diff options
| author | Jason Gunthorpe <[email protected]> | 2022-04-11 12:16:08 -0300 |
|---|---|---|
| committer | Joerg Roedel <[email protected]> | 2022-04-28 17:24:57 +0200 |
| commit | e8ae0e140c05319fa47bb3bf615c3a585f404b9d (patch) | |
| tree | f89d392587f2fe0bcde53e962999d4423ac4e971 | |
| parent | f78dc1dad829e505d83e33dc0879887f074c52e1 (diff) | |
vfio: Require that devices support DMA cache coherence
IOMMU_CACHE means that normal DMAs do not require any additional coherency
mechanism and is the basic uAPI that VFIO exposes to userspace. For
instance VFIO applications like DPDK will not work if additional coherency
operations are required.
Therefore check IOMMU_CAP_CACHE_COHERENCY like vdpa & usnic do before
allowing an IOMMU backed VFIO device to be created.
Reviewed-by: Kevin Tian <[email protected]>
Acked-by: Alex Williamson <[email protected]>
Acked-by: Robin Murphy <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Joerg Roedel <[email protected]>
| -rw-r--r-- | drivers/vfio/vfio.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index a4555014bd1e..9edad767cfda 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -815,6 +815,13 @@ static int __vfio_register_dev(struct vfio_device *device, int vfio_register_group_dev(struct vfio_device *device) { + /* + * VFIO always sets IOMMU_CACHE because we offer no way for userspace to + * restore cache coherency. + */ + if (!iommu_capable(device->dev->bus, IOMMU_CAP_CACHE_COHERENCY)) + return -EINVAL; + return __vfio_register_dev(device, vfio_group_find_or_alloc(device->dev)); } |