On Tue, Sep 12, 2023 at 11:00 AM Cindy Lu <lulu@xxxxxxxxxx> wrote:
>
> 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@xxxxxxxxxx>
> ---
> drivers/vdpa/vdpa_user/vduse_dev.c | 63 ++++++++++++++++++++++++++++++
> 1 file changed, 63 insertions(+)
>
> diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
> index 4c256fa31fc4..2c69f4004a6e 100644
> --- a/drivers/vdpa/vdpa_user/vduse_dev.c
> +++ b/drivers/vdpa/vdpa_user/vduse_dev.c
> @@ -1388,6 +1388,67 @@ 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;
> +
> + if (index == 0) {
> + info = &dev->reconnect_status;
> + } else {
> + vq = &dev->vqs[index - 1];
> + info = &vq->reconnect_info;
> + }
> + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
> + if (remap_pfn_range(vma, vmf->address & PAGE_MASK, PFN_DOWN(info->addr),
> + 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;
> +
> + if (index > 65535)
> + return -EINVAL;
> +
> + if (index == 0) {
> + info = &dev->reconnect_status;
> + } else {
> + vq = &dev->vqs[index - 1];
> + info = &vq->reconnect_info;
> + }
> +
> + if (info->index != index)
> + return -EINVAL;
Under which case could we meet this?
> +
> + if (info->addr & (PAGE_SIZE - 1))
> + return -EINVAL;
And this?
> + if (vma->vm_end - vma->vm_start != info->size)
> + return -EOPNOTSUPP;
> +
> + vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTDUMP);
Why do you use VM_IO, VM_PFNMAP and VM_DONTDUMP?
Thanks
> + vma->vm_ops = &vduse_vm_ops;
> +
> + return 0;
> +}
> +
> static int vduse_dev_open(struct inode *inode, struct file *file)
> {
> int ret;
> @@ -1420,6 +1481,8 @@ 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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