From b1145698dd8acdac2d7d6b876665fb8199952148 Mon Sep 17 00:00:00 2001 From: Xie Yongji Date: Wed, 3 Aug 2022 12:55:22 +0800 Subject: [PATCH] vduse: Support registering userspace memory for IOVA regions Introduce two ioctls: VDUSE_IOTLB_REG_UMEM and VDUSE_IOTLB_DEREG_UMEM to support registering and de-registering userspace memory for IOVA regions. Now it only supports registering userspace memory for bounce buffer region in virtio-vdpa case. Signed-off-by: Xie Yongji Acked-by: Jason Wang Message-Id: <20220803045523.23851-5-xieyongji@bytedance.com> Signed-off-by: Michael S. Tsirkin --- drivers/vdpa/vdpa_user/vduse_dev.c | 141 +++++++++++++++++++++++++++++ include/uapi/linux/vduse.h | 23 +++++ 2 files changed, 164 insertions(+) diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c index 3bc27de58f46b..eedff0a3885a4 100644 --- a/drivers/vdpa/vdpa_user/vduse_dev.c +++ b/drivers/vdpa/vdpa_user/vduse_dev.c @@ -21,6 +21,8 @@ #include #include #include +#include +#include #include #include #include @@ -64,6 +66,13 @@ struct vduse_vdpa { struct vduse_dev *dev; }; +struct vduse_umem { + unsigned long iova; + unsigned long npages; + struct page **pages; + struct mm_struct *mm; +}; + struct vduse_dev { struct vduse_vdpa *vdev; struct device *dev; @@ -95,6 +104,8 @@ struct vduse_dev { u8 status; u32 vq_num; u32 vq_align; + struct vduse_umem *umem; + struct mutex mem_lock; }; struct vduse_dev_msg { @@ -917,6 +928,102 @@ unlock: return ret; } +static int vduse_dev_dereg_umem(struct vduse_dev *dev, + u64 iova, u64 size) +{ + int ret; + + mutex_lock(&dev->mem_lock); + ret = -ENOENT; + if (!dev->umem) + goto unlock; + + ret = -EINVAL; + if (dev->umem->iova != iova || size != dev->domain->bounce_size) + goto unlock; + + vduse_domain_remove_user_bounce_pages(dev->domain); + unpin_user_pages_dirty_lock(dev->umem->pages, + dev->umem->npages, true); + atomic64_sub(dev->umem->npages, &dev->umem->mm->pinned_vm); + mmdrop(dev->umem->mm); + vfree(dev->umem->pages); + kfree(dev->umem); + dev->umem = NULL; + ret = 0; +unlock: + mutex_unlock(&dev->mem_lock); + return ret; +} + +static int vduse_dev_reg_umem(struct vduse_dev *dev, + u64 iova, u64 uaddr, u64 size) +{ + struct page **page_list = NULL; + struct vduse_umem *umem = NULL; + long pinned = 0; + unsigned long npages, lock_limit; + int ret; + + if (!dev->domain->bounce_map || + size != dev->domain->bounce_size || + iova != 0 || uaddr & ~PAGE_MASK) + return -EINVAL; + + mutex_lock(&dev->mem_lock); + ret = -EEXIST; + if (dev->umem) + goto unlock; + + ret = -ENOMEM; + npages = size >> PAGE_SHIFT; + page_list = __vmalloc(array_size(npages, sizeof(struct page *)), + GFP_KERNEL_ACCOUNT); + umem = kzalloc(sizeof(*umem), GFP_KERNEL); + if (!page_list || !umem) + goto unlock; + + mmap_read_lock(current->mm); + + lock_limit = PFN_DOWN(rlimit(RLIMIT_MEMLOCK)); + if (npages + atomic64_read(¤t->mm->pinned_vm) > lock_limit) + goto out; + + pinned = pin_user_pages(uaddr, npages, FOLL_LONGTERM | FOLL_WRITE, + page_list, NULL); + if (pinned != npages) { + ret = pinned < 0 ? pinned : -ENOMEM; + goto out; + } + + ret = vduse_domain_add_user_bounce_pages(dev->domain, + page_list, pinned); + if (ret) + goto out; + + atomic64_add(npages, ¤t->mm->pinned_vm); + + umem->pages = page_list; + umem->npages = pinned; + umem->iova = iova; + umem->mm = current->mm; + mmgrab(current->mm); + + dev->umem = umem; +out: + if (ret && pinned > 0) + unpin_user_pages(page_list, pinned); + + mmap_read_unlock(current->mm); +unlock: + if (ret) { + vfree(page_list); + kfree(umem); + } + mutex_unlock(&dev->mem_lock); + return ret; +} + static long vduse_dev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -1089,6 +1196,38 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd, ret = vduse_dev_queue_irq_work(dev, &dev->vqs[index].inject); break; } + case VDUSE_IOTLB_REG_UMEM: { + struct vduse_iova_umem umem; + + ret = -EFAULT; + if (copy_from_user(&umem, argp, sizeof(umem))) + break; + + ret = -EINVAL; + if (!is_mem_zero((const char *)umem.reserved, + sizeof(umem.reserved))) + break; + + ret = vduse_dev_reg_umem(dev, umem.iova, + umem.uaddr, umem.size); + break; + } + case VDUSE_IOTLB_DEREG_UMEM: { + struct vduse_iova_umem umem; + + ret = -EFAULT; + if (copy_from_user(&umem, argp, sizeof(umem))) + break; + + ret = -EINVAL; + if (!is_mem_zero((const char *)umem.reserved, + sizeof(umem.reserved))) + break; + + ret = vduse_dev_dereg_umem(dev, umem.iova, + umem.size); + break; + } default: ret = -ENOIOCTLCMD; break; @@ -1101,6 +1240,7 @@ static int vduse_dev_release(struct inode *inode, struct file *file) { struct vduse_dev *dev = file->private_data; + vduse_dev_dereg_umem(dev, 0, dev->domain->bounce_size); spin_lock(&dev->msg_lock); /* Make sure the inflight messages can processed after reconncection */ list_splice_init(&dev->recv_list, &dev->send_list); @@ -1163,6 +1303,7 @@ static struct vduse_dev *vduse_dev_create(void) return NULL; mutex_init(&dev->lock); + mutex_init(&dev->mem_lock); spin_lock_init(&dev->msg_lock); INIT_LIST_HEAD(&dev->send_list); INIT_LIST_HEAD(&dev->recv_list); diff --git a/include/uapi/linux/vduse.h b/include/uapi/linux/vduse.h index 7cfe1c1280c0f..9885e0571f098 100644 --- a/include/uapi/linux/vduse.h +++ b/include/uapi/linux/vduse.h @@ -210,6 +210,29 @@ struct vduse_vq_eventfd { */ #define VDUSE_VQ_INJECT_IRQ _IOW(VDUSE_BASE, 0x17, __u32) +/** + * struct vduse_iova_umem - userspace memory configuration for one IOVA region + * @uaddr: start address of userspace memory, it must be aligned to page size + * @iova: start of the IOVA region + * @size: size of the IOVA region + * @reserved: for future use, needs to be initialized to zero + * + * Structure used by VDUSE_IOTLB_REG_UMEM and VDUSE_IOTLB_DEREG_UMEM + * ioctls to register/de-register userspace memory for IOVA regions + */ +struct vduse_iova_umem { + __u64 uaddr; + __u64 iova; + __u64 size; + __u64 reserved[3]; +}; + +/* Register userspace memory for IOVA regions */ +#define VDUSE_IOTLB_REG_UMEM _IOW(VDUSE_BASE, 0x18, struct vduse_iova_umem) + +/* De-register the userspace memory. Caller should set iova and size field. */ +#define VDUSE_IOTLB_DEREG_UMEM _IOW(VDUSE_BASE, 0x19, struct vduse_iova_umem) + /* The control messages definition for read(2)/write(2) on /dev/vduse/$NAME */ /** -- 2.39.5