diff mbox series

[RFC,v2,2/4] vduse: Add file operation for mmap

Message ID 20230912030008.3599514-3-lulu@redhat.com (mailing list archive)
State New, archived
Headers show
Series Support reconnection in vduse | expand

Commit Message

Cindy Lu Sept. 12, 2023, 3 a.m. UTC 
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 | 63 ++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

Comments

Jason Wang Sept. 18, 2023, 8:46 a.m. UTC | #1 
On Tue, Sep 12, 2023 at 11:00 AM Cindy Lu <lulu@redhat.com> 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@redhat.com>
> ---
>  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
>
diff mbox series

Patch

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;
+
+	if (info->addr & (PAGE_SIZE - 1))
+		return -EINVAL;
+	if (vma->vm_end - vma->vm_start != info->size)
+		return -EOPNOTSUPP;
+
+	vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTDUMP);
+	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)