Re: [PATCH v3 01/10] vfio: Make vfio_unpin_pages() return void

Nicolin Chen
2022-07-12T18:20:19Z

On Tue, Jul 12, 2022 at 10:21:14AM -0400, Anthony Krowiak wrote:

> > +void vfio_unpin_pages(struct vfio_device *device, unsigned long *user_pfn,
> > + int npage)
> > {
> > struct vfio_container *container;
> > struct vfio_iommu_driver *driver;
> > - int ret;
> >
> > - if (!user_pfn || !npage || !vfio_assert_device_open(device))
> > - return -EINVAL;
>
>
> You left out the check for !user_pfn?

Yes. I mentioned in the commit log. And it's in response to Jason's
remark: https://lore.kernel.org/kvm/20220707192210.GC1705032@nvidia.com/

Btw, user_pfn is removed in one of the following patches anyway.

> > +static void vfio_iommu_type1_unpin_pages(void *iommu_data,
> > + unsigned long *user_pfn, int npage)
> > {
> > struct vfio_iommu *iommu = iommu_data;
> > bool do_accounting;
> > int i;
> >
> > - if (!iommu || !user_pfn || npage <= 0)
> > - return -EINVAL;
>
>
> Is there a reason the checks above were not checked for WARN_ON?

For pointers, same reason here.

For npage, it's checked in its caller vfio_unpin_pages -- mentioned
in the commit log too. The VFIO core is the only caller and it is
unlikely to change. On the other hand, the plan is to replace this
vfio_iommu_type1_unpin_pages with IOMMUFD implementation.