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=-13.8 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 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 D1EA5C433E2 for ; Thu, 25 Mar 2021 07:49:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 984DC61A28 for ; Thu, 25 Mar 2021 07:49:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229781AbhCYHsu (ORCPT ); Thu, 25 Mar 2021 03:48:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48458 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229779AbhCYHsV (ORCPT ); Thu, 25 Mar 2021 03:48:21 -0400 Received: from mail-ed1-x52f.google.com (mail-ed1-x52f.google.com [IPv6:2a00:1450:4864:20::52f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D21D7C061760 for ; Thu, 25 Mar 2021 00:48:09 -0700 (PDT) Received: by mail-ed1-x52f.google.com with SMTP id dm8so1334007edb.2 for ; Thu, 25 Mar 2021 00:48:09 -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=jPVU1zDx+gPfddW1l2Sp3qHqiDdfq/9iywYyYxO4dvQ=; b=O226bpbPRxQS7RUsgp+9K2DOYJcTUJXC2ylp5rHUzy80WR37ORma7khDag84K02rjy BjgFnumccSJ8QLUxMQ8uGYvG3KCDl8FohzwZdQN1SSr1pYDUar7pUNikCtMk4p6TqaaR RQYDzs1mG4APX6HYPl9jpuA3USgIM3Fy3W6FRCJtCekV78Uk7SG4Bhxm9k1EefkZpuab m/kvNbf64U0hl1WOMdNZh6LFNJmIt112aXLDdKZuLWlkRCF+30+NPrxnC4+gpR8bQ5KL vrVfhwX+4vpPIwacW1gCHWMcjLIjl/0BjhJH9e8A5IOPKyzgkHScHk/UJN1Grc0S3FCP 2WvQ== 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=jPVU1zDx+gPfddW1l2Sp3qHqiDdfq/9iywYyYxO4dvQ=; b=XJkolryakk7dZPdB8b0vboVVVl3I+2qeMQ087XcwhG8yQ0sqNTiuoSjDhUzGmbqg4q jvg74fGLxXskWE+nKI97xSS3DAqt7KgVfV+r0yTZseCV/ipm3S9P5ENuWeCIXkh0l++2 u377zi2+rMv/vhSiaz913ALJHUf/39HekfYCuTT3pw789WzTujqbbm/ukLuwA1irTO+S nQhoELRiKtSx242RXc+pwYrWwE924i9N8eezBP53zgOjKZsTfnioAmVCPaJw+qcqbmuO tyveWaoIGRn1KHaeqThMf4aWWk1Zq8ivCVYaY0qTiw5Dg238vbEk0M0PtY8+xC/cowRk SR7A== X-Gm-Message-State: AOAM533/5Qvz8+U4gcai7Tzs5eEjcLVNBtAi5xanyrsR6ptVelHLsoOA N36mRRys+dUa2ff3oJGRBchDlOVkdxgKXqLlNDCw X-Google-Smtp-Source: ABdhPJxORfFH5PJytDgt4ntUTad9Ib0wolp3zJXtSWQT0zMIYq82pj3lRwK9BWs2tF2InuQIKpdOoyJbSwwJDWvk+Lo= X-Received: by 2002:a05:6402:4314:: with SMTP id m20mr7411663edc.5.1616658488289; Thu, 25 Mar 2021 00:48:08 -0700 (PDT) MIME-Version: 1.0 References: <20210315053721.189-1-xieyongji@bytedance.com> <20210315053721.189-10-xieyongji@bytedance.com> <21c780a3-b9ea-4705-9ede-abc73496236c@redhat.com> <0b2c66fe-35eb-89c4-92ac-fae9d78b3ca2@redhat.com> In-Reply-To: <0b2c66fe-35eb-89c4-92ac-fae9d78b3ca2@redhat.com> From: Yongji Xie Date: Thu, 25 Mar 2021 15:47:56 +0800 Message-ID: Subject: Re: Re: [PATCH v5 09/11] vduse: Introduce VDUSE - vDPA Device in Userspace To: Jason Wang Cc: "Michael S. Tsirkin" , Stefan Hajnoczi , Stefano Garzarella , Parav Pandit , Bob Liu , Christoph Hellwig , 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: netdev@vger.kernel.org On Thu, Mar 25, 2021 at 2:31 PM Jason Wang wrote: > > > =E5=9C=A8 2021/3/24 =E4=B8=8B=E5=8D=884:55, Yongji Xie =E5=86=99=E9=81=93= : > > On Wed, Mar 24, 2021 at 12:43 PM Jason Wang wrote= : > >> > >> =E5=9C=A8 2021/3/15 =E4=B8=8B=E5=8D=881:37, 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, userspace can use mmap() to access vDPA device's > >>> iova regions obtained through VDUSE_IOTLB_GET_ENTRY ioctl. 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 | 1281 ++++++++= ++++++++++++ > >>> include/uapi/linux/vduse.h | 153 +++ > >>> 6 files changed, 1451 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/Doc= umentation/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= /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 :=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_u= ser/vduse_dev.c > >>> new file mode 100644 > >>> index 000000000000..07d0ae92d470 > >>> --- /dev/null > >>> +++ b/drivers/vdpa/vdpa_user/vduse_dev.c > >>> @@ -0,0 +1,1281 @@ > >>> +// SPDX-License-Identifier: GPL-2.0-only > >>> +/* > >>> + * VDUSE: vDPA Device in Userspace > >>> + * > >>> + * Copyright (C) 2020 Bytedance Inc. and/or its affiliates. All righ= ts 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; > >>> + 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; > >>> + 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; > >>> +}; > >>> + > >>> +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. (defa= ult: 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: 1= 28M)"); > >>> + > >>> +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 *vd= pa) > >>> +{ > >>> + struct vduse_vdpa *vdev =3D container_of(vdpa, struct vduse_vdp= a, 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 *hea= d) > >>> +{ > >>> + struct vduse_dev_msg *msg =3D NULL; > >>> + > >>> + if (!list_empty(head)) { > >>> + msg =3D list_first_entry(head, struct vduse_dev_msg, li= st); > >>> + 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 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 atomic64_fetch_inc(&dev->msg_unique); > >> > >> Let's introduce a helper for the atomic64_fetch_inc() here. > >> > > Fine. > > > >>> + > >>> + return vduse_dev_msg_sync(dev, &msg) ? 0 : msg.resp.f.features; > >>> +} > >>> + > >>> +static int vduse_dev_set_features(struct vduse_dev *dev, u64 feature= s) > >>> +{ > >>> + struct vduse_dev_msg msg =3D { 0 }; > >>> + > >>> + msg.req.type =3D VDUSE_SET_FEATURES; > >>> + msg.req.request_id =3D atomic64_fetch_inc(&dev->msg_unique); > >>> + 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 atomic64_fetch_inc(&dev->msg_unique); > >>> + > >>> + 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 atomic64_fetch_inc(&dev->msg_unique); > >>> + msg.req.s.status =3D 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 =3D { 0 }; > >>> + unsigned int sz; > >>> + > >>> + while (len) { > >>> + sz =3D min_t(unsigned int, len, sizeof(msg.req.config.d= ata)); > >>> + msg.req.type =3D VDUSE_GET_CONFIG; > >>> + msg.req.request_id =3D atomic64_fetch_inc(&dev->msg_uni= que); > >>> + 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= offset, > >>> + 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.d= ata)); > >>> + msg.req.type =3D VDUSE_SET_CONFIG; > >>> + msg.req.request_id =3D atomic64_fetch_inc(&dev->msg_uni= que); > >>> + 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 atomic64_fetch_inc(&dev->msg_unique); > >>> + 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_a= ddr, > >>> + 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 atomic64_fetch_inc(&dev->msg_unique); > >>> + 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 atomic64_fetch_inc(&dev->msg_unique); > >>> + 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 atomic64_fetch_inc(&dev->msg_unique); > >>> + msg.req.vq_ready.index =3D vq->index; > >>> + > >>> + return vduse_dev_msg_sync(dev, &msg) ? false : msg.resp.vq_read= y.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 atomic64_fetch_inc(&dev->msg_unique); > >>> + 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 atomic64_fetch_inc(&dev->msg_unique); > >>> + 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; > >>> + > >>> + if (last < start) > >>> + return -EINVAL; > >>> + > >>> + msg =3D kzalloc(sizeof(*msg), GFP_ATOMIC); > >> > >> The return value is not checked. > >> > > Will fix it. > > > >>> + msg->req.type =3D VDUSE_UPDATE_IOTLB; > >> > >> What would usespace do after receiving VDUSE_UPDATE_IOTLB? If it still > >> needs to issue VDUSE_GET_ENTRY with probably -EINVAL, it's kind of > >> overkill. So it looks to me that the VDUSE_UPDATE_IOTLB is acutally ki= nd > >> of flush or unmap here. If this is true, should we introduce a new typ= e > >> or just rename it as VDUSE_IOTLB_UNMAP? > >> > > VDUSE_UPDATE_IOTLB is used to notify userspace of refreshing (include > > mapping and unmapping) the iotlb mapping. The reason why we can't use > > flush/unmap is explained below. > > > >>> + msg->req.request_id =3D atomic64_fetch_inc(&dev->msg_unique); > >>> + 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_it= er *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); > >>> +unlock: > >>> + spin_unlock(&dev->msg_lock); > >>> + > >>> + return ret; > >>> +} > >>> + > >>> +static ssize_t vduse_dev_write_iter(struct kiocb *iocb, struct iov_i= ter *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; > >> > >> EPOLLOUT is missed here? > >> > > Why do we need EPOLLOUT here? > > > It means the fd is ready to be wrote? > OK, I got it. > > > > >>> + > >>> + return mask; > >>> +} > >>> + > >>> +static void vduse_dev_reset(struct vduse_dev *dev) > >>> +{ > >>> + int i; > >>> + > >>> + vduse_domain_reset_bounce_map(dev->domain); > >>> + vduse_dev_update_iotlb(dev, 0ULL, ULLONG_MAX); > >> > >> Simialrly, IOTLB update should be done before the resetting? > >> > > The problem is userspace can still get valid bounce mapping through > > VDUSE_IOTLB_GET_ENTRY between receiving IOTLB_UNMAP and bounce mapping > > reset. Then userspace has no way to know when to invalidate these > > mappings. > > > Right, I think it might be helpful to add a comment here to explain the > order. > Fine with me. > > > > >> And it would be helpful to add comment to explain how coherent mapping= s > >> is handled. > >> > > OK. It would be handled in vduse_dev_free_coherent(). > > > >>> + > >>> + 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 i= dx, > >>> + 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,= u32 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 id= x) > >>> +{ > >>> + 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 fea= tures) > >>> +{ > >>> + 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) > >>> +{ > >>> + /* We don't support config interrupt */ > >>> +} > >>> + > >>> +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 statu= s) > >>> +{ > >>> + struct vduse_dev *dev =3D vdpa_to_vduse(vdpa); > >>> + > >>> + if (status =3D=3D 0) > >>> + vduse_dev_reset(dev); > >>> + > >>> + vduse_dev_set_status(dev, status); > >>> +} > >>> + > >>> +static void vduse_vdpa_get_config(struct vdpa_device *vdpa, unsigned= int 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= int 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; > >>> + > >> > >> So I wonder we need to do the vhost_dev_update_iotlb() before > >> vduse_domain_set_map(). > >> > >> That is, we need to make sure the userspace's IOTLB is cleared after > >> setting up the new map? > >> > > The same problem I described above. So we use UPDATE_IOTLB messages to > > notify userspace of refreshing the IOTLB after we change the iotlb > > itree. > > > Yes. > > > > > >>> + 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, a= ttrs); > >>> +} > >>> + > >>> +static void vduse_dev_unmap_page(struct device *dev, dma_addr_t dma_= addr, > >>> + size_t size, enum dma_data_direction di= r, > >>> + 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, att= rs); > >>> +} > >>> + > >>> +static void *vduse_dev_alloc_coherent(struct device *dev, size_t siz= e, > >>> + dma_addr_t *dma_addr, gfp_t fla= g, > >>> + 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_add= r, > >>> + 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; > >>> + > >>> + 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_ENTRY: { > >>> + 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; > >>> + > >>> + spin_lock(&domain->iotlb_lock); > >>> + map =3D vhost_iotlb_itree_first(domain->iotlb, > >>> + entry.start, entry.start = + 1); > >>> + if (map) { > >>> + map_file =3D (struct vdpa_map_file *)map->opaqu= e; > >>> + 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; > >> > >> So we need document this in the uAPI doc. I think when userspace see > >> -EINVAL it means the map doesn't exist. > >> > > Fine with me. > > > >> Or should we make it more explicitly by e.g introduing new flags. > >> > >> > >>> + if (!f) > >>> + break; > >>> + > >>> + ret =3D -EFAULT; > >>> + if (copy_to_user(argp, &entry, sizeof(entry))) { > >>> + fput(f); > >>> + break; > >>> + } > >>> + ret =3D receive_fd_user(f, argp, perm_to_file_flags(ent= ry.perm)); > >>> + fput(f); > >>> + 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; > >>> + 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); > >>> + while ((msg =3D vduse_dequeue_msg(&dev->recv_list))) > >>> + vduse_enqueue_msg(&dev->send_list, msg); > >> > >> What's the goal of this? > >> > > Support reconnecting. Make sure userspace daemon can get the inflight > > messages after reboot. > > > I see, plase add a comment for this. > OK. > > > > >> In addition to free the messages, we need wake up the processes that i= s > >> in the waitq in this case. > >> > >> > >>> + spin_unlock(&dev->msg_lock); > >>> + > >>> + dev->connected =3D false; > >> > >> Do we need to hold vduse mutex here? > >> > > Looks like I didn't find any situation that requires the mutex. > > > Ok, I guess the reason is because there will be no external reference > for the device? > Yes, only one process can open this device now. > > > > >>> + > >>> + 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(&vduse_lock); > >>> + if (dev->connected) > >>> + goto unlock; > >>> + > >>> + ret =3D 0; > >>> + dev->connected =3D true; > >>> + file->private_data =3D dev; > >>> +unlock: > >>> + mutex_unlock(&vduse_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; > >>> + > >>> + spin_lock_init(&dev->msg_lock); > >>> + INIT_LIST_HEAD(&dev->send_list); > >>> + INIT_LIST_HEAD(&dev->recv_list); > >>> + atomic64_set(&dev->msg_unique, 0); > >>> + > >>> + 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; > >>> + > >>> + if (dev->vdev || dev->connected) > >>> + return -EBUSY; > >>> + > >>> + dev->connected =3D true; > >> > >> Need mutex here? > >> > > vduse_destroy_dev() is protected by the vduse_mutex. > > > I see. > > > > > >>> + list_del(&dev->list); > >>> + cdev_device_del(&dev->cdev, &dev->dev); > >>> + put_device(&dev->dev); > >>> + > >>> + 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); > >>> + module_put(THIS_MODULE); > >>> +} > >>> + > >>> +static int vduse_create_dev(struct vduse_dev_config *config) > >>> +{ > >>> + 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->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) > >>> + goto err_name; > >>> + > >>> + 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; > >>> + } > >>> + list_add(&dev->list, &vduse_devs); > >>> + __module_get(THIS_MODULE); > >>> + > >>> + return 0; > >>> +err_name: > >>> + ida_simple_remove(&vduse_ida, dev->minor); > >>> +err_ida: > >>> + kfree(dev->vqs); > >>> +err_vqs: > >>> + vduse_domain_destroy(dev->domain); > >>> +err_domain: > >> > >> So the rewind after device_initialize() looks wrong, we should use > >> put_device() which will use dev.relase(). > >> > > Oh, yes. We should also call put_device() in err_name case. > > > >> See the comment of device_initialize(): > >> > >> * NOTE: Use put_device() to give up your reference instead of freei= ng > >> * @dev directly once you have called this function. > >> */ > >> > >>> + 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; > >>> + > >>> + mutex_lock(&vduse_lock); > >>> + switch (cmd) { > >>> + case VDUSE_GET_API_VERSION: > >>> + ret =3D VDUSE_API_VERSION; > >> > >> To preseve the uAPI compatibility, besides GET_API_VERSION, we need > >> SET_API_VERSION to support older userspace. > >> > > Shouldn't the userspace keep compatibility to support older kernel? If > > so, we only need GET_API_VERSION here. > > > Actually the reverse. The new kernel need to make sure the old userspace > can work. That is to say the kenrel should support version 0 forever > even if it supports e.g version 1. > OK, I see. Thanks, Yongji