Messages in this thread Patch in this message | | | From | Cindy Lu <> | Subject | [PATCH v2 2/5] vduse: Add file operation for mmap | Date | Tue, 21 Nov 2023 15:30:47 +0800 |
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Add the operation for mmap, The user space APP will use this function to map the pages to userspace
Signed-off-by: Cindy Lu <lulu@redhat.com> --- drivers/vdpa/vdpa_user/vduse_dev.c | 79 ++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+)
diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c index 6209e2f00278..ccb30e98bab5 100644 --- a/drivers/vdpa/vdpa_user/vduse_dev.c +++ b/drivers/vdpa/vdpa_user/vduse_dev.c @@ -1376,6 +1376,83 @@ static struct vduse_dev *vduse_dev_get_from_minor(int minor) return dev; } +static vm_fault_t vduse_vm_fault(struct vm_fault *vmf) +{ + struct vduse_dev *dev = vmf->vma->vm_file->private_data; + struct vm_area_struct *vma = vmf->vma; + u16 index = vma->vm_pgoff; + struct vduse_virtqueue *vq; + struct vdpa_reconnect_info *info; + + /* index 0 page reserved for vduse status*/ + if (index == 0) { + info = &dev->reconnect_info; + } else { + /* index 1+vq_number page reserved for vduse vqs*/ + vq = &dev->vqs[index - 1]; + info = &vq->reconnect_info; + } + if (remap_pfn_range(vma, vmf->address & PAGE_MASK, + PFN_DOWN(virt_to_phys((void *)info->vaddr)), + PAGE_SIZE, vma->vm_page_prot)) + return VM_FAULT_SIGBUS; + return VM_FAULT_NOPAGE; +} + +static const struct vm_operations_struct vduse_vm_ops = { + .fault = vduse_vm_fault, +}; + +static int vduse_dev_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct vduse_dev *dev = file->private_data; + struct vdpa_reconnect_info *info; + unsigned long index = vma->vm_pgoff; + struct vduse_virtqueue *vq; + + if (vma->vm_end - vma->vm_start != PAGE_SIZE) + return -EINVAL; + if ((vma->vm_flags & VM_SHARED) == 0) + return -EINVAL; + + /*check if Userspace App map the page number larger than kernel allocated*/ + if (index > dev->vq_num + 1) + return -EINVAL; + + /* index 0 page reserved for vduse status*/ + if (index == 0) { + info = &dev->reconnect_info; + } else { + /* index 1+vq_number page reserved for vduse vqs*/ + vq = &dev->vqs[index - 1]; + info = &vq->reconnect_info; + } + /*check if map pages was allocated and inited by kernel */ + if (info->vaddr == 0) + return -EOPNOTSUPP; + + /* check if the address is page aligned, if not, + * this address maybe damaged + */ + if (virt_to_phys((void *)info->vaddr) & (PAGE_SIZE - 1)) + return -EINVAL; + + /* check if Userspace App mapped the correct size + * the userspace App should map one page each time + */ + if (vma->vm_end - vma->vm_start != PAGE_SIZE) + return -EOPNOTSUPP; + /* VM_IO: set as a memory-mapped I/O region,This will for vq information + * VM_PFNMAP: only need the pure PFN + * VM_DONTEXPAND: do not need to use mremap() in this function + * VM_DONTDUMP:Do not include in the core dump + */ + vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP); + vma->vm_ops = &vduse_vm_ops; + + return 0; +} + static int vduse_dev_open(struct inode *inode, struct file *file) { int ret; @@ -1408,6 +1485,8 @@ static const struct file_operations vduse_dev_fops = { .unlocked_ioctl = vduse_dev_ioctl, .compat_ioctl = compat_ptr_ioctl, .llseek = noop_llseek, + .mmap = vduse_dev_mmap, + }; static struct vduse_dev *vduse_dev_create(void) -- 2.34.3
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