This adds two new APIs for the use cases like vfio/mdev where subdevices derived from physical devices are created and put in an iommu_group. The new IOMMU API interfaces mimic the vfio_mdev_at(de)tach_domain() directly, testing whether the resulting device supports IOMMU_DEV_FEAT_AUX and using an aux vs non-aux at(de)tach. By doing this we could - Set the iommu_group.domain. The iommu_group.domain is private to iommu core (therefore vfio code cannot set it), but we need it set in order for iommu_get_domain_for_dev() to work with a group attached to an aux domain. - Prefer to use the _attach_group() interfaces while the _attach_device() interfaces are relegated to special cases. Link: https://lore.kernel.org/linux-iommu/20200730134658.44c57a67@xxxxxxx/ Link: https://lore.kernel.org/linux-iommu/20200730151703.5daf8ad4@xxxxxxx/ Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> --- drivers/iommu/iommu.c | 136 ++++++++++++++++++++++++++++++++++++++++++ include/linux/iommu.h | 20 +++++++ 2 files changed, 156 insertions(+) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 38cdfeb887e1..fb21c2ff4861 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2757,6 +2757,142 @@ int iommu_aux_get_pasid(struct iommu_domain *domain, struct device *dev) } EXPORT_SYMBOL_GPL(iommu_aux_get_pasid); +static int __iommu_aux_attach_device(struct iommu_domain *domain, + struct device *phys_dev, + struct device *sub_dev) +{ + int ret; + + if (unlikely(!domain->ops->aux_attach_dev)) + return -ENODEV; + + ret = domain->ops->aux_attach_dev(domain, phys_dev, sub_dev); + if (!ret) + trace_attach_device_to_domain(sub_dev); + + return ret; +} + +static void __iommu_aux_detach_device(struct iommu_domain *domain, + struct device *phys_dev, + struct device *sub_dev) +{ + if (unlikely(!domain->ops->aux_detach_dev)) + return; + + domain->ops->aux_detach_dev(domain, phys_dev, sub_dev); + trace_detach_device_from_domain(sub_dev); +} + +static int __iommu_attach_subdev_group(struct iommu_domain *domain, + struct iommu_group *group, + iommu_device_lookup_t fn) +{ + struct group_device *device; + struct device *phys_dev; + int ret = -ENODEV; + + list_for_each_entry(device, &group->devices, list) { + phys_dev = fn(device->dev); + if (!phys_dev) { + ret = -ENODEV; + break; + } + + if (iommu_dev_feature_enabled(phys_dev, IOMMU_DEV_FEAT_AUX)) + ret = __iommu_aux_attach_device(domain, phys_dev, + device->dev); + else + ret = __iommu_attach_device(domain, phys_dev); + + if (ret) + break; + } + + return ret; +} + +static void __iommu_detach_subdev_group(struct iommu_domain *domain, + struct iommu_group *group, + iommu_device_lookup_t fn) +{ + struct group_device *device; + struct device *phys_dev; + + list_for_each_entry(device, &group->devices, list) { + phys_dev = fn(device->dev); + if (!phys_dev) + break; + + if (iommu_dev_feature_enabled(phys_dev, IOMMU_DEV_FEAT_AUX)) + __iommu_aux_detach_device(domain, phys_dev, device->dev); + else + __iommu_detach_device(domain, phys_dev); + } +} + +/** + * iommu_attach_subdev_group - attach domain to an iommu_group which + * contains subdevices. + * + * @domain: domain + * @group: iommu_group which contains subdevices + * @fn: callback for each subdevice in the @iommu_group to retrieve the + * physical device where the subdevice was created from. + * + * Returns 0 on success, or an error value. + */ +int iommu_attach_subdev_group(struct iommu_domain *domain, + struct iommu_group *group, + iommu_device_lookup_t fn) +{ + int ret = -ENODEV; + + mutex_lock(&group->mutex); + if (group->domain) { + ret = -EBUSY; + goto unlock_out; + } + + ret = __iommu_attach_subdev_group(domain, group, fn); + if (ret) + __iommu_detach_subdev_group(domain, group, fn); + else + group->domain = domain; + +unlock_out: + mutex_unlock(&group->mutex); + return ret; +} +EXPORT_SYMBOL_GPL(iommu_attach_subdev_group); + +/** + * iommu_detach_subdev_group - detach domain from an iommu_group which + * contains subdevices + * + * @domain: domain + * @group: iommu_group which contains subdevices + * @fn: callback for each subdevice in the @iommu_group to retrieve the + * physical device where the subdevice was created from. + * + * The domain must have been attached to @group via iommu_attach_subdev_group(). + */ +void iommu_detach_subdev_group(struct iommu_domain *domain, + struct iommu_group *group, + iommu_device_lookup_t fn) +{ + mutex_lock(&group->mutex); + if (!group->domain) + goto unlock_out; + + __iommu_detach_subdev_group(domain, group, fn); + group->domain = NULL; + +unlock_out: + mutex_unlock(&group->mutex); +} +EXPORT_SYMBOL_GPL(iommu_detach_subdev_group); + /** * iommu_sva_bind_device() - Bind a process address space to a device * @dev: the device diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 871267104915..b9df8b510d4f 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -48,6 +48,7 @@ struct iommu_fault_event; typedef int (*iommu_fault_handler_t)(struct iommu_domain *, struct device *, unsigned long, int, void *); typedef int (*iommu_dev_fault_handler_t)(struct iommu_fault *, void *); +typedef struct device *(*iommu_device_lookup_t)(struct device *); struct iommu_domain_geometry { dma_addr_t aperture_start; /* First address that can be mapped */ @@ -631,6 +632,12 @@ bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features f); int iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev); void iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev); int iommu_aux_get_pasid(struct iommu_domain *domain, struct device *dev); +int iommu_attach_subdev_group(struct iommu_domain *domain, + struct iommu_group *group, + iommu_device_lookup_t fn); +void iommu_detach_subdev_group(struct iommu_domain *domain, + struct iommu_group *group, + iommu_device_lookup_t fn); struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, @@ -1019,6 +1026,19 @@ iommu_aux_get_pasid(struct iommu_domain *domain, struct device *dev) return -ENODEV; } +static inline int +iommu_attach_subdev_group(struct iommu_domain *domain, struct iommu_group *group, + iommu_device_lookup_t fn) +{ + return -ENODEV; +} + +static inline void +iommu_detach_subdev_group(struct iommu_domain *domain, struct iommu_group *group, + iommu_device_lookup_t fn) +{ +} + static inline struct iommu_sva * iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata) { -- 2.17.1
