Re: Re: [PATCH v8 09/10] vduse: Introduce VDUSE - vDPA Device in Userspace
From: Yongji Xie <hidden>
Date: 2021-06-22 07:22:25
Also in:
kvm, linux-fsdevel, linux-iommu, lkml
.On Tue, Jun 22, 2021 at 1:07 PM Jason Wang [off-list ref] wrote:
在 2021/6/21 下午6:41, Yongji Xie 写道:quoted
On Mon, Jun 21, 2021 at 5:14 PM Jason Wang [off-list ref] wrote:quoted
在 2021/6/15 下午10:13, Xie Yongji 写道:quoted
This VDUSE driver enables implementing vDPA devices in userspace. The vDPA device's control path is handled in kernel and the data path is handled in userspace. A message mechnism is used by VDUSE driver to forward some control messages such as starting/stopping datapath to userspace. Userspace can use read()/write() to receive/reply those control messages. And some ioctls are introduced to help userspace to implement the data path. VDUSE_IOTLB_GET_FD ioctl can be used to get the file descriptors referring to vDPA device's iova regions. Then userspace can use mmap() to access those iova regions. VDUSE_DEV_GET_FEATURES and VDUSE_VQ_GET_INFO ioctls are used to get the negotiated features and metadata of virtqueues. VDUSE_INJECT_VQ_IRQ and VDUSE_VQ_SETUP_KICKFD ioctls can be used to inject interrupt and setup the kickfd for virtqueues. VDUSE_DEV_UPDATE_CONFIG ioctl is used to update the configuration space and inject a config interrupt. Signed-off-by: Xie Yongji <redacted> --- Documentation/userspace-api/ioctl/ioctl-number.rst | 1 + drivers/vdpa/Kconfig | 10 + drivers/vdpa/Makefile | 1 + drivers/vdpa/vdpa_user/Makefile | 5 + drivers/vdpa/vdpa_user/vduse_dev.c | 1453 ++++++++++++++++++++ include/uapi/linux/vduse.h | 143 ++ 6 files changed, 1613 insertions(+) create mode 100644 drivers/vdpa/vdpa_user/Makefile create mode 100644 drivers/vdpa/vdpa_user/vduse_dev.c create mode 100644 include/uapi/linux/vduse.hdiff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst index 9bfc2b510c64..acd95e9dcfe7 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 rangediff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig index a503c1b2bfd9..6e23bce6433a 100644 --- a/drivers/vdpa/Kconfig +++ b/drivers/vdpa/Kconfig@@ -33,6 +33,16 @@ config VDPA_SIM_BLOCK vDPA block device simulator which terminates IO request in a memory buffer. +config VDPA_USER + tristate "VDUSE (vDPA Device in Userspace) support" + depends on EVENTFD && MMU && HAS_DMA + select DMA_OPS + select VHOST_IOTLB + select IOMMU_IOVA + help + With VDUSE it is possible to emulate a vDPA Device + in a userspace program. + config IFCVF tristate "Intel IFC VF vDPA driver" depends on PCI_MSIdiff --git a/drivers/vdpa/Makefile b/drivers/vdpa/Makefile index 67fe7f3d6943..f02ebed33f19 100644 --- a/drivers/vdpa/Makefile +++ b/drivers/vdpa/Makefile@@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_VDPA) += vdpa.o obj-$(CONFIG_VDPA_SIM) += vdpa_sim/ +obj-$(CONFIG_VDPA_USER) += vdpa_user/ obj-$(CONFIG_IFCVF) += ifcvf/ obj-$(CONFIG_MLX5_VDPA) += mlx5/ obj-$(CONFIG_VP_VDPA) += virtio_pci/diff --git a/drivers/vdpa/vdpa_user/Makefile b/drivers/vdpa/vdpa_user/Makefile new file mode 100644 index 000000000000..260e0b26af99 --- /dev/null +++ b/drivers/vdpa/vdpa_user/Makefile@@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0 + +vduse-y := vduse_dev.o iova_domain.o + +obj-$(CONFIG_VDPA_USER) += vduse.odiff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c new file mode 100644 index 000000000000..5271cbd15e28 --- /dev/null +++ b/drivers/vdpa/vdpa_user/vduse_dev.c@@ -0,0 +1,1453 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * VDUSE: vDPA Device in Userspace + * + * Copyright (C) 2020-2021 Bytedance Inc. and/or its affiliates. All rights reserved. + * + * Author: Xie Yongji <xieyongji@bytedance.com> + * + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/cdev.h> +#include <linux/device.h> +#include <linux/eventfd.h> +#include <linux/slab.h> +#include <linux/wait.h> +#include <linux/dma-map-ops.h> +#include <linux/poll.h> +#include <linux/file.h> +#include <linux/uio.h> +#include <linux/vdpa.h> +#include <linux/nospec.h> +#include <uapi/linux/vduse.h> +#include <uapi/linux/vdpa.h> +#include <uapi/linux/virtio_config.h> +#include <uapi/linux/virtio_ids.h> +#include <uapi/linux/virtio_blk.h> +#include <linux/mod_devicetable.h> + +#include "iova_domain.h" + +#define DRV_AUTHOR "Yongji Xie <xieyongji@bytedance.com>" +#define DRV_DESC "vDPA Device in Userspace" +#define DRV_LICENSE "GPL v2" + +#define VDUSE_DEV_MAX (1U << MINORBITS) +#define VDUSE_MAX_BOUNCE_SIZE (64 * 1024 * 1024) +#define VDUSE_IOVA_SIZE (128 * 1024 * 1024) +#define VDUSE_REQUEST_TIMEOUT 30 + +struct vduse_virtqueue { + u16 index; + u32 num; + u32 avail_idx; + u64 desc_addr; + u64 driver_addr; + u64 device_addr; + bool ready; + bool kicked; + spinlock_t kick_lock; + spinlock_t irq_lock; + struct eventfd_ctx *kickfd; + struct vdpa_callback cb; + struct work_struct inject; +}; + +struct vduse_dev; + +struct vduse_vdpa { + struct vdpa_device vdpa; + struct vduse_dev *dev; +}; + +struct vduse_dev { + struct vduse_vdpa *vdev; + struct device *dev; + struct vduse_virtqueue *vqs; + struct vduse_iova_domain *domain; + char *name; + struct mutex lock; + spinlock_t msg_lock; + u64 msg_unique; + wait_queue_head_t waitq; + struct list_head send_list; + struct list_head recv_list; + struct vdpa_callback config_cb; + struct work_struct inject; + spinlock_t irq_lock; + int minor; + bool connected; + bool started; + u64 api_version; + u64 user_features;Let's use device_features.OK.quoted
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+ u64 features;And driver features.OK.quoted
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+ u32 device_id; + u32 vendor_id; + u32 generation; + u32 config_size; + void *config; + u8 status; + u16 vq_size_max; + u32 vq_num; + u32 vq_align; +}; + +struct vduse_dev_msg { + struct vduse_dev_request req; + struct vduse_dev_response resp; + struct list_head list; + wait_queue_head_t waitq; + bool completed; +}; + +struct vduse_control { + u64 api_version; +}; + +static DEFINE_MUTEX(vduse_lock); +static DEFINE_IDR(vduse_idr); + +static dev_t vduse_major; +static struct class *vduse_class; +static struct cdev vduse_ctrl_cdev; +static struct cdev vduse_cdev; +static struct workqueue_struct *vduse_irq_wq; + +static u32 allowed_device_id[] = { + VIRTIO_ID_BLOCK, +}; + +static inline struct vduse_dev *vdpa_to_vduse(struct vdpa_device *vdpa) +{ + struct vduse_vdpa *vdev = container_of(vdpa, struct vduse_vdpa, vdpa); + + return vdev->dev; +} + +static inline struct vduse_dev *dev_to_vduse(struct device *dev) +{ + struct vdpa_device *vdpa = dev_to_vdpa(dev); + + return vdpa_to_vduse(vdpa); +} + +static struct vduse_dev_msg *vduse_find_msg(struct list_head *head, + uint32_t request_id) +{ + struct vduse_dev_msg *msg; + + list_for_each_entry(msg, head, list) { + if (msg->req.request_id == request_id) { + list_del(&msg->list); + return msg; + } + } + + return NULL; +} + +static struct vduse_dev_msg *vduse_dequeue_msg(struct list_head *head) +{ + struct vduse_dev_msg *msg = NULL; + + if (!list_empty(head)) { + msg = list_first_entry(head, struct vduse_dev_msg, list); + list_del(&msg->list); + } + + return msg; +} + +static void vduse_enqueue_msg(struct list_head *head, + struct vduse_dev_msg *msg) +{ + list_add_tail(&msg->list, head); +} + +static int vduse_dev_msg_send(struct vduse_dev *dev, + struct vduse_dev_msg *msg, bool no_reply) +{It looks to me the only user for no_reply=true is the dataplane start. I wonder no_reply is really needed consider we have switched to use wait_event_killable_timeout().Do we need to handle the error in this case if we remove the no_reply flag. Print a warning message?See below.quoted
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In another way, no_reply is false for vq state synchronization and IOTLB updating. I wonder if we can simply use no_reply = true for them.Looks like we can't, e.g. we need to get a reply from userspace for vq state.Right.quoted
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+ init_waitqueue_head(&msg->waitq); + spin_lock(&dev->msg_lock); + msg->req.request_id = dev->msg_unique++; + vduse_enqueue_msg(&dev->send_list, msg); + wake_up(&dev->waitq); + spin_unlock(&dev->msg_lock); + if (no_reply) + return 0; + + wait_event_killable_timeout(msg->waitq, msg->completed, + VDUSE_REQUEST_TIMEOUT * HZ); + spin_lock(&dev->msg_lock); + if (!msg->completed) { + list_del(&msg->list); + msg->resp.result = VDUSE_REQ_RESULT_FAILED; + } + spin_unlock(&dev->msg_lock); + + return (msg->resp.result == VDUSE_REQ_RESULT_OK) ? 0 : -EIO;Do we need to serialize the check by protecting it with the spinlock above?Good point.quoted
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+} + +static void vduse_dev_msg_cleanup(struct vduse_dev *dev) +{ + struct vduse_dev_msg *msg; + + spin_lock(&dev->msg_lock); + while ((msg = vduse_dequeue_msg(&dev->send_list))) { + if (msg->req.flags & VDUSE_REQ_FLAGS_NO_REPLY) + kfree(msg); + else + vduse_enqueue_msg(&dev->recv_list, msg); + } + while ((msg = vduse_dequeue_msg(&dev->recv_list))) { + msg->resp.result = VDUSE_REQ_RESULT_FAILED; + msg->completed = 1; + wake_up(&msg->waitq); + } + spin_unlock(&dev->msg_lock); +} + +static void vduse_dev_start_dataplane(struct vduse_dev *dev) +{ + struct vduse_dev_msg *msg = kzalloc(sizeof(*msg), + GFP_KERNEL | __GFP_NOFAIL); + + msg->req.type = VDUSE_START_DATAPLANE; + msg->req.flags |= VDUSE_REQ_FLAGS_NO_REPLY; + vduse_dev_msg_send(dev, msg, true); +} + +static void vduse_dev_stop_dataplane(struct vduse_dev *dev) +{ + struct vduse_dev_msg *msg = kzalloc(sizeof(*msg), + GFP_KERNEL | __GFP_NOFAIL); + + msg->req.type = VDUSE_STOP_DATAPLANE; + msg->req.flags |= VDUSE_REQ_FLAGS_NO_REPLY;Can we simply use this flag instead of introducing a new parameter (no_reply) in vduse_dev_msg_send()?Looks good to me.quoted
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+ vduse_dev_msg_send(dev, msg, true); +} + +static int vduse_dev_get_vq_state(struct vduse_dev *dev, + struct vduse_virtqueue *vq, + struct vdpa_vq_state *state) +{ + struct vduse_dev_msg msg = { 0 }; + int ret;Note that I post a series that implement the packed virtqueue support: https://lists.linuxfoundation.org/pipermail/virtualization/2021-June/054501.html So this patch needs to be updated as well.Will do it.quoted
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+ + msg.req.type = VDUSE_GET_VQ_STATE; + msg.req.vq_state.index = vq->index; + + ret = vduse_dev_msg_send(dev, &msg, false); + if (ret) + return ret; + + state->avail_index = msg.resp.vq_state.avail_idx; + return 0; +} + +static int vduse_dev_update_iotlb(struct vduse_dev *dev, + u64 start, u64 last) +{ + struct vduse_dev_msg msg = { 0 }; + + if (last < start) + return -EINVAL; + + msg.req.type = VDUSE_UPDATE_IOTLB; + msg.req.iova.start = start; + msg.req.iova.last = last; + + return vduse_dev_msg_send(dev, &msg, false); +} + +static ssize_t vduse_dev_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ + struct file *file = iocb->ki_filp; + struct vduse_dev *dev = file->private_data; + struct vduse_dev_msg *msg; + int size = sizeof(struct vduse_dev_request); + ssize_t ret; + + if (iov_iter_count(to) < size) + return -EINVAL; + + spin_lock(&dev->msg_lock); + while (1) { + msg = vduse_dequeue_msg(&dev->send_list); + if (msg) + break; + + ret = -EAGAIN; + if (file->f_flags & O_NONBLOCK) + goto unlock; + + spin_unlock(&dev->msg_lock); + ret = wait_event_interruptible_exclusive(dev->waitq, + !list_empty(&dev->send_list)); + if (ret) + return ret; + + spin_lock(&dev->msg_lock); + } + spin_unlock(&dev->msg_lock); + ret = copy_to_iter(&msg->req, size, to); + spin_lock(&dev->msg_lock); + if (ret != size) { + ret = -EFAULT; + vduse_enqueue_msg(&dev->send_list, msg); + goto unlock; + } + if (msg->req.flags & VDUSE_REQ_FLAGS_NO_REPLY) + kfree(msg); + else + vduse_enqueue_msg(&dev->recv_list, msg); +unlock: + spin_unlock(&dev->msg_lock); + + return ret; +} + +static ssize_t vduse_dev_write_iter(struct kiocb *iocb, struct iov_iter *from) +{ + struct file *file = iocb->ki_filp; + struct vduse_dev *dev = file->private_data; + struct vduse_dev_response resp; + struct vduse_dev_msg *msg; + size_t ret; + + ret = copy_from_iter(&resp, sizeof(resp), from); + if (ret != sizeof(resp)) + return -EINVAL; + + spin_lock(&dev->msg_lock); + msg = vduse_find_msg(&dev->recv_list, resp.request_id); + if (!msg) { + ret = -ENOENT; + goto unlock; + } + + memcpy(&msg->resp, &resp, sizeof(resp)); + msg->completed = 1; + wake_up(&msg->waitq); +unlock: + spin_unlock(&dev->msg_lock); + + return ret; +} + +static __poll_t vduse_dev_poll(struct file *file, poll_table *wait) +{ + struct vduse_dev *dev = file->private_data; + __poll_t mask = 0; + + poll_wait(file, &dev->waitq, wait); + + if (!list_empty(&dev->send_list)) + mask |= EPOLLIN | EPOLLRDNORM; + if (!list_empty(&dev->recv_list)) + mask |= EPOLLOUT | EPOLLWRNORM; + + return mask; +} + +static void vduse_dev_reset(struct vduse_dev *dev) +{ + int i; + struct vduse_iova_domain *domain = dev->domain; + + /* The coherent mappings are handled in vduse_dev_free_coherent() */ + if (domain->bounce_map) + vduse_domain_reset_bounce_map(domain); + + dev->features = 0; + dev->generation++; + spin_lock(&dev->irq_lock); + dev->config_cb.callback = NULL; + dev->config_cb.private = NULL; + spin_unlock(&dev->irq_lock); + + for (i = 0; i < dev->vq_num; i++) { + struct vduse_virtqueue *vq = &dev->vqs[i]; + + vq->ready = false; + vq->desc_addr = 0; + vq->driver_addr = 0; + vq->device_addr = 0; + vq->avail_idx = 0; + vq->num = 0; + + spin_lock(&vq->kick_lock); + vq->kicked = false; + if (vq->kickfd) + eventfd_ctx_put(vq->kickfd); + vq->kickfd = NULL; + spin_unlock(&vq->kick_lock); + + spin_lock(&vq->irq_lock); + vq->cb.callback = NULL; + vq->cb.private = NULL; + spin_unlock(&vq->irq_lock); + } +} + +static int vduse_vdpa_set_vq_address(struct vdpa_device *vdpa, u16 idx, + u64 desc_area, u64 driver_area, + u64 device_area) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + struct vduse_virtqueue *vq = &dev->vqs[idx]; + + vq->desc_addr = desc_area; + vq->driver_addr = driver_area; + vq->device_addr = device_area; + + return 0; +} + +static void vduse_vdpa_kick_vq(struct vdpa_device *vdpa, u16 idx) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + struct vduse_virtqueue *vq = &dev->vqs[idx]; + + spin_lock(&vq->kick_lock); + if (!vq->ready) + goto unlock; + + if (vq->kickfd) + eventfd_signal(vq->kickfd, 1); + else + vq->kicked = true; +unlock: + spin_unlock(&vq->kick_lock); +} + +static void vduse_vdpa_set_vq_cb(struct vdpa_device *vdpa, u16 idx, + struct vdpa_callback *cb) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + struct vduse_virtqueue *vq = &dev->vqs[idx]; + + spin_lock(&vq->irq_lock); + vq->cb.callback = cb->callback; + vq->cb.private = cb->private; + spin_unlock(&vq->irq_lock); +} + +static void vduse_vdpa_set_vq_num(struct vdpa_device *vdpa, u16 idx, u32 num) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + struct vduse_virtqueue *vq = &dev->vqs[idx]; + + vq->num = num; +} + +static void vduse_vdpa_set_vq_ready(struct vdpa_device *vdpa, + u16 idx, bool ready) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + struct vduse_virtqueue *vq = &dev->vqs[idx]; + + vq->ready = ready; +} + +static bool vduse_vdpa_get_vq_ready(struct vdpa_device *vdpa, u16 idx) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + struct vduse_virtqueue *vq = &dev->vqs[idx]; + + return vq->ready; +} + +static int vduse_vdpa_set_vq_state(struct vdpa_device *vdpa, u16 idx, + const struct vdpa_vq_state *state) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + struct vduse_virtqueue *vq = &dev->vqs[idx]; + + vq->avail_idx = state->avail_index; + return 0; +} + +static int vduse_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 idx, + struct vdpa_vq_state *state) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + struct vduse_virtqueue *vq = &dev->vqs[idx]; + + return vduse_dev_get_vq_state(dev, vq, state); +} + +static u32 vduse_vdpa_get_vq_align(struct vdpa_device *vdpa) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + + return dev->vq_align; +} + +static u64 vduse_vdpa_get_features(struct vdpa_device *vdpa) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + + return dev->user_features; +} + +static int vduse_vdpa_set_features(struct vdpa_device *vdpa, u64 features) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + + dev->features = features; + return 0; +} + +static void vduse_vdpa_set_config_cb(struct vdpa_device *vdpa, + struct vdpa_callback *cb) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + + spin_lock(&dev->irq_lock); + dev->config_cb.callback = cb->callback; + dev->config_cb.private = cb->private; + spin_unlock(&dev->irq_lock); +} + +static u16 vduse_vdpa_get_vq_num_max(struct vdpa_device *vdpa) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + + return dev->vq_size_max; +} + +static u32 vduse_vdpa_get_device_id(struct vdpa_device *vdpa) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + + return dev->device_id; +} + +static u32 vduse_vdpa_get_vendor_id(struct vdpa_device *vdpa) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + + return dev->vendor_id; +} + +static u8 vduse_vdpa_get_status(struct vdpa_device *vdpa) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + + return dev->status; +} + +static void vduse_vdpa_set_status(struct vdpa_device *vdpa, u8 status) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + bool started = !!(status & VIRTIO_CONFIG_S_DRIVER_OK); + + dev->status = status; + + if (dev->started == started) + return;If we check dev->status == status, (or only check the DRIVER_OK bit) then there's no need to introduce an extra dev->started.Will do it.quoted
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+ + dev->started = started; + if (dev->started) { + vduse_dev_start_dataplane(dev); + } else { + vduse_dev_reset(dev); + vduse_dev_stop_dataplane(dev);I wonder if no_reply work for the case of vhost-vdpa. For virtio-vDPA, we have bouncing buffers so it's harmless if usersapce dataplane keeps performing read/write. For vhost-vDPA we don't have such stuffs.OK. So it still needs to be synchronized here. If so, how to handle the error? Looks like printing a warning message should be enough.We need fix a way to propagate the error to the userspace. E.g if we want to stop the deivce, we will delay the status reset until we get respose from the userspace?
I didn't get how to delay the status reset. And should it be a DoS that we want to fix if the userspace doesn't give a response forever?
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+ } +} + +static size_t vduse_vdpa_get_config_size(struct vdpa_device *vdpa) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + + return dev->config_size; +} + +static void vduse_vdpa_get_config(struct vdpa_device *vdpa, unsigned int offset, + void *buf, unsigned int len) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + + memcpy(buf, dev->config + offset, len); +} + +static void vduse_vdpa_set_config(struct vdpa_device *vdpa, unsigned int offset, + const void *buf, unsigned int len) +{ + /* Now we only support read-only configuration space */ +} + +static u32 vduse_vdpa_get_generation(struct vdpa_device *vdpa) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + + return dev->generation; +} + +static int vduse_vdpa_set_map(struct vdpa_device *vdpa, + struct vhost_iotlb *iotlb) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + int ret; + + ret = vduse_domain_set_map(dev->domain, iotlb); + if (ret) + return ret; + + ret = vduse_dev_update_iotlb(dev, 0ULL, ULLONG_MAX); + if (ret) { + vduse_domain_clear_map(dev->domain, iotlb); + return ret; + } + + return 0; +} + +static void vduse_vdpa_free(struct vdpa_device *vdpa) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + + dev->vdev = NULL; +} + +static const struct vdpa_config_ops vduse_vdpa_config_ops = { + .set_vq_address = vduse_vdpa_set_vq_address, + .kick_vq = vduse_vdpa_kick_vq, + .set_vq_cb = vduse_vdpa_set_vq_cb, + .set_vq_num = vduse_vdpa_set_vq_num, + .set_vq_ready = vduse_vdpa_set_vq_ready, + .get_vq_ready = vduse_vdpa_get_vq_ready, + .set_vq_state = vduse_vdpa_set_vq_state, + .get_vq_state = vduse_vdpa_get_vq_state, + .get_vq_align = vduse_vdpa_get_vq_align, + .get_features = vduse_vdpa_get_features, + .set_features = vduse_vdpa_set_features, + .set_config_cb = vduse_vdpa_set_config_cb, + .get_vq_num_max = vduse_vdpa_get_vq_num_max, + .get_device_id = vduse_vdpa_get_device_id, + .get_vendor_id = vduse_vdpa_get_vendor_id, + .get_status = vduse_vdpa_get_status, + .set_status = vduse_vdpa_set_status, + .get_config_size = vduse_vdpa_get_config_size, + .get_config = vduse_vdpa_get_config, + .set_config = vduse_vdpa_set_config, + .get_generation = vduse_vdpa_get_generation, + .set_map = vduse_vdpa_set_map, + .free = vduse_vdpa_free, +}; + +static dma_addr_t vduse_dev_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction dir, + unsigned long attrs) +{ + struct vduse_dev *vdev = dev_to_vduse(dev); + struct vduse_iova_domain *domain = vdev->domain; + + return vduse_domain_map_page(domain, page, offset, size, dir, attrs); +} + +static void vduse_dev_unmap_page(struct device *dev, dma_addr_t dma_addr, + size_t size, enum dma_data_direction dir, + unsigned long attrs) +{ + struct vduse_dev *vdev = dev_to_vduse(dev); + struct vduse_iova_domain *domain = vdev->domain; + + return vduse_domain_unmap_page(domain, dma_addr, size, dir, attrs); +} + +static void *vduse_dev_alloc_coherent(struct device *dev, size_t size, + dma_addr_t *dma_addr, gfp_t flag, + unsigned long attrs) +{ + struct vduse_dev *vdev = dev_to_vduse(dev); + struct vduse_iova_domain *domain = vdev->domain; + unsigned long iova; + void *addr; + + *dma_addr = DMA_MAPPING_ERROR; + addr = vduse_domain_alloc_coherent(domain, size, + (dma_addr_t *)&iova, flag, attrs); + if (!addr) + return NULL; + + *dma_addr = (dma_addr_t)iova; + + return addr; +} + +static void vduse_dev_free_coherent(struct device *dev, size_t size, + void *vaddr, dma_addr_t dma_addr, + unsigned long attrs) +{ + struct vduse_dev *vdev = dev_to_vduse(dev); + struct vduse_iova_domain *domain = vdev->domain; + + vduse_domain_free_coherent(domain, size, vaddr, dma_addr, attrs); +} + +static size_t vduse_dev_max_mapping_size(struct device *dev) +{ + struct vduse_dev *vdev = dev_to_vduse(dev); + struct vduse_iova_domain *domain = vdev->domain; + + return domain->bounce_size; +} + +static const struct dma_map_ops vduse_dev_dma_ops = { + .map_page = vduse_dev_map_page, + .unmap_page = vduse_dev_unmap_page, + .alloc = vduse_dev_alloc_coherent, + .free = vduse_dev_free_coherent, + .max_mapping_size = vduse_dev_max_mapping_size, +}; + +static unsigned int perm_to_file_flags(u8 perm) +{ + unsigned int flags = 0; + + switch (perm) { + case VDUSE_ACCESS_WO: + flags |= O_WRONLY; + break; + case VDUSE_ACCESS_RO: + flags |= O_RDONLY; + break; + case VDUSE_ACCESS_RW: + flags |= O_RDWR; + break; + default: + WARN(1, "invalidate vhost IOTLB permission\n"); + break; + } + + return flags; +} + +static int vduse_kickfd_setup(struct vduse_dev *dev, + struct vduse_vq_eventfd *eventfd) +{ + struct eventfd_ctx *ctx = NULL; + struct vduse_virtqueue *vq; + u32 index; + + if (eventfd->index >= dev->vq_num) + return -EINVAL; + + index = array_index_nospec(eventfd->index, dev->vq_num); + vq = &dev->vqs[index]; + if (eventfd->fd >= 0) { + ctx = eventfd_ctx_fdget(eventfd->fd); + if (IS_ERR(ctx)) + return PTR_ERR(ctx); + } else if (eventfd->fd != VDUSE_EVENTFD_DEASSIGN) + return 0; + + spin_lock(&vq->kick_lock); + if (vq->kickfd) + eventfd_ctx_put(vq->kickfd); + vq->kickfd = ctx; + if (vq->ready && vq->kicked && vq->kickfd) { + eventfd_signal(vq->kickfd, 1); + vq->kicked = false; + } + spin_unlock(&vq->kick_lock); + + return 0; +} + +static void vduse_dev_irq_inject(struct work_struct *work) +{ + struct vduse_dev *dev = container_of(work, struct vduse_dev, inject); + + spin_lock_irq(&dev->irq_lock); + if (dev->config_cb.callback) + dev->config_cb.callback(dev->config_cb.private); + spin_unlock_irq(&dev->irq_lock); +} + +static void vduse_vq_irq_inject(struct work_struct *work) +{ + struct vduse_virtqueue *vq = container_of(work, + struct vduse_virtqueue, inject); + + spin_lock_irq(&vq->irq_lock); + if (vq->ready && vq->cb.callback) + vq->cb.callback(vq->cb.private); + spin_unlock_irq(&vq->irq_lock); +} + +static long vduse_dev_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct vduse_dev *dev = file->private_data; + void __user *argp = (void __user *)arg; + int ret; + + switch (cmd) { + case VDUSE_IOTLB_GET_FD: { + struct vduse_iotlb_entry entry; + struct vhost_iotlb_map *map; + struct vdpa_map_file *map_file; + struct vduse_iova_domain *domain = dev->domain; + struct file *f = NULL; + + ret = -EFAULT; + if (copy_from_user(&entry, argp, sizeof(entry))) + break; + + ret = -EINVAL; + if (entry.start > entry.last) + break; + + spin_lock(&domain->iotlb_lock); + map = vhost_iotlb_itree_first(domain->iotlb, + entry.start, entry.last); + if (map) { + map_file = (struct vdpa_map_file *)map->opaque; + f = get_file(map_file->file); + entry.offset = map_file->offset; + entry.start = map->start; + entry.last = map->last; + entry.perm = map->perm; + } + spin_unlock(&domain->iotlb_lock); + ret = -EINVAL; + if (!f) + break; + + ret = -EFAULT; + if (copy_to_user(argp, &entry, sizeof(entry))) { + fput(f); + break; + } + ret = receive_fd(f, perm_to_file_flags(entry.perm)); + fput(f); + break; + } + case VDUSE_DEV_GET_FEATURES: + ret = put_user(dev->features, (u64 __user *)argp); + break; + case VDUSE_DEV_UPDATE_CONFIG: { + struct vduse_config_update config; + unsigned long size = offsetof(struct vduse_config_update, + buffer); + + ret = -EFAULT; + if (copy_from_user(&config, argp, size)) + break; + + ret = -EINVAL; + if (config.length == 0 || + config.length > dev->config_size - config.offset) + break; + + ret = -EFAULT; + if (copy_from_user(dev->config + config.offset, argp + size, + config.length)) + break; + + ret = 0; + queue_work(vduse_irq_wq, &dev->inject);I wonder if it's better to separate config interrupt out of config update or we need document this.I have documented it in the docs. Looks like a config update should be always followed by a config interrupt. I didn't find a case that uses them separately.The uAPI doesn't prevent us from the following scenario: update_config(mac[0], ..); update_config(max[1], ..); So it looks to me it's better to separate the config interrupt from the config updating.
Fine.
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+ break; + } + case VDUSE_VQ_GET_INFO: {Do we need to limit this only when DRIVER_OK is set?Any reason to add this limitation?Otherwise the vq is not fully initialized, e.g the desc_addr might not be correct.
The vq_info->ready can be used to tell userspace whether the vq is initialized or not. Thanks, Yongji