Re: [PATCH 14/14] vhost-vdpa: convert mmap hook to mmap_prepare

On Thu, Nov 05, 2026 at 09:05:45PM +0000, Lorenzo Stoakes (ARM) wrote:

Move from the deprecated mmap hook to the new mmap_prepare hook. The hook only validates the request and sets the VMA flags, operations and page protection.

Signed-off-by: Lorenzo Stoakes (ARM) ljs@kernel.org

Acked-by: Michael S. Tsirkin mst@redhat.com

Who's merging this, me?

---

drivers/vhost/vdpa.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index ff7d90719171..993b2d7c8927 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -1573,19 +1573,19 @@ static const struct vm_operations_struct vhost_vdpa_vm_ops = { .fault = vhost_vdpa_fault, }; -static int vhost_vdpa_mmap(struct file *file, struct vm_area_struct *vma) +static int vhost_vdpa_mmap_prepare(struct vm_area_desc *desc) {

• struct vhost_vdpa *v = vma->vm_file->private_data;

• struct vhost_vdpa *v = desc->file->private_data; struct vdpa_device *vdpa = v->vdpa; const struct vdpa_config_ops *ops = vdpa->config; struct vdpa_notification_area notify;

• unsigned long index = vma->vm_pgoff;

• unsigned long index = desc->pgoff;

• if (vma->vm_end - vma->vm_start != PAGE_SIZE)

• if (vma_desc_size(desc) != PAGE_SIZE) return -EINVAL;

• if ((vma->vm_flags & VM_SHARED) == 0)

• if (!vma_desc_test(desc, VMA_SHARED_BIT)) return -EINVAL;

• if (vma->vm_flags & VM_READ)

• if (vma_desc_test(desc, VMA_READ_BIT)) return -EINVAL; if (!ops->get_vq_notification) return -ENOTSUPP;

@@ -1598,12 +1598,13 @@ static int vhost_vdpa_mmap(struct file *file, struct vm_area_struct *vma) return -EINVAL; if (notify.addr & (PAGE_SIZE - 1)) return -EINVAL;

• if (vma->vm_end - vma->vm_start != notify.size)

• if (vma_desc_size(desc) != notify.size) return -ENOTSUPP;

• vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
• vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP);
• vma->vm_ops = &vhost_vdpa_vm_ops;

• desc->page_prot = pgprot_noncached(desc->page_prot);
• vma_desc_set_flags(desc, VMA_IO_BIT, VMA_PFNMAP_BIT, VMA_DONTEXPAND_BIT,

• 	   VMA_DONTDUMP_BIT);
  

• desc->vm_ops = &vhost_vdpa_vm_ops; return 0;

} #endif /* CONFIG_MMU */ @@ -1615,7 +1616,7 @@ static const struct file_operations vhost_vdpa_fops = { .write_iter = vhost_vdpa_chr_write_iter, .unlocked_ioctl = vhost_vdpa_unlocked_ioctl, #ifdef CONFIG_MMU

• .mmap = vhost_vdpa_mmap,

• .mmap_prepare = vhost_vdpa_mmap_prepare,

#endif /* CONFIG_MMU */ .compat_ioctl = compat_ptr_ioctl, };

-- 2.56.0