diff options
| author | Jason Gunthorpe <jgg@nvidia.com> | 2022-07-04 22:10:50 -0300 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2022-07-05 16:06:50 -0600 |
| commit | afe4e376ac5d568367b447ca90c12858d0935b86 (patch) | |
| tree | 89e345299ad4ff7242765f11edc7694603b6756d /drivers/vfio | |
| parent | 88084a3df1672e131ddc1b4e39eeacfd39864acf (diff) | |
vfio: Move IOMMU_CAP_CACHE_COHERENCY test to after we know we have a group
The test isn't going to work if a group doesn't exist. Normally this isn't
a problem since VFIO isn't going to create a device if there is no group,
but the special CONFIG_VFIO_NOIOMMU behavior allows bypassing this
prevention. The new cap test effectively forces a group and breaks this
config option.
Move the cap test to vfio_group_find_or_alloc() which is the earliest time
we know we have a group available and thus are not running in noiommu mode.
Fixes: e8ae0e140c05 ("vfio: Require that devices support DMA cache coherence")
Reported-by: Xiang Chen <chenxiang66@hisilicon.com>
Tested-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/0-v1-e8934b490f36+f4-vfio_cap_fix_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio')
| -rw-r--r-- | drivers/vfio/vfio.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 61e71c1154be..e60b06f2ac22 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -549,6 +549,16 @@ static struct vfio_group *vfio_group_find_or_alloc(struct device *dev) if (!iommu_group) return ERR_PTR(-EINVAL); + /* + * VFIO always sets IOMMU_CACHE because we offer no way for userspace to + * restore cache coherency. It has to be checked here because it is only + * valid for cases where we are using iommu groups. + */ + if (!iommu_capable(dev->bus, IOMMU_CAP_CACHE_COHERENCY)) { + iommu_group_put(iommu_group); + return ERR_PTR(-EINVAL); + } + group = vfio_group_get_from_iommu(iommu_group); if (!group) group = vfio_create_group(iommu_group, VFIO_IOMMU); @@ -601,13 +611,6 @@ 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)); } |