[RFC,05/10] vhost: extract common code for file_operations handling

Message ID	20210929151119.14778-6-vincent.whitchurch@axis.com (mailing list archive)
State	RFC
Headers	show Return-Path: <netdev-owner@kernel.org> From: Vincent Whitchurch <vincent.whitchurch@axis.com> To: <mst@redhat.com>, <jasowang@redhat.com> CC: <kernel@axis.com>, <kvm@vger.kernel.org>, <virtualization@lists.linux-foundation.org>, <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <pbonzini@redhat.com>, <stefanha@redhat.com>, <sgarzare@redhat.com>, Vincent Whitchurch <vincent.whitchurch@axis.com> Subject: [RFC PATCH 05/10] vhost: extract common code for file_operations handling Date: Wed, 29 Sep 2021 17:11:14 +0200 Message-ID: <20210929151119.14778-6-vincent.whitchurch@axis.com> In-Reply-To: <20210929151119.14778-1-vincent.whitchurch@axis.com> References: <20210929151119.14778-1-vincent.whitchurch@axis.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain Precedence: bulk
Series	Support kernel buffers in vhost \| expand [RFC,00/10] Support kernel buffers in vhost [RFC,01/10] vhost: scsi: use copy_to_iter() [RFC,02/10] vhost: push virtqueue area pointers into a user struct [RFC,03/10] vhost: add iov wrapper [RFC,04/10] vhost: add support for kernel buffers [RFC,05/10] vhost: extract common code for file_operations handling [RFC,06/10] vhost: extract ioctl locking to common code [RFC,07/10] vhost: add support for kernel control [RFC,08/10] vhost: net: add support for kernel control [RFC,09/10] vdpa: add test driver for kernel buffers in vhost [RFC,10/10] selftests: add vhost_kernel tests

Context	Check	Description
netdev/tree_selection	success	Not a local patch

diff --git a/drivers/vhost/Makefile b/drivers/vhost/Makefile index f3e1897cce85..b1ddc976aede 100644 --- a/drivers/vhost/Makefile +++ b/drivers/vhost/Makefile @@ -15,5 +15,8 @@ vhost_vdpa-y := vdpa.o obj-$(CONFIG_VHOST) += vhost.o +obj-$(CONFIG_VHOST) += vhost_common.o +vhost_common-y := common.o + obj-$(CONFIG_VHOST_IOTLB) += vhost_iotlb.o vhost_iotlb-y := iotlb.o diff --git a/drivers/vhost/common.c b/drivers/vhost/common.c new file mode 100644 index 000000000000..27d4672b15d3 --- /dev/null +++ b/drivers/vhost/common.c @@ -0,0 +1,134 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/eventfd.h> +#include <linux/vhost.h> +#include <linux/uio.h> +#include <linux/mm.h> +#include <linux/miscdevice.h> +#include <linux/mutex.h> +#include <linux/poll.h> +#include <linux/file.h> +#include <linux/highmem.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/kthread.h> +#include <linux/cgroup.h> +#include <linux/module.h> +#include <linux/sort.h> +#include <linux/sched/mm.h> +#include <linux/sched/signal.h> +#include <linux/interval_tree_generic.h> +#include <linux/nospec.h> +#include <linux/kcov.h> + +#include "vhost.h" + +struct vhost_ops; + +struct vhost { + struct miscdevice misc; + const struct vhost_ops *ops; +}; + +static int vhost_open(struct inode *inode, struct file *file) +{ + struct miscdevice *misc = file->private_data; + struct vhost *vhost = container_of(misc, struct vhost, misc); + struct vhost_dev *dev; + + dev = vhost->ops->open(vhost); + if (IS_ERR(dev)) + return PTR_ERR(dev); + + dev->vhost = vhost; + dev->file = file; + file->private_data = dev; + + return 0; +} + +static int vhost_release(struct inode *inode, struct file *file) +{ + struct vhost_dev *dev = file->private_data; + struct vhost *vhost = dev->vhost; + + vhost->ops->release(dev); + + return 0; +} + +static long vhost_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) +{ + struct vhost_dev *dev = file->private_data; + struct vhost *vhost = dev->vhost; + + return vhost->ops->ioctl(dev, ioctl, arg); +} + +static ssize_t vhost_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ + struct file *file = iocb->ki_filp; + struct vhost_dev *dev = file->private_data; + int noblock = file->f_flags & O_NONBLOCK; + + return vhost_chr_read_iter(dev, to, noblock); +} + +static ssize_t vhost_write_iter(struct kiocb *iocb, struct iov_iter *from) +{ + struct file *file = iocb->ki_filp; + struct vhost_dev *dev = file->private_data; + + return vhost_chr_write_iter(dev, from); +} + +static __poll_t vhost_poll(struct file *file, poll_table *wait) +{ + struct vhost_dev *dev = file->private_data; + + return vhost_chr_poll(file, dev, wait); +} + +static const struct file_operations vhost_fops = { + .owner = THIS_MODULE, + .open = vhost_open, + .release = vhost_release, + .llseek = noop_llseek, + .unlocked_ioctl = vhost_ioctl, + .compat_ioctl = compat_ptr_ioctl, + .read_iter = vhost_read_iter, + .write_iter = vhost_write_iter, + .poll = vhost_poll, +}; + +struct vhost *vhost_register(const struct vhost_ops *ops) +{ + struct vhost *vhost; + int ret; + + vhost = kzalloc(sizeof(*vhost), GFP_KERNEL); + if (!vhost) + return ERR_PTR(-ENOMEM); + + vhost->misc.minor = ops->minor; + vhost->misc.name = ops->name; + vhost->misc.fops = &vhost_fops; + vhost->ops = ops; + + ret = misc_register(&vhost->misc); + if (ret) { + kfree(vhost); + return ERR_PTR(ret); + } + + return vhost; +} +EXPORT_SYMBOL_GPL(vhost_register); + +void vhost_unregister(struct vhost *vhost) +{ + misc_deregister(&vhost->misc); + kfree(vhost); +} +EXPORT_SYMBOL_GPL(vhost_unregister); + +MODULE_LICENSE("GPL v2"); diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 8f82b646d4af..8910d9e2a74e 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -1281,7 +1281,7 @@ static void handle_rx_net(struct vhost_work *work) handle_rx(net); } -static int vhost_net_open(struct inode *inode, struct file *f) +static struct vhost_dev *vhost_net_open(struct vhost *vhost) { struct vhost_net *n; struct vhost_dev *dev; @@ -1292,11 +1292,11 @@ static int vhost_net_open(struct inode *inode, struct file *f) n = kvmalloc(sizeof *n, GFP_KERNEL | __GFP_RETRY_MAYFAIL); if (!n) - return -ENOMEM; + return ERR_PTR(-ENOMEM); vqs = kmalloc_array(VHOST_NET_VQ_MAX, sizeof(*vqs), GFP_KERNEL); if (!vqs) { kvfree(n); - return -ENOMEM; + return ERR_PTR(-ENOMEM); } queue = kmalloc_array(VHOST_NET_BATCH, sizeof(void *), @@ -1304,7 +1304,7 @@ static int vhost_net_open(struct inode *inode, struct file *f) if (!queue) { kfree(vqs); kvfree(n); - return -ENOMEM; + return ERR_PTR(-ENOMEM); } n->vqs[VHOST_NET_VQ_RX].rxq.queue = queue; @@ -1313,7 +1313,7 @@ static int vhost_net_open(struct inode *inode, struct file *f) kfree(vqs); kvfree(n); kfree(queue); - return -ENOMEM; + return ERR_PTR(-ENOMEM); } n->vqs[VHOST_NET_VQ_TX].xdp = xdp; @@ -1341,11 +1341,10 @@ static int vhost_net_open(struct inode *inode, struct file *f) vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, EPOLLOUT, dev); vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, EPOLLIN, dev); - f->private_data = n; n->page_frag.page = NULL; n->refcnt_bias = 0; - return 0; + return dev; } static struct socket *vhost_net_stop_vq(struct vhost_net *n, @@ -1395,9 +1394,9 @@ static void vhost_net_flush(struct vhost_net *n) } } -static int vhost_net_release(struct inode *inode, struct file *f) +static void vhost_net_release(struct vhost_dev *dev) { - struct vhost_net *n = f->private_data; + struct vhost_net *n = container_of(dev, struct vhost_net, dev); struct socket *tx_sock; struct socket *rx_sock; @@ -1421,7 +1420,6 @@ static int vhost_net_release(struct inode *inode, struct file *f) if (n->page_frag.page) __page_frag_cache_drain(n->page_frag.page, n->refcnt_bias); kvfree(n); - return 0; } static struct socket *get_raw_socket(int fd) @@ -1687,10 +1685,10 @@ static long vhost_net_set_owner(struct vhost_net *n) return r; } -static long vhost_net_ioctl(struct file *f, unsigned int ioctl, +static long vhost_net_ioctl(struct vhost_dev *dev, unsigned int ioctl, unsigned long arg) { - struct vhost_net *n = f->private_data; + struct vhost_net *n = container_of(dev, struct vhost_net, dev); void __user *argp = (void __user *)arg; u64 __user *featurep = argp; struct vhost_vring_file backend; @@ -1741,63 +1739,32 @@ static long vhost_net_ioctl(struct file *f, unsigned int ioctl, } } -static ssize_t vhost_net_chr_read_iter(struct kiocb *iocb, struct iov_iter *to) -{ - struct file *file = iocb->ki_filp; - struct vhost_net *n = file->private_data; - struct vhost_dev *dev = &n->dev; - int noblock = file->f_flags & O_NONBLOCK; - - return vhost_chr_read_iter(dev, to, noblock); -} - -static ssize_t vhost_net_chr_write_iter(struct kiocb *iocb, - struct iov_iter *from) -{ - struct file *file = iocb->ki_filp; - struct vhost_net *n = file->private_data; - struct vhost_dev *dev = &n->dev; - - return vhost_chr_write_iter(dev, from); -} - -static __poll_t vhost_net_chr_poll(struct file *file, poll_table *wait) -{ - struct vhost_net *n = file->private_data; - struct vhost_dev *dev = &n->dev; - - return vhost_chr_poll(file, dev, wait); -} - -static const struct file_operations vhost_net_fops = { - .owner = THIS_MODULE, - .release = vhost_net_release, - .read_iter = vhost_net_chr_read_iter, - .write_iter = vhost_net_chr_write_iter, - .poll = vhost_net_chr_poll, - .unlocked_ioctl = vhost_net_ioctl, - .compat_ioctl = compat_ptr_ioctl, +static const struct vhost_ops vhost_net_ops = { + .minor = VHOST_NET_MINOR, + .name = "vhost-net", .open = vhost_net_open, - .llseek = noop_llseek, + .release = vhost_net_release, + .ioctl = vhost_net_ioctl, }; -static struct miscdevice vhost_net_misc = { - .minor = VHOST_NET_MINOR, - .name = "vhost-net", - .fops = &vhost_net_fops, -}; +static struct vhost *vhost_net; static int vhost_net_init(void) { if (experimental_zcopytx) vhost_net_enable_zcopy(VHOST_NET_VQ_TX); - return misc_register(&vhost_net_misc); + + vhost_net = vhost_register(&vhost_net_ops); + if (IS_ERR(vhost_net)) + return PTR_ERR(vhost_net); + + return 0; } module_init(vhost_net_init); static void vhost_net_exit(void) { - misc_deregister(&vhost_net_misc); + vhost_unregister(vhost_net); } module_exit(vhost_net_exit); diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index ded1b39d7852..562387b92730 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -15,6 +15,19 @@ #include <linux/vhost_iotlb.h> #include <linux/irqbypass.h> +struct vhost; + +struct vhost_ops { + int minor; + const char *name; + struct vhost_dev * (*open)(struct vhost *vhost); + long (*ioctl)(struct vhost_dev *dev, unsigned int ioctl, unsigned long arg); + void (*release)(struct vhost_dev *dev); +}; + +struct vhost *vhost_register(const struct vhost_ops *ops); +void vhost_unregister(struct vhost *vhost); + struct vhost_work; typedef void (*vhost_work_fn_t)(struct vhost_work *work); @@ -160,6 +173,8 @@ struct vhost_dev { struct mm_struct *mm; struct mutex mutex; struct vhost_virtqueue **vqs; + struct vhost *vhost; + struct file *file; int nvqs; struct eventfd_ctx *log_ctx; struct llist_head work_list; diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 190e5a6ea045..93f74a0010d5 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -662,7 +662,7 @@ static void vhost_vsock_free(struct vhost_vsock *vsock) kvfree(vsock); } -static int vhost_vsock_dev_open(struct inode *inode, struct file *file) +static struct vhost_dev *vhost_vsock_dev_open(struct vhost *vhost) { struct vhost_virtqueue **vqs; struct vhost_vsock *vsock; @@ -673,7 +673,7 @@ static int vhost_vsock_dev_open(struct inode *inode, struct file *file) */ vsock = kvmalloc(sizeof(*vsock), GFP_KERNEL | __GFP_RETRY_MAYFAIL); if (!vsock) - return -ENOMEM; + return ERR_PTR(-ENOMEM); vqs = kmalloc_array(ARRAY_SIZE(vsock->vqs), sizeof(*vqs), GFP_KERNEL); if (!vqs) { @@ -694,15 +694,14 @@ static int vhost_vsock_dev_open(struct inode *inode, struct file *file) UIO_MAXIOV, VHOST_VSOCK_PKT_WEIGHT, VHOST_VSOCK_WEIGHT, true, NULL); - file->private_data = vsock; spin_lock_init(&vsock->send_pkt_list_lock); INIT_LIST_HEAD(&vsock->send_pkt_list); vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work); - return 0; + return &vsock->dev; out: vhost_vsock_free(vsock); - return ret; + return ERR_PTR(ret); } static void vhost_vsock_flush(struct vhost_vsock *vsock) @@ -741,9 +740,9 @@ static void vhost_vsock_reset_orphans(struct sock *sk) sk_error_report(sk); } -static int vhost_vsock_dev_release(struct inode *inode, struct file *file) +static void vhost_vsock_dev_release(struct vhost_dev *dev) { - struct vhost_vsock *vsock = file->private_data; + struct vhost_vsock *vsock = container_of(dev, struct vhost_vsock, dev); mutex_lock(&vhost_vsock_mutex); if (vsock->guest_cid) @@ -775,7 +774,6 @@ static int vhost_vsock_dev_release(struct inode *inode, struct file *file) vhost_dev_cleanup(&vsock->dev); kfree(vsock->dev.vqs); vhost_vsock_free(vsock); - return 0; } static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid) @@ -851,10 +849,10 @@ static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features) return -EFAULT; } -static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl, +static long vhost_vsock_dev_ioctl(struct vhost_dev *dev, unsigned int ioctl, unsigned long arg) { - struct vhost_vsock *vsock = f->private_data; + struct vhost_vsock *vsock = container_of(dev, struct vhost_vsock, dev); void __user *argp = (void __user *)arg; u64 guest_cid; u64 features; @@ -906,51 +904,15 @@ static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl, } } -static ssize_t vhost_vsock_chr_read_iter(struct kiocb *iocb, struct iov_iter *to) -{ - struct file *file = iocb->ki_filp; - struct vhost_vsock *vsock = file->private_data; - struct vhost_dev *dev = &vsock->dev; - int noblock = file->f_flags & O_NONBLOCK; - - return vhost_chr_read_iter(dev, to, noblock); -} - -static ssize_t vhost_vsock_chr_write_iter(struct kiocb *iocb, - struct iov_iter *from) -{ - struct file *file = iocb->ki_filp; - struct vhost_vsock *vsock = file->private_data; - struct vhost_dev *dev = &vsock->dev; - - return vhost_chr_write_iter(dev, from); -} - -static __poll_t vhost_vsock_chr_poll(struct file *file, poll_table *wait) -{ - struct vhost_vsock *vsock = file->private_data; - struct vhost_dev *dev = &vsock->dev; - - return vhost_chr_poll(file, dev, wait); -} - -static const struct file_operations vhost_vsock_fops = { - .owner = THIS_MODULE, +static const struct vhost_ops vhost_vsock_ops = { + .minor = VHOST_VSOCK_MINOR, + .name = "vhost-vsock", .open = vhost_vsock_dev_open, .release = vhost_vsock_dev_release, - .llseek = noop_llseek, - .unlocked_ioctl = vhost_vsock_dev_ioctl, - .compat_ioctl = compat_ptr_ioctl, - .read_iter = vhost_vsock_chr_read_iter, - .write_iter = vhost_vsock_chr_write_iter, - .poll = vhost_vsock_chr_poll, + .ioctl = vhost_vsock_dev_ioctl, }; -static struct miscdevice vhost_vsock_misc = { - .minor = VHOST_VSOCK_MINOR, - .name = "vhost-vsock", - .fops = &vhost_vsock_fops, -}; +static struct vhost *vhost_vsock; static int __init vhost_vsock_init(void) { @@ -960,12 +922,19 @@ static int __init vhost_vsock_init(void) VSOCK_TRANSPORT_F_H2G); if (ret < 0) return ret; - return misc_register(&vhost_vsock_misc); + + vhost_vsock = vhost_register(&vhost_vsock_ops); + if (IS_ERR(vhost_vsock)) { + vsock_core_unregister(&vhost_transport.transport); + return PTR_ERR(vhost_vsock); + } + + return 0; }; static void __exit vhost_vsock_exit(void) { - misc_deregister(&vhost_vsock_misc); + vhost_unregister(vhost_vsock); vsock_core_unregister(&vhost_transport.transport); };

[RFC,05/10] vhost: extract common code for file_operations handling

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