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=-13.7 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,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 8BE45C433E0 for ; Wed, 27 Jan 2021 09:59:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2AEC72076D for ; Wed, 27 Jan 2021 09:59:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233842AbhA0J7G (ORCPT ); Wed, 27 Jan 2021 04:59:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56480 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232884AbhA0IvV (ORCPT ); Wed, 27 Jan 2021 03:51:21 -0500 Received: from mail-ej1-x631.google.com (mail-ej1-x631.google.com [IPv6:2a00:1450:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CA4D5C0613ED for ; Wed, 27 Jan 2021 00:50:40 -0800 (PST) Received: by mail-ej1-x631.google.com with SMTP id hs11so1548869ejc.1 for ; Wed, 27 Jan 2021 00:50:40 -0800 (PST) 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=e09jAteL+X1SNXVK1+WdIGxvPgZc4/o/o5GaDdGJeSU=; b=TmmT2T5k3pB6PbEYpwrp9TVMHrgpeXC729V/EkGHFIn/SoNG1ZsoUm71vi/W7wu9jC eYBSwx34yz4cQVRQEiQPc33dmD9WGPr17qIxMDEiam89ijd6EQ5bXz/1uTfQ6JCuydaE 9BHLIB9k9Qehc/ehhD/YEk82HcRNIK/rCTYcycElGFeUlDKufny6CbIShuFTBzDNb1hh V7aSFNau5eIlTii9iX9cUQ+ZV3RKEUHvmW+ta4goGDKHfeChdYuPV7n43iGqMsfoqZ1Z UG3Vr1TJFGwTw3ztUEMZ3TdJ/T550utd5Jom1aQtMbeaFlHXPRkm3UUii8vICoY4ZcA9 HAqA== 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=e09jAteL+X1SNXVK1+WdIGxvPgZc4/o/o5GaDdGJeSU=; b=I1ZIFn8zzMemwIj6X6OfJcTFPSolN92MMQyQ8MvjzD51XIP5n+SNu1NBodOhvu3Zyw UZF2JrJ2hvxScgiTFuxrODFhSvHc0YMvqWgmN/2B3VBpfJk1XtuA2YuBP/w7qM3o6Y+m Hv2EGQ/oS0d3jHumdiZvjmCSYvlubvrXW3tAInbj8y/0LA4jafGvN2z7yP+Bo5R7DpoE KnRG5lCaInZX26BDJbFfWImedYqCJSXBxCBwQ3UutZXZk9qln94FpbG1NMm9hvmCq6un vV0Uv+0ibMnlQTJHTV7onAQ7Kjo0D6HwaA4P9gP9PSIcXCNgaNZfljC9k/SPnaqmQ3HG gOPw== X-Gm-Message-State: AOAM530YTYdZn+ZfG7wxZGWGynDuBHA57/UC+KCSrbs4PU92a8pb+I/i +y5e97IY3eKFzbTQXzwnYg9H068yx2/k49/6ckYW X-Google-Smtp-Source: ABdhPJyqMXZs5gVYJHTzcAOqMVzCZqOI3wNbMA9fZiznhf9D3Y9EUivyx7tXFyhrVyiS3YRXxR8F2gHEj0bJAa5jmyE= X-Received: by 2002:a17:907:3d86:: with SMTP id he6mr5980287ejc.174.1611737439076; Wed, 27 Jan 2021 00:50:39 -0800 (PST) MIME-Version: 1.0 References: <20210119045920.447-1-xieyongji@bytedance.com> <20210119050756.600-1-xieyongji@bytedance.com> <20210119050756.600-2-xieyongji@bytedance.com> <1bb3af07-0ec2-109c-d6d1-83d4d1f410c3@redhat.com> In-Reply-To: <1bb3af07-0ec2-109c-d6d1-83d4d1f410c3@redhat.com> From: Yongji Xie Date: Wed, 27 Jan 2021 16:50:27 +0800 Message-ID: Subject: Re: Re: [RFC v3 08/11] vduse: Introduce VDUSE - vDPA Device in Userspace To: Jason Wang Cc: "Michael S. Tsirkin" , Stefan Hajnoczi , sgarzare@redhat.com, Parav Pandit , Bob Liu , Christoph Hellwig , Randy Dunlap , Matthew Wilcox , viro@zeniv.linux.org.uk, axboe@kernel.dk, bcrl@kvack.org, Jonathan Corbet , virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, kvm@vger.kernel.org, linux-aio@kvack.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 Tue, Jan 26, 2021 at 4:09 PM Jason Wang wrote: > > > On 2021/1/19 =E4=B8=8B=E5=8D=881:07, Xie Yongji wrote: > > 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, > > the eventfd mechanism is used to trigger interrupt callbacks and > > receive virtqueue kicks in userspace. > > > > Signed-off-by: Xie Yongji > > --- > > Documentation/driver-api/vduse.rst | 85 ++ > > Documentation/userspace-api/ioctl/ioctl-number.rst | 1 + > > drivers/vdpa/Kconfig | 7 + > > drivers/vdpa/Makefile | 1 + > > drivers/vdpa/vdpa_user/Makefile | 5 + > > drivers/vdpa/vdpa_user/eventfd.c | 221 ++++ > > drivers/vdpa/vdpa_user/eventfd.h | 48 + > > drivers/vdpa/vdpa_user/iova_domain.c | 426 +++++++ > > drivers/vdpa/vdpa_user/iova_domain.h | 68 ++ > > drivers/vdpa/vdpa_user/vduse.h | 62 + > > drivers/vdpa/vdpa_user/vduse_dev.c | 1217 +++++++++++= +++++++++ > > include/uapi/linux/vdpa.h | 1 + > > include/uapi/linux/vduse.h | 125 ++ > > 13 files changed, 2267 insertions(+) > > create mode 100644 Documentation/driver-api/vduse.rst > > create mode 100644 drivers/vdpa/vdpa_user/Makefile > > create mode 100644 drivers/vdpa/vdpa_user/eventfd.c > > create mode 100644 drivers/vdpa/vdpa_user/eventfd.h > > create mode 100644 drivers/vdpa/vdpa_user/iova_domain.c > > create mode 100644 drivers/vdpa/vdpa_user/iova_domain.h > > create mode 100644 drivers/vdpa/vdpa_user/vduse.h > > create mode 100644 drivers/vdpa/vdpa_user/vduse_dev.c > > create mode 100644 include/uapi/linux/vduse.h > > > > diff --git a/Documentation/driver-api/vduse.rst b/Documentation/driver-= api/vduse.rst > > new file mode 100644 > > index 000000000000..9418a7f6646b > > --- /dev/null > > +++ b/Documentation/driver-api/vduse.rst > > @@ -0,0 +1,85 @@ > > +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > > +VDUSE - "vDPA Device in Userspace" > > +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > > + > > +vDPA (virtio data path acceleration) device is a device that uses a > > +datapath which complies with the virtio specifications with vendor > > +specific control path. vDPA devices can be both physically located on > > +the hardware or emulated by software. VDUSE is a framework that makes = it > > +possible to implement software-emulated vDPA devices in userspace. > > + > > +How VDUSE works > > +------------ > > +Each userspace vDPA device is created by the VDUSE_CREATE_DEV ioctl on > > +the VDUSE character device (/dev/vduse). Then a file descriptor pointi= ng > > +to the new resources will be returned, which can be used to implement = the > > +userspace vDPA device's control path and data path. > > + > > +To implement control path, the read/write operations to the file descr= iptor > > +will be used to receive/reply the control messages from/to VDUSE drive= r. > > > It's better to document the protocol here. E.g the identifier stuffs. > I have documented those stuffs in include/uapi/linux/vduse.h, is it OK? Or add something like "Please see include/uapi/linux/vduse.h for details." > > > +Those control messages are mostly based on the vdpa_config_ops which d= efines > > +a unified interface to control different types of vDPA device. > > + > > +The following types of messages are provided by the VDUSE framework no= w: > > + > > +- VDUSE_SET_VQ_ADDR: Set the addresses of the different aspects of vir= tqueue. > > > "Set the vring address of a virtqueue" might be better here. > OK. > > > + > > +- VDUSE_SET_VQ_NUM: Set the size of virtqueue > > + > > +- VDUSE_SET_VQ_READY: Set ready status of virtqueue > > + > > +- VDUSE_GET_VQ_READY: Get ready status of virtqueue > > + > > +- VDUSE_SET_VQ_STATE: Set the state (last_avail_idx) for virtqueue > > + > > +- VDUSE_GET_VQ_STATE: Get the state (last_avail_idx) for virtqueue > > > It's better not to mention layout specific stuffs here (last_avail_idx). > Consider we should support packed virtqueue in the future. > I see. > > > + > > +- VDUSE_SET_FEATURES: Set virtio features supported by the driver > > + > > +- VDUSE_GET_FEATURES: Get virtio features supported by the device > > + > > +- VDUSE_SET_STATUS: Set the device status > > + > > +- VDUSE_GET_STATUS: Get the device status > > + > > +- VDUSE_SET_CONFIG: Write to device specific configuration space > > + > > +- VDUSE_GET_CONFIG: Read from device specific configuration space > > + > > +- VDUSE_UPDATE_IOTLB: Notify userspace to update the memory mapping in= device IOTLB > > + > > +Please see include/linux/vdpa.h for details. > > + > > +In the data path, vDPA device's iova regions will be mapped into users= pace with > > +the help of VDUSE_IOTLB_GET_FD ioctl on the userspace vDPA device fd: > > + > > +- VDUSE_IOTLB_GET_FD: get the file descriptor to iova region. Userspac= e can > > + access this iova region by passing the fd to mmap(2). > > + > > +Besides, the eventfd mechanism is used to trigger interrupt callbacks = and > > +receive virtqueue kicks in userspace. The following ioctls on the user= space > > +vDPA device fd are provided to support that: > > + > > +- VDUSE_VQ_SETUP_KICKFD: set the kickfd for virtqueue, this eventfd is= used > > + by VDUSE driver to notify userspace to consume the vring. > > + > > +- VDUSE_VQ_SETUP_IRQFD: set the irqfd for virtqueue, this eventfd is u= sed > > + by userspace to notify VDUSE driver to trigger interrupt callbacks. > > + > > +MMU-based IOMMU Driver > > +---------------------- > > +In virtio-vdpa case, VDUSE framework implements a MMU-based on-chip IO= MMU > > +driver to support mapping the kernel dma buffer into the userspace iov= a > > +region dynamically. > > + > > +The basic idea behind this driver is treating MMU (VA->PA) as IOMMU (I= OVA->PA). > > +The driver will set up MMU mapping instead of IOMMU mapping for the DM= A transfer > > +so that the userspace process is able to use its virtual address to ac= cess > > +the dma buffer in kernel. > > + > > +And to avoid security issue, a bounce-buffering mechanism is introduce= d to > > +prevent userspace accessing the original buffer directly which may con= tain other > > +kernel data. During the mapping, unmapping, the driver will copy the d= ata from > > +the original buffer to the bounce buffer and back, depending on the di= rection of > > +the transfer. And the bounce-buffer addresses will be mapped into the = user address > > +space instead of the original one. > > 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 4be7be39be26..667354309bf4 100644 > > --- a/drivers/vdpa/Kconfig > > +++ b/drivers/vdpa/Kconfig > > @@ -21,6 +21,13 @@ config VDPA_SIM > > to RX. This device is used for testing, prototyping and > > development of vDPA. > > > > +config VDPA_USER > > + tristate "VDUSE (vDPA Device in Userspace) support" > > + depends on EVENTFD && MMU && HAS_DMA > > > Need select VHOST_IOTLB. > OK. > > > + 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 d160e9b63a66..66e97778ad03 100644 > > --- a/drivers/vdpa/Makefile > > +++ b/drivers/vdpa/Makefile > > @@ -1,5 +1,6 @@ > > # 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-$(CONFIG_MLX5_VDPA) +=3D mlx5/ > > diff --git a/drivers/vdpa/vdpa_user/Makefile b/drivers/vdpa/vdpa_user/M= akefile > > new file mode 100644 > > index 000000000000..b7645e36992b > > --- /dev/null > > +++ b/drivers/vdpa/vdpa_user/Makefile > > @@ -0,0 +1,5 @@ > > +# SPDX-License-Identifier: GPL-2.0 > > + > > +vduse-y :=3D vduse_dev.o iova_domain.o eventfd.o > > + > > +obj-$(CONFIG_VDPA_USER) +=3D vduse.o > > diff --git a/drivers/vdpa/vdpa_user/eventfd.c b/drivers/vdpa/vdpa_user/= eventfd.c > > new file mode 100644 > > index 000000000000..dbffddb08908 > > --- /dev/null > > +++ b/drivers/vdpa/vdpa_user/eventfd.c > > @@ -0,0 +1,221 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > +/* > > + * Eventfd support for VDUSE > > + * > > + * Copyright (C) 2020 Bytedance Inc. and/or its affiliates. All rights= reserved. > > + * > > + * Author: Xie Yongji > > + * > > + */ > > + > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > + > > +#include "eventfd.h" > > + > > +static struct workqueue_struct *vduse_irqfd_cleanup_wq; > > + > > +static void vduse_virqfd_shutdown(struct work_struct *work) > > +{ > > + u64 cnt; > > + struct vduse_virqfd *virqfd =3D container_of(work, > > + struct vduse_virqfd, shutdown); > > + > > + eventfd_ctx_remove_wait_queue(virqfd->ctx, &virqfd->wait, &cnt); > > + flush_work(&virqfd->inject); > > + eventfd_ctx_put(virqfd->ctx); > > + kfree(virqfd); > > +} > > + > > +static void vduse_virqfd_inject(struct work_struct *work) > > +{ > > + struct vduse_virqfd *virqfd =3D container_of(work, > > + struct vduse_virqfd, inject); > > + struct vduse_virtqueue *vq =3D virqfd->vq; > > + > > + spin_lock_irq(&vq->irq_lock); > > + if (vq->ready && vq->cb) > > + vq->cb(vq->private); > > + spin_unlock_irq(&vq->irq_lock); > > +} > > + > > +static void virqfd_deactivate(struct vduse_virqfd *virqfd) > > +{ > > + queue_work(vduse_irqfd_cleanup_wq, &virqfd->shutdown); > > +} > > + > > +static int vduse_virqfd_wakeup(wait_queue_entry_t *wait, unsigned int = mode, > > + int sync, void *key) > > +{ > > + struct vduse_virqfd *virqfd =3D container_of(wait, struct vduse_v= irqfd, wait); > > + struct vduse_virtqueue *vq =3D virqfd->vq; > > + > > + __poll_t flags =3D key_to_poll(key); > > + > > + if (flags & EPOLLIN) > > + schedule_work(&virqfd->inject); > > + > > + if (flags & EPOLLHUP) { > > + spin_lock(&vq->irq_lock); > > + if (vq->virqfd =3D=3D virqfd) { > > + vq->virqfd =3D NULL; > > + virqfd_deactivate(virqfd); > > + } > > + spin_unlock(&vq->irq_lock); > > + } > > + > > + return 0; > > +} > > + > > +static void vduse_virqfd_ptable_queue_proc(struct file *file, > > + wait_queue_head_t *wqh, poll_table *pt) > > +{ > > + struct vduse_virqfd *virqfd =3D container_of(pt, struct vduse_vir= qfd, pt); > > + > > + add_wait_queue(wqh, &virqfd->wait); > > +} > > + > > +int vduse_virqfd_setup(struct vduse_dev *dev, > > + struct vduse_vq_eventfd *eventfd) > > +{ > > + struct vduse_virqfd *virqfd; > > + struct fd irqfd; > > + struct eventfd_ctx *ctx; > > + struct vduse_virtqueue *vq; > > + __poll_t events; > > + int ret; > > + > > + if (eventfd->index >=3D dev->vq_num) > > + return -EINVAL; > > + > > + vq =3D &dev->vqs[eventfd->index]; > > + virqfd =3D kzalloc(sizeof(*virqfd), GFP_KERNEL); > > + if (!virqfd) > > + return -ENOMEM; > > + > > + INIT_WORK(&virqfd->shutdown, vduse_virqfd_shutdown); > > + INIT_WORK(&virqfd->inject, vduse_virqfd_inject); > > + > > + ret =3D -EBADF; > > + irqfd =3D fdget(eventfd->fd); > > + if (!irqfd.file) > > + goto err_fd; > > + > > + ctx =3D eventfd_ctx_fileget(irqfd.file); > > + if (IS_ERR(ctx)) { > > + ret =3D PTR_ERR(ctx); > > + goto err_ctx; > > + } > > + > > + virqfd->vq =3D vq; > > + virqfd->ctx =3D ctx; > > + spin_lock(&vq->irq_lock); > > + if (vq->virqfd) > > + virqfd_deactivate(virqfd); > > + vq->virqfd =3D virqfd; > > + spin_unlock(&vq->irq_lock); > > + > > + init_waitqueue_func_entry(&virqfd->wait, vduse_virqfd_wakeup); > > + init_poll_funcptr(&virqfd->pt, vduse_virqfd_ptable_queue_proc); > > + > > + events =3D vfs_poll(irqfd.file, &virqfd->pt); > > + > > + /* > > + * Check if there was an event already pending on the eventfd > > + * before we registered and trigger it as if we didn't miss it. > > + */ > > + if (events & EPOLLIN) > > + schedule_work(&virqfd->inject); > > + > > + fdput(irqfd); > > + > > + return 0; > > +err_ctx: > > + fdput(irqfd); > > +err_fd: > > + kfree(virqfd); > > + return ret; > > +} > > + > > +void vduse_virqfd_release(struct vduse_dev *dev) > > +{ > > + int i; > > + > > + for (i =3D 0; i < dev->vq_num; i++) { > > + struct vduse_virtqueue *vq =3D &dev->vqs[i]; > > + > > + spin_lock(&vq->irq_lock); > > + if (vq->virqfd) { > > + virqfd_deactivate(vq->virqfd); > > + vq->virqfd =3D NULL; > > + } > > + spin_unlock(&vq->irq_lock); > > + } > > + flush_workqueue(vduse_irqfd_cleanup_wq); > > +} > > + > > +int vduse_virqfd_init(void) > > +{ > > + vduse_irqfd_cleanup_wq =3D alloc_workqueue("vduse-irqfd-cleanup", > > + WQ_UNBOUND, 0); > > + if (!vduse_irqfd_cleanup_wq) > > + return -ENOMEM; > > + > > + return 0; > > +} > > + > > +void vduse_virqfd_exit(void) > > +{ > > + destroy_workqueue(vduse_irqfd_cleanup_wq); > > +} > > + > > +void vduse_vq_kick(struct vduse_virtqueue *vq) > > +{ > > + spin_lock(&vq->kick_lock); > > + if (vq->ready && vq->kickfd) > > + eventfd_signal(vq->kickfd, 1); > > + spin_unlock(&vq->kick_lock); > > +} > > + > > +int vduse_kickfd_setup(struct vduse_dev *dev, > > + struct vduse_vq_eventfd *eventfd) > > +{ > > + struct eventfd_ctx *ctx; > > + struct vduse_virtqueue *vq; > > + > > + if (eventfd->index >=3D dev->vq_num) > > + return -EINVAL; > > + > > + vq =3D &dev->vqs[eventfd->index]; > > + ctx =3D eventfd_ctx_fdget(eventfd->fd); > > + if (IS_ERR(ctx)) > > + return PTR_ERR(ctx); > > + > > + spin_lock(&vq->kick_lock); > > + if (vq->kickfd) > > + eventfd_ctx_put(vq->kickfd); > > + vq->kickfd =3D ctx; > > + spin_unlock(&vq->kick_lock); > > + > > + return 0; > > +} > > + > > +void vduse_kickfd_release(struct vduse_dev *dev) > > +{ > > + 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); > > + } > > +} > > diff --git a/drivers/vdpa/vdpa_user/eventfd.h b/drivers/vdpa/vdpa_user/= eventfd.h > > new file mode 100644 > > index 000000000000..14269ff27f47 > > --- /dev/null > > +++ b/drivers/vdpa/vdpa_user/eventfd.h > > @@ -0,0 +1,48 @@ > > +/* SPDX-License-Identifier: GPL-2.0-only */ > > +/* > > + * Eventfd support for VDUSE > > + * > > + * Copyright (C) 2020 Bytedance Inc. and/or its affiliates. All rights= reserved. > > + * > > + * Author: Xie Yongji > > + * > > + */ > > + > > +#ifndef _VDUSE_EVENTFD_H > > +#define _VDUSE_EVENTFD_H > > + > > +#include > > +#include > > +#include > > +#include > > + > > +#include "vduse.h" > > + > > +struct vduse_dev; > > + > > +struct vduse_virqfd { > > + struct eventfd_ctx *ctx; > > + struct vduse_virtqueue *vq; > > + struct work_struct inject; > > + struct work_struct shutdown; > > + wait_queue_entry_t wait; > > + poll_table pt; > > +}; > > + > > +int vduse_virqfd_setup(struct vduse_dev *dev, > > + struct vduse_vq_eventfd *eventfd); > > + > > +void vduse_virqfd_release(struct vduse_dev *dev); > > + > > +int vduse_virqfd_init(void); > > + > > +void vduse_virqfd_exit(void); > > + > > +void vduse_vq_kick(struct vduse_virtqueue *vq); > > + > > +int vduse_kickfd_setup(struct vduse_dev *dev, > > + struct vduse_vq_eventfd *eventfd); > > + > > +void vduse_kickfd_release(struct vduse_dev *dev); > > + > > +#endif /* _VDUSE_EVENTFD_H */ > > diff --git a/drivers/vdpa/vdpa_user/iova_domain.c b/drivers/vdpa/vdpa_u= ser/iova_domain.c > > new file mode 100644 > > index 000000000000..cdfef8e9f9d6 > > --- /dev/null > > +++ b/drivers/vdpa/vdpa_user/iova_domain.c > > @@ -0,0 +1,426 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > +/* > > + * MMU-based IOMMU implementation > > + * > > + * Copyright (C) 2020 Bytedance Inc. and/or its affiliates. All rights= reserved. > > + * > > + * Author: Xie Yongji > > + * > > + */ > > + > > +#include > > +#include > > +#include > > + > > +#include "iova_domain.h" > > + > > +#define IOVA_START_PFN 1 > > +#define IOVA_ALLOC_ORDER 12 > > +#define IOVA_ALLOC_SIZE (1 << IOVA_ALLOC_ORDER) > > > Can this work for all archs (e.g why not use PAGE_SIZE)? > It can work for all archs. Use IOVA_ALLOC_SIZE might save some space in some cases/archs (e.g. PAGE_SIZE =3D 64K) when we have lots of small-size I/Os. > > > + > > +#define CONSISTENT_DMA_SIZE (1024 * 1024 * 1024) > > + > > +static inline struct page * > > +vduse_domain_get_bounce_page(struct vduse_iova_domain *domain, > > + unsigned long iova) > > +{ > > + unsigned long index =3D iova >> PAGE_SHIFT; > > + > > + return domain->bounce_pages[index]; > > +} > > + > > +static inline void > > +vduse_domain_set_bounce_page(struct vduse_iova_domain *domain, > > + unsigned long iova, struct page *page) > > +{ > > + unsigned long index =3D iova >> PAGE_SHIFT; > > + > > + domain->bounce_pages[index] =3D page; > > +} > > + > > +static struct vduse_iova_map * > > +vduse_domain_alloc_iova_map(struct vduse_iova_domain *domain, > > + unsigned long iova, unsigned long orig, > > + size_t size, enum dma_data_direction dir) > > +{ > > + struct vduse_iova_map *map; > > + > > + map =3D kzalloc(sizeof(struct vduse_iova_map), GFP_ATOMIC); > > + if (!map) > > + return NULL; > > + > > + map->iova.start =3D iova; > > + map->iova.last =3D iova + size - 1; > > + map->orig =3D orig; > > + map->size =3D size; > > + map->dir =3D dir; > > + > > + return map; > > +} > > + > > +static struct page * > > +vduse_domain_get_mapping_page(struct vduse_iova_domain *domain, > > + unsigned long iova) > > +{ > > + unsigned long start =3D iova & PAGE_MASK; > > + unsigned long last =3D start + PAGE_SIZE - 1; > > + struct vduse_iova_map *map; > > + struct interval_tree_node *node; > > + struct page *page =3D NULL; > > + > > + spin_lock(&domain->map_lock); > > + node =3D interval_tree_iter_first(&domain->mappings, start, last)= ; > > + if (!node) > > + goto out; > > + > > + map =3D container_of(node, struct vduse_iova_map, iova); > > + page =3D virt_to_page(map->orig + iova - map->iova.start); > > + get_page(page); > > +out: > > + spin_unlock(&domain->map_lock); > > + > > + return page; > > +} > > + > > +static struct page * > > +vduse_domain_alloc_bounce_page(struct vduse_iova_domain *domain, > > + unsigned long iova) > > +{ > > + unsigned long start =3D iova & PAGE_MASK; > > + unsigned long last =3D start + PAGE_SIZE - 1; > > + struct vduse_iova_map *map; > > + struct interval_tree_node *node; > > + struct page *page =3D NULL, *new_page =3D alloc_page(GFP_KERNEL); > > + > > + if (!new_page) > > + return NULL; > > + > > + spin_lock(&domain->map_lock); > > + node =3D interval_tree_iter_first(&domain->mappings, start, last)= ; > > + if (!node) { > > + __free_page(new_page); > > + goto out; > > + } > > + page =3D vduse_domain_get_bounce_page(domain, iova); > > + if (page) { > > + get_page(page); > > + __free_page(new_page); > > > Let's delay the allocation of new_page until it is really required. If so, we need to allocate the page in atomic context. > > > + goto out; > > + } > > + vduse_domain_set_bounce_page(domain, iova, new_page); > > + get_page(new_page); > > + page =3D new_page; > > + > > + while (node) { > > > I may miss something but which case should we do the loop here? > When IOVA_ALLOC_SIZE !=3D PAGE_SIZE > > > + unsigned int src_offset =3D 0, dst_offset =3D 0; > > + void *src, *dst; > > + size_t copy_len; > > + > > + map =3D container_of(node, struct vduse_iova_map, iova); > > + node =3D interval_tree_iter_next(node, start, last); > > + if (map->dir =3D=3D DMA_FROM_DEVICE) > > + continue; > > + > > + if (start > map->iova.start) > > + src_offset =3D start - map->iova.start; > > + else > > + dst_offset =3D map->iova.start - start; > > + > > + src =3D (void *)(map->orig + src_offset); > > + dst =3D page_address(page) + dst_offset; > > + copy_len =3D min_t(size_t, map->size - src_offset, > > + PAGE_SIZE - dst_offset); > > + memcpy(dst, src, copy_len); > > + } > > +out: > > + spin_unlock(&domain->map_lock); > > + > > + return page; > > +} > > + > > +static void > > +vduse_domain_free_bounce_pages(struct vduse_iova_domain *domain, > > + unsigned long iova, size_t size) > > +{ > > + struct page *page; > > + struct interval_tree_node *node; > > + unsigned long last =3D iova + size - 1; > > + > > + spin_lock(&domain->map_lock); > > + node =3D interval_tree_iter_first(&domain->mappings, iova, last); > > + if (WARN_ON(node)) > > + goto out; > > + > > + while (size > 0) { > > + page =3D vduse_domain_get_bounce_page(domain, iova); > > + if (page) { > > + vduse_domain_set_bounce_page(domain, iova, NULL); > > + __free_page(page); > > + } > > + size -=3D PAGE_SIZE; > > + iova +=3D PAGE_SIZE; > > + } > > +out: > > + spin_unlock(&domain->map_lock); > > +} > > + > > +static void vduse_domain_bounce(struct vduse_iova_domain *domain, > > + unsigned long iova, unsigned long orig, > > + size_t size, enum dma_data_direction dir) > > +{ > > + unsigned int offset =3D offset_in_page(iova); > > + > > + while (size) { > > + struct page *p =3D vduse_domain_get_bounce_page(domain, i= ova); > > + size_t copy_len =3D min_t(size_t, PAGE_SIZE - offset, siz= e); > > + void *addr; > > + > > + WARN_ON(!p && dir =3D=3D DMA_FROM_DEVICE); > > + > > + if (p) { > > + addr =3D page_address(p) + offset; > > + if (dir =3D=3D DMA_TO_DEVICE) > > + memcpy(addr, (void *)orig, copy_len); > > + else if (dir =3D=3D DMA_FROM_DEVICE) > > + memcpy((void *)orig, addr, copy_len); > > + } > > + > > + size -=3D copy_len; > > + orig +=3D copy_len; > > + iova +=3D copy_len; > > + offset =3D 0; > > + } > > +} > > + > > +static unsigned long vduse_domain_alloc_iova(struct iova_domain *iovad= , > > + unsigned long size, unsigned long limit) > > +{ > > + unsigned long shift =3D iova_shift(iovad); > > + unsigned long iova_len =3D iova_align(iovad, size) >> shift; > > + unsigned long iova_pfn; > > + > > + if (iova_len < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1))) > > + iova_len =3D roundup_pow_of_two(iova_len); > > + iova_pfn =3D alloc_iova_fast(iovad, iova_len, limit >> shift, tru= e); > > + > > + return iova_pfn << shift; > > +} > > + > > +static void vduse_domain_free_iova(struct iova_domain *iovad, > > + unsigned long iova, size_t size) > > +{ > > + unsigned long shift =3D iova_shift(iovad); > > + unsigned long iova_len =3D iova_align(iovad, size) >> shift; > > + > > + free_iova_fast(iovad, iova >> shift, iova_len); > > +} > > + > > +dma_addr_t vduse_domain_map_page(struct vduse_iova_domain *domain, > > + struct page *page, unsigned long offset, > > + size_t size, enum dma_data_direction dir, > > + unsigned long attrs) > > +{ > > + struct iova_domain *iovad =3D &domain->stream_iovad; > > + unsigned long limit =3D domain->bounce_size - 1; > > + unsigned long iova =3D vduse_domain_alloc_iova(iovad, size, limit= ); > > + unsigned long orig =3D (unsigned long)page_address(page) + offset= ; > > + struct vduse_iova_map *map; > > + > > + if (!iova) > > + return DMA_MAPPING_ERROR; > > + > > + map =3D vduse_domain_alloc_iova_map(domain, iova, orig, size, dir= ); > > + if (!map) { > > + vduse_domain_free_iova(iovad, iova, size); > > + return DMA_MAPPING_ERROR; > > + } > > + > > + spin_lock(&domain->map_lock); > > + interval_tree_insert(&map->iova, &domain->mappings); > > + spin_unlock(&domain->map_lock); > > + > > + if (dir =3D=3D DMA_TO_DEVICE || dir =3D=3D DMA_BIDIRECTIONAL) > > + vduse_domain_bounce(domain, iova, orig, size, DMA_TO_DEVI= CE); > > + > > + return (dma_addr_t)iova; > > +} > > + > > +void vduse_domain_unmap_page(struct vduse_iova_domain *domain, > > + dma_addr_t dma_addr, size_t size, > > + enum dma_data_direction dir, unsigned long attrs) > > +{ > > + struct iova_domain *iovad =3D &domain->stream_iovad; > > + unsigned long iova =3D (unsigned long)dma_addr; > > + struct interval_tree_node *node; > > + struct vduse_iova_map *map; > > + > > + spin_lock(&domain->map_lock); > > + node =3D interval_tree_iter_first(&domain->mappings, iova, iova += 1); > > + if (WARN_ON(!node)) { > > + spin_unlock(&domain->map_lock); > > + return; > > + } > > + interval_tree_remove(node, &domain->mappings); > > + spin_unlock(&domain->map_lock); > > + > > + map =3D container_of(node, struct vduse_iova_map, iova); > > + if (dir =3D=3D DMA_FROM_DEVICE || dir =3D=3D DMA_BIDIRECTIONAL) > > + vduse_domain_bounce(domain, iova, map->orig, > > + size, DMA_FROM_DEVICE); > > + vduse_domain_free_iova(iovad, iova, size); > > + kfree(map); > > +} > > + > > +void *vduse_domain_alloc_coherent(struct vduse_iova_domain *domain, > > + size_t size, dma_addr_t *dma_addr, > > + gfp_t flag, unsigned long attrs) > > +{ > > + struct iova_domain *iovad =3D &domain->consistent_iovad; > > + unsigned long limit =3D domain->bounce_size + CONSISTENT_DMA_SIZE= - 1; > > + unsigned long iova =3D vduse_domain_alloc_iova(iovad, size, limit= ); > > + void *orig =3D alloc_pages_exact(size, flag); > > + struct vduse_iova_map *map; > > + > > + if (!iova || !orig) > > + goto err; > > + > > + map =3D vduse_domain_alloc_iova_map(domain, iova, (unsigned long)= orig, > > + size, DMA_BIDIRECTIONAL); > > + if (!map) > > + goto err; > > + > > + spin_lock(&domain->map_lock); > > + interval_tree_insert(&map->iova, &domain->mappings); > > + spin_unlock(&domain->map_lock); > > + *dma_addr =3D (dma_addr_t)iova; > > + > > + return orig; > > +err: > > + *dma_addr =3D DMA_MAPPING_ERROR; > > + if (orig) > > + free_pages_exact(orig, size); > > + if (iova) > > + vduse_domain_free_iova(iovad, iova, size); > > + > > + return NULL; > > +} > > + > > +void vduse_domain_free_coherent(struct vduse_iova_domain *domain, size= _t size, > > + void *vaddr, dma_addr_t dma_addr, > > + unsigned long attrs) > > +{ > > + struct iova_domain *iovad =3D &domain->consistent_iovad; > > + unsigned long iova =3D (unsigned long)dma_addr; > > + struct interval_tree_node *node; > > + struct vduse_iova_map *map; > > + > > + spin_lock(&domain->map_lock); > > + node =3D interval_tree_iter_first(&domain->mappings, iova, iova += 1); > > + if (WARN_ON(!node)) { > > + spin_unlock(&domain->map_lock); > > + return; > > + } > > + interval_tree_remove(node, &domain->mappings); > > + spin_unlock(&domain->map_lock); > > + > > + map =3D container_of(node, struct vduse_iova_map, iova); > > + vduse_domain_free_iova(iovad, iova, size); > > + free_pages_exact(vaddr, size); > > + kfree(map); > > +} > > + > > +static vm_fault_t vduse_domain_mmap_fault(struct vm_fault *vmf) > > +{ > > + struct vduse_iova_domain *domain =3D vmf->vma->vm_private_data; > > + unsigned long iova =3D vmf->pgoff << PAGE_SHIFT; > > + struct page *page; > > + > > + if (!domain) > > + return VM_FAULT_SIGBUS; > > + > > + if (iova < domain->bounce_size) > > + page =3D vduse_domain_alloc_bounce_page(domain, iova); > > + else > > + page =3D vduse_domain_get_mapping_page(domain, iova); > > + > > + if (!page) > > + return VM_FAULT_SIGBUS; > > + > > + vmf->page =3D page; > > + > > + return 0; > > +} > > + > > +static const struct vm_operations_struct vduse_domain_mmap_ops =3D { > > + .fault =3D vduse_domain_mmap_fault, > > +}; > > + > > +static int vduse_domain_mmap(struct file *file, struct vm_area_struct = *vma) > > +{ > > + struct vduse_iova_domain *domain =3D file->private_data; > > + > > + vma->vm_flags |=3D VM_DONTCOPY | VM_DONTDUMP | VM_DONTEXPAND; > > + vma->vm_private_data =3D domain; > > + vma->vm_ops =3D &vduse_domain_mmap_ops; > > + > > + return 0; > > +} > > + > > +static int vduse_domain_release(struct inode *inode, struct file *file= ) > > +{ > > + struct vduse_iova_domain *domain =3D file->private_data; > > + > > + vduse_domain_free_bounce_pages(domain, 0, domain->bounce_size); > > + put_iova_domain(&domain->stream_iovad); > > + put_iova_domain(&domain->consistent_iovad); > > + vfree(domain->bounce_pages); > > + kfree(domain); > > + > > + return 0; > > +} > > + > > +static const struct file_operations vduse_domain_fops =3D { > > + .mmap =3D vduse_domain_mmap, > > + .release =3D vduse_domain_release, > > +}; > > > It's better to explain the reason for introducing a dedicated file for > mmap() here. > To make the implementation of iova_domain independent with vduse_dev. > > > + > > +void vduse_domain_destroy(struct vduse_iova_domain *domain) > > +{ > > + fput(domain->file); > > +} > > + > > +struct vduse_iova_domain *vduse_domain_create(size_t bounce_size) > > +{ > > + struct vduse_iova_domain *domain; > > + struct file *file; > > + unsigned long bounce_pfns =3D PAGE_ALIGN(bounce_size) >> PAGE_SHI= FT; > > + > > + domain =3D kzalloc(sizeof(*domain), GFP_KERNEL); > > + if (!domain) > > + return NULL; > > + > > + domain->bounce_size =3D PAGE_ALIGN(bounce_size); > > + domain->bounce_pages =3D vzalloc(bounce_pfns * sizeof(struct page= *)); > > + if (!domain->bounce_pages) > > + goto err_page; > > + > > + file =3D anon_inode_getfile("[vduse-domain]", &vduse_domain_fops, > > + domain, O_RDWR); > > + if (IS_ERR(file)) > > + goto err_file; > > + > > + domain->file =3D file; > > + spin_lock_init(&domain->map_lock); > > + domain->mappings =3D RB_ROOT_CACHED; > > + init_iova_domain(&domain->stream_iovad, > > + IOVA_ALLOC_SIZE, IOVA_START_PFN); > > + init_iova_domain(&domain->consistent_iovad, > > + PAGE_SIZE, bounce_pfns); > > + > > + return domain; > > +err_file: > > + vfree(domain->bounce_pages); > > +err_page: > > + kfree(domain); > > + return NULL; > > +} > > diff --git a/drivers/vdpa/vdpa_user/iova_domain.h b/drivers/vdpa/vdpa_u= ser/iova_domain.h > > new file mode 100644 > > index 000000000000..cc61866acb56 > > --- /dev/null > > +++ b/drivers/vdpa/vdpa_user/iova_domain.h > > @@ -0,0 +1,68 @@ > > +/* SPDX-License-Identifier: GPL-2.0-only */ > > +/* > > + * MMU-based IOMMU implementation > > + * > > + * Copyright (C) 2020 Bytedance Inc. and/or its affiliates. All rights= reserved. > > + * > > + * Author: Xie Yongji > > + * > > + */ > > + > > +#ifndef _VDUSE_IOVA_DOMAIN_H > > +#define _VDUSE_IOVA_DOMAIN_H > > + > > +#include > > +#include > > +#include > > + > > +struct vduse_iova_map { > > + struct interval_tree_node iova; > > + unsigned long orig; > > > Need a better name, probably "va"? > Fine. > > > + size_t size; > > + enum dma_data_direction dir; > > +}; > > + > > +struct vduse_iova_domain { > > + struct iova_domain stream_iovad; > > + struct iova_domain consistent_iovad; > > + struct page **bounce_pages; > > + size_t bounce_size; > > + struct rb_root_cached mappings; > > > We had IOTLB, any reason for this extra mappings here? > It is used to store iova <-> vduse_iova_map (vaddr, size, dir) mapping. We must use it to know how to do DMA bouncing during dma unmapping. > > > + spinlock_t map_lock; > > + struct file *file; > > +}; > > + > > +static inline struct file * > > +vduse_domain_file(struct vduse_iova_domain *domain) > > +{ > > + return domain->file; > > +} > > + > > +static inline unsigned long > > +vduse_domain_get_offset(struct vduse_iova_domain *domain, unsigned lon= g iova) > > +{ > > + return iova; > > +} > > + > > +dma_addr_t vduse_domain_map_page(struct vduse_iova_domain *domain, > > + struct page *page, unsigned long offset, > > + size_t size, enum dma_data_direction dir, > > + unsigned long attrs); > > + > > +void vduse_domain_unmap_page(struct vduse_iova_domain *domain, > > + dma_addr_t dma_addr, size_t size, > > + enum dma_data_direction dir, unsigned long attrs)= ; > > + > > +void *vduse_domain_alloc_coherent(struct vduse_iova_domain *domain, > > + size_t size, dma_addr_t *dma_addr, > > + gfp_t flag, unsigned long attrs); > > + > > +void vduse_domain_free_coherent(struct vduse_iova_domain *domain, size= _t size, > > + void *vaddr, dma_addr_t dma_addr, > > + unsigned long attrs); > > + > > +void vduse_domain_destroy(struct vduse_iova_domain *domain); > > + > > +struct vduse_iova_domain *vduse_domain_create(size_t bounce_size); > > + > > +#endif /* _VDUSE_IOVA_DOMAIN_H */ > > diff --git a/drivers/vdpa/vdpa_user/vduse.h b/drivers/vdpa/vdpa_user/vd= use.h > > new file mode 100644 > > index 000000000000..3566d229382e > > --- /dev/null > > +++ b/drivers/vdpa/vdpa_user/vduse.h > > @@ -0,0 +1,62 @@ > > +/* SPDX-License-Identifier: GPL-2.0-only */ > > +/* > > + * VDUSE: vDPA Device in Userspace > > + * > > + * Copyright (C) 2020 Bytedance Inc. and/or its affiliates. All rights= reserved. > > + * > > + * Author: Xie Yongji > > + * > > + */ > > + > > +#ifndef _VDUSE_H > > +#define _VDUSE_H > > + > > +#include > > +#include > > +#include > > + > > +#include "iova_domain.h" > > +#include "eventfd.h" > > + > > +struct vduse_virtqueue { > > + u16 index; > > + bool ready; > > + spinlock_t kick_lock; > > + spinlock_t irq_lock; > > + struct eventfd_ctx *kickfd; > > + struct vduse_virqfd *virqfd; > > + void *private; > > + irqreturn_t (*cb)(void *data); > > +}; > > + > > +struct vduse_dev; > > + > > +struct vduse_vdpa { > > + struct vdpa_device vdpa; > > + struct vduse_dev *dev; > > +}; > > + > > +struct vduse_dev { > > + struct vduse_vdpa *vdev; > > + struct mutex lock; > > + struct vduse_virtqueue *vqs; > > + struct vduse_iova_domain *domain; > > + struct vhost_iotlb *iommu; > > + spinlock_t iommu_lock; > > + atomic_t bounce_map; > > + 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; > > + u32 id; > > + u16 vq_size_max; > > + u16 vq_num; > > + u32 vq_align; > > + u32 device_id; > > + u32 vendor_id; > > +}; > > + > > +#endif /* _VDUSE_H_ */ > > 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..1cf759bc5914 > > --- /dev/null > > +++ b/drivers/vdpa/vdpa_user/vduse_dev.c > > @@ -0,0 +1,1217 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > +/* > > + * VDUSE: vDPA Device in Userspace > > + * > > + * Copyright (C) 2020 Bytedance Inc. and/or its affiliates. All rights= reserved. > > + * > > + * Author: Xie Yongji > > + * > > + */ > > + > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > + > > +#include "vduse.h" > > + > > +#define DRV_VERSION "1.0" > > +#define DRV_AUTHOR "Yongji Xie " > > +#define DRV_DESC "vDPA Device in Userspace" > > +#define DRV_LICENSE "GPL v2" > > + > > +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; > > + refcount_t refcnt; > > > The reference count here will bring extra complexity. I think we can > sync through msg_lock. > Do you mean using wait_event_interruptible_locked() and wake_up_locked()? I think it works. > > > > +}; > > + > > +static struct workqueue_struct *vduse_vdpa_wq; > > +static DEFINE_MUTEX(vduse_lock); > > +static LIST_HEAD(vduse_devs); > > + > > +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_dev_new_msg(struct vduse_dev *dev, = int type) > > +{ > > + struct vduse_dev_msg *msg =3D kzalloc(sizeof(*msg), > > + GFP_KERNEL | __GFP_NOFAIL); > > + > > + msg->req.type =3D type; > > + msg->req.unique =3D atomic64_fetch_inc(&dev->msg_unique); > > > This looks not safe, let's use idr here. > Could you give more details? Looks like idr should not used in this case which can not tolerate failure. And using a list to store the msg is better than using idr when the msg needs to be re-inserted in some cases. > > > + init_waitqueue_head(&msg->waitq); > > + refcount_set(&msg->refcnt, 1); > > + > > + return msg; > > +} > > + > > +static void vduse_dev_msg_get(struct vduse_dev_msg *msg) > > +{ > > + refcount_inc(&msg->refcnt); > > +} > > + > > +static void vduse_dev_msg_put(struct vduse_dev_msg *msg) > > +{ > > + if (refcount_dec_and_test(&msg->refcnt)) > > + kfree(msg); > > +} > > + > > +static struct vduse_dev_msg *vduse_dev_find_msg(struct vduse_dev *dev, > > + struct list_head *head, > > + uint32_t unique) > > +{ > > + struct vduse_dev_msg *tmp, *msg =3D NULL; > > + > > + spin_lock(&dev->msg_lock); > > + list_for_each_entry(tmp, head, list) { > > + if (tmp->req.unique =3D=3D unique) { > > + msg =3D tmp; > > + list_del(&tmp->list); > > + break; > > + } > > + } > > + spin_unlock(&dev->msg_lock); > > + > > + return msg; > > +} > > + > > +static struct vduse_dev_msg *vduse_dev_dequeue_msg(struct vduse_dev *d= ev, > > + struct list_head *head) > > +{ > > + struct vduse_dev_msg *msg =3D NULL; > > + > > + spin_lock(&dev->msg_lock); > > + if (!list_empty(head)) { > > + msg =3D list_first_entry(head, struct vduse_dev_msg, list= ); > > + list_del(&msg->list); > > + } > > + spin_unlock(&dev->msg_lock); > > + > > + return msg; > > +} > > + > > +static void vduse_dev_enqueue_msg(struct vduse_dev *dev, > > + struct vduse_dev_msg *msg, struct list_head *head= ) > > +{ > > + spin_lock(&dev->msg_lock); > > + list_add_tail(&msg->list, head); > > + spin_unlock(&dev->msg_lock); > > +} > > + > > +static int vduse_dev_msg_sync(struct vduse_dev *dev, struct vduse_dev_= msg *msg) > > +{ > > + int ret; > > + > > + vduse_dev_enqueue_msg(dev, msg, &dev->send_list); > > + wake_up(&dev->waitq); > > + wait_event(msg->waitq, msg->completed); > > > This is uninterruptible wait, it means if the userspace forget to > process the command, we will stuck here forever. > Yes, wait_event_interruptible() should be better here. > > > + /* coupled with smp_wmb() in vduse_dev_msg_complete() */ > > + smp_rmb(); > > > Instead of using barriers, I wonder why not simply use msg lock here? > As mentioned above, using wait_event_interruptible_locked()/wake_up_locked() is OK to me. > > > + ret =3D msg->resp.result; > > + > > + return ret; > > +} > > + > > +static void vduse_dev_msg_complete(struct vduse_dev_msg *msg, > > + struct vduse_dev_response *resp) > > +{ > > + vduse_dev_msg_get(msg); > > + memcpy(&msg->resp, resp, sizeof(*resp)); > > + /* coupled with smp_rmb() in vduse_dev_msg_sync() */ > > + smp_wmb(); > > + msg->completed =3D 1; > > + wake_up(&msg->waitq); > > + vduse_dev_msg_put(msg); > > +} > > + > > +static u64 vduse_dev_get_features(struct vduse_dev *dev) > > +{ > > + struct vduse_dev_msg *msg =3D vduse_dev_new_msg(dev, VDUSE_GET_FE= ATURES); > > + u64 features; > > + > > + vduse_dev_msg_sync(dev, msg); > > + features =3D msg->resp.features; > > + vduse_dev_msg_put(msg); > > + > > + return features; > > +} > > + > > +static int vduse_dev_set_features(struct vduse_dev *dev, u64 features) > > +{ > > + struct vduse_dev_msg *msg =3D vduse_dev_new_msg(dev, VDUSE_SET_FE= ATURES); > > + int ret; > > + > > + msg->req.size =3D sizeof(features); > > + msg->req.features =3D features; > > + > > + ret =3D vduse_dev_msg_sync(dev, msg); > > + vduse_dev_msg_put(msg); > > + > > + return ret; > > +} > > + > > +static u8 vduse_dev_get_status(struct vduse_dev *dev) > > +{ > > + struct vduse_dev_msg *msg =3D vduse_dev_new_msg(dev, VDUSE_GET_ST= ATUS); > > + u8 status; > > + > > + vduse_dev_msg_sync(dev, msg); > > + status =3D msg->resp.status; > > + vduse_dev_msg_put(msg); > > + > > + return status; > > +} > > + > > +static void vduse_dev_set_status(struct vduse_dev *dev, u8 status) > > +{ > > + struct vduse_dev_msg *msg =3D vduse_dev_new_msg(dev, VDUSE_SET_ST= ATUS); > > + > > + msg->req.size =3D sizeof(status); > > + msg->req.status =3D status; > > + > > + vduse_dev_msg_sync(dev, msg); > > + vduse_dev_msg_put(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 vduse_dev_new_msg(dev, VDUSE_GET_CO= NFIG); > > + > > + WARN_ON(len > sizeof(msg->req.config.data)); > > + > > + msg->req.size =3D sizeof(struct vduse_dev_config_data); > > + msg->req.config.offset =3D offset; > > + msg->req.config.len =3D len; > > + vduse_dev_msg_sync(dev, msg); > > + memcpy(buf, msg->resp.config.data, len); > > + vduse_dev_msg_put(msg); > > +} > > + > > +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 vduse_dev_new_msg(dev, VDUSE_SET_CO= NFIG); > > + > > + WARN_ON(len > sizeof(msg->req.config.data)); > > + > > + msg->req.size =3D sizeof(struct vduse_dev_config_data); > > + msg->req.config.offset =3D offset; > > + msg->req.config.len =3D len; > > + memcpy(msg->req.config.data, buf, len); > > + vduse_dev_msg_sync(dev, msg); > > + vduse_dev_msg_put(msg); > > +} > > + > > +static void vduse_dev_set_vq_num(struct vduse_dev *dev, > > + struct vduse_virtqueue *vq, u32 num) > > +{ > > + struct vduse_dev_msg *msg =3D vduse_dev_new_msg(dev, VDUSE_SET_VQ= _NUM); > > + > > + msg->req.size =3D sizeof(struct vduse_vq_num); > > + msg->req.vq_num.index =3D vq->index; > > + msg->req.vq_num.num =3D num; > > + > > + vduse_dev_msg_sync(dev, msg); > > + vduse_dev_msg_put(msg); > > +} > > + > > +static int vduse_dev_set_vq_addr(struct vduse_dev *dev, > > + struct vduse_virtqueue *vq, u64 desc_addr= , > > + u64 driver_addr, u64 device_addr) > > +{ > > + struct vduse_dev_msg *msg =3D vduse_dev_new_msg(dev, VDUSE_SET_VQ= _ADDR); > > + int ret; > > + > > + msg->req.size =3D sizeof(struct vduse_vq_addr); > > + 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; > > + > > + ret =3D vduse_dev_msg_sync(dev, msg); > > + vduse_dev_msg_put(msg); > > + > > + return ret; > > +} > > + > > +static void vduse_dev_set_vq_ready(struct vduse_dev *dev, > > + struct vduse_virtqueue *vq, bool ready) > > +{ > > + struct vduse_dev_msg *msg =3D vduse_dev_new_msg(dev, VDUSE_SET_VQ= _READY); > > + > > + msg->req.size =3D sizeof(struct vduse_vq_ready); > > + msg->req.vq_ready.index =3D vq->index; > > + msg->req.vq_ready.ready =3D ready; > > + > > + vduse_dev_msg_sync(dev, msg); > > + vduse_dev_msg_put(msg); > > +} > > + > > +static bool vduse_dev_get_vq_ready(struct vduse_dev *dev, > > + struct vduse_virtqueue *vq) > > +{ > > + struct vduse_dev_msg *msg =3D vduse_dev_new_msg(dev, VDUSE_GET_VQ= _READY); > > + bool ready; > > + > > + msg->req.size =3D sizeof(struct vduse_vq_ready); > > + msg->req.vq_ready.index =3D vq->index; > > + > > + vduse_dev_msg_sync(dev, msg); > > + ready =3D msg->resp.vq_ready.ready; > > + vduse_dev_msg_put(msg); > > + > > + return 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 vduse_dev_new_msg(dev, VDUSE_GET_VQ= _STATE); > > + int ret; > > + > > + msg->req.size =3D sizeof(struct vduse_vq_state); > > + msg->req.vq_state.index =3D vq->index; > > + > > + ret =3D vduse_dev_msg_sync(dev, msg); > > + state->avail_index =3D msg->resp.vq_state.avail_idx; > > + vduse_dev_msg_put(msg); > > + > > + 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 vduse_dev_new_msg(dev, VDUSE_SET_VQ= _STATE); > > + int ret; > > + > > + msg->req.size =3D sizeof(struct vduse_vq_state); > > + msg->req.vq_state.index =3D vq->index; > > + msg->req.vq_state.avail_idx =3D state->avail_index; > > + > > + ret =3D vduse_dev_msg_sync(dev, msg); > > + vduse_dev_msg_put(msg); > > + > > + return ret; > > +} > > + > > +static int vduse_dev_update_iotlb(struct vduse_dev *dev, > > + u64 start, u64 last) > > +{ > > + struct vduse_dev_msg *msg; > > + int ret; > > + > > + if (last < start) > > + return -EINVAL; > > + > > + msg =3D vduse_dev_new_msg(dev, VDUSE_UPDATE_IOTLB); > > > This is actually a IOTLB invalidation. So let's rename the function and > message type. > Actually VDUSE_UPDATE_IOTLB now is used to notify userspace that IOTLB is changed rather than IOTLB needs to be invalidated. Then userspace can use GET_IOTLB ioctl to get the change. It seems to be more friendly to userspace. > > > + msg->req.size =3D sizeof(struct vduse_iova_range); > > + msg->req.iova.start =3D start; > > + msg->req.iova.last =3D last; > > + > > + ret =3D vduse_dev_msg_sync(dev, msg); > > + vduse_dev_msg_put(msg); > > + > > + return ret; > > +} > > + > > +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; > > + > > + while (1) { > > + msg =3D vduse_dev_dequeue_msg(dev, &dev->send_list); > > + if (msg) > > + break; > > + > > + if (file->f_flags & O_NONBLOCK) > > + return -EAGAIN; > > + > > + ret =3D wait_event_interruptible_exclusive(dev->waitq, > > + !list_empty(&dev->send_list)); > > + if (ret) > > + return ret; > > + } > > + ret =3D copy_to_iter(&msg->req, size, to); > > + if (ret !=3D size) { > > + vduse_dev_enqueue_msg(dev, msg, &dev->send_list); > > + return -EFAULT; > > + } > > + vduse_dev_enqueue_msg(dev, msg, &dev->recv_list); > > + > > + 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; > > + > > + msg =3D vduse_dev_find_msg(dev, &dev->recv_list, resp.unique); > > + if (!msg) > > + return -EINVAL; > > + > > + vduse_dev_msg_complete(msg, &resp); > > > So we had multiple types of requests/responses, is this better to > introduce a queue based admin interface other than ioctl? > Sorry, I didn't get your point. What do you mean by queue-based admin interface? Virtqueue-based? > > > + > > + 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; > > + > > + return mask; > > +} > > + > > +static int vduse_iotlb_add_range(struct vduse_dev *dev, > > + u64 start, u64 last, > > + u64 addr, unsigned int perm, > > + struct file *file, u64 offset) > > +{ > > + struct vhost_iotlb_file *iotlb_file; > > + int ret; > > + > > + iotlb_file =3D kmalloc(sizeof(*iotlb_file), GFP_ATOMIC); > > + if (!iotlb_file) > > + return -ENOMEM; > > + > > + iotlb_file->file =3D get_file(file); > > + iotlb_file->offset =3D offset; > > + > > + spin_lock(&dev->iommu_lock); > > + ret =3D vhost_iotlb_add_range(dev->iommu, start, last, > > + addr, perm, iotlb_file); > > + spin_unlock(&dev->iommu_lock); > > + if (ret) { > > + fput(iotlb_file->file); > > + kfree(iotlb_file); > > + return ret; > > + } > > + return 0; > > +} > > + > > +static void vduse_iotlb_del_range(struct vduse_dev *dev, u64 start, u6= 4 last) > > +{ > > + struct vhost_iotlb_file *iotlb_file; > > + struct vhost_iotlb_map *map; > > + > > + spin_lock(&dev->iommu_lock); > > + while ((map =3D vhost_iotlb_itree_first(dev->iommu, start, last))= ) { > > + iotlb_file =3D (struct vhost_iotlb_file *)map->opaque; > > + fput(iotlb_file->file); > > + kfree(iotlb_file); > > + vhost_iotlb_map_free(dev->iommu, map); > > + } > > + spin_unlock(&dev->iommu_lock); > > +} > > + > > +static void vduse_dev_reset(struct vduse_dev *dev) > > +{ > > + int i; > > + > > + atomic_set(&dev->bounce_map, 0); > > + vduse_iotlb_del_range(dev, 0ULL, 0ULL - 1); > > + vduse_dev_update_iotlb(dev, 0ULL, 0ULL - 1); > > > ULLONG_MAX please. > OK. > > > + > > + 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 =3D NULL; > > + vq->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]; > > + > > + vduse_vq_kick(vq); > > +} > > + > > +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]; > > + > > + vq->cb =3D cb->callback; > > + vq->private =3D cb->private; > > +} > > + > > +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); > > + u64 fixed =3D (1ULL << VIRTIO_F_ACCESS_PLATFORM); > > + > > + return (vduse_dev_get_features(dev) | fixed); > > +} > > + > > +static int vduse_vdpa_set_features(struct vdpa_device *vdpa, u64 featu= res) > > +{ > > + struct vduse_dev *dev =3D vdpa_to_vduse(vdpa); > > + > > + 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 */ > > > If it's not hard, let's add this. Otherwise we need a per device feature > blacklist to filter out all features that depends on config interrupt. > Will do it. > > > +} > > + > > +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); > > + > > + if (status =3D=3D 0) > > + vduse_dev_reset(dev); > > + else > > + vduse_dev_update_iotlb(dev, 0ULL, 0ULL - 1); > > > Any reason for such IOTLB invalidation here? > As I mentioned before, this is used to notify userspace to update the IOTLB. Mainly for virtio-vdpa case. > > > + > > + vduse_dev_set_status(dev, status); > > +} > > + > > +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); > > + struct vhost_iotlb_map *map; > > + struct vhost_iotlb_file *iotlb_file; > > + u64 start =3D 0ULL, last =3D 0ULL - 1; > > + int ret =3D 0; > > + > > + vduse_iotlb_del_range(dev, start, last); > > + > > + for (map =3D vhost_iotlb_itree_first(iotlb, start, last); map; > > + map =3D vhost_iotlb_itree_next(map, start, last)) { > > + if (!map->opaque) > > + continue; > > > What will happen if we simply accept NULL opaque here? > No file to mmap in userspace. So it's useless. > > > + > > + iotlb_file =3D (struct vhost_iotlb_file *)map->opaque; > > + ret =3D vduse_iotlb_add_range(dev, map->start, map->last, > > + map->addr, map->perm, > > + iotlb_file->file, > > + iotlb_file->offset); > > + if (ret) > > + break; > > + } > > + vduse_dev_update_iotlb(dev, start, last); > > + > > + 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; > > + > > + if (atomic_xchg(&vdev->bounce_map, 1) =3D=3D 0 && > > + vduse_iotlb_add_range(vdev, 0, domain->bounce_size - 1, > > + 0, VDUSE_ACCESS_RW, > > > Is this safe to use VDUSE_ACCESS_RW here, consider we might have device > readonly mappings. > This mapping is for the whole bounce buffer. Maybe userspace needs to tell us if it only support readonly mappings. > > > + vduse_domain_file(domain), > > + vduse_domain_get_offset(domain, 0))= ) { > > + atomic_set(&vdev->bounce_map, 0); > > + return DMA_MAPPING_ERROR; > > + } > > + > > + 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; > > + > > + if (vduse_iotlb_add_range(vdev, iova, iova + size - 1, > > + iova, VDUSE_ACCESS_RW, > > + vduse_domain_file(domain), > > + vduse_domain_get_offset(domain, iova)))= { > > + vduse_domain_free_coherent(domain, size, addr, iova, attr= s); > > + return NULL; > > + } > > + *dma_addr =3D (dma_addr_t)iova; > > + > > + 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_iotlb_del_range(vdev, start, last); > > + vduse_dev_update_iotlb(vdev, start, last); > > + vduse_domain_free_coherent(domain, size, vaddr, dma_addr, attrs); > > +} > > + > > +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 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; > > + > > + mutex_lock(&dev->lock); > > + switch (cmd) { > > + case VDUSE_IOTLB_GET_FD: { > > + struct vduse_iotlb_entry entry; > > + struct vhost_iotlb_map *map; > > + struct vhost_iotlb_file *iotlb_file; > > + struct file *f =3D NULL; > > + > > + ret =3D -EFAULT; > > + if (copy_from_user(&entry, argp, sizeof(entry))) > > + break; > > + > > + spin_lock(&dev->iommu_lock); > > + map =3D vhost_iotlb_itree_first(dev->iommu, entry.start, > > + entry.last); > > + if (map) { > > + iotlb_file =3D (struct vhost_iotlb_file *)map->op= aque; > > + f =3D get_file(iotlb_file->file); > > + entry.offset =3D iotlb_file->offset; > > + entry.start =3D map->start; > > + entry.last =3D map->last; > > + entry.perm =3D map->perm; > > + } > > + spin_unlock(&dev->iommu_lock); > > + if (!f) { > > + ret =3D -EINVAL; > > + break; > > + } > > + if (copy_to_user(argp, &entry, sizeof(entry))) { > > + fput(f); > > + ret =3D -EFAULT; > > + break; > > + } > > + ret =3D get_unused_fd_flags(perm_to_file_flags(entry.perm= )); > > + if (ret < 0) { > > + fput(f); > > + break; > > + } > > + fd_install(ret, 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_VQ_SETUP_IRQFD: { > > + struct vduse_vq_eventfd eventfd; > > + > > + ret =3D -EFAULT; > > + if (copy_from_user(&eventfd, argp, sizeof(eventfd))) > > + break; > > + > > + ret =3D vduse_virqfd_setup(dev, &eventfd); > > + break; > > + } > > + } > > + mutex_unlock(&dev->lock); > > + > > + return ret; > > +} > > + > > +static int vduse_dev_release(struct inode *inode, struct file *file) > > +{ > > + struct vduse_dev *dev =3D file->private_data; > > + > > + vduse_kickfd_release(dev); > > + vduse_virqfd_release(dev); > > + dev->connected =3D false; > > + > > + return 0; > > +} > > + > > +static const struct file_operations vduse_dev_fops =3D { > > + .owner =3D THIS_MODULE, > > + .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; > > + > > + dev->iommu =3D vhost_iotlb_alloc(2048, 0); > > > Is 2048 sufficient here? > How about letting userspace to define it? > > > + if (!dev->iommu) { > > + kfree(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->iommu_lock); > > + atomic_set(&dev->bounce_map, 0); > > + > > + init_waitqueue_head(&dev->waitq); > > + > > + return dev; > > +} > > + > > +static void vduse_dev_destroy(struct vduse_dev *dev) > > +{ > > + vhost_iotlb_free(dev->iommu); > > + mutex_destroy(&dev->lock); > > + kfree(dev); > > +} > > + > > +static struct vduse_dev *vduse_find_dev(u32 id) > > +{ > > + struct vduse_dev *tmp, *dev =3D NULL; > > + > > + list_for_each_entry(tmp, &vduse_devs, list) { > > + if (tmp->id =3D=3D id) { > > + dev =3D tmp; > > + break; > > + } > > + } > > + return dev; > > +} > > + > > +static int vduse_destroy_dev(u32 id) > > +{ > > + struct vduse_dev *dev =3D vduse_find_dev(id); > > + > > + if (!dev) > > + return -EINVAL; > > + > > + if (dev->vdev || dev->connected) > > + return -EBUSY; > > + > > + list_del(&dev->list); > > + kfree(dev->vqs); > > + vduse_domain_destroy(dev->domain); > > + vduse_dev_destroy(dev); > > + > > + return 0; > > +} > > + > > +static int vduse_create_dev(struct vduse_dev_config *config) > > +{ > > + int i, fd; > > + struct vduse_dev *dev; > > + char name[64]; > > + > > + if (vduse_find_dev(config->id)) > > + return -EEXIST; > > + > > + dev =3D vduse_dev_create(); > > + if (!dev) > > + return -ENOMEM; > > + > > + dev->id =3D config->id; > > + dev->device_id =3D config->device_id; > > + dev->vendor_id =3D config->vendor_id; > > + dev->domain =3D vduse_domain_create(config->bounce_size); > > > Do we need a upper limit of bounce_size? > I agree. Any comment for the value? > > > + 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; > > + spin_lock_init(&dev->vqs[i].kick_lock); > > + spin_lock_init(&dev->vqs[i].irq_lock); > > + } > > + > > + snprintf(name, sizeof(name), "[vduse-dev:%u]", config->id); > > + fd =3D anon_inode_getfd(name, &vduse_dev_fops, dev, O_RDWR | O_CL= OEXEC); > > > Any reason for closing on exec here? > Looks like we can remove this flag. > > > + if (fd < 0) > > + goto err_fd; > > + > > + dev->connected =3D true; > > + list_add(&dev->list, &vduse_devs); > > + > > + return fd; > > +err_fd: > > + kfree(dev->vqs); > > +err_vqs: > > + vduse_domain_destroy(dev->domain); > > +err_domain: > > + vduse_dev_destroy(dev); > > + return fd; > > +} > > + > > +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_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); > > + break; > > + } > > + case VDUSE_DESTROY_DEV: > > + ret =3D vduse_destroy_dev(arg); > > + break; > > + default: > > + ret =3D -EINVAL; > > + break; > > + } > > + mutex_unlock(&vduse_lock); > > + > > + return ret; > > +} > > + > > +static const struct file_operations vduse_fops =3D { > > + .owner =3D THIS_MODULE, > > + .unlocked_ioctl =3D vduse_ioctl, > > + .compat_ioctl =3D compat_ptr_ioctl, > > + .llseek =3D noop_llseek, > > +}; > > + > > +static struct miscdevice vduse_misc =3D { > > + .fops =3D &vduse_fops, > > + .minor =3D MISC_DYNAMIC_MINOR, > > + .name =3D "vduse", > > +}; > > + > > +static void vduse_parent_release(struct device *dev) > > +{ > > +} > > + > > +static struct device vduse_parent =3D { > > + .init_name =3D "vduse", > > + .release =3D vduse_parent_release, > > +}; > > + > > +static struct vdpa_parent_dev parent_dev; > > + > > +static int vduse_dev_add_vdpa(struct vduse_dev *dev, const char *name) > > +{ > > + struct vduse_vdpa *vdev =3D dev->vdev; > > + int ret; > > + > > + if (vdev) > > + return -EEXIST; > > + > > + vdev =3D vdpa_alloc_device(struct vduse_vdpa, vdpa, NULL, > > + &vduse_vdpa_config_ops, > > + dev->vq_num, name, true); > > + if (!vdev) > > + return -ENOMEM; > > + > > + 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) > > + goto err; > > + > > + set_dma_ops(&vdev->vdpa.dev, &vduse_dev_dma_ops); > > + vdev->vdpa.dma_dev =3D &vdev->vdpa.dev; > > + vdev->vdpa.pdev =3D &parent_dev; > > + > > + ret =3D _vdpa_register_device(&vdev->vdpa); > > + if (ret) > > + goto err; > > + > > + dev->vdev =3D vdev; > > + > > + return 0; > > +err: > > + put_device(&vdev->vdpa.dev); > > + return ret; > > +} > > + > > +static struct vdpa_device *vdpa_dev_add(struct vdpa_parent_dev *pdev, > > + const char *name, u32 device_id, > > + struct nlattr **attrs) > > +{ > > + u32 vduse_id; > > + struct vduse_dev *dev; > > + int ret =3D -EINVAL; > > + > > + if (!attrs[VDPA_ATTR_BACKEND_ID]) > > + return ERR_PTR(-EINVAL); > > + > > + mutex_lock(&vduse_lock); > > + vduse_id =3D nla_get_u32(attrs[VDPA_ATTR_BACKEND_ID]); > > > I wonder why not using name here? > Do you mean use the same name for both backend and frontend? If so, we need to add a name for vduse device or replace id with name to identify a vduse device. Which way do you prefer? > And it looks to me it would be easier if we create a char device per > vduse. This makes the device addressing more robust than passing id > silently among processes. > It's OK to me. > > > + dev =3D vduse_find_dev(vduse_id); > > + if (!dev) > > + goto unlock; > > + > > + if (dev->device_id !=3D device_id) > > + goto unlock; > > + > > + ret =3D vduse_dev_add_vdpa(dev, name); > > +unlock: > > + mutex_unlock(&vduse_lock); > > + if (ret) > > + return ERR_PTR(ret); > > + > > + return &dev->vdev->vdpa; > > +} > > + > > +static void vdpa_dev_del(struct vdpa_parent_dev *pdev, struct vdpa_dev= ice *dev) > > +{ > > + _vdpa_unregister_device(dev); > > +} > > + > > +static const struct vdpa_dev_ops vdpa_dev_parent_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_parent_dev parent_dev =3D { > > + .device =3D &vduse_parent, > > + .id_table =3D id_table, > > + .ops =3D &vdpa_dev_parent_ops, > > +}; > > + > > +static int vduse_parentdev_init(void) > > +{ > > + int ret; > > + > > + ret =3D device_register(&vduse_parent); > > + if (ret) > > + return ret; > > + > > + ret =3D vdpa_parentdev_register(&parent_dev); > > + if (ret) > > + goto err; > > + > > + return 0; > > +err: > > + device_unregister(&vduse_parent); > > + return ret; > > +} > > + > > +static void vduse_parentdev_exit(void) > > +{ > > + vdpa_parentdev_unregister(&parent_dev); > > + device_unregister(&vduse_parent); > > +} > > + > > +static int vduse_init(void) > > +{ > > + int ret; > > + > > + ret =3D misc_register(&vduse_misc); > > + if (ret) > > + return ret; > > + > > + ret =3D -ENOMEM; > > + vduse_vdpa_wq =3D alloc_workqueue("vduse-vdpa", WQ_UNBOUND, 1); > > + if (!vduse_vdpa_wq) > > + goto err_vdpa_wq; > > + > > + ret =3D vduse_virqfd_init(); > > + if (ret) > > + goto err_irqfd; > > + > > + ret =3D vduse_parentdev_init(); > > + if (ret) > > + goto err_parentdev; > > + > > + return 0; > > +err_parentdev: > > + vduse_virqfd_exit(); > > +err_irqfd: > > + destroy_workqueue(vduse_vdpa_wq); > > +err_vdpa_wq: > > + misc_deregister(&vduse_misc); > > + return ret; > > +} > > +module_init(vduse_init); > > + > > +static void vduse_exit(void) > > +{ > > + misc_deregister(&vduse_misc); > > + destroy_workqueue(vduse_vdpa_wq); > > + vduse_virqfd_exit(); > > + vduse_parentdev_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/vdpa.h b/include/uapi/linux/vdpa.h > > index bba8b83a94b5..a7a841e5ffc7 100644 > > --- a/include/uapi/linux/vdpa.h > > +++ b/include/uapi/linux/vdpa.h > > @@ -33,6 +33,7 @@ enum vdpa_attr { > > VDPA_ATTR_DEV_VENDOR_ID, /* u32 */ > > VDPA_ATTR_DEV_MAX_VQS, /* u32 */ > > VDPA_ATTR_DEV_MAX_VQ_SIZE, /* u16 */ > > + VDPA_ATTR_BACKEND_ID, /* u32 */ > > > As discussed, this needs more thought. But if necessary, we need a > separate patch for this. > OK. > > > > > /* new attributes must be added above here */ > > VDPA_ATTR_MAX, > > diff --git a/include/uapi/linux/vduse.h b/include/uapi/linux/vduse.h > > new file mode 100644 > > index 000000000000..9fb555ddcfbd > > --- /dev/null > > +++ b/include/uapi/linux/vduse.h > > @@ -0,0 +1,125 @@ > > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > > +#ifndef _UAPI_VDUSE_H_ > > +#define _UAPI_VDUSE_H_ > > + > > +#include > > + > > +/* the control messages definition for read/write */ > > + > > +#define VDUSE_CONFIG_DATA_LEN 256 > > + > > +enum vduse_req_type { > > + VDUSE_SET_VQ_NUM, > > + VDUSE_SET_VQ_ADDR, > > + VDUSE_SET_VQ_READY, > > + VDUSE_GET_VQ_READY, > > + VDUSE_SET_VQ_STATE, > > + VDUSE_GET_VQ_STATE, > > + VDUSE_SET_FEATURES, > > + VDUSE_GET_FEATURES, > > + VDUSE_SET_STATUS, > > + VDUSE_GET_STATUS, > > + VDUSE_SET_CONFIG, > > + VDUSE_GET_CONFIG, > > + VDUSE_UPDATE_IOTLB, > > +}; > > + > > +struct vduse_vq_num { > > + __u32 index; > > + __u32 num; > > +}; > > + > > +struct vduse_vq_addr { > > + __u32 index; > > + __u64 desc_addr; > > + __u64 driver_addr; > > + __u64 device_addr; > > +}; > > + > > +struct vduse_vq_ready { > > + __u32 index; > > + __u8 ready; > > +}; > > + > > +struct vduse_vq_state { > > + __u32 index; > > + __u16 avail_idx; > > +}; > > + > > +struct vduse_dev_config_data { > > + __u32 offset; > > + __u32 len; > > + __u8 data[VDUSE_CONFIG_DATA_LEN]; > > > This no guarantee that 256 is sufficient here. > If the size is larger than 256, we can try to split the original request. > > > +}; > > + > > +struct vduse_iova_range { > > + __u64 start; > > + __u64 last; > > +}; > > + > > +struct vduse_dev_request { > > + __u32 type; /* request type */ > > + __u32 unique; /* request id */ > > + __u32 flags; /* request flags */ > > > Seems unused in this series. > This is for future use. > > > + __u32 size; /* the payload size */ > > > Unused. > Will remove it. > > > + 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 = */ > > + __u64 features; /* virtio features */ > > + __u8 status; /* device status */ > > > Let's add some padding for future extensions. > Is sizeof(vduse_dev_config_data) ok? Or char[1024]? > > > + }; > > +}; > > + > > +struct vduse_dev_response { > > + __u32 unique; /* corresponding request id */ > > > Let's use request id. > Fine. > > > + __s32 result; /* the result of request */ > > > Let's use macro or enum to define the success and failure value. > Will do it. > > > + 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 */ > > + __u64 features; /* virtio features */ > > + __u8 status; /* device status */ > > + }; > > +}; > > + > > +/* ioctls */ > > + > > +struct vduse_dev_config { > > + __u32 id; /* vduse device id */ > > + __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 */ > > +}; > > + > > +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 */ > > + __u32 fd; /* eventfd */ > > > Any reason for not using int here? > Will use __s32 instead. > > > +}; > > + > > +#define VDUSE_BASE 0x81 > > + > > +#define VDUSE_CREATE_DEV _IOW(VDUSE_BASE, 0x01, struct vduse_dev_c= onfig) > > +#define VDUSE_DESTROY_DEV _IO(VDUSE_BASE, 0x02) > > + > > +#define VDUSE_IOTLB_GET_FD _IOWR(VDUSE_BASE, 0x04, struct vduse_iotl= b_entry) > > +#define VDUSE_VQ_SETUP_KICKFD _IOW(VDUSE_BASE, 0x05, struct vdu= se_vq_eventfd) > > +#define VDUSE_VQ_SETUP_IRQFD _IOW(VDUSE_BASE, 0x06, struct vduse_vq_ev= entfd) > > > Better with documentation to explain those ioctls. > Will do it. Thanks, Yongji