From: Nicolin Chen nicolinc@nvidia.com 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@intel.com Signed-off-by: Nicolin Chen nicolinc@nvidia.com
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.