.On Tue, Jun 22, 2021 at 1:07 PM Jason Wang <jasow...@redhat.com> wrote: > > > 在 2021/6/21 下午6:41, Yongji Xie 写道: > > On Mon, Jun 21, 2021 at 5:14 PM Jason Wang <jasow...@redhat.com> wrote: > >> > >> 在 2021/6/15 下午10:13, Xie Yongji 写道: > >>> 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 <xieyon...@bytedance.com> > >>> --- > >>> 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.h > >>> > >>> diff --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 range > >>> diff --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_MSI > >>> diff --git a/drivers/vdpa/Makefile b/drivers/vdpa/Makefile > >>> index 67fe7f3d6943..f02ebed33f19 100644 > >>> --- a/drivers/vdpa/Makefile > >>> +++ b/drivers/vdpa/Makefile > >>> @@ -1,6 +1,7 @@ > >>> # SPDX-License-Identifier: GPL-2.0 > >>> obj-$(CONFIG_VDPA) += vdpa.o > >>> obj-$(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.o > >>> diff --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 <xieyon...@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 <xieyon...@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. > > > >>> + u64 features; > >> > >> And driver features. > >> > > OK. > > > >>> + 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. > > > > > >> 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. > > > > > >>> + 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. > > > >>> +} > >>> + > >>> +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. > > > >>> + 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. > > > >>> + > >>> + 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. > > > >>> + > >>> + 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? > > > > >>> + } > >>> +} > >>> + > >>> +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. > > > > >>> + 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 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu