m, argp); + break; + case VHOST_MDEV_GET_STATUS: + r = vhost_mdev_get_status(m, argp); + break; + case VHOST_MDEV_SET_STATUS: + r = vhost_mdev_set_status(m, argp); + break; + case VHOST_MDEV_GET_CONFIG: + r = vhost_mdev_get_config(m, argp); + break; + case VHOST_MDEV_SET_CONFIG: + r = vhost_mdev_set_config(m, argp); + break; + case VHOST_GET_FEATURES: + r = vhost_mdev_get_features(m, argp); + break; + case VHOST_SET_FEATURES: + r = vhost_mdev_set_features(m, argp); + break; + case VHOST_MDEV_GET_VRING_NUM: + r = vhost_mdev_get_vring_num(m, argp); + break; + default: + /* + * VHOST_SET_MEM_TABLE, VHOST_SET_LOG_BASE, and + * VHOST_SET_LOG_FD are not used yet. + */ + r = vhost_dev_ioctl(&m->dev, cmd, argp); + if (r == -ENOIOCTLCMD) + r = vhost_mdev_vring_ioctl(m, cmd, argp); + } + + mutex_unlock(&m->mutex); + return r; +} + +static const struct vfio_device_ops vfio_vhost_mdev_dev_ops = { + .name = "vfio-vhost-mdev", + .open = vhost_mdev_open, + .release = vhost_mdev_release, + .ioctl = vhost_mdev_unlocked_ioctl, +}; + +static int vhost_mdev_probe(struct device *dev) +{ + struct mdev_device *mdev = mdev_from_dev(dev); + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + struct vhost_mdev *m; + int nvqs, r; + + /* Currently, we only accept the network devices. */ + if (ops->get_device_id(mdev) != VIRTIO_ID_NET) + return -ENOTSUPP; + + if (ops->get_mdev_features(mdev) != VIRTIO_MDEV_F_VERSION_1) + return -ENOTSUPP; + + m = devm_kzalloc(dev, sizeof(*m), GFP_KERNEL | __GFP_RETRY_MAYFAIL); + if (!m) + return -ENOMEM; + + nvqs = VHOST_MDEV_VQ_MAX; + + m->vqs = devm_kmalloc_array(dev, nvqs, sizeof(struct vhost_virtqueue), + GFP_KERNEL); + if (!m->vqs) + return -ENOMEM; + + mutex_init(&m->mutex); + + m->mdev = mdev; + m->nvqs = nvqs; + m->virtio_id = ops->get_device_id(mdev); + + r = vfio_add_group_dev(dev, &vfio_vhost_mdev_dev_ops, m); + if (r) { + mutex_destroy(&m->mutex); + return r; + } + + return 0; +} + +static void vhost_mdev_remove(struct device *dev) +{ + struct vhost_mdev *m; + + m = vfio_del_group_dev(dev); + mutex_destroy(&m->mutex); +} + +static const struct mdev_class_id vhost_mdev_match[] = { + { MDEV_CLASS_ID_VHOST }, + { 0 }, +}; +MODULE_DEVICE_TABLE(mdev, vhost_mdev_match); + +static struct mdev_driver vhost_mdev_driver = { + .name = "vhost_mdev", + .probe = vhost_mdev_probe, + .remove = vhost_mdev_remove, + .id_table = vhost_mdev_match, +}; + +static int __init vhost_mdev_init(void) +{ + return mdev_register_driver(&vhost_mdev_driver, THIS_MODULE); +} +module_init(vhost_mdev_init); + +static void __exit vhost_mdev_exit(void) +{ + mdev_unregister_driver(&vhost_mdev_driver); +} +module_exit(vhost_mdev_exit); + +MODULE_VERSION("0.0.1"); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Intel Corporation"); +MODULE_DESCRIPTION("Mediated device based accelerator for virtio"); diff --git a/include/linux/mdev.h b/include/linux/mdev.h index 9b69b0bbebfd..3e1e03926355 100644 --- a/include/linux/mdev.h +++ b/include/linux/mdev.h @@ -117,6 +117,10 @@ void mdev_set_virtio_ops(struct mdev_device *mdev, const struct virtio_mdev_device_ops *virtio_ops); const struct virtio_mdev_device_ops * mdev_get_virtio_ops(struct mdev_device *mdev); +void mdev_set_vhost_ops(struct mdev_device *mdev, + const struct virtio_mdev_device_ops *vhost_ops); +const struct virtio_mdev_device_ops * +mdev_get_vhost_ops(struct mdev_device *mdev); extern struct bus_type mdev_bus_type; @@ -133,6 +137,7 @@ struct mdev_device *mdev_from_dev(struct device *dev); enum { MDEV_CLASS_ID_VFIO = 1, MDEV_CLASS_ID_VIRTIO = 2, + MDEV_CLASS_ID_VHOST = 3, /* New entries must be added here */ }; diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h index 40d028eed645..061a2824a1b3 100644 --- a/include/uapi/linux/vhost.h +++ b/include/uapi/linux/vhost.h @@ -116,4 +116,22 @@ #define VHOST_VSOCK_SET_GUEST_CID _IOW(VHOST_VIRTIO, 0x60, __u64) #define VHOST_VSOCK_SET_RUNNING _IOW(VHOST_VIRTIO, 0x61, int) +/* VHOST_MDEV specific defines */ + +/* Get the device id. The device ids follow the same definition of + * the device id defined in virtio-spec. */ +#define VHOST_MDEV_GET_DEVICE_ID _IOR(VHOST_VIRTIO, 0x70, __u32) +/* Get and set the status. The status bits follow the same definition + * of the device status defined in virtio-spec. */ +#define VHOST_MDEV_GET_STATUS _IOR(VHOST_VIRTIO, 0x71, __u8) +#define VHOST_MDEV_SET_STATUS _IOW(VHOST_VIRTIO, 0x72, __u8) +/* Get and set the device config. The device config follows the same + * definition of the device config defined in virtio-spec. */ +#define VHOST_MDEV_GET_CONFIG _IOR(VHOST_VIRTIO, 0x73, struct vhost_mdev_config) +#define VHOST_MDEV_SET_CONFIG _IOW(VHOST_VIRTIO, 0x74, struct vhost_mdev_config) +/* Enable/disable the ring. */ +#define VHOST_MDEV_SET_VRING_ENABLE _IOW(VHOST_VIRTIO, 0x75, struct vhost_vring_state) +/* Get the max ring size. */ +#define VHOST_MDEV_GET_VRING_NUM _IOR(VHOST_VIRTIO, 0x76, __u16) + #endif diff --git a/include/uapi/linux/vhost_types.h b/include/uapi/linux/vhost_types.h index c907290ff065..7b105d0b2fb9 100644 --- a/include/uapi/linux/vhost_types.h +++ b/include/uapi/linux/vhost_types.h @@ -119,6 +119,14 @@ struct vhost_scsi_target { unsigned short reserved; }; +/* VHOST_MDEV specific definitions */ + +struct vhost_mdev_config { + __u32 off; + __u32 len; + __u8 buf[0]; +}; + /* Feature bits */ /* Log all write descriptors. Can be changed while device is active. */ #define VHOST_F_LOG_ALL 26 -- 2.23.0 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tiwei Bie Subject: [PATCH v3] vhost: introduce mdev based hardware backend Date: Tue, 29 Oct 2019 18:07:34 +0800 Message-ID: <20191029100734.9861-1-tiwei.bie@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: mst@redhat.com, jasowang@redhat.com, alex.williamson@redhat.com, maxime.coquelin@redhat.com Cc: kvm@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, zhihong.wang@intel.com, lingshan.zhu@intel.com List-Id: virtualization@lists.linuxfoundation.org This patch introduces a mdev based hardware vhost backend. This backend is built on top of the same abstraction used in virtio-mdev and provides a generic vhost interface for userspace to accelerate the virtio devices in guest. This backend is implemented as a mdev device driver on top of the same mdev device ops used in virtio-mdev but using a different mdev class id, and it will register the device as a VFIO device for userspace to use. Userspace can setup the IOMMU with the existing VFIO container/group APIs and then get the device fd with the device name. After getting the device fd of this device, userspace can use vhost ioctls to setup the backend. Signed-off-by: Tiwei Bie --- This patch depends on below series: https://lkml.org/lkml/2019/10/23/614 v2 -> v3: - Fix the return value (Jason); - Don't cache unnecessary information in vhost-mdev (Jason); - Get rid of the memset in open (Jason); - Add comments for VHOST_SET_MEM_TABLE, ... (Jason); - Filter out unsupported features in vhost-mdev (Jason); - Add _GET_DEVICE_ID ioctl (Jason); - Add _GET_CONFIG/_SET_CONFIG ioctls (Jason); - Drop _GET_QUEUE_NUM ioctl (Jason); - Fix the copy-paste errors in _IOW/_IOR usage; - Some minor fixes and improvements; v1 -> v2: - Replace _SET_STATE with _SET_STATUS (MST); - Check status bits at each step (MST); - Report the max ring size and max number of queues (MST); - Add missing MODULE_DEVICE_TABLE (Jason); - Only support the network backend w/o multiqueue for now; - Some minor fixes and improvements; - Rebase on top of virtio-mdev series v4; RFC v4 -> v1: - Implement vhost-mdev as a mdev device driver directly and connect it to VFIO container/group. (Jason); - Pass ring addresses as GPAs/IOVAs in vhost-mdev to avoid meaningless HVA->GPA translations (Jason); RFC v3 -> RFC v4: - Build vhost-mdev on top of the same abstraction used by virtio-mdev (Jason); - Introduce vhost fd and pass VFIO fd via SET_BACKEND ioctl (MST); RFC v2 -> RFC v3: - Reuse vhost's ioctls instead of inventing a VFIO regions/irqs based vhost protocol on top of vfio-mdev (Jason); RFC v1 -> RFC v2: - Introduce a new VFIO device type to build a vhost protocol on top of vfio-mdev; drivers/vfio/mdev/mdev_core.c | 20 ++ drivers/vfio/mdev/mdev_private.h | 1 + drivers/vhost/Kconfig | 12 + drivers/vhost/Makefile | 3 + drivers/vhost/mdev.c | 554 +++++++++++++++++++++++++++++++ include/linux/mdev.h | 5 + include/uapi/linux/vhost.h | 18 + include/uapi/linux/vhost_types.h | 8 + 8 files changed, 621 insertions(+) create mode 100644 drivers/vhost/mdev.c diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c index 9b00c3513120..3cfd787d605c 100644 --- a/drivers/vfio/mdev/mdev_core.c +++ b/drivers/vfio/mdev/mdev_core.c @@ -96,6 +96,26 @@ mdev_get_virtio_ops(struct mdev_device *mdev) } EXPORT_SYMBOL(mdev_get_virtio_ops); +/* Specify the vhost device ops for the mdev device, this + * must be called during create() callback for vhost mdev device. + */ +void mdev_set_vhost_ops(struct mdev_device *mdev, + const struct virtio_mdev_device_ops *vhost_ops) +{ + mdev_set_class(mdev, MDEV_CLASS_ID_VHOST); + mdev->vhost_ops = vhost_ops; +} +EXPORT_SYMBOL(mdev_set_vhost_ops); + +/* Get the vhost device ops for the mdev device. */ +const struct virtio_mdev_device_ops * +mdev_get_vhost_ops(struct mdev_device *mdev) +{ + WARN_ON(mdev->class_id != MDEV_CLASS_ID_VHOST); + return mdev->vhost_ops; +} +EXPORT_SYMBOL(mdev_get_vhost_ops); + struct device *mdev_dev(struct mdev_device *mdev) { return &mdev->dev; diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h index 7b47890c34e7..5597c846e52f 100644 --- a/drivers/vfio/mdev/mdev_private.h +++ b/drivers/vfio/mdev/mdev_private.h @@ -40,6 +40,7 @@ struct mdev_device { union { const struct vfio_mdev_device_ops *vfio_ops; const struct virtio_mdev_device_ops *virtio_ops; + const struct virtio_mdev_device_ops *vhost_ops; }; }; diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig index 3d03ccbd1adc..062cada28f89 100644 --- a/drivers/vhost/Kconfig +++ b/drivers/vhost/Kconfig @@ -34,6 +34,18 @@ config VHOST_VSOCK To compile this driver as a module, choose M here: the module will be called vhost_vsock. +config VHOST_MDEV + tristate "Vhost driver for Mediated devices" + depends on EVENTFD && VFIO && VFIO_MDEV + select VHOST + default n + ---help--- + This kernel module can be loaded in host kernel to accelerate + guest virtio devices with the mediated device based backends. + + To compile this driver as a module, choose M here: the module will + be called vhost_mdev. + config VHOST tristate ---help--- diff --git a/drivers/vhost/Makefile b/drivers/vhost/Makefile index 6c6df24f770c..ad9c0f8c6d8c 100644 --- a/drivers/vhost/Makefile +++ b/drivers/vhost/Makefile @@ -10,4 +10,7 @@ vhost_vsock-y := vsock.o obj-$(CONFIG_VHOST_RING) += vringh.o +obj-$(CONFIG_VHOST_MDEV) += vhost_mdev.o +vhost_mdev-y := mdev.o + obj-$(CONFIG_VHOST) += vhost.o diff --git a/drivers/vhost/mdev.c b/drivers/vhost/mdev.c new file mode 100644 index 000000000000..35b2fb33e686 --- /dev/null +++ b/drivers/vhost/mdev.c @@ -0,0 +1,554 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Vhost driver for mediated device based backends. + * + * Copyright (C) 2018-2019 Intel Corporation. + * + * Author: Tiwei Bie + * + * Thanks to Jason Wang and Michael S. Tsirkin for the valuable + * comments and suggestions. And thanks to Cunming Liang and + * Zhihong Wang for all their supports. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include "vhost.h" + +enum { + VHOST_MDEV_FEATURES = + (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | + (1ULL << VIRTIO_F_ANY_LAYOUT) | + (1ULL << VIRTIO_F_VERSION_1) | + (1ULL << VIRTIO_F_IOMMU_PLATFORM) | + (1ULL << VIRTIO_F_RING_PACKED) | + (1ULL << VIRTIO_F_ORDER_PLATFORM) | + (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | + (1ULL << VIRTIO_RING_F_EVENT_IDX), + + VHOST_MDEV_NET_FEATURES = VHOST_MDEV_FEATURES | + (1ULL << VIRTIO_NET_F_CSUM) | + (1ULL << VIRTIO_NET_F_GUEST_CSUM) | + (1ULL << VIRTIO_NET_F_MTU) | + (1ULL << VIRTIO_NET_F_MAC) | + (1ULL << VIRTIO_NET_F_GUEST_TSO4) | + (1ULL << VIRTIO_NET_F_GUEST_TSO6) | + (1ULL << VIRTIO_NET_F_GUEST_ECN) | + (1ULL << VIRTIO_NET_F_GUEST_UFO) | + (1ULL << VIRTIO_NET_F_HOST_TSO4) | + (1ULL << VIRTIO_NET_F_HOST_TSO6) | + (1ULL << VIRTIO_NET_F_HOST_ECN) | + (1ULL << VIRTIO_NET_F_HOST_UFO) | + (1ULL << VIRTIO_NET_F_MRG_RXBUF) | + (1ULL << VIRTIO_NET_F_STATUS) | + (1ULL << VIRTIO_NET_F_SPEED_DUPLEX), +}; + +/* Currently, only network backend w/o multiqueue is supported. */ +#define VHOST_MDEV_VQ_MAX 2 + +struct vhost_mdev { + /* The lock is to protect this structure. */ + struct mutex mutex; + struct vhost_dev dev; + struct vhost_virtqueue *vqs; + int nvqs; + int virtio_id; + bool opened; + struct mdev_device *mdev; +}; + +static const u64 vhost_mdev_features[] = { + [VIRTIO_ID_NET] = VHOST_MDEV_NET_FEATURES, +}; + +static void handle_vq_kick(struct vhost_work *work) +{ + struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, + poll.work); + struct vhost_mdev *m = container_of(vq->dev, struct vhost_mdev, dev); + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(m->mdev); + + ops->kick_vq(m->mdev, vq - m->vqs); +} + +static irqreturn_t vhost_mdev_virtqueue_cb(void *private) +{ + struct vhost_virtqueue *vq = private; + struct eventfd_ctx *call_ctx = vq->call_ctx; + + if (call_ctx) + eventfd_signal(call_ctx, 1); + + return IRQ_HANDLED; +} + +static void vhost_mdev_reset(struct vhost_mdev *m) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + + ops->set_status(mdev, 0); +} + +static long vhost_mdev_get_device_id(struct vhost_mdev *m, u8 __user *argp) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + u32 device_id; + + device_id = ops->get_device_id(mdev); + + if (copy_to_user(argp, &device_id, sizeof(device_id))) + return -EFAULT; + + return 0; +} + +static long vhost_mdev_get_status(struct vhost_mdev *m, u8 __user *statusp) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + u8 status; + + status = ops->get_status(mdev); + + if (copy_to_user(statusp, &status, sizeof(status))) + return -EFAULT; + + return 0; +} + +static long vhost_mdev_set_status(struct vhost_mdev *m, u8 __user *statusp) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + u8 status; + + if (copy_from_user(&status, statusp, sizeof(status))) + return -EFAULT; + + /* + * Userspace shouldn't remove status bits unless reset the + * status to 0. + */ + if (status != 0 && (ops->get_status(mdev) & ~status) != 0) + return -EINVAL; + + ops->set_status(mdev, status); + + return 0; +} + +static int vhost_mdev_config_validate(struct vhost_mdev *m, + struct vhost_mdev_config *c) +{ + long size = 0; + + switch (m->virtio_id) { + case VIRTIO_ID_NET: + size = sizeof(struct virtio_net_config); + break; + } + + if (c->len == 0) + return -EINVAL; + + if (c->off >= size || c->len > size || c->off + c->len > size) + return -E2BIG; + + return 0; +} + +static long vhost_mdev_get_config(struct vhost_mdev *m, + struct vhost_mdev_config __user *c) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + struct vhost_mdev_config config; + unsigned long size = offsetof(struct vhost_mdev_config, buf); + u8 *buf; + + if (copy_from_user(&config, c, size)) + return -EFAULT; + if (vhost_mdev_config_validate(m, &config)) + return -EINVAL; + buf = kvzalloc(config.len, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + ops->get_config(mdev, config.off, buf, config.len); + + if (copy_to_user(c->buf, buf, config.len)) { + kvfree(buf); + return -EFAULT; + } + + kvfree(buf); + return 0; +} + +static long vhost_mdev_set_config(struct vhost_mdev *m, + struct vhost_mdev_config __user *c) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + struct vhost_mdev_config config; + unsigned long size = offsetof(struct vhost_mdev_config, buf); + u8 *buf; + + if (copy_from_user(&config, c, size)) + return -EFAULT; + if (vhost_mdev_config_validate(m, &config)) + return -EINVAL; + buf = kvzalloc(config.len, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + if (copy_from_user(buf, c->buf, config.len)) { + kvfree(buf); + return -EFAULT; + } + + ops->set_config(mdev, config.off, buf, config.len); + + kvfree(buf); + return 0; +} + +static long vhost_mdev_get_features(struct vhost_mdev *m, u64 __user *featurep) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + u64 features; + + features = ops->get_features(mdev); + features &= vhost_mdev_features[m->virtio_id]; + + if (copy_to_user(featurep, &features, sizeof(features))) + return -EFAULT; + + return 0; +} + +static long vhost_mdev_set_features(struct vhost_mdev *m, u64 __user *featurep) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + u64 features; + + /* + * It's not allowed to change the features after they have + * been negotiated. + */ + if (ops->get_status(mdev) & VIRTIO_CONFIG_S_FEATURES_OK) + return -EBUSY; + + if (copy_from_user(&features, featurep, sizeof(features))) + return -EFAULT; + + if (features & ~vhost_mdev_features[m->virtio_id]) + return -EINVAL; + + if (ops->set_features(mdev, features)) + return -EINVAL; + + return 0; +} + +static long vhost_mdev_get_vring_num(struct vhost_mdev *m, u16 __user *argp) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + u16 num; + + num = ops->get_vq_num_max(mdev); + + if (copy_to_user(argp, &num, sizeof(num))) + return -EFAULT; + + return 0; +} + +static long vhost_mdev_vring_ioctl(struct vhost_mdev *m, unsigned int cmd, + void __user *argp) +{ + struct mdev_device *mdev = m->mdev; + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + struct virtio_mdev_callback cb; + struct vhost_virtqueue *vq; + struct vhost_vring_state s; + u8 status; + u32 idx; + long r; + + r = get_user(idx, (u32 __user *)argp); + if (r < 0) + return r; + if (idx >= m->nvqs) + return -ENOBUFS; + + status = ops->get_status(mdev); + + /* + * It's not allowed to detect and program vqs before + * features negotiation or after enabling driver. + */ + if (!(status & VIRTIO_CONFIG_S_FEATURES_OK) || + (status & VIRTIO_CONFIG_S_DRIVER_OK)) + return -EBUSY; + + vq = &m->vqs[idx]; + + if (cmd == VHOST_MDEV_SET_VRING_ENABLE) { + if (copy_from_user(&s, argp, sizeof(s))) + return -EFAULT; + ops->set_vq_ready(mdev, idx, s.num); + return 0; + } + + /* + * It's not allowed to detect and program vqs with + * vqs enabled. + */ + if (ops->get_vq_ready(mdev, idx)) + return -EBUSY; + + if (cmd == VHOST_GET_VRING_BASE) + vq->last_avail_idx = ops->get_vq_state(m->mdev, idx); + + r = vhost_vring_ioctl(&m->dev, cmd, argp); + if (r) + return r; + + switch (cmd) { + case VHOST_SET_VRING_ADDR: + /* + * In vhost-mdev, the ring addresses set by userspace should + * be the DMA addresses within the VFIO container/group. + */ + if (ops->set_vq_address(mdev, idx, (u64)vq->desc, + (u64)vq->avail, (u64)vq->used)) + r = -ENODEV; + break; + + case VHOST_SET_VRING_BASE: + if (ops->set_vq_state(mdev, idx, vq->last_avail_idx)) + r = -ENODEV; + break; + + case VHOST_SET_VRING_CALL: + if (vq->call_ctx) { + cb.callback = vhost_mdev_virtqueue_cb; + cb.private = vq; + } else { + cb.callback = NULL; + cb.private = NULL; + } + ops->set_vq_cb(mdev, idx, &cb); + break; + + case VHOST_SET_VRING_NUM: + ops->set_vq_num(mdev, idx, vq->num); + break; + } + + return r; +} + +static int vhost_mdev_open(void *device_data) +{ + struct vhost_mdev *m = device_data; + struct vhost_dev *dev; + struct vhost_virtqueue **vqs; + int nvqs, i, r; + + if (!try_module_get(THIS_MODULE)) + return -ENODEV; + + mutex_lock(&m->mutex); + + if (m->opened) { + r = -EBUSY; + goto err; + } + + nvqs = m->nvqs; + vhost_mdev_reset(m); + + vqs = kmalloc_array(nvqs, sizeof(*vqs), GFP_KERNEL); + if (!vqs) { + r = -ENOMEM; + goto err; + } + + dev = &m->dev; + for (i = 0; i < nvqs; i++) { + vqs[i] = &m->vqs[i]; + vqs[i]->handle_kick = handle_vq_kick; + } + vhost_dev_init(dev, vqs, nvqs, 0, 0, 0); + m->opened = true; + mutex_unlock(&m->mutex); + + return 0; + +err: + mutex_unlock(&m->mutex); + module_put(THIS_MODULE); + return r; +} + +static void vhost_mdev_release(void *device_data) +{ + struct vhost_mdev *m = device_data; + + mutex_lock(&m->mutex); + vhost_mdev_reset(m); + vhost_dev_stop(&m->dev); + vhost_dev_cleanup(&m->dev); + + kfree(m->dev.vqs); + m->opened = false; + mutex_unlock(&m->mutex); + module_put(THIS_MODULE); +} + +static long vhost_mdev_unlocked_ioctl(void *device_data, + unsigned int cmd, unsigned long arg) +{ + struct vhost_mdev *m = device_data; + void __user *argp = (void __user *)arg; + long r; + + mutex_lock(&m->mutex); + + switch (cmd) { + case VHOST_MDEV_GET_DEVICE_ID: + r = vhost_mdev_get_device_id(m, argp); + break; + case VHOST_MDEV_GET_STATUS: + r = vhost_mdev_get_status(m, argp); + break; + case VHOST_MDEV_SET_STATUS: + r = vhost_mdev_set_status(m, argp); + break; + case VHOST_MDEV_GET_CONFIG: + r = vhost_mdev_get_config(m, argp); + break; + case VHOST_MDEV_SET_CONFIG: + r = vhost_mdev_set_config(m, argp); + break; + case VHOST_GET_FEATURES: + r = vhost_mdev_get_features(m, argp); + break; + case VHOST_SET_FEATURES: + r = vhost_mdev_set_features(m, argp); + break; + case VHOST_MDEV_GET_VRING_NUM: + r = vhost_mdev_get_vring_num(m, argp); + break; + default: + /* + * VHOST_SET_MEM_TABLE, VHOST_SET_LOG_BASE, and + * VHOST_SET_LOG_FD are not used yet. + */ + r = vhost_dev_ioctl(&m->dev, cmd, argp); + if (r == -ENOIOCTLCMD) + r = vhost_mdev_vring_ioctl(m, cmd, argp); + } + + mutex_unlock(&m->mutex); + return r; +} + +static const struct vfio_device_ops vfio_vhost_mdev_dev_ops = { + .name = "vfio-vhost-mdev", + .open = vhost_mdev_open, + .release = vhost_mdev_release, + .ioctl = vhost_mdev_unlocked_ioctl, +}; + +static int vhost_mdev_probe(struct device *dev) +{ + struct mdev_device *mdev = mdev_from_dev(dev); + const struct virtio_mdev_device_ops *ops = mdev_get_vhost_ops(mdev); + struct vhost_mdev *m; + int nvqs, r; + + /* Currently, we only accept the network devices. */ + if (ops->get_device_id(mdev) != VIRTIO_ID_NET) + return -ENOTSUPP; + + if (ops->get_mdev_features(mdev) != VIRTIO_MDEV_F_VERSION_1) + return -ENOTSUPP; + + m = devm_kzalloc(dev, sizeof(*m), GFP_KERNEL | __GFP_RETRY_MAYFAIL); + if (!m) + return -ENOMEM; + + nvqs = VHOST_MDEV_VQ_MAX; + + m->vqs = devm_kmalloc_array(dev, nvqs, sizeof(struct vhost_virtqueue), + GFP_KERNEL); + if (!m->vqs) + return -ENOMEM; + + mutex_init(&m->mutex); + + m->mdev = mdev; + m->nvqs = nvqs; + m->virtio_id = ops->get_device_id(mdev); + + r = vfio_add_group_dev(dev, &vfio_vhost_mdev_dev_ops, m); + if (r) { + mutex_destroy(&m->mutex); + return r; + } + + return 0; +} + +static void vhost_mdev_remove(struct device *dev) +{ + struct vhost_mdev *m; + + m = vfio_del_group_dev(dev); + mutex_destroy(&m->mutex); +} + +static const struct mdev_class_id vhost_mdev_match[] = { + { MDEV_CLASS_ID_VHOST }, + { 0 }, +}; +MODULE_DEVICE_TABLE(mdev, vhost_mdev_match); + +static struct mdev_driver vhost_mdev_driver = { + .name = "vhost_mdev", + .probe = vhost_mdev_probe, + .remove = vhost_mdev_remove, + .id_table = vhost_mdev_match, +}; + +static int __init vhost_mdev_init(void) +{ + return mdev_register_driver(&vhost_mdev_driver, THIS_MODULE); +} +module_init(vhost_mdev_init); + +static void __exit vhost_mdev_exit(void) +{ + mdev_unregister_driver(&vhost_mdev_driver); +} +module_exit(vhost_mdev_exit); + +MODULE_VERSION("0.0.1"); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Intel Corporation"); +MODULE_DESCRIPTION("Mediated device based accelerator for virtio"); diff --git a/include/linux/mdev.h b/include/linux/mdev.h index 9b69b0bbebfd..3e1e03926355 100644 --- a/include/linux/mdev.h +++ b/include/linux/mdev.h @@ -117,6 +117,10 @@ void mdev_set_virtio_ops(struct mdev_device *mdev, const struct virtio_mdev_device_ops *virtio_ops); const struct virtio_mdev_device_ops * mdev_get_virtio_ops(struct mdev_device *mdev); +void mdev_set_vhost_ops(struct mdev_device *mdev, + const struct virtio_mdev_device_ops *vhost_ops); +const struct virtio_mdev_device_ops * +mdev_get_vhost_ops(struct mdev_device *mdev); extern struct bus_type mdev_bus_type; @@ -133,6 +137,7 @@ struct mdev_device *mdev_from_dev(struct device *dev); enum { MDEV_CLASS_ID_VFIO = 1, MDEV_CLASS_ID_VIRTIO = 2, + MDEV_CLASS_ID_VHOST = 3, /* New entries must be added here */ }; diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h index 40d028eed645..061a2824a1b3 100644 --- a/include/uapi/linux/vhost.h +++ b/include/uapi/linux/vhost.h @@ -116,4 +116,22 @@ #define VHOST_VSOCK_SET_GUEST_CID _IOW(VHOST_VIRTIO, 0x60, __u64) #define VHOST_VSOCK_SET_RUNNING _IOW(VHOST_VIRTIO, 0x61, int) +/* VHOST_MDEV specific defines */ + +/* Get the device id. The device ids follow the same definition of + * the device id defined in virtio-spec. */ +#define VHOST_MDEV_GET_DEVICE_ID _IOR(VHOST_VIRTIO, 0x70, __u32) +/* Get and set the status. The status bits follow the same definition + * of the device status defined in virtio-spec. */ +#define VHOST_MDEV_GET_STATUS _IOR(VHOST_VIRTIO, 0x71, __u8) +#define VHOST_MDEV_SET_STATUS _IOW(VHOST_VIRTIO, 0x72, __u8) +/* Get and set the device config. The device config follows the same + * definition of the device config defined in virtio-spec. */ +#define VHOST_MDEV_GET_CONFIG _IOR(VHOST_VIRTIO, 0x73, struct vhost_mdev_config) +#define VHOST_MDEV_SET_CONFIG _IOW(VHOST_VIRTIO, 0x74, struct vhost_mdev_config) +/* Enable/disable the ring. */ +#define VHOST_MDEV_SET_VRING_ENABLE _IOW(VHOST_VIRTIO, 0x75, struct vhost_vring_state) +/* Get the max ring size. */ +#define VHOST_MDEV_GET_VRING_NUM _IOR(VHOST_VIRTIO, 0x76, __u16) + #endif diff --git a/include/uapi/linux/vhost_types.h b/include/uapi/linux/vhost_types.h index c907290ff065..7b105d0b2fb9 100644 --- a/include/uapi/linux/vhost_types.h +++ b/include/uapi/linux/vhost_types.h @@ -119,6 +119,14 @@ struct vhost_scsi_target { unsigned short reserved; }; +/* VHOST_MDEV specific definitions */ + +struct vhost_mdev_config { + __u32 off; + __u32 len; + __u8 buf[0]; +}; + /* Feature bits */ /* Log all write descriptors. Can be changed while device is active. */ #define VHOST_F_LOG_ALL 26 -- 2.23.0