Commit 6ffe939b authored by Leon Romanovsky's avatar Leon Romanovsky Committed by Christian König
Browse files

vfio: Permit VFIO to work with pinned importers 



Till now VFIO has rejected pinned importers, largely to avoid being used
with the RDMA pinned importer that cannot handle a move_notify() to revoke
access.

Using dma_buf_attach_revocable() it can tell the difference between pinned
importers that support the flow described in dma_buf_invalidate_mappings()
and those that don't.

Thus permit compatible pinned importers.

This is one of two items IOMMUFD requires to remove its private interface
to VFIO's dma-buf.

Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Reviewed-by: default avatarAlex Williamson <alex@shazbot.org>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/r/20260131-dmabuf-revoke-v7-7-463d956bd527@nvidia.com
parent be6d4c9e

drivers/vfio/pci/vfio_pci_dmabuf.c

+3 −12
Original line number Diff line number Diff line
@@ -22,16 +22,6 @@ struct vfio_pci_dma_buf { 
	u8 revoked : 1;

};



static int vfio_pci_dma_buf_pin(struct dma_buf_attachment *attachment)

{

	return -EOPNOTSUPP;

}



static void vfio_pci_dma_buf_unpin(struct dma_buf_attachment *attachment)

{

	/* Do nothing */

}



static int vfio_pci_dma_buf_attach(struct dma_buf *dmabuf,

				   struct dma_buf_attachment *attachment)

{
@@ -43,6 +33,9 @@ static int vfio_pci_dma_buf_attach(struct dma_buf *dmabuf, 
	if (priv->revoked)

		return -ENODEV;



	if (!dma_buf_attach_revocable(attachment))

		return -EOPNOTSUPP;



	return 0;

}
@@ -107,8 +100,6 @@ static void vfio_pci_dma_buf_release(struct dma_buf *dmabuf) 
}



static const struct dma_buf_ops vfio_pci_dmabuf_ops = {

	.pin = vfio_pci_dma_buf_pin,

	.unpin = vfio_pci_dma_buf_unpin,

	.attach = vfio_pci_dma_buf_attach,

	.map_dma_buf = vfio_pci_dma_buf_map,

	.unmap_dma_buf = vfio_pci_dma_buf_unmap,