From e1ea9d30d84c65e96eba27b240be5b6798350490 Mon Sep 17 00:00:00 2001 From: Yi Liu Date: Tue, 25 Feb 2025 17:18:48 -0800 Subject: [PATCH] iommu: Store either domain or handle in group->pasid_array iommu_attach_device_pasid() only stores handle to group->pasid_array when there is a valid handle input. However, it makes the iommu_attach_device_pasid() unable to detect if the pasid has been attached or not previously. To be complete, let the iommu_attach_device_pasid() store the domain to group->pasid_array if no valid handle. The other users of the group->pasid_array should be updated to be consistent. e.g. the iommu_attach_group_handle() and iommu_replace_group_handle(). Link: https://patch.msgid.link/r/20250226011849.5102-4-yi.l.liu@intel.com Suggested-by: Jason Gunthorpe Reviewed-by: Jason Gunthorpe Reviewed-by: Nicolin Chen Reviewed-by: Kevin Tian Signed-off-by: Yi Liu Reviewed-by: Lu Baolu Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommu.c | 43 +++++++++++++++++++++++++++++++------------ 1 file changed, 31 insertions(+), 12 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 37c8cc6a9f79..d3652518c734 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -45,6 +45,9 @@ static unsigned int iommu_def_domain_type __read_mostly; static bool iommu_dma_strict __read_mostly = IS_ENABLED(CONFIG_IOMMU_DEFAULT_DMA_STRICT); static u32 iommu_cmd_line __read_mostly; +/* Tags used with xa_tag_pointer() in group->pasid_array */ +enum { IOMMU_PASID_ARRAY_DOMAIN = 0, IOMMU_PASID_ARRAY_HANDLE = 1 }; + struct iommu_group { struct kobject kobj; struct kobject *devices_kobj; @@ -2147,6 +2150,17 @@ struct iommu_domain *iommu_get_dma_domain(struct device *dev) return dev->iommu_group->default_domain; } +static void *iommu_make_pasid_array_entry(struct iommu_domain *domain, + struct iommu_attach_handle *handle) +{ + if (handle) { + handle->domain = domain; + return xa_tag_pointer(handle, IOMMU_PASID_ARRAY_HANDLE); + } + + return xa_tag_pointer(domain, IOMMU_PASID_ARRAY_DOMAIN); +} + static int __iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group) { @@ -3348,6 +3362,7 @@ int iommu_attach_device_pasid(struct iommu_domain *domain, struct iommu_group *group = dev->iommu_group; struct group_device *device; const struct iommu_ops *ops; + void *entry; int ret; if (!group) @@ -3371,10 +3386,9 @@ int iommu_attach_device_pasid(struct iommu_domain *domain, } } - if (handle) - handle->domain = domain; + entry = iommu_make_pasid_array_entry(domain, handle); - ret = xa_insert(&group->pasid_array, pasid, handle, GFP_KERNEL); + ret = xa_insert(&group->pasid_array, pasid, entry, GFP_KERNEL); if (ret) goto out_unlock; @@ -3454,13 +3468,17 @@ struct iommu_attach_handle * iommu_attach_handle_get(struct iommu_group *group, ioasid_t pasid, unsigned int type) { struct iommu_attach_handle *handle; + void *entry; xa_lock(&group->pasid_array); - handle = xa_load(&group->pasid_array, pasid); - if (!handle) + entry = xa_load(&group->pasid_array, pasid); + if (!entry || xa_pointer_tag(entry) != IOMMU_PASID_ARRAY_HANDLE) { handle = ERR_PTR(-ENOENT); - else if (type && handle->domain->type != type) - handle = ERR_PTR(-EBUSY); + } else { + handle = xa_untag_pointer(entry); + if (type && handle->domain->type != type) + handle = ERR_PTR(-EBUSY); + } xa_unlock(&group->pasid_array); return handle; @@ -3483,14 +3501,15 @@ int iommu_attach_group_handle(struct iommu_domain *domain, struct iommu_group *group, struct iommu_attach_handle *handle) { + void *entry; int ret; if (!handle) return -EINVAL; mutex_lock(&group->mutex); - handle->domain = domain; - ret = xa_insert(&group->pasid_array, IOMMU_NO_PASID, handle, GFP_KERNEL); + entry = iommu_make_pasid_array_entry(domain, handle); + ret = xa_insert(&group->pasid_array, IOMMU_NO_PASID, entry, GFP_KERNEL); if (ret) goto err_unlock; @@ -3543,14 +3562,14 @@ int iommu_replace_group_handle(struct iommu_group *group, struct iommu_domain *new_domain, struct iommu_attach_handle *handle) { - void *curr; + void *curr, *entry; int ret; if (!new_domain || !handle) return -EINVAL; mutex_lock(&group->mutex); - handle->domain = new_domain; + entry = iommu_make_pasid_array_entry(new_domain, handle); ret = xa_reserve(&group->pasid_array, IOMMU_NO_PASID, GFP_KERNEL); if (ret) goto err_unlock; @@ -3559,7 +3578,7 @@ int iommu_replace_group_handle(struct iommu_group *group, if (ret) goto err_release; - curr = xa_store(&group->pasid_array, IOMMU_NO_PASID, handle, GFP_KERNEL); + curr = xa_store(&group->pasid_array, IOMMU_NO_PASID, entry, GFP_KERNEL); WARN_ON(xa_is_err(curr)); mutex_unlock(&group->mutex);