mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-05-16 06:41:39 -04:00
Code Issues Packages Projects Releases Wiki Activity

iommufd: Add dma_buf_pin()

Browse Source 
IOMMUFD relies on a private protocol with VFIO, and this always operated
in pinned mode.

Now that VFIO can support pinned importers update IOMMUFD to invoke the
normal dma-buf flow to request pin.

This isn't enough to allow IOMMUFD to work with other exporters, it still
needs a way to get the physical address list which is another series.

IOMMUFD supports the defined revoke semantics. It immediately stops and
fences access to the memory inside it's invalidate_mappings() callback,
and it currently doesn't use scatterlists so doesn't call map/unmap at
all.

It is expected that a future revision can synchronously call unmap from
the move_notify callback as well.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/r/20260131-dmabuf-revoke-v7-8-463d956bd527@nvidia.com
This commit is contained in:
Leon Romanovsky
2026-01-31 07:34:18 +02:00
committed by Christian König
parent 6ffe939bf9
commit 8c5f9645c3
1 changed files with 8 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
drivers/iommu/iommufd/pages.c
View File

@@ -1502,16 +1502,22 @@ static int iopt_map_dmabuf(struct iommufd_ctx *ictx, struct iopt_pages *pages,
mutex_unlock(&pages->mutex);
}
rc = sym_vfio_pci_dma_buf_iommufd_map(attach, &pages->dmabuf.phys);
rc = dma_buf_pin(attach);
if (rc)
goto err_detach;
rc = sym_vfio_pci_dma_buf_iommufd_map(attach, &pages->dmabuf.phys);
if (rc)
goto err_unpin;
dma_resv_unlock(dmabuf->resv);
/* On success iopt_release_pages() will detach and put the dmabuf. */
pages->dmabuf.attach = attach;
return 0;
err_unpin:
dma_buf_unpin(attach);
err_detach:
dma_resv_unlock(dmabuf->resv);
dma_buf_detach(dmabuf, attach);
@@ -1657,6 +1663,7 @@ void iopt_release_pages(struct kref *kref)
if (iopt_is_dmabuf(pages) && pages->dmabuf.attach) {
struct dma_buf *dmabuf = pages->dmabuf.attach->dmabuf;
dma_buf_unpin(pages->dmabuf.attach);
dma_buf_detach(dmabuf, pages->dmabuf.attach);
dma_buf_put(dmabuf);
WARN_ON(!list_empty(&pages->dmabuf.tracker));