The vfio needs to set DMA_OWNER_PRIVATE_DOMAIN_USER for the entire group when attaching it to a vfio container. Expose group variants of setting/ releasing dma ownership for this purpose. This also exposes the helper iommu_group_dma_owner_unclaimed() for vfio to report to userspace if the group is viable to user assignment for compatibility with VFIO_GROUP_FLAGS_VIABLE. Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> --- include/linux/iommu.h | 21 ++++++++++++++++ drivers/iommu/iommu.c | 58 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 79 insertions(+) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 24676b498f38..afcc07bc8d41 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -701,6 +701,10 @@ u32 iommu_sva_get_pasid(struct iommu_sva *handle); int iommu_device_set_dma_owner(struct device *dev, enum iommu_dma_owner owner, void *owner_cookie); void iommu_device_release_dma_owner(struct device *dev, enum iommu_dma_owner owner); +int iommu_group_set_dma_owner(struct iommu_group *group, enum iommu_dma_owner owner, + void *owner_cookie); +void iommu_group_release_dma_owner(struct iommu_group *group, enum iommu_dma_owner owner); +bool iommu_group_dma_owner_unclaimed(struct iommu_group *group); #else /* CONFIG_IOMMU_API */ @@ -1117,6 +1121,23 @@ static inline void iommu_device_release_dma_owner(struct device *dev, enum iommu_dma_owner owner) { } + +static inline int iommu_group_set_dma_owner(struct iommu_group *group, + enum iommu_dma_owner owner, + void *owner_cookie) +{ + return -EINVAL; +} + +static inline void iommu_group_release_dma_owner(struct iommu_group *group, + enum iommu_dma_owner owner) +{ +} + +static inline bool iommu_group_dma_owner_unclaimed(struct iommu_group *group) +{ + return false; +} #endif /* CONFIG_IOMMU_API */ /** diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 0cba04a8ea3b..423197db99a9 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -3425,6 +3425,64 @@ static void __iommu_group_release_dma_owner(struct iommu_group *group, } } +/** + * iommu_group_set_dma_owner() - Set DMA ownership of a group + * @group: The group. + * @owner: DMA owner type. + * @owner_cookie: Caller specified pointer. Could be used for exclusive + * declaration. Could be NULL. + * + * This is to support backward compatibility for legacy vfio which manages + * dma ownership in group level. New invocations on this interface should be + * prohibited. Instead, please turn to iommu_device_set_dma_owner(). + */ +int iommu_group_set_dma_owner(struct iommu_group *group, enum iommu_dma_owner owner, + void *owner_cookie) +{ + int ret; + + mutex_lock(&group->mutex); + ret = __iommu_group_set_dma_owner(group, owner, owner_cookie); + mutex_unlock(&group->mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_group_set_dma_owner); + +/** + * iommu_group_release_dma_owner() - Release DMA ownership of a group + * @group: The group. + * @owner: DMA owner type. + * + * Release the DMA ownership claimed by iommu_group_set_dma_owner(). + */ +void iommu_group_release_dma_owner(struct iommu_group *group, enum iommu_dma_owner owner) +{ + mutex_lock(&group->mutex); + __iommu_group_release_dma_owner(group, owner); + mutex_unlock(&group->mutex); +} +EXPORT_SYMBOL_GPL(iommu_group_release_dma_owner); + +/** + * iommu_group_dma_owner_unclaimed() - Is group dma ownership claimed + * @group: The group. + * + * This provides status check on a given group. It is racey and only for + * non-binding status reporting. + */ +bool iommu_group_dma_owner_unclaimed(struct iommu_group *group) +{ + enum iommu_dma_owner owner; + + mutex_lock(&group->mutex); + owner = group->dma_owner; + mutex_unlock(&group->mutex); + + return owner == DMA_OWNER_NONE; +} +EXPORT_SYMBOL_GPL(iommu_group_dma_owner_unclaimed); + /** * iommu_device_set_dma_owner() - Set DMA ownership of a device * @dev: The device. -- 2.25.1