On Thu, Feb 09, 2023 at 04:10:04AM +0000, Tian, Kevin wrote:
> > From: Nicolin Chen <nicolinc@xxxxxxxxxx>
> > Sent: Wednesday, February 8, 2023 5:18 AM
> >
> > A driver that doesn't implement ops->dma_unmap shouldn't be allowed to
> > do
> > vfio_pin/unpin_pages(), though it can use vfio_dma_rw() to access an iova
> > range. Deny !ops->dma_unmap cases in vfio_pin/unpin_pages().
> >
> > Suggested-by: Kevin Tian <kevin.tian@xxxxxxxxx>
> > Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
> > ---
> > drivers/vfio/vfio_main.c | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> > index 8559c3dfb335..c7f3251ad6e5 100644
> > --- a/drivers/vfio/vfio_main.c
> > +++ b/drivers/vfio/vfio_main.c
> > @@ -1543,6 +1543,8 @@ int vfio_pin_pages(struct vfio_device *device,
> > dma_addr_t iova,
> >
> > if (iova > ULONG_MAX)
> > return -EINVAL;
> > + if (!device->ops->dma_unmap)
> > + return -EINVAL;
> > /*
> > * VFIO ignores the sub page offset, npages is from the start
> > of
> > * a PAGE_SIZE chunk of IOVA. The caller is expected to
> > recover
> > @@ -1580,6 +1582,8 @@ void vfio_unpin_pages(struct vfio_device *device,
> > dma_addr_t iova, int npage)
> > if (device->iommufd_access) {
> > if (WARN_ON(iova > ULONG_MAX))
> > return;
> > + if (!device->ops->dma_unmap)
> > + return;
>
> IMHO this restriction applies to both iommufd and legacy container.
Yeah that makes sense
Jason
