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=-14.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,UNWANTED_LANGUAGE_BODY,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 A161AC433B4 for ; Fri, 9 Apr 2021 05:36:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6CD3661165 for ; Fri, 9 Apr 2021 05:36:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233006AbhDIFhF (ORCPT ); Fri, 9 Apr 2021 01:37:05 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:28544 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229526AbhDIFhD (ORCPT ); Fri, 9 Apr 2021 01:37:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617946610; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=S1T8e4eiQ0afmoZnCPw7nH/vwV1wUTly4y3pWLklyQs=; b=K4RUtN4cP4PRS3+/2hdyCopqZ78rDWdb8i8LatNXblYmPbhsFfS1ZnKsYnTIfRI0ysK3t+ ckg/GuzIT9Dkil90raKh0BTipTZl9oRieSiSto+nY9HdaQejnMroOXaSu5sJWVwjbpZgLZ zaW0aeL4msBvy0q5Zc7wM9yE6Piy750= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-349-8VJNKZnENDG_M7jhIHx-Iw-1; Fri, 09 Apr 2021 01:36:46 -0400 X-MC-Unique: 8VJNKZnENDG_M7jhIHx-Iw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 139AB8030A1; Fri, 9 Apr 2021 05:36:44 +0000 (UTC) Received: from wangxiaodeMacBook-Air.local (ovpn-13-155.pek2.redhat.com [10.72.13.155]) by smtp.corp.redhat.com (Postfix) with ESMTP id 588EF5C1D0; Fri, 9 Apr 2021 05:36:29 +0000 (UTC) Subject: Re: [PATCH v6 09/10] vduse: Introduce VDUSE - vDPA Device in Userspace To: Yongji Xie Cc: "Michael S. Tsirkin" , Stefan Hajnoczi , Stefano Garzarella , Parav Pandit , Christoph Hellwig , Christian Brauner , Randy Dunlap , Matthew Wilcox , viro@zeniv.linux.org.uk, Jens Axboe , bcrl@kvack.org, Jonathan Corbet , =?UTF-8?Q?Mika_Penttil=c3=a4?= , Dan Carpenter , virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, kvm@vger.kernel.org, linux-fsdevel@vger.kernel.org References: <20210331080519.172-1-xieyongji@bytedance.com> <20210331080519.172-10-xieyongji@bytedance.com> From: Jason Wang Message-ID: <091dde74-449b-385c-0ec9-11e4847c6c4c@redhat.com> Date: Fri, 9 Apr 2021 13:36:27 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 在 2021/4/8 下午5:36, Yongji Xie 写道: > On Thu, Apr 8, 2021 at 2:57 PM Jason Wang wrote: >> >> 在 2021/3/31 下午4:05, Xie Yongji 写道: >>> This VDUSE driver enables implementing vDPA devices in userspace. >>> Both control path and data path of vDPA devices will be able to >>> be handled in userspace. >>> >>> In the control path, the VDUSE driver will make use of message >>> mechnism to forward the config operation from vdpa bus driver >>> to userspace. Userspace can use read()/write() to receive/reply >>> those control messages. >>> >>> In the data path, VDUSE_IOTLB_GET_FD ioctl will be used to get >>> the file descriptors referring to vDPA device's iova regions. Then >>> userspace can use mmap() to access those iova regions. Besides, >>> userspace can use ioctl() to inject interrupt and use the eventfd >>> mechanism to receive virtqueue kicks. >>> >>> Signed-off-by: Xie Yongji >>> --- >>> Documentation/userspace-api/ioctl/ioctl-number.rst | 1 + >>> drivers/vdpa/Kconfig | 10 + >>> drivers/vdpa/Makefile | 1 + >>> drivers/vdpa/vdpa_user/Makefile | 5 + >>> drivers/vdpa/vdpa_user/vduse_dev.c | 1362 ++++++++++++++++++++ >>> include/uapi/linux/vduse.h | 175 +++ >>> 6 files changed, 1554 insertions(+) >>> create mode 100644 drivers/vdpa/vdpa_user/Makefile >>> create mode 100644 drivers/vdpa/vdpa_user/vduse_dev.c >>> create mode 100644 include/uapi/linux/vduse.h >>> >>> diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst >>> index a4c75a28c839..71722e6f8f23 100644 >>> --- a/Documentation/userspace-api/ioctl/ioctl-number.rst >>> +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst >>> @@ -300,6 +300,7 @@ Code Seq# Include File Comments >>> 'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict! >>> '|' 00-7F linux/media.h >>> 0x80 00-1F linux/fb.h >>> +0x81 00-1F linux/vduse.h >>> 0x89 00-06 arch/x86/include/asm/sockios.h >>> 0x89 0B-DF linux/sockios.h >>> 0x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range >>> diff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig >>> index a245809c99d0..77a1da522c21 100644 >>> --- a/drivers/vdpa/Kconfig >>> +++ b/drivers/vdpa/Kconfig >>> @@ -25,6 +25,16 @@ config VDPA_SIM_NET >>> help >>> vDPA networking device simulator which loops TX traffic back to RX. >>> >>> +config VDPA_USER >>> + tristate "VDUSE (vDPA Device in Userspace) support" >>> + depends on EVENTFD && MMU && HAS_DMA >>> + select DMA_OPS >>> + select VHOST_IOTLB >>> + select IOMMU_IOVA >>> + help >>> + With VDUSE it is possible to emulate a vDPA Device >>> + in a userspace program. >>> + >>> config IFCVF >>> tristate "Intel IFC VF vDPA driver" >>> depends on PCI_MSI >>> diff --git a/drivers/vdpa/Makefile b/drivers/vdpa/Makefile >>> index 67fe7f3d6943..f02ebed33f19 100644 >>> --- a/drivers/vdpa/Makefile >>> +++ b/drivers/vdpa/Makefile >>> @@ -1,6 +1,7 @@ >>> # SPDX-License-Identifier: GPL-2.0 >>> obj-$(CONFIG_VDPA) += vdpa.o >>> obj-$(CONFIG_VDPA_SIM) += vdpa_sim/ >>> +obj-$(CONFIG_VDPA_USER) += vdpa_user/ >>> obj-$(CONFIG_IFCVF) += ifcvf/ >>> obj-$(CONFIG_MLX5_VDPA) += mlx5/ >>> obj-$(CONFIG_VP_VDPA) += virtio_pci/ >>> diff --git a/drivers/vdpa/vdpa_user/Makefile b/drivers/vdpa/vdpa_user/Makefile >>> new file mode 100644 >>> index 000000000000..260e0b26af99 >>> --- /dev/null >>> +++ b/drivers/vdpa/vdpa_user/Makefile >>> @@ -0,0 +1,5 @@ >>> +# SPDX-License-Identifier: GPL-2.0 >>> + >>> +vduse-y := vduse_dev.o iova_domain.o >>> + >>> +obj-$(CONFIG_VDPA_USER) += vduse.o >>> diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c >>> new file mode 100644 >>> index 000000000000..51ca73464d0d >>> --- /dev/null >>> +++ b/drivers/vdpa/vdpa_user/vduse_dev.c >>> @@ -0,0 +1,1362 @@ >>> +// SPDX-License-Identifier: GPL-2.0-only >>> +/* >>> + * VDUSE: vDPA Device in Userspace >>> + * >>> + * Copyright (C) 2020-2021 Bytedance Inc. and/or its affiliates. All rights reserved. >>> + * >>> + * Author: Xie Yongji >>> + * >>> + */ >>> + >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> + >>> +#include "iova_domain.h" >>> + >>> +#define DRV_VERSION "1.0" >>> +#define DRV_AUTHOR "Yongji Xie " >>> +#define DRV_DESC "vDPA Device in Userspace" >>> +#define DRV_LICENSE "GPL v2" >>> + >>> +#define VDUSE_DEV_MAX (1U << MINORBITS) >>> + >>> +struct vduse_virtqueue { >>> + u16 index; >>> + bool ready; >>> + spinlock_t kick_lock; >>> + spinlock_t irq_lock; >>> + struct eventfd_ctx *kickfd; >>> + struct vdpa_callback cb; >>> + struct work_struct inject; >>> +}; >>> + >>> +struct vduse_dev; >>> + >>> +struct vduse_vdpa { >>> + struct vdpa_device vdpa; >>> + struct vduse_dev *dev; >>> +}; >>> + >>> +struct vduse_dev { >>> + struct vduse_vdpa *vdev; >>> + struct device dev; >>> + struct cdev cdev; >>> + struct vduse_virtqueue *vqs; >>> + struct vduse_iova_domain *domain; >>> + struct mutex lock; >>> + spinlock_t msg_lock; >>> + atomic64_t msg_unique; >>> + wait_queue_head_t waitq; >>> + struct list_head send_list; >>> + struct list_head recv_list; >>> + struct list_head list; >>> + struct vdpa_callback config_cb; >>> + spinlock_t irq_lock; >>> + unsigned long api_version; >>> + bool connected; >>> + int minor; >>> + u16 vq_size_max; >>> + u16 vq_num; >>> + u32 vq_align; >>> + u32 device_id; >>> + u32 vendor_id; >>> +}; >>> + >>> +struct vduse_dev_msg { >>> + struct vduse_dev_request req; >>> + struct vduse_dev_response resp; >>> + struct list_head list; >>> + wait_queue_head_t waitq; >>> + bool completed; >>> +}; >>> + >>> +struct vduse_control { >>> + unsigned long api_version; >>> +}; >>> + >>> +static unsigned long max_bounce_size = (64 * 1024 * 1024); >>> +module_param(max_bounce_size, ulong, 0444); >>> +MODULE_PARM_DESC(max_bounce_size, "Maximum bounce buffer size. (default: 64M)"); >>> + >>> +static unsigned long max_iova_size = (128 * 1024 * 1024); >>> +module_param(max_iova_size, ulong, 0444); >>> +MODULE_PARM_DESC(max_iova_size, "Maximum iova space size (default: 128M)"); >>> + >>> +static DEFINE_MUTEX(vduse_lock); >>> +static LIST_HEAD(vduse_devs); >>> +static DEFINE_IDA(vduse_ida); >>> + >>> +static dev_t vduse_major; >>> +static struct class *vduse_class; >>> +static struct workqueue_struct *vduse_irq_wq; >>> + >>> +static inline struct vduse_dev *vdpa_to_vduse(struct vdpa_device *vdpa) >>> +{ >>> + struct vduse_vdpa *vdev = container_of(vdpa, struct vduse_vdpa, vdpa); >>> + >>> + return vdev->dev; >>> +} >>> + >>> +static inline struct vduse_dev *dev_to_vduse(struct device *dev) >>> +{ >>> + struct vdpa_device *vdpa = dev_to_vdpa(dev); >>> + >>> + return vdpa_to_vduse(vdpa); >>> +} >>> + >>> +static struct vduse_dev_msg *vduse_find_msg(struct list_head *head, >>> + uint32_t request_id) >>> +{ >>> + struct vduse_dev_msg *tmp, *msg = NULL; >>> + >>> + list_for_each_entry(tmp, head, list) { >>> + if (tmp->req.request_id == request_id) { >>> + msg = tmp; >>> + list_del(&tmp->list); >>> + break; >>> + } >>> + } >>> + >>> + return msg; >>> +} >>> + >>> +static struct vduse_dev_msg *vduse_dequeue_msg(struct list_head *head) >>> +{ >>> + struct vduse_dev_msg *msg = NULL; >>> + >>> + if (!list_empty(head)) { >>> + msg = list_first_entry(head, struct vduse_dev_msg, list); >>> + list_del(&msg->list); >>> + } >>> + >>> + return msg; >>> +} >>> + >>> +static void vduse_enqueue_msg(struct list_head *head, >>> + struct vduse_dev_msg *msg) >>> +{ >>> + list_add_tail(&msg->list, head); >>> +} >>> + >>> +static int vduse_dev_msg_sync(struct vduse_dev *dev, >>> + struct vduse_dev_msg *msg) >>> +{ >>> + init_waitqueue_head(&msg->waitq); >>> + spin_lock(&dev->msg_lock); >>> + vduse_enqueue_msg(&dev->send_list, msg); >>> + wake_up(&dev->waitq); >>> + spin_unlock(&dev->msg_lock); >>> + wait_event_interruptible(msg->waitq, msg->completed); >>> + spin_lock(&dev->msg_lock); >>> + if (!msg->completed) >>> + list_del(&msg->list); >>> + spin_unlock(&dev->msg_lock); >>> + >>> + return (msg->resp.result == VDUSE_REQUEST_OK) ? 0 : -1; >>> +} >>> + >>> +static u32 vduse_dev_get_request_id(struct vduse_dev *dev) >>> +{ >>> + return atomic64_fetch_inc(&dev->msg_unique); >>> +} >>> + >>> +static u64 vduse_dev_get_features(struct vduse_dev *dev) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_GET_FEATURES; >>> + msg.req.request_id = vduse_dev_get_request_id(dev); >>> + >>> + return vduse_dev_msg_sync(dev, &msg) ? 0 : msg.resp.f.features; >>> +} >>> + >>> +static int vduse_dev_set_features(struct vduse_dev *dev, u64 features) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_SET_FEATURES; >>> + msg.req.request_id = vduse_dev_get_request_id(dev); >>> + msg.req.f.features = features; >>> + >>> + return vduse_dev_msg_sync(dev, &msg); >>> +} >>> + >>> +static u8 vduse_dev_get_status(struct vduse_dev *dev) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_GET_STATUS; >>> + msg.req.request_id = vduse_dev_get_request_id(dev); >>> + >>> + return vduse_dev_msg_sync(dev, &msg) ? 0 : msg.resp.s.status; >>> +} >>> + >>> +static void vduse_dev_set_status(struct vduse_dev *dev, u8 status) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_SET_STATUS; >>> + msg.req.request_id = vduse_dev_get_request_id(dev); >>> + msg.req.s.status = status; >>> + >>> + vduse_dev_msg_sync(dev, &msg); >>> +} >>> + >>> +static void vduse_dev_get_config(struct vduse_dev *dev, unsigned int offset, >>> + void *buf, unsigned int len) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + unsigned int sz; >>> + >>> + while (len) { >>> + sz = min_t(unsigned int, len, sizeof(msg.req.config.data)); >>> + msg.req.type = VDUSE_GET_CONFIG; >>> + msg.req.request_id = vduse_dev_get_request_id(dev); >>> + msg.req.config.offset = offset; >>> + msg.req.config.len = sz; >>> + vduse_dev_msg_sync(dev, &msg); >>> + memcpy(buf, msg.resp.config.data, sz); >>> + buf += sz; >>> + offset += sz; >>> + len -= sz; >>> + } >>> +} >>> + >>> +static void vduse_dev_set_config(struct vduse_dev *dev, unsigned int offset, >>> + const void *buf, unsigned int len) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + unsigned int sz; >>> + >>> + while (len) { >>> + sz = min_t(unsigned int, len, sizeof(msg.req.config.data)); >>> + msg.req.type = VDUSE_SET_CONFIG; >>> + msg.req.request_id = vduse_dev_get_request_id(dev); >>> + msg.req.config.offset = offset; >>> + msg.req.config.len = sz; >>> + memcpy(msg.req.config.data, buf, sz); >>> + vduse_dev_msg_sync(dev, &msg); >>> + buf += sz; >>> + offset += sz; >>> + len -= sz; >>> + } >>> +} >>> + >>> +static void vduse_dev_set_vq_num(struct vduse_dev *dev, >>> + struct vduse_virtqueue *vq, u32 num) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_SET_VQ_NUM; >>> + msg.req.request_id = vduse_dev_get_request_id(dev); >>> + msg.req.vq_num.index = vq->index; >>> + msg.req.vq_num.num = num; >>> + >>> + vduse_dev_msg_sync(dev, &msg); >>> +} >>> + >>> +static int vduse_dev_set_vq_addr(struct vduse_dev *dev, >>> + struct vduse_virtqueue *vq, u64 desc_addr, >>> + u64 driver_addr, u64 device_addr) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_SET_VQ_ADDR; >>> + msg.req.request_id = vduse_dev_get_request_id(dev); >>> + msg.req.vq_addr.index = vq->index; >>> + msg.req.vq_addr.desc_addr = desc_addr; >>> + msg.req.vq_addr.driver_addr = driver_addr; >>> + msg.req.vq_addr.device_addr = device_addr; >>> + >>> + return vduse_dev_msg_sync(dev, &msg); >>> +} >>> + >>> +static void vduse_dev_set_vq_ready(struct vduse_dev *dev, >>> + struct vduse_virtqueue *vq, bool ready) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_SET_VQ_READY; >>> + msg.req.request_id = vduse_dev_get_request_id(dev); >>> + msg.req.vq_ready.index = vq->index; >>> + msg.req.vq_ready.ready = ready; >>> + >>> + vduse_dev_msg_sync(dev, &msg); >>> +} >>> + >>> +static bool vduse_dev_get_vq_ready(struct vduse_dev *dev, >>> + struct vduse_virtqueue *vq) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_GET_VQ_READY; >>> + msg.req.request_id = vduse_dev_get_request_id(dev); >>> + msg.req.vq_ready.index = vq->index; >>> + >>> + return vduse_dev_msg_sync(dev, &msg) ? false : msg.resp.vq_ready.ready; >>> +} >>> + >>> +static int vduse_dev_get_vq_state(struct vduse_dev *dev, >>> + struct vduse_virtqueue *vq, >>> + struct vdpa_vq_state *state) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + int ret; >>> + >>> + msg.req.type = VDUSE_GET_VQ_STATE; >>> + msg.req.request_id = vduse_dev_get_request_id(dev); >>> + msg.req.vq_state.index = vq->index; >>> + >>> + ret = vduse_dev_msg_sync(dev, &msg); >>> + if (!ret) >>> + state->avail_index = msg.resp.vq_state.avail_idx; >>> + >>> + return ret; >>> +} >>> + >>> +static int vduse_dev_set_vq_state(struct vduse_dev *dev, >>> + struct vduse_virtqueue *vq, >>> + const struct vdpa_vq_state *state) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_SET_VQ_STATE; >>> + msg.req.request_id = vduse_dev_get_request_id(dev); >>> + msg.req.vq_state.index = vq->index; >>> + msg.req.vq_state.avail_idx = state->avail_index; >>> + >>> + return vduse_dev_msg_sync(dev, &msg); >>> +} >>> + >>> +static int vduse_dev_update_iotlb(struct vduse_dev *dev, >>> + u64 start, u64 last) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + if (last < start) >>> + return -EINVAL; >>> + >>> + msg.req.type = VDUSE_UPDATE_IOTLB; >>> + msg.req.request_id = vduse_dev_get_request_id(dev); >>> + msg.req.iova.start = start; >>> + msg.req.iova.last = last; >>> + >>> + return vduse_dev_msg_sync(dev, &msg); >>> +} >>> + >>> +static ssize_t vduse_dev_read_iter(struct kiocb *iocb, struct iov_iter *to) >>> +{ >>> + struct file *file = iocb->ki_filp; >>> + struct vduse_dev *dev = file->private_data; >>> + struct vduse_dev_msg *msg; >>> + int size = sizeof(struct vduse_dev_request); >>> + ssize_t ret = 0; >>> + >>> + if (iov_iter_count(to) < size) >>> + return 0; >>> + >>> + spin_lock(&dev->msg_lock); >>> + while (1) { >>> + msg = vduse_dequeue_msg(&dev->send_list); >>> + if (msg) >>> + break; >>> + >>> + ret = -EAGAIN; >>> + if (file->f_flags & O_NONBLOCK) >>> + goto unlock; >>> + >>> + spin_unlock(&dev->msg_lock); >>> + ret = wait_event_interruptible_exclusive(dev->waitq, >>> + !list_empty(&dev->send_list)); >>> + if (ret) >>> + return ret; >>> + >>> + spin_lock(&dev->msg_lock); >>> + } >>> + spin_unlock(&dev->msg_lock); >>> + ret = copy_to_iter(&msg->req, size, to); >>> + spin_lock(&dev->msg_lock); >>> + if (ret != size) { >>> + ret = -EFAULT; >>> + vduse_enqueue_msg(&dev->send_list, msg); >>> + goto unlock; >>> + } >>> + vduse_enqueue_msg(&dev->recv_list, msg); >>> + wake_up(&dev->waitq); >>> +unlock: >>> + spin_unlock(&dev->msg_lock); >>> + >>> + return ret; >>> +} >>> + >>> +static ssize_t vduse_dev_write_iter(struct kiocb *iocb, struct iov_iter *from) >>> +{ >>> + struct file *file = iocb->ki_filp; >>> + struct vduse_dev *dev = file->private_data; >>> + struct vduse_dev_response resp; >>> + struct vduse_dev_msg *msg; >>> + size_t ret; >>> + >>> + ret = copy_from_iter(&resp, sizeof(resp), from); >>> + if (ret != sizeof(resp)) >>> + return -EINVAL; >>> + >>> + spin_lock(&dev->msg_lock); >>> + msg = vduse_find_msg(&dev->recv_list, resp.request_id); >>> + if (!msg) { >>> + ret = -EINVAL; >>> + goto unlock; >>> + } >>> + >>> + memcpy(&msg->resp, &resp, sizeof(resp)); >>> + msg->completed = 1; >>> + wake_up(&msg->waitq); >>> +unlock: >>> + spin_unlock(&dev->msg_lock); >>> + >>> + return ret; >>> +} >>> + >>> +static __poll_t vduse_dev_poll(struct file *file, poll_table *wait) >>> +{ >>> + struct vduse_dev *dev = file->private_data; >>> + __poll_t mask = 0; >>> + >>> + poll_wait(file, &dev->waitq, wait); >>> + >>> + if (!list_empty(&dev->send_list)) >>> + mask |= EPOLLIN | EPOLLRDNORM; >>> + if (!list_empty(&dev->recv_list)) >>> + mask |= EPOLLOUT; >>> + >>> + return mask; >>> +} >>> + >>> +static void vduse_dev_reset(struct vduse_dev *dev) >>> +{ >>> + int i; >>> + >>> + /* The coherent mappings are handled in vduse_dev_free_coherent() */ >>> + vduse_domain_reset_bounce_map(dev->domain); >>> + vduse_dev_update_iotlb(dev, 0ULL, ULLONG_MAX); >>> + >>> + spin_lock(&dev->irq_lock); >>> + dev->config_cb.callback = NULL; >>> + dev->config_cb.private = NULL; >>> + spin_unlock(&dev->irq_lock); >>> + >>> + for (i = 0; i < dev->vq_num; i++) { >>> + struct vduse_virtqueue *vq = &dev->vqs[i]; >>> + >>> + spin_lock(&vq->irq_lock); >>> + vq->ready = false; >>> + vq->cb.callback = NULL; >>> + vq->cb.private = NULL; >>> + spin_unlock(&vq->irq_lock); >>> + } >>> +} >>> + >>> +static int vduse_vdpa_set_vq_address(struct vdpa_device *vdpa, u16 idx, >>> + u64 desc_area, u64 driver_area, >>> + u64 device_area) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + struct vduse_virtqueue *vq = &dev->vqs[idx]; >>> + >>> + return vduse_dev_set_vq_addr(dev, vq, desc_area, >>> + driver_area, device_area); >>> +} >>> + >>> +static void vduse_vdpa_kick_vq(struct vdpa_device *vdpa, u16 idx) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + struct vduse_virtqueue *vq = &dev->vqs[idx]; >>> + >>> + spin_lock(&vq->kick_lock); >>> + if (vq->ready && vq->kickfd) >>> + eventfd_signal(vq->kickfd, 1); >>> + spin_unlock(&vq->kick_lock); >>> +} >>> + >>> +static void vduse_vdpa_set_vq_cb(struct vdpa_device *vdpa, u16 idx, >>> + struct vdpa_callback *cb) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + struct vduse_virtqueue *vq = &dev->vqs[idx]; >>> + >>> + spin_lock(&vq->irq_lock); >>> + vq->cb.callback = cb->callback; >>> + vq->cb.private = cb->private; >>> + spin_unlock(&vq->irq_lock); >>> +} >>> + >>> +static void vduse_vdpa_set_vq_num(struct vdpa_device *vdpa, u16 idx, u32 num) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + struct vduse_virtqueue *vq = &dev->vqs[idx]; >>> + >>> + vduse_dev_set_vq_num(dev, vq, num); >>> +} >>> + >>> +static void vduse_vdpa_set_vq_ready(struct vdpa_device *vdpa, >>> + u16 idx, bool ready) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + struct vduse_virtqueue *vq = &dev->vqs[idx]; >>> + >>> + vduse_dev_set_vq_ready(dev, vq, ready); >>> + vq->ready = ready; >>> +} >>> + >>> +static bool vduse_vdpa_get_vq_ready(struct vdpa_device *vdpa, u16 idx) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + struct vduse_virtqueue *vq = &dev->vqs[idx]; >>> + >>> + vq->ready = vduse_dev_get_vq_ready(dev, vq); >>> + >>> + return vq->ready; >>> +} >>> + >>> +static int vduse_vdpa_set_vq_state(struct vdpa_device *vdpa, u16 idx, >>> + const struct vdpa_vq_state *state) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + struct vduse_virtqueue *vq = &dev->vqs[idx]; >>> + >>> + return vduse_dev_set_vq_state(dev, vq, state); >>> +} >>> + >>> +static int vduse_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 idx, >>> + struct vdpa_vq_state *state) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + struct vduse_virtqueue *vq = &dev->vqs[idx]; >>> + >>> + return vduse_dev_get_vq_state(dev, vq, state); >>> +} >>> + >>> +static u32 vduse_vdpa_get_vq_align(struct vdpa_device *vdpa) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + >>> + return dev->vq_align; >>> +} >>> + >>> +static u64 vduse_vdpa_get_features(struct vdpa_device *vdpa) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + >>> + return vduse_dev_get_features(dev); >>> +} >>> + >>> +static int vduse_vdpa_set_features(struct vdpa_device *vdpa, u64 features) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + >>> + if (!(features & (1ULL << VIRTIO_F_ACCESS_PLATFORM))) >>> + return -EINVAL; >>> + >>> + return vduse_dev_set_features(dev, features); >>> +} >>> + >>> +static void vduse_vdpa_set_config_cb(struct vdpa_device *vdpa, >>> + struct vdpa_callback *cb) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + >>> + spin_lock(&dev->irq_lock); >>> + dev->config_cb.callback = cb->callback; >>> + dev->config_cb.private = cb->private; >>> + spin_unlock(&dev->irq_lock); >>> +} >>> + >>> +static u16 vduse_vdpa_get_vq_num_max(struct vdpa_device *vdpa) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + >>> + return dev->vq_size_max; >>> +} >>> + >>> +static u32 vduse_vdpa_get_device_id(struct vdpa_device *vdpa) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + >>> + return dev->device_id; >>> +} >>> + >>> +static u32 vduse_vdpa_get_vendor_id(struct vdpa_device *vdpa) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + >>> + return dev->vendor_id; >>> +} >>> + >>> +static u8 vduse_vdpa_get_status(struct vdpa_device *vdpa) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + >>> + return vduse_dev_get_status(dev); >>> +} >>> + >>> +static void vduse_vdpa_set_status(struct vdpa_device *vdpa, u8 status) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + >>> + vduse_dev_set_status(dev, status); >>> + >>> + if (status == 0) >>> + vduse_dev_reset(dev); >>> +} >>> + >>> +static void vduse_vdpa_get_config(struct vdpa_device *vdpa, unsigned int offset, >>> + void *buf, unsigned int len) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + >>> + vduse_dev_get_config(dev, offset, buf, len); >>> +} >>> + >>> +static void vduse_vdpa_set_config(struct vdpa_device *vdpa, unsigned int offset, >>> + const void *buf, unsigned int len) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + >>> + vduse_dev_set_config(dev, offset, buf, len); >>> +} >>> + >>> +static int vduse_vdpa_set_map(struct vdpa_device *vdpa, >>> + struct vhost_iotlb *iotlb) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + int ret; >>> + >>> + ret = vduse_domain_set_map(dev->domain, iotlb); >>> + vduse_dev_update_iotlb(dev, 0ULL, ULLONG_MAX); >>> + >>> + return ret; >>> +} >>> + >>> +static void vduse_vdpa_free(struct vdpa_device *vdpa) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + >>> + WARN_ON(!list_empty(&dev->send_list)); >>> + WARN_ON(!list_empty(&dev->recv_list)); >>> + dev->vdev = NULL; >>> +} >>> + >>> +static const struct vdpa_config_ops vduse_vdpa_config_ops = { >>> + .set_vq_address = vduse_vdpa_set_vq_address, >>> + .kick_vq = vduse_vdpa_kick_vq, >>> + .set_vq_cb = vduse_vdpa_set_vq_cb, >>> + .set_vq_num = vduse_vdpa_set_vq_num, >>> + .set_vq_ready = vduse_vdpa_set_vq_ready, >>> + .get_vq_ready = vduse_vdpa_get_vq_ready, >>> + .set_vq_state = vduse_vdpa_set_vq_state, >>> + .get_vq_state = vduse_vdpa_get_vq_state, >>> + .get_vq_align = vduse_vdpa_get_vq_align, >>> + .get_features = vduse_vdpa_get_features, >>> + .set_features = vduse_vdpa_set_features, >>> + .set_config_cb = vduse_vdpa_set_config_cb, >>> + .get_vq_num_max = vduse_vdpa_get_vq_num_max, >>> + .get_device_id = vduse_vdpa_get_device_id, >>> + .get_vendor_id = vduse_vdpa_get_vendor_id, >>> + .get_status = vduse_vdpa_get_status, >>> + .set_status = vduse_vdpa_set_status, >>> + .get_config = vduse_vdpa_get_config, >>> + .set_config = vduse_vdpa_set_config, >>> + .set_map = vduse_vdpa_set_map, >>> + .free = vduse_vdpa_free, >>> +}; >>> + >>> +static dma_addr_t vduse_dev_map_page(struct device *dev, struct page *page, >>> + unsigned long offset, size_t size, >>> + enum dma_data_direction dir, >>> + unsigned long attrs) >>> +{ >>> + struct vduse_dev *vdev = dev_to_vduse(dev); >>> + struct vduse_iova_domain *domain = vdev->domain; >>> + >>> + return vduse_domain_map_page(domain, page, offset, size, dir, attrs); >>> +} >>> + >>> +static void vduse_dev_unmap_page(struct device *dev, dma_addr_t dma_addr, >>> + size_t size, enum dma_data_direction dir, >>> + unsigned long attrs) >>> +{ >>> + struct vduse_dev *vdev = dev_to_vduse(dev); >>> + struct vduse_iova_domain *domain = vdev->domain; >>> + >>> + return vduse_domain_unmap_page(domain, dma_addr, size, dir, attrs); >>> +} >>> + >>> +static void *vduse_dev_alloc_coherent(struct device *dev, size_t size, >>> + dma_addr_t *dma_addr, gfp_t flag, >>> + unsigned long attrs) >>> +{ >>> + struct vduse_dev *vdev = dev_to_vduse(dev); >>> + struct vduse_iova_domain *domain = vdev->domain; >>> + unsigned long iova; >>> + void *addr; >>> + >>> + *dma_addr = DMA_MAPPING_ERROR; >>> + addr = vduse_domain_alloc_coherent(domain, size, >>> + (dma_addr_t *)&iova, flag, attrs); >>> + if (!addr) >>> + return NULL; >>> + >>> + *dma_addr = (dma_addr_t)iova; >>> + vduse_dev_update_iotlb(vdev, iova, iova + size - 1); >>> + >>> + return addr; >>> +} >>> + >>> +static void vduse_dev_free_coherent(struct device *dev, size_t size, >>> + void *vaddr, dma_addr_t dma_addr, >>> + unsigned long attrs) >>> +{ >>> + struct vduse_dev *vdev = dev_to_vduse(dev); >>> + struct vduse_iova_domain *domain = vdev->domain; >>> + unsigned long start = (unsigned long)dma_addr; >>> + unsigned long last = start + size - 1; >>> + >>> + vduse_domain_free_coherent(domain, size, vaddr, dma_addr, attrs); >>> + vduse_dev_update_iotlb(vdev, start, last); >>> +} >>> + >>> +static const struct dma_map_ops vduse_dev_dma_ops = { >>> + .map_page = vduse_dev_map_page, >>> + .unmap_page = vduse_dev_unmap_page, >>> + .alloc = vduse_dev_alloc_coherent, >>> + .free = vduse_dev_free_coherent, >>> +}; >>> + >>> +static unsigned int perm_to_file_flags(u8 perm) >>> +{ >>> + unsigned int flags = 0; >>> + >>> + switch (perm) { >>> + case VDUSE_ACCESS_WO: >>> + flags |= O_WRONLY; >>> + break; >>> + case VDUSE_ACCESS_RO: >>> + flags |= O_RDONLY; >>> + break; >>> + case VDUSE_ACCESS_RW: >>> + flags |= O_RDWR; >>> + break; >>> + default: >>> + WARN(1, "invalidate vhost IOTLB permission\n"); >>> + break; >>> + } >>> + >>> + return flags; >>> +} >>> + >>> +static int vduse_kickfd_setup(struct vduse_dev *dev, >>> + struct vduse_vq_eventfd *eventfd) >>> +{ >>> + struct eventfd_ctx *ctx = NULL; >>> + struct vduse_virtqueue *vq; >>> + >>> + if (eventfd->index >= dev->vq_num) >>> + return -EINVAL; >>> + >>> + vq = &dev->vqs[eventfd->index]; >>> + if (eventfd->fd > 0) { >>> + ctx = eventfd_ctx_fdget(eventfd->fd); >>> + if (IS_ERR(ctx)) >>> + return PTR_ERR(ctx); >>> + } else if (eventfd->fd != VDUSE_EVENTFD_DEASSIGN) >>> + return 0; >> >> Do we allow the userspace to switch kickfd here? If yes, we need to deal >> with that. >> > Do you mean the case that eventfd->fd > 0? I think we have dealt with it. Ok, but the above code still looks suspicious. E.g what happens if eventfd->fd is 0? > >>> + >>> + spin_lock(&vq->kick_lock); >>> + if (vq->kickfd) >>> + eventfd_ctx_put(vq->kickfd); >>> + vq->kickfd = ctx; >>> + spin_unlock(&vq->kick_lock); >>> + >>> + return 0; >>> +} >>> + >>> +static void vduse_vq_irq_inject(struct work_struct *work) >>> +{ >>> + struct vduse_virtqueue *vq = container_of(work, >>> + struct vduse_virtqueue, inject); >>> + >>> + spin_lock_irq(&vq->irq_lock); >>> + if (vq->ready && vq->cb.callback) >>> + vq->cb.callback(vq->cb.private); >>> + spin_unlock_irq(&vq->irq_lock); >>> +} >>> + >>> +static long vduse_dev_ioctl(struct file *file, unsigned int cmd, >>> + unsigned long arg) >>> +{ >>> + struct vduse_dev *dev = file->private_data; >>> + void __user *argp = (void __user *)arg; >>> + int ret; >>> + >>> + switch (cmd) { >>> + case VDUSE_IOTLB_GET_FD: { >>> + struct vduse_iotlb_entry entry; >>> + struct vhost_iotlb_map *map; >>> + struct vdpa_map_file *map_file; >>> + struct vduse_iova_domain *domain = dev->domain; >>> + struct file *f = NULL; >>> + >>> + ret = -EFAULT; >>> + if (copy_from_user(&entry, argp, sizeof(entry))) >>> + break; >>> + >>> + ret = -EINVAL; >>> + if (entry.start > entry.last) >>> + break; >>> + >>> + spin_lock(&domain->iotlb_lock); >>> + map = vhost_iotlb_itree_first(domain->iotlb, >>> + entry.start, entry.last); >>> + if (map) { >>> + map_file = (struct vdpa_map_file *)map->opaque; >>> + f = get_file(map_file->file); >>> + entry.offset = map_file->offset; >>> + entry.start = map->start; >>> + entry.last = map->last; >>> + entry.perm = map->perm; >>> + } >>> + spin_unlock(&domain->iotlb_lock); >>> + ret = -EINVAL; >>> + if (!f) >>> + break; >>> + >>> + ret = -EFAULT; >>> + if (copy_to_user(argp, &entry, sizeof(entry))) { >>> + fput(f); >>> + break; >>> + } >>> + ret = receive_fd(f, perm_to_file_flags(entry.perm)); >>> + fput(f); >> >> Any reason to drop the refcnt here? >> > We will do get_file() in receive_fd() too. I see. > >>> + break; >>> + } >>> + case VDUSE_VQ_SETUP_KICKFD: { >>> + struct vduse_vq_eventfd eventfd; >>> + >>> + ret = -EFAULT; >>> + if (copy_from_user(&eventfd, argp, sizeof(eventfd))) >>> + break; >>> + >>> + ret = vduse_kickfd_setup(dev, &eventfd); >>> + break; >>> + } >>> + case VDUSE_INJECT_VQ_IRQ: >>> + ret = -EINVAL; >>> + if (arg >= dev->vq_num) >>> + break; >>> + >>> + ret = 0; >>> + queue_work(vduse_irq_wq, &dev->vqs[arg].inject); >>> + break; >>> + case VDUSE_INJECT_CONFIG_IRQ: >>> + ret = -EINVAL; >>> + spin_lock_irq(&dev->irq_lock); >>> + if (dev->config_cb.callback) { >>> + dev->config_cb.callback(dev->config_cb.private); >>> + ret = 0; >>> + } >>> + spin_unlock_irq(&dev->irq_lock); >> >> For consistency, is it better to use vduse_irq_wq here? >> > Looks good to me. > >>> + break; >>> + default: >>> + ret = -ENOIOCTLCMD; >>> + break; >>> + } >>> + >>> + return ret; >>> +} >>> + >>> +static int vduse_dev_release(struct inode *inode, struct file *file) >>> +{ >>> + struct vduse_dev *dev = file->private_data; >>> + struct vduse_dev_msg *msg; >>> + int i; >>> + >>> + for (i = 0; i < dev->vq_num; i++) { >>> + struct vduse_virtqueue *vq = &dev->vqs[i]; >>> + >>> + spin_lock(&vq->kick_lock); >>> + if (vq->kickfd) >>> + eventfd_ctx_put(vq->kickfd); >>> + vq->kickfd = NULL; >>> + spin_unlock(&vq->kick_lock); >>> + } >>> + >>> + spin_lock(&dev->msg_lock); >>> + /* Make sure the inflight messages can processed */ >> >> This might be better: >> >> /* Make sure the inflight messages can processed after reconncection */ >> > OK. > >>> + while ((msg = vduse_dequeue_msg(&dev->recv_list))) >>> + vduse_enqueue_msg(&dev->send_list, msg); >>> + spin_unlock(&dev->msg_lock); >>> + >>> + dev->connected = false; >>> + >>> + return 0; >>> +} >>> + >>> +static int vduse_dev_open(struct inode *inode, struct file *file) >>> +{ >>> + struct vduse_dev *dev = container_of(inode->i_cdev, >>> + struct vduse_dev, cdev); >>> + int ret = -EBUSY; >>> + >>> + mutex_lock(&dev->lock); >>> + if (dev->connected) >>> + goto unlock; >>> + >>> + ret = 0; >>> + dev->connected = true; >>> + file->private_data = dev; >>> +unlock: >>> + mutex_unlock(&dev->lock); >>> + >>> + return ret; >>> +} >>> + >>> +static const struct file_operations vduse_dev_fops = { >>> + .owner = THIS_MODULE, >>> + .open = vduse_dev_open, >>> + .release = vduse_dev_release, >>> + .read_iter = vduse_dev_read_iter, >>> + .write_iter = vduse_dev_write_iter, >>> + .poll = vduse_dev_poll, >>> + .unlocked_ioctl = vduse_dev_ioctl, >>> + .compat_ioctl = compat_ptr_ioctl, >>> + .llseek = noop_llseek, >>> +}; >>> + >>> +static struct vduse_dev *vduse_dev_create(void) >>> +{ >>> + struct vduse_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL); >>> + >>> + if (!dev) >>> + return NULL; >>> + >>> + mutex_init(&dev->lock); >>> + spin_lock_init(&dev->msg_lock); >>> + INIT_LIST_HEAD(&dev->send_list); >>> + INIT_LIST_HEAD(&dev->recv_list); >>> + atomic64_set(&dev->msg_unique, 0); >>> + spin_lock_init(&dev->irq_lock); >>> + >>> + init_waitqueue_head(&dev->waitq); >>> + >>> + return dev; >>> +} >>> + >>> +static void vduse_dev_destroy(struct vduse_dev *dev) >>> +{ >>> + kfree(dev); >>> +} >>> + >>> +static struct vduse_dev *vduse_find_dev(const char *name) >>> +{ >>> + struct vduse_dev *tmp, *dev = NULL; >>> + >>> + list_for_each_entry(tmp, &vduse_devs, list) { >>> + if (!strcmp(dev_name(&tmp->dev), name)) { >>> + dev = tmp; >>> + break; >>> + } >>> + } >>> + return dev; >>> +} >>> + >>> +static int vduse_destroy_dev(char *name) >>> +{ >>> + struct vduse_dev *dev = vduse_find_dev(name); >>> + >>> + if (!dev) >>> + return -EINVAL; >>> + >>> + mutex_lock(&dev->lock); >>> + if (dev->vdev || dev->connected) { >>> + mutex_unlock(&dev->lock); >>> + return -EBUSY; >>> + } >>> + dev->connected = true; >>> + mutex_unlock(&dev->lock); >>> + >>> + list_del(&dev->list); >>> + cdev_device_del(&dev->cdev, &dev->dev); >>> + put_device(&dev->dev); >>> + module_put(THIS_MODULE); >>> + >>> + return 0; >>> +} >>> + >>> +static void vduse_release_dev(struct device *device) >>> +{ >>> + struct vduse_dev *dev = >>> + container_of(device, struct vduse_dev, dev); >>> + >>> + ida_simple_remove(&vduse_ida, dev->minor); >>> + kfree(dev->vqs); >>> + vduse_domain_destroy(dev->domain); >>> + vduse_dev_destroy(dev); >>> +} >>> + >>> +static int vduse_create_dev(struct vduse_dev_config *config, >>> + unsigned long api_version) >>> +{ >>> + int i, ret = -ENOMEM; >>> + struct vduse_dev *dev; >>> + >>> + if (config->bounce_size > max_bounce_size) >>> + return -EINVAL; >>> + >>> + if (config->bounce_size > max_iova_size) >>> + return -EINVAL; >>> + >>> + if (vduse_find_dev(config->name)) >>> + return -EEXIST; >>> + >>> + dev = vduse_dev_create(); >>> + if (!dev) >>> + return -ENOMEM; >>> + >>> + dev->api_version = api_version; >>> + dev->device_id = config->device_id; >>> + dev->vendor_id = config->vendor_id; >>> + dev->domain = vduse_domain_create(max_iova_size - 1, >>> + config->bounce_size); >>> + if (!dev->domain) >>> + goto err_domain; >>> + >>> + dev->vq_align = config->vq_align; >>> + dev->vq_size_max = config->vq_size_max; >>> + dev->vq_num = config->vq_num; >>> + dev->vqs = kcalloc(dev->vq_num, sizeof(*dev->vqs), GFP_KERNEL); >>> + if (!dev->vqs) >>> + goto err_vqs; >>> + >>> + for (i = 0; i < dev->vq_num; i++) { >>> + dev->vqs[i].index = i; >>> + INIT_WORK(&dev->vqs[i].inject, vduse_vq_irq_inject); >>> + spin_lock_init(&dev->vqs[i].kick_lock); >>> + spin_lock_init(&dev->vqs[i].irq_lock); >>> + } >>> + >>> + ret = ida_simple_get(&vduse_ida, 0, VDUSE_DEV_MAX, GFP_KERNEL); >>> + if (ret < 0) >>> + goto err_ida; >>> + >>> + dev->minor = ret; >>> + device_initialize(&dev->dev); >>> + dev->dev.release = vduse_release_dev; >>> + dev->dev.class = vduse_class; >>> + dev->dev.devt = MKDEV(MAJOR(vduse_major), dev->minor); >>> + ret = dev_set_name(&dev->dev, "%s", config->name); >>> + if (ret) { >>> + put_device(&dev->dev); >>> + return ret; >>> + } >>> + cdev_init(&dev->cdev, &vduse_dev_fops); >>> + dev->cdev.owner = THIS_MODULE; >>> + >>> + ret = cdev_device_add(&dev->cdev, &dev->dev); >>> + if (ret) { >>> + put_device(&dev->dev); >>> + return ret; >> >> Let's introduce an error label for this. >> > But put_device() would be duplicated with the below error handling. I think it's as simple as put the error label after the return. > >>> + } >>> + list_add(&dev->list, &vduse_devs); >>> + __module_get(THIS_MODULE); >>> + >>> + return 0; >>> +err_ida: >>> + kfree(dev->vqs); >>> +err_vqs: >>> + vduse_domain_destroy(dev->domain); >>> +err_domain: >>> + vduse_dev_destroy(dev); >>> + return ret; >>> +} >>> + >>> +static long vduse_ioctl(struct file *file, unsigned int cmd, >>> + unsigned long arg) >>> +{ >>> + int ret; >>> + void __user *argp = (void __user *)arg; >>> + struct vduse_control *control = file->private_data; >>> + >>> + mutex_lock(&vduse_lock); >>> + switch (cmd) { >>> + case VDUSE_GET_API_VERSION: >>> + ret = control->api_version; >>> + break; >>> + case VDUSE_SET_API_VERSION: >>> + ret = -EINVAL; >>> + if (arg > VDUSE_API_VERSION) >>> + break; >>> + >>> + ret = 0; >>> + control->api_version = arg; >>> + break; >>> + case VDUSE_CREATE_DEV: { >>> + struct vduse_dev_config config; >>> + >>> + ret = -EFAULT; >>> + if (copy_from_user(&config, argp, sizeof(config))) >>> + break; >>> + >>> + ret = vduse_create_dev(&config, control->api_version); >>> + break; >>> + } >>> + case VDUSE_DESTROY_DEV: { >>> + char name[VDUSE_NAME_MAX]; >>> + >>> + ret = -EFAULT; >>> + if (copy_from_user(name, argp, VDUSE_NAME_MAX)) >>> + break; >>> + >>> + ret = vduse_destroy_dev(name); >>> + break; >>> + } >>> + default: >>> + ret = -EINVAL; >>> + break; >>> + } >>> + mutex_unlock(&vduse_lock); >>> + >>> + return ret; >>> +} >>> + >>> +static int vduse_release(struct inode *inode, struct file *file) >>> +{ >>> + struct vduse_control *control = file->private_data; >>> + >>> + kfree(control); >>> + return 0; >>> +} >>> + >>> +static int vduse_open(struct inode *inode, struct file *file) >>> +{ >>> + struct vduse_control *control; >>> + >>> + control = kmalloc(sizeof(struct vduse_control), GFP_KERNEL); >>> + if (!control) >>> + return -ENOMEM; >>> + >>> + control->api_version = VDUSE_API_VERSION; >>> + file->private_data = control; >>> + >>> + return 0; >>> +} >>> + >>> +static const struct file_operations vduse_fops = { >>> + .owner = THIS_MODULE, >>> + .open = vduse_open, >>> + .release = vduse_release, >>> + .unlocked_ioctl = vduse_ioctl, >>> + .compat_ioctl = compat_ptr_ioctl, >>> + .llseek = noop_llseek, >>> +}; >>> + >>> +static char *vduse_devnode(struct device *dev, umode_t *mode) >>> +{ >>> + return kasprintf(GFP_KERNEL, "vduse/%s", dev_name(dev)); >>> +} >>> + >>> +static struct miscdevice vduse_misc = { >>> + .fops = &vduse_fops, >>> + .minor = MISC_DYNAMIC_MINOR, >>> + .name = "vduse", >>> + .nodename = "vduse/control", >>> +}; >>> + >>> +static void vduse_mgmtdev_release(struct device *dev) >>> +{ >>> +} >>> + >>> +static struct device vduse_mgmtdev = { >>> + .init_name = "vduse", >>> + .release = vduse_mgmtdev_release, >>> +}; >>> + >>> +static struct vdpa_mgmt_dev mgmt_dev; >>> + >>> +static int vduse_dev_init_vdpa(struct vduse_dev *dev, const char *name) >>> +{ >>> + struct vduse_vdpa *vdev; >>> + int ret; >>> + >>> + if (dev->vdev) >>> + return -EEXIST; >>> + >>> + vdev = vdpa_alloc_device(struct vduse_vdpa, vdpa, &dev->dev, >>> + &vduse_vdpa_config_ops, name, true); >>> + if (!vdev) >>> + return -ENOMEM; >>> + >>> + dev->vdev = vdev; >>> + vdev->dev = dev; >>> + vdev->vdpa.dev.dma_mask = &vdev->vdpa.dev.coherent_dma_mask; >>> + ret = dma_set_mask_and_coherent(&vdev->vdpa.dev, DMA_BIT_MASK(64)); >>> + if (ret) { >>> + put_device(&vdev->vdpa.dev); >>> + return ret; >>> + } >>> + set_dma_ops(&vdev->vdpa.dev, &vduse_dev_dma_ops); >>> + vdev->vdpa.dma_dev = &vdev->vdpa.dev; >>> + vdev->vdpa.mdev = &mgmt_dev; >>> + >>> + return 0; >>> +} >>> + >>> +static int vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name) >>> +{ >>> + struct vduse_dev *dev; >>> + int ret = -EINVAL; >>> + >>> + mutex_lock(&vduse_lock); >>> + dev = vduse_find_dev(name); >>> + if (!dev) { >>> + mutex_unlock(&vduse_lock); >>> + return -EINVAL; >>> + } >>> + ret = vduse_dev_init_vdpa(dev, name); >>> + mutex_unlock(&vduse_lock); >>> + if (ret) >>> + return ret; >>> + >>> + ret = _vdpa_register_device(&dev->vdev->vdpa, dev->vq_num); >>> + if (ret) { >>> + put_device(&dev->vdev->vdpa.dev); >>> + return ret; >>> + } >>> + >>> + return 0; >>> +} >>> + >>> +static void vdpa_dev_del(struct vdpa_mgmt_dev *mdev, struct vdpa_device *dev) >>> +{ >>> + _vdpa_unregister_device(dev); >>> +} >>> + >>> +static const struct vdpa_mgmtdev_ops vdpa_dev_mgmtdev_ops = { >>> + .dev_add = vdpa_dev_add, >>> + .dev_del = vdpa_dev_del, >>> +}; >>> + >>> +static struct virtio_device_id id_table[] = { >>> + { VIRTIO_DEV_ANY_ID, VIRTIO_DEV_ANY_ID }, >>> + { 0 }, >>> +}; >>> + >>> +static struct vdpa_mgmt_dev mgmt_dev = { >>> + .device = &vduse_mgmtdev, >>> + .id_table = id_table, >>> + .ops = &vdpa_dev_mgmtdev_ops, >>> +}; >>> + >>> +static int vduse_mgmtdev_init(void) >>> +{ >>> + int ret; >>> + >>> + ret = device_register(&vduse_mgmtdev); >>> + if (ret) >>> + return ret; >>> + >>> + ret = vdpa_mgmtdev_register(&mgmt_dev); >>> + if (ret) >>> + goto err; >>> + >>> + return 0; >>> +err: >>> + device_unregister(&vduse_mgmtdev); >>> + return ret; >>> +} >>> + >>> +static void vduse_mgmtdev_exit(void) >>> +{ >>> + vdpa_mgmtdev_unregister(&mgmt_dev); >>> + device_unregister(&vduse_mgmtdev); >>> +} >>> + >>> +static int vduse_init(void) >>> +{ >>> + int ret; >>> + >>> + if (max_bounce_size >= max_iova_size) >>> + return -EINVAL; >>> + >>> + ret = misc_register(&vduse_misc); >>> + if (ret) >>> + return ret; >>> + >>> + vduse_class = class_create(THIS_MODULE, "vduse"); >>> + if (IS_ERR(vduse_class)) { >>> + ret = PTR_ERR(vduse_class); >>> + goto err_class; >>> + } >>> + vduse_class->devnode = vduse_devnode; >>> + >>> + ret = alloc_chrdev_region(&vduse_major, 0, VDUSE_DEV_MAX, "vduse"); >>> + if (ret) >>> + goto err_chardev; >>> + >>> + vduse_irq_wq = alloc_workqueue("vduse-irq", >>> + WQ_HIGHPRI | WQ_SYSFS | WQ_UNBOUND, 0); >>> + if (!vduse_irq_wq) >>> + goto err_wq; >>> + >>> + ret = vduse_domain_init(); >>> + if (ret) >>> + goto err_domain; >>> + >>> + ret = vduse_mgmtdev_init(); >>> + if (ret) >>> + goto err_mgmtdev; >>> + >>> + return 0; >>> +err_mgmtdev: >>> + vduse_domain_exit(); >>> +err_domain: >>> + destroy_workqueue(vduse_irq_wq); >>> +err_wq: >>> + unregister_chrdev_region(vduse_major, VDUSE_DEV_MAX); >>> +err_chardev: >>> + class_destroy(vduse_class); >>> +err_class: >>> + misc_deregister(&vduse_misc); >>> + return ret; >>> +} >>> +module_init(vduse_init); >>> + >>> +static void vduse_exit(void) >>> +{ >>> + misc_deregister(&vduse_misc); >>> + class_destroy(vduse_class); >>> + unregister_chrdev_region(vduse_major, VDUSE_DEV_MAX); >>> + destroy_workqueue(vduse_irq_wq); >>> + vduse_domain_exit(); >>> + vduse_mgmtdev_exit(); >>> +} >>> +module_exit(vduse_exit); >>> + >>> +MODULE_VERSION(DRV_VERSION); >>> +MODULE_LICENSE(DRV_LICENSE); >>> +MODULE_AUTHOR(DRV_AUTHOR); >>> +MODULE_DESCRIPTION(DRV_DESC); >>> diff --git a/include/uapi/linux/vduse.h b/include/uapi/linux/vduse.h >>> new file mode 100644 >>> index 000000000000..66a6e5212226 >>> --- /dev/null >>> +++ b/include/uapi/linux/vduse.h >>> @@ -0,0 +1,175 @@ >>> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ >>> +#ifndef _UAPI_VDUSE_H_ >>> +#define _UAPI_VDUSE_H_ >>> + >>> +#include >>> + >>> +#define VDUSE_API_VERSION 0 >>> + >>> +#define VDUSE_CONFIG_DATA_LEN 256 >>> +#define VDUSE_NAME_MAX 256 >>> + >>> +/* the control messages definition for read/write */ >>> + >>> +enum vduse_req_type { >>> + /* Set the vring address of virtqueue. */ >>> + VDUSE_SET_VQ_NUM, >>> + /* Set the vring address of virtqueue. */ >>> + VDUSE_SET_VQ_ADDR, >>> + /* Set ready status of virtqueue */ >>> + VDUSE_SET_VQ_READY, >>> + /* Get ready status of virtqueue */ >>> + VDUSE_GET_VQ_READY, >>> + /* Set the state for virtqueue */ >>> + VDUSE_SET_VQ_STATE, >>> + /* Get the state for virtqueue */ >>> + VDUSE_GET_VQ_STATE, >>> + /* Set virtio features supported by the driver */ >>> + VDUSE_SET_FEATURES, >>> + /* Get virtio features supported by the device */ >>> + VDUSE_GET_FEATURES, >>> + /* Set the device status */ >>> + VDUSE_SET_STATUS, >>> + /* Get the device status */ >>> + VDUSE_GET_STATUS, >>> + /* Write to device specific configuration space */ >>> + VDUSE_SET_CONFIG, >>> + /* Read from device specific configuration space */ >>> + VDUSE_GET_CONFIG, >>> + /* Notify userspace to update the memory mapping in device IOTLB */ >>> + VDUSE_UPDATE_IOTLB, >>> +}; >>> + >>> +struct vduse_vq_num { >>> + __u32 index; /* virtqueue index */ >> >> I think it's better to have a consistent style of the doc/comment. If >> yes, let's move those comment above the field. >> > Fine. > >>> + __u32 num; /* the size of virtqueue */ >>> +}; >>> + >>> +struct vduse_vq_addr { >>> + __u32 index; /* virtqueue index */ >>> + __u64 desc_addr; /* address of desc area */ >>> + __u64 driver_addr; /* address of driver area */ >>> + __u64 device_addr; /* address of device area */ >>> +}; >>> + >>> +struct vduse_vq_ready { >>> + __u32 index; /* virtqueue index */ >>> + __u8 ready; /* ready status of virtqueue */ >>> +}; >>> + >>> +struct vduse_vq_state { >>> + __u32 index; /* virtqueue index */ >>> + __u16 avail_idx; /* virtqueue state (last_avail_idx) */ >> >> Let's use __u64 here to be consistent with get_vq_state(). __u32 actually: struct vhost_vring_state {         unsigned int index;         unsigned int num; }; >> The idea is >> to support packed virtqueue. >> > OK. But looks like sizeof(struct vdpa_vq_state) is still equal to 2. It's a bug that needs to be fixed. > Do you mean we will extend it in the future? u32 should be fine, and it's not for future. For packed virtqueue we need something like: le32 {     last_avai_idx : 15;     last_avail_wrap_counter : 1;     used_idx : 15;     used_wrap_counter : 1; } As has been done in https://lore.kernel.org/lkml/20190717105255.63488-3-jasowang@redhat.com/T/ > >>> +}; >>> + >>> +struct vduse_dev_config_data { >>> + __u32 offset; /* offset from the beginning of config space */ >>> + __u32 len; /* the length to read/write */ >>> + __u8 data[VDUSE_CONFIG_DATA_LEN]; /* data buffer used to read/write */ >> >> Note that since VDUSE_CONFIG_DATA_LEN is part of uAPI it means we can >> not change it in the future. >> >> So this might suffcient for future features or all type of virtio devices. >> > Do you mean 256 is no enough here？ Yes. > >>> +}; >>> + >>> +struct vduse_iova_range { >>> + __u64 start; /* start of the IOVA range */ >>> + __u64 last; /* end of the IOVA range */ >>> +}; >>> + >>> +struct vduse_features { >>> + __u64 features; /* virtio features */ >>> +}; >>> + >>> +struct vduse_status { >>> + __u8 status; /* device status */ >>> +}; >>> + >>> +struct vduse_dev_request { >>> + __u32 type; /* request type */ >>> + __u32 request_id; /* request id */ >>> + __u32 reserved[2]; /* for future use */ >>> + union { >>> + struct vduse_vq_num vq_num; /* virtqueue num */ >>> + struct vduse_vq_addr vq_addr; /* virtqueue address */ >>> + struct vduse_vq_ready vq_ready; /* virtqueue ready status */ >>> + struct vduse_vq_state vq_state; /* virtqueue state */ >>> + struct vduse_dev_config_data config; /* virtio device config space */ >>> + struct vduse_iova_range iova; /* iova range for updating */ >>> + struct vduse_features f; /* virtio features */ >>> + struct vduse_status s; /* device status */ >>> + __u32 padding[16]; /* padding */ >>> + }; >>> +}; >>> + >>> +struct vduse_dev_response { >>> + __u32 request_id; /* corresponding request id */ >>> +#define VDUSE_REQUEST_OK 0x00 >>> +#define VDUSE_REQUEST_FAILED 0x01 >>> + __u32 result; /* the result of request */ >>> + __u32 reserved[2]; /* for future use */ >>> + union { >>> + struct vduse_vq_ready vq_ready; /* virtqueue ready status */ >>> + struct vduse_vq_state vq_state; /* virtqueue state */ >>> + struct vduse_dev_config_data config; /* virtio device config space */ >>> + struct vduse_features f; /* virtio features */ >>> + struct vduse_status s; /* device status */ >>> + __u32 padding[16]; /* padding */ >> >> So it looks to me this padding doesn't work since vduse_dev_config_data >> is larger than it. >> > Oh, my bad. Will fix it. > >>> + }; >>> +}; >>> + >>> +/* ioctls */ >>> + >>> +struct vduse_dev_config { >>> + char name[VDUSE_NAME_MAX]; /* vduse device name */ >>> + __u32 vendor_id; /* virtio vendor id */ >>> + __u32 device_id; /* virtio device id */ >>> + __u64 bounce_size; /* bounce buffer size for iommu */ >>> + __u16 vq_num; /* the number of virtqueues */ >>> + __u16 vq_size_max; /* the max size of virtqueue */ >>> + __u32 vq_align; /* the allocation alignment of virtqueue's metadata */ >>> + __u32 reserved[8]; /* for future use */ >> >> Is there a hole before reserved? >> > But I don't find the hole in below layout: > > | 256 | 4 | 4 | 8 | 2 | 2 | 4 | 32 | > Looks correct, better to check with pahole to double confirm. >>> +}; >>> + >>> +struct vduse_iotlb_entry { >>> + __u64 offset; /* the mmap offset on fd */ >>> + __u64 start; /* start of the IOVA range */ >>> + __u64 last; /* last of the IOVA range */ >>> +#define VDUSE_ACCESS_RO 0x1 >>> +#define VDUSE_ACCESS_WO 0x2 >>> +#define VDUSE_ACCESS_RW 0x3 >>> + __u8 perm; /* access permission of this range */ >>> +}; >>> + >>> +struct vduse_vq_eventfd { >>> + __u32 index; /* virtqueue index */ >>> +#define VDUSE_EVENTFD_DEASSIGN -1 >>> + int fd; /* eventfd, -1 means de-assigning the eventfd */ >>> +}; >>> + >>> +#define VDUSE_BASE 0x81 >>> + >>> +/* Get the version of VDUSE API. This is used for future extension */ >>> +#define VDUSE_GET_API_VERSION _IO(VDUSE_BASE, 0x00) >>> + >>> +/* Set the version of VDUSE API. */ >>> +#define VDUSE_SET_API_VERSION _IO(VDUSE_BASE, 0x01) >>> + >>> +/* Create a vduse device which is represented by a char device (/dev/vduse/) */ >>> +#define VDUSE_CREATE_DEV _IOW(VDUSE_BASE, 0x02, struct vduse_dev_config) >>> + >>> +/* Destroy a vduse device. Make sure there are no references to the char device */ >>> +#define VDUSE_DESTROY_DEV _IOW(VDUSE_BASE, 0x03, char[VDUSE_NAME_MAX]) >>> + >>> +/* >>> + * Get a file descriptor for the first overlapped iova region, >>> + * -EINVAL means the iova region doesn't exist. >>> + */ >>> +#define VDUSE_IOTLB_GET_FD _IOWR(VDUSE_BASE, 0x04, struct vduse_iotlb_entry) >>> + >>> +/* Setup an eventfd to receive kick for virtqueue */ >>> +#define VDUSE_VQ_SETUP_KICKFD _IOW(VDUSE_BASE, 0x05, struct vduse_vq_eventfd) >>> + >>> +/* Inject an interrupt for specific virtqueue */ >>> +#define VDUSE_INJECT_VQ_IRQ _IO(VDUSE_BASE, 0x06) >> >> Missing parameter? >> > We use the argp to store the virtqueue index here. Is it OK? So I meant it should be something like: #define VDUSE_INJECT_VQ_IRQ  _IOW(VDUSE_BASE, 0x06, unsigned int) ? Thanks > > Thanks, > Yongji >