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=-10.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNWANTED_LANGUAGE_BODY, URIBL_BLOCKED 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 073DEC433ED for ; Thu, 8 Apr 2021 09:36:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C5C1261151 for ; Thu, 8 Apr 2021 09:36:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231269AbhDHJhD (ORCPT ); Thu, 8 Apr 2021 05:37:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231208AbhDHJhC (ORCPT ); Thu, 8 Apr 2021 05:37:02 -0400 Received: from mail-ed1-x533.google.com (mail-ed1-x533.google.com [IPv6:2a00:1450:4864:20::533]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4CC68C061762 for ; Thu, 8 Apr 2021 02:36:51 -0700 (PDT) Received: by mail-ed1-x533.google.com with SMTP id e7so1567836edu.10 for ; Thu, 08 Apr 2021 02:36:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=cKwiO5Y5h2KML4o8yFvUgVxTtRYQSCUamHqd2+f3y0I=; b=j4sfjea/tchLTp6ZSK598YLKrCstRcNj1ZaiHrvBoLI8x+jy6sjDscQhwK9LB6QVNu hPD9iP1rT8UG0r8FbLT9CLFAfT/+Vit+ujJeXY1sIwbY3X/G0C/qgLSHq9EqsHWX/dkG oJnReK+27NKvgogSsoNovQFhsJ5UlqrNhpO8BAZ4rfp9/7bQRxm/FIxCXUxWiaA3evys FuViZq0QSpgv4BEjKerlJwvIM87T8JF/ye4gfKtyVgcoagR0M8BXDe8JX/gmsBmQsBqD +xfiqEf//b5paha9menW1chjWgjUUg1Ha/bX1+xVU1yV6TV4PIUk1uR0Gaa4w9mLWtEf Yjbw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=cKwiO5Y5h2KML4o8yFvUgVxTtRYQSCUamHqd2+f3y0I=; b=SCk9yQOyOc7P3wTE8fq6LPW9W/B3nSqnHoVe3Hv0nPRZh5QUgwqgOgGqNmQw7kvCvW m8GYGzvC0yOeN56Ea/LR+5U74i4jR8jaJzEseJCbk+q3c8ysztncYl9tqeIQ6mjwXqU8 tDNJxdkE1RZO6BnzIIOxAtbkfQ5dFofM3OsNmuBXAit2UvMr/rbcXVP5Z7u7eNAVswCx IyTj7sPK9f8Gjf5xouqSG0scWUnpDQt9aN0bB+ZCuZo9v7mU6Sa9X3HOHPkk4pUVRbM/ kpMzLiKD5AVQiMCKwmcz8Jaa93j5aHAIuARv7ibiZwVlL2pHv06qQDwjDliIztR3+OQ5 vCVw== X-Gm-Message-State: AOAM532vO5ootqTxyOKPvLMmP4f24mdCAlNr6N2YY/rpQ6AGcVblfaoY kaINmou3CRi/YthaJnk5gT5ysLkw7QTUdaLqydVf X-Google-Smtp-Source: ABdhPJw8UTDNbXraSKt3+hdOZojJybGSBd97V26Y0foclh0yv0c7OOPwpLHMYBk3bJIHe4ss/DyOmBEPgAklToOurW8= X-Received: by 2002:a05:6402:34f:: with SMTP id r15mr9854272edw.195.1617874609567; Thu, 08 Apr 2021 02:36:49 -0700 (PDT) MIME-Version: 1.0 References: <20210331080519.172-1-xieyongji@bytedance.com> <20210331080519.172-10-xieyongji@bytedance.com> In-Reply-To: From: Yongji Xie Date: Thu, 8 Apr 2021 17:36:38 +0800 Message-ID: Subject: Re: Re: [PATCH v6 09/10] vduse: Introduce VDUSE - vDPA Device in Userspace To: Jason Wang 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 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, Apr 8, 2021 at 2:57 PM Jason Wang wrote: > > > =E5=9C=A8 2021/3/31 =E4=B8=8B=E5=8D=884:05, Xie Yongji =E5=86=99=E9=81=93= : > > 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/Docum= entation/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-$(CONFIG_VDPA) +=3D vdpa.o > > obj-$(CONFIG_VDPA_SIM) +=3D vdpa_sim/ > > +obj-$(CONFIG_VDPA_USER) +=3D vdpa_user/ > > obj-$(CONFIG_IFCVF) +=3D ifcvf/ > > obj-$(CONFIG_MLX5_VDPA) +=3D mlx5/ > > obj-$(CONFIG_VP_VDPA) +=3D virtio_pci/ > > diff --git a/drivers/vdpa/vdpa_user/Makefile b/drivers/vdpa/vdpa_user/M= akefile > > 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 :=3D vduse_dev.o iova_domain.o > > + > > +obj-$(CONFIG_VDPA_USER) +=3D vduse.o > > diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_use= r/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 r= ights 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 =3D (64 * 1024 * 1024); > > +module_param(max_bounce_size, ulong, 0444); > > +MODULE_PARM_DESC(max_bounce_size, "Maximum bounce buffer size. (defaul= t: 64M)"); > > + > > +static unsigned long max_iova_size =3D (128 * 1024 * 1024); > > +module_param(max_iova_size, ulong, 0444); > > +MODULE_PARM_DESC(max_iova_size, "Maximum iova space size (default: 128= M)"); > > + > > +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 =3D 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 =3D 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 =3D NULL; > > + > > + list_for_each_entry(tmp, head, list) { > > + if (tmp->req.request_id =3D=3D request_id) { > > + msg =3D 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 =3D NULL; > > + > > + if (!list_empty(head)) { > > + msg =3D 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 =3D=3D 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 =3D { 0 }; > > + > > + msg.req.type =3D VDUSE_GET_FEATURES; > > + msg.req.request_id =3D 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 =3D { 0 }; > > + > > + msg.req.type =3D VDUSE_SET_FEATURES; > > + msg.req.request_id =3D vduse_dev_get_request_id(dev); > > + msg.req.f.features =3D features; > > + > > + return vduse_dev_msg_sync(dev, &msg); > > +} > > + > > +static u8 vduse_dev_get_status(struct vduse_dev *dev) > > +{ > > + struct vduse_dev_msg msg =3D { 0 }; > > + > > + msg.req.type =3D VDUSE_GET_STATUS; > > + msg.req.request_id =3D 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 =3D { 0 }; > > + > > + msg.req.type =3D VDUSE_SET_STATUS; > > + msg.req.request_id =3D vduse_dev_get_request_id(dev); > > + msg.req.s.status =3D status; > > + > > + vduse_dev_msg_sync(dev, &msg); > > +} > > + > > +static void vduse_dev_get_config(struct vduse_dev *dev, unsigned int o= ffset, > > + void *buf, unsigned int len) > > +{ > > + struct vduse_dev_msg msg =3D { 0 }; > > + unsigned int sz; > > + > > + while (len) { > > + sz =3D min_t(unsigned int, len, sizeof(msg.req.config.dat= a)); > > + msg.req.type =3D VDUSE_GET_CONFIG; > > + msg.req.request_id =3D vduse_dev_get_request_id(dev); > > + msg.req.config.offset =3D offset; > > + msg.req.config.len =3D sz; > > + vduse_dev_msg_sync(dev, &msg); > > + memcpy(buf, msg.resp.config.data, sz); > > + buf +=3D sz; > > + offset +=3D sz; > > + len -=3D sz; > > + } > > +} > > + > > +static void vduse_dev_set_config(struct vduse_dev *dev, unsigned int o= ffset, > > + const void *buf, unsigned int len) > > +{ > > + struct vduse_dev_msg msg =3D { 0 }; > > + unsigned int sz; > > + > > + while (len) { > > + sz =3D min_t(unsigned int, len, sizeof(msg.req.config.dat= a)); > > + msg.req.type =3D VDUSE_SET_CONFIG; > > + msg.req.request_id =3D vduse_dev_get_request_id(dev); > > + msg.req.config.offset =3D offset; > > + msg.req.config.len =3D sz; > > + memcpy(msg.req.config.data, buf, sz); > > + vduse_dev_msg_sync(dev, &msg); > > + buf +=3D sz; > > + offset +=3D sz; > > + len -=3D sz; > > + } > > +} > > + > > +static void vduse_dev_set_vq_num(struct vduse_dev *dev, > > + struct vduse_virtqueue *vq, u32 num) > > +{ > > + struct vduse_dev_msg msg =3D { 0 }; > > + > > + msg.req.type =3D VDUSE_SET_VQ_NUM; > > + msg.req.request_id =3D vduse_dev_get_request_id(dev); > > + msg.req.vq_num.index =3D vq->index; > > + msg.req.vq_num.num =3D num; > > + > > + vduse_dev_msg_sync(dev, &msg); > > +} > > + > > +static int vduse_dev_set_vq_addr(struct vduse_dev *dev, > > + struct vduse_virtqueue *vq, u64 desc_add= r, > > + u64 driver_addr, u64 device_addr) > > +{ > > + struct vduse_dev_msg msg =3D { 0 }; > > + > > + msg.req.type =3D VDUSE_SET_VQ_ADDR; > > + msg.req.request_id =3D vduse_dev_get_request_id(dev); > > + msg.req.vq_addr.index =3D vq->index; > > + msg.req.vq_addr.desc_addr =3D desc_addr; > > + msg.req.vq_addr.driver_addr =3D driver_addr; > > + msg.req.vq_addr.device_addr =3D 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 =3D { 0 }; > > + > > + msg.req.type =3D VDUSE_SET_VQ_READY; > > + msg.req.request_id =3D vduse_dev_get_request_id(dev); > > + msg.req.vq_ready.index =3D vq->index; > > + msg.req.vq_ready.ready =3D 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 =3D { 0 }; > > + > > + msg.req.type =3D VDUSE_GET_VQ_READY; > > + msg.req.request_id =3D vduse_dev_get_request_id(dev); > > + msg.req.vq_ready.index =3D 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 =3D { 0 }; > > + int ret; > > + > > + msg.req.type =3D VDUSE_GET_VQ_STATE; > > + msg.req.request_id =3D vduse_dev_get_request_id(dev); > > + msg.req.vq_state.index =3D vq->index; > > + > > + ret =3D vduse_dev_msg_sync(dev, &msg); > > + if (!ret) > > + state->avail_index =3D 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 =3D { 0 }; > > + > > + msg.req.type =3D VDUSE_SET_VQ_STATE; > > + msg.req.request_id =3D vduse_dev_get_request_id(dev); > > + msg.req.vq_state.index =3D vq->index; > > + msg.req.vq_state.avail_idx =3D 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 =3D { 0 }; > > + > > + if (last < start) > > + return -EINVAL; > > + > > + msg.req.type =3D VDUSE_UPDATE_IOTLB; > > + msg.req.request_id =3D vduse_dev_get_request_id(dev); > > + msg.req.iova.start =3D start; > > + msg.req.iova.last =3D 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 =3D iocb->ki_filp; > > + struct vduse_dev *dev =3D file->private_data; > > + struct vduse_dev_msg *msg; > > + int size =3D sizeof(struct vduse_dev_request); > > + ssize_t ret =3D 0; > > + > > + if (iov_iter_count(to) < size) > > + return 0; > > + > > + spin_lock(&dev->msg_lock); > > + while (1) { > > + msg =3D vduse_dequeue_msg(&dev->send_list); > > + if (msg) > > + break; > > + > > + ret =3D -EAGAIN; > > + if (file->f_flags & O_NONBLOCK) > > + goto unlock; > > + > > + spin_unlock(&dev->msg_lock); > > + ret =3D 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 =3D copy_to_iter(&msg->req, size, to); > > + spin_lock(&dev->msg_lock); > > + if (ret !=3D size) { > > + ret =3D -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_ite= r *from) > > +{ > > + struct file *file =3D iocb->ki_filp; > > + struct vduse_dev *dev =3D file->private_data; > > + struct vduse_dev_response resp; > > + struct vduse_dev_msg *msg; > > + size_t ret; > > + > > + ret =3D copy_from_iter(&resp, sizeof(resp), from); > > + if (ret !=3D sizeof(resp)) > > + return -EINVAL; > > + > > + spin_lock(&dev->msg_lock); > > + msg =3D vduse_find_msg(&dev->recv_list, resp.request_id); > > + if (!msg) { > > + ret =3D -EINVAL; > > + goto unlock; > > + } > > + > > + memcpy(&msg->resp, &resp, sizeof(resp)); > > + msg->completed =3D 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 =3D file->private_data; > > + __poll_t mask =3D 0; > > + > > + poll_wait(file, &dev->waitq, wait); > > + > > + if (!list_empty(&dev->send_list)) > > + mask |=3D EPOLLIN | EPOLLRDNORM; > > + if (!list_empty(&dev->recv_list)) > > + mask |=3D 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 =3D NULL; > > + dev->config_cb.private =3D NULL; > > + spin_unlock(&dev->irq_lock); > > + > > + for (i =3D 0; i < dev->vq_num; i++) { > > + struct vduse_virtqueue *vq =3D &dev->vqs[i]; > > + > > + spin_lock(&vq->irq_lock); > > + vq->ready =3D false; > > + vq->cb.callback =3D NULL; > > + vq->cb.private =3D 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 =3D vdpa_to_vduse(vdpa); > > + struct vduse_virtqueue *vq =3D &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 =3D vdpa_to_vduse(vdpa); > > + struct vduse_virtqueue *vq =3D &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 =3D vdpa_to_vduse(vdpa); > > + struct vduse_virtqueue *vq =3D &dev->vqs[idx]; > > + > > + spin_lock(&vq->irq_lock); > > + vq->cb.callback =3D cb->callback; > > + vq->cb.private =3D cb->private; > > + spin_unlock(&vq->irq_lock); > > +} > > + > > +static void vduse_vdpa_set_vq_num(struct vdpa_device *vdpa, u16 idx, u= 32 num) > > +{ > > + struct vduse_dev *dev =3D vdpa_to_vduse(vdpa); > > + struct vduse_virtqueue *vq =3D &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 =3D vdpa_to_vduse(vdpa); > > + struct vduse_virtqueue *vq =3D &dev->vqs[idx]; > > + > > + vduse_dev_set_vq_ready(dev, vq, ready); > > + vq->ready =3D ready; > > +} > > + > > +static bool vduse_vdpa_get_vq_ready(struct vdpa_device *vdpa, u16 idx) > > +{ > > + struct vduse_dev *dev =3D vdpa_to_vduse(vdpa); > > + struct vduse_virtqueue *vq =3D &dev->vqs[idx]; > > + > > + vq->ready =3D 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 =3D vdpa_to_vduse(vdpa); > > + struct vduse_virtqueue *vq =3D &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 =3D vdpa_to_vduse(vdpa); > > + struct vduse_virtqueue *vq =3D &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 =3D vdpa_to_vduse(vdpa); > > + > > + return dev->vq_align; > > +} > > + > > +static u64 vduse_vdpa_get_features(struct vdpa_device *vdpa) > > +{ > > + struct vduse_dev *dev =3D vdpa_to_vduse(vdpa); > > + > > + return vduse_dev_get_features(dev); > > +} > > + > > +static int vduse_vdpa_set_features(struct vdpa_device *vdpa, u64 featu= res) > > +{ > > + struct vduse_dev *dev =3D 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 =3D vdpa_to_vduse(vdpa); > > + > > + spin_lock(&dev->irq_lock); > > + dev->config_cb.callback =3D cb->callback; > > + dev->config_cb.private =3D cb->private; > > + spin_unlock(&dev->irq_lock); > > +} > > + > > +static u16 vduse_vdpa_get_vq_num_max(struct vdpa_device *vdpa) > > +{ > > + struct vduse_dev *dev =3D vdpa_to_vduse(vdpa); > > + > > + return dev->vq_size_max; > > +} > > + > > +static u32 vduse_vdpa_get_device_id(struct vdpa_device *vdpa) > > +{ > > + struct vduse_dev *dev =3D vdpa_to_vduse(vdpa); > > + > > + return dev->device_id; > > +} > > + > > +static u32 vduse_vdpa_get_vendor_id(struct vdpa_device *vdpa) > > +{ > > + struct vduse_dev *dev =3D vdpa_to_vduse(vdpa); > > + > > + return dev->vendor_id; > > +} > > + > > +static u8 vduse_vdpa_get_status(struct vdpa_device *vdpa) > > +{ > > + struct vduse_dev *dev =3D 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 =3D vdpa_to_vduse(vdpa); > > + > > + vduse_dev_set_status(dev, status); > > + > > + if (status =3D=3D 0) > > + vduse_dev_reset(dev); > > +} > > + > > +static void vduse_vdpa_get_config(struct vdpa_device *vdpa, unsigned i= nt offset, > > + void *buf, unsigned int len) > > +{ > > + struct vduse_dev *dev =3D vdpa_to_vduse(vdpa); > > + > > + vduse_dev_get_config(dev, offset, buf, len); > > +} > > + > > +static void vduse_vdpa_set_config(struct vdpa_device *vdpa, unsigned i= nt offset, > > + const void *buf, unsigned int len) > > +{ > > + struct vduse_dev *dev =3D 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 =3D vdpa_to_vduse(vdpa); > > + int ret; > > + > > + ret =3D 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 =3D vdpa_to_vduse(vdpa); > > + > > + WARN_ON(!list_empty(&dev->send_list)); > > + WARN_ON(!list_empty(&dev->recv_list)); > > + dev->vdev =3D NULL; > > +} > > + > > +static const struct vdpa_config_ops vduse_vdpa_config_ops =3D { > > + .set_vq_address =3D vduse_vdpa_set_vq_address, > > + .kick_vq =3D vduse_vdpa_kick_vq, > > + .set_vq_cb =3D vduse_vdpa_set_vq_cb, > > + .set_vq_num =3D vduse_vdpa_set_vq_num, > > + .set_vq_ready =3D vduse_vdpa_set_vq_ready, > > + .get_vq_ready =3D vduse_vdpa_get_vq_ready, > > + .set_vq_state =3D vduse_vdpa_set_vq_state, > > + .get_vq_state =3D vduse_vdpa_get_vq_state, > > + .get_vq_align =3D vduse_vdpa_get_vq_align, > > + .get_features =3D vduse_vdpa_get_features, > > + .set_features =3D vduse_vdpa_set_features, > > + .set_config_cb =3D vduse_vdpa_set_config_cb, > > + .get_vq_num_max =3D vduse_vdpa_get_vq_num_max, > > + .get_device_id =3D vduse_vdpa_get_device_id, > > + .get_vendor_id =3D vduse_vdpa_get_vendor_id, > > + .get_status =3D vduse_vdpa_get_status, > > + .set_status =3D vduse_vdpa_set_status, > > + .get_config =3D vduse_vdpa_get_config, > > + .set_config =3D vduse_vdpa_set_config, > > + .set_map =3D vduse_vdpa_set_map, > > + .free =3D 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 =3D dev_to_vduse(dev); > > + struct vduse_iova_domain *domain =3D vdev->domain; > > + > > + return vduse_domain_map_page(domain, page, offset, size, dir, att= rs); > > +} > > + > > +static void vduse_dev_unmap_page(struct device *dev, dma_addr_t dma_ad= dr, > > + size_t size, enum dma_data_direction dir, > > + unsigned long attrs) > > +{ > > + struct vduse_dev *vdev =3D dev_to_vduse(dev); > > + struct vduse_iova_domain *domain =3D 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 =3D dev_to_vduse(dev); > > + struct vduse_iova_domain *domain =3D vdev->domain; > > + unsigned long iova; > > + void *addr; > > + > > + *dma_addr =3D DMA_MAPPING_ERROR; > > + addr =3D vduse_domain_alloc_coherent(domain, size, > > + (dma_addr_t *)&iova, flag, attrs); > > + if (!addr) > > + return NULL; > > + > > + *dma_addr =3D (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 =3D dev_to_vduse(dev); > > + struct vduse_iova_domain *domain =3D vdev->domain; > > + unsigned long start =3D (unsigned long)dma_addr; > > + unsigned long last =3D 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 =3D { > > + .map_page =3D vduse_dev_map_page, > > + .unmap_page =3D vduse_dev_unmap_page, > > + .alloc =3D vduse_dev_alloc_coherent, > > + .free =3D vduse_dev_free_coherent, > > +}; > > + > > +static unsigned int perm_to_file_flags(u8 perm) > > +{ > > + unsigned int flags =3D 0; > > + > > + switch (perm) { > > + case VDUSE_ACCESS_WO: > > + flags |=3D O_WRONLY; > > + break; > > + case VDUSE_ACCESS_RO: > > + flags |=3D O_RDONLY; > > + break; > > + case VDUSE_ACCESS_RW: > > + flags |=3D 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 =3D NULL; > > + struct vduse_virtqueue *vq; > > + > > + if (eventfd->index >=3D dev->vq_num) > > + return -EINVAL; > > + > > + vq =3D &dev->vqs[eventfd->index]; > > + if (eventfd->fd > 0) { > > + ctx =3D eventfd_ctx_fdget(eventfd->fd); > > + if (IS_ERR(ctx)) > > + return PTR_ERR(ctx); > > + } else if (eventfd->fd !=3D 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. > > > + > > + spin_lock(&vq->kick_lock); > > + if (vq->kickfd) > > + eventfd_ctx_put(vq->kickfd); > > + vq->kickfd =3D ctx; > > + spin_unlock(&vq->kick_lock); > > + > > + return 0; > > +} > > + > > +static void vduse_vq_irq_inject(struct work_struct *work) > > +{ > > + struct vduse_virtqueue *vq =3D 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 =3D file->private_data; > > + void __user *argp =3D (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 =3D dev->domain; > > + struct file *f =3D NULL; > > + > > + ret =3D -EFAULT; > > + if (copy_from_user(&entry, argp, sizeof(entry))) > > + break; > > + > > + ret =3D -EINVAL; > > + if (entry.start > entry.last) > > + break; > > + > > + spin_lock(&domain->iotlb_lock); > > + map =3D vhost_iotlb_itree_first(domain->iotlb, > > + entry.start, entry.last); > > + if (map) { > > + map_file =3D (struct vdpa_map_file *)map->opaque; > > + f =3D get_file(map_file->file); > > + entry.offset =3D map_file->offset; > > + entry.start =3D map->start; > > + entry.last =3D map->last; > > + entry.perm =3D map->perm; > > + } > > + spin_unlock(&domain->iotlb_lock); > > + ret =3D -EINVAL; > > + if (!f) > > + break; > > + > > + ret =3D -EFAULT; > > + if (copy_to_user(argp, &entry, sizeof(entry))) { > > + fput(f); > > + break; > > + } > > + ret =3D 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. > > > + break; > > + } > > + case VDUSE_VQ_SETUP_KICKFD: { > > + struct vduse_vq_eventfd eventfd; > > + > > + ret =3D -EFAULT; > > + if (copy_from_user(&eventfd, argp, sizeof(eventfd))) > > + break; > > + > > + ret =3D vduse_kickfd_setup(dev, &eventfd); > > + break; > > + } > > + case VDUSE_INJECT_VQ_IRQ: > > + ret =3D -EINVAL; > > + if (arg >=3D dev->vq_num) > > + break; > > + > > + ret =3D 0; > > + queue_work(vduse_irq_wq, &dev->vqs[arg].inject); > > + break; > > + case VDUSE_INJECT_CONFIG_IRQ: > > + ret =3D -EINVAL; > > + spin_lock_irq(&dev->irq_lock); > > + if (dev->config_cb.callback) { > > + dev->config_cb.callback(dev->config_cb.private); > > + ret =3D 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 =3D -ENOIOCTLCMD; > > + break; > > + } > > + > > + return ret; > > +} > > + > > +static int vduse_dev_release(struct inode *inode, struct file *file) > > +{ > > + struct vduse_dev *dev =3D file->private_data; > > + struct vduse_dev_msg *msg; > > + int i; > > + > > + for (i =3D 0; i < dev->vq_num; i++) { > > + struct vduse_virtqueue *vq =3D &dev->vqs[i]; > > + > > + spin_lock(&vq->kick_lock); > > + if (vq->kickfd) > > + eventfd_ctx_put(vq->kickfd); > > + vq->kickfd =3D 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 =3D vduse_dequeue_msg(&dev->recv_list))) > > + vduse_enqueue_msg(&dev->send_list, msg); > > + spin_unlock(&dev->msg_lock); > > + > > + dev->connected =3D false; > > + > > + return 0; > > +} > > + > > +static int vduse_dev_open(struct inode *inode, struct file *file) > > +{ > > + struct vduse_dev *dev =3D container_of(inode->i_cdev, > > + struct vduse_dev, cdev); > > + int ret =3D -EBUSY; > > + > > + mutex_lock(&dev->lock); > > + if (dev->connected) > > + goto unlock; > > + > > + ret =3D 0; > > + dev->connected =3D true; > > + file->private_data =3D dev; > > +unlock: > > + mutex_unlock(&dev->lock); > > + > > + return ret; > > +} > > + > > +static const struct file_operations vduse_dev_fops =3D { > > + .owner =3D THIS_MODULE, > > + .open =3D vduse_dev_open, > > + .release =3D vduse_dev_release, > > + .read_iter =3D vduse_dev_read_iter, > > + .write_iter =3D vduse_dev_write_iter, > > + .poll =3D vduse_dev_poll, > > + .unlocked_ioctl =3D vduse_dev_ioctl, > > + .compat_ioctl =3D compat_ptr_ioctl, > > + .llseek =3D noop_llseek, > > +}; > > + > > +static struct vduse_dev *vduse_dev_create(void) > > +{ > > + struct vduse_dev *dev =3D 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 =3D NULL; > > + > > + list_for_each_entry(tmp, &vduse_devs, list) { > > + if (!strcmp(dev_name(&tmp->dev), name)) { > > + dev =3D tmp; > > + break; > > + } > > + } > > + return dev; > > +} > > + > > +static int vduse_destroy_dev(char *name) > > +{ > > + struct vduse_dev *dev =3D 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 =3D 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 =3D > > + 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 =3D -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 =3D vduse_dev_create(); > > + if (!dev) > > + return -ENOMEM; > > + > > + dev->api_version =3D api_version; > > + dev->device_id =3D config->device_id; > > + dev->vendor_id =3D config->vendor_id; > > + dev->domain =3D vduse_domain_create(max_iova_size - 1, > > + config->bounce_size); > > + if (!dev->domain) > > + goto err_domain; > > + > > + dev->vq_align =3D config->vq_align; > > + dev->vq_size_max =3D config->vq_size_max; > > + dev->vq_num =3D config->vq_num; > > + dev->vqs =3D kcalloc(dev->vq_num, sizeof(*dev->vqs), GFP_KERNEL); > > + if (!dev->vqs) > > + goto err_vqs; > > + > > + for (i =3D 0; i < dev->vq_num; i++) { > > + dev->vqs[i].index =3D 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 =3D ida_simple_get(&vduse_ida, 0, VDUSE_DEV_MAX, GFP_KERNEL); > > + if (ret < 0) > > + goto err_ida; > > + > > + dev->minor =3D ret; > > + device_initialize(&dev->dev); > > + dev->dev.release =3D vduse_release_dev; > > + dev->dev.class =3D vduse_class; > > + dev->dev.devt =3D MKDEV(MAJOR(vduse_major), dev->minor); > > + ret =3D 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 =3D THIS_MODULE; > > + > > + ret =3D 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. > > > + } > > + 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 =3D (void __user *)arg; > > + struct vduse_control *control =3D file->private_data; > > + > > + mutex_lock(&vduse_lock); > > + switch (cmd) { > > + case VDUSE_GET_API_VERSION: > > + ret =3D control->api_version; > > + break; > > + case VDUSE_SET_API_VERSION: > > + ret =3D -EINVAL; > > + if (arg > VDUSE_API_VERSION) > > + break; > > + > > + ret =3D 0; > > + control->api_version =3D arg; > > + break; > > + case VDUSE_CREATE_DEV: { > > + struct vduse_dev_config config; > > + > > + ret =3D -EFAULT; > > + if (copy_from_user(&config, argp, sizeof(config))) > > + break; > > + > > + ret =3D vduse_create_dev(&config, control->api_version); > > + break; > > + } > > + case VDUSE_DESTROY_DEV: { > > + char name[VDUSE_NAME_MAX]; > > + > > + ret =3D -EFAULT; > > + if (copy_from_user(name, argp, VDUSE_NAME_MAX)) > > + break; > > + > > + ret =3D vduse_destroy_dev(name); > > + break; > > + } > > + default: > > + ret =3D -EINVAL; > > + break; > > + } > > + mutex_unlock(&vduse_lock); > > + > > + return ret; > > +} > > + > > +static int vduse_release(struct inode *inode, struct file *file) > > +{ > > + struct vduse_control *control =3D file->private_data; > > + > > + kfree(control); > > + return 0; > > +} > > + > > +static int vduse_open(struct inode *inode, struct file *file) > > +{ > > + struct vduse_control *control; > > + > > + control =3D kmalloc(sizeof(struct vduse_control), GFP_KERNEL); > > + if (!control) > > + return -ENOMEM; > > + > > + control->api_version =3D VDUSE_API_VERSION; > > + file->private_data =3D control; > > + > > + return 0; > > +} > > + > > +static const struct file_operations vduse_fops =3D { > > + .owner =3D THIS_MODULE, > > + .open =3D vduse_open, > > + .release =3D vduse_release, > > + .unlocked_ioctl =3D vduse_ioctl, > > + .compat_ioctl =3D compat_ptr_ioctl, > > + .llseek =3D 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 =3D { > > + .fops =3D &vduse_fops, > > + .minor =3D MISC_DYNAMIC_MINOR, > > + .name =3D "vduse", > > + .nodename =3D "vduse/control", > > +}; > > + > > +static void vduse_mgmtdev_release(struct device *dev) > > +{ > > +} > > + > > +static struct device vduse_mgmtdev =3D { > > + .init_name =3D "vduse", > > + .release =3D 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 =3D vdpa_alloc_device(struct vduse_vdpa, vdpa, &dev->dev, > > + &vduse_vdpa_config_ops, name, true); > > + if (!vdev) > > + return -ENOMEM; > > + > > + dev->vdev =3D vdev; > > + vdev->dev =3D dev; > > + vdev->vdpa.dev.dma_mask =3D &vdev->vdpa.dev.coherent_dma_mask; > > + ret =3D dma_set_mask_and_coherent(&vdev->vdpa.dev, DMA_BIT_MASK(6= 4)); > > + if (ret) { > > + put_device(&vdev->vdpa.dev); > > + return ret; > > + } > > + set_dma_ops(&vdev->vdpa.dev, &vduse_dev_dma_ops); > > + vdev->vdpa.dma_dev =3D &vdev->vdpa.dev; > > + vdev->vdpa.mdev =3D &mgmt_dev; > > + > > + return 0; > > +} > > + > > +static int vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name) > > +{ > > + struct vduse_dev *dev; > > + int ret =3D -EINVAL; > > + > > + mutex_lock(&vduse_lock); > > + dev =3D vduse_find_dev(name); > > + if (!dev) { > > + mutex_unlock(&vduse_lock); > > + return -EINVAL; > > + } > > + ret =3D vduse_dev_init_vdpa(dev, name); > > + mutex_unlock(&vduse_lock); > > + if (ret) > > + return ret; > > + > > + ret =3D _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_devic= e *dev) > > +{ > > + _vdpa_unregister_device(dev); > > +} > > + > > +static const struct vdpa_mgmtdev_ops vdpa_dev_mgmtdev_ops =3D { > > + .dev_add =3D vdpa_dev_add, > > + .dev_del =3D vdpa_dev_del, > > +}; > > + > > +static struct virtio_device_id id_table[] =3D { > > + { VIRTIO_DEV_ANY_ID, VIRTIO_DEV_ANY_ID }, > > + { 0 }, > > +}; > > + > > +static struct vdpa_mgmt_dev mgmt_dev =3D { > > + .device =3D &vduse_mgmtdev, > > + .id_table =3D id_table, > > + .ops =3D &vdpa_dev_mgmtdev_ops, > > +}; > > + > > +static int vduse_mgmtdev_init(void) > > +{ > > + int ret; > > + > > + ret =3D device_register(&vduse_mgmtdev); > > + if (ret) > > + return ret; > > + > > + ret =3D 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 >=3D max_iova_size) > > + return -EINVAL; > > + > > + ret =3D misc_register(&vduse_misc); > > + if (ret) > > + return ret; > > + > > + vduse_class =3D class_create(THIS_MODULE, "vduse"); > > + if (IS_ERR(vduse_class)) { > > + ret =3D PTR_ERR(vduse_class); > > + goto err_class; > > + } > > + vduse_class->devnode =3D vduse_devnode; > > + > > + ret =3D alloc_chrdev_region(&vduse_major, 0, VDUSE_DEV_MAX, "vdus= e"); > > + if (ret) > > + goto err_chardev; > > + > > + vduse_irq_wq =3D alloc_workqueue("vduse-irq", > > + WQ_HIGHPRI | WQ_SYSFS | WQ_UNBOUND, 0); > > + if (!vduse_irq_wq) > > + goto err_wq; > > + > > + ret =3D vduse_domain_init(); > > + if (ret) > > + goto err_domain; > > + > > + ret =3D 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(). The idea is > to support packed virtqueue. > OK. But looks like sizeof(struct vdpa_vq_state) is still equal to 2. Do you mean we will extend it in the future? > > > +}; > > + > > +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/wri= te */ > > > 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=EF=BC=9F > > > +}; > > + > > +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 con= fig 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 con= fig 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 metada= ta */ > > + __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 | > > > +}; > > + > > +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/v= duse/) */ > > +#define VDUSE_CREATE_DEV _IOW(VDUSE_BASE, 0x02, struct vduse_dev_c= onfig) > > + > > +/* Destroy a vduse device. Make sure there are no references to the ch= ar device */ > > +#define VDUSE_DESTROY_DEV _IOW(VDUSE_BASE, 0x03, char[VDUSE_NAME_MA= X]) > > + > > +/* > > + * 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_iotl= b_entry) > > + > > +/* Setup an eventfd to receive kick for virtqueue */ > > +#define VDUSE_VQ_SETUP_KICKFD _IOW(VDUSE_BASE, 0x05, struct vdu= se_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? Thanks, Yongji