From: Lu Baolu baolu.lu@linux.intel.com
mainline inclusion from mainline-v6.11-rc1 commit 14678219cf4093e897ab353fd78eab7994d1be7d category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB4WDJ CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Currently, when attaching a domain to a device or its PASID, domain is stored within the iommu group. It could be retrieved for use during the window between attachment and detachment.
With new features introduced, there's a need to store more information than just a domain pointer. This information essentially represents the association between a domain and a device. For example, the SVA code already has a custom struct iommu_sva which represents a bond between sva domain and a PASID of a device. Looking forward, the IOMMUFD needs a place to store the iommufd_device pointer in the core, so that the device object ID could be quickly retrieved in the critical fault handling path.
Introduce domain attachment handle that explicitly represents the attachment relationship between a domain and a device or its PASID.
Co-developed-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Lu Baolu baolu.lu@linux.intel.com Reviewed-by: Jason Gunthorpe jgg@nvidia.com Reviewed-by: Kevin Tian kevin.tian@intel.com Link: https://lore.kernel.org/r/20240702063444.105814-2-baolu.lu@linux.intel.com Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Kunkun Jiang jiangkunkun@huawei.com --- drivers/dma/idxd/init.c | 2 +- drivers/iommu/iommu-sva.c | 13 ++++++++----- drivers/iommu/iommu.c | 26 ++++++++++++++++---------- include/linux/iommu.h | 18 +++++++++++++++--- 4 files changed, 40 insertions(+), 19 deletions(-)
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c index a7295943fa22..385c488c9cd1 100644 --- a/drivers/dma/idxd/init.c +++ b/drivers/dma/idxd/init.c @@ -584,7 +584,7 @@ static int idxd_enable_system_pasid(struct idxd_device *idxd) * DMA domain is owned by the driver, it should support all valid * types such as DMA-FQ, identity, etc. */ - ret = iommu_attach_device_pasid(domain, dev, pasid); + ret = iommu_attach_device_pasid(domain, dev, pasid, NULL); if (ret) { dev_err(dev, "failed to attach device pasid %d, domain type %d", pasid, domain->type); diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c index 18a35e798b72..0fb923254062 100644 --- a/drivers/iommu/iommu-sva.c +++ b/drivers/iommu/iommu-sva.c @@ -99,7 +99,9 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm
/* Search for an existing domain. */ list_for_each_entry(domain, &mm->iommu_mm->sva_domains, next) { - ret = iommu_attach_device_pasid(domain, dev, iommu_mm->pasid); + handle->handle.domain = domain; + ret = iommu_attach_device_pasid(domain, dev, iommu_mm->pasid, + &handle->handle); if (!ret) { domain->users++; goto out; @@ -113,7 +115,9 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm goto out_free_handle; }
- ret = iommu_attach_device_pasid(domain, dev, iommu_mm->pasid); + handle->handle.domain = domain; + ret = iommu_attach_device_pasid(domain, dev, iommu_mm->pasid, + &handle->handle); if (ret) goto out_free_domain; domain->users = 1; @@ -124,7 +128,6 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm list_add(&handle->handle_item, &mm->iommu_mm->sva_handles); mutex_unlock(&iommu_sva_lock); handle->dev = dev; - handle->domain = domain; return handle;
out_free_domain: @@ -147,7 +150,7 @@ EXPORT_SYMBOL_GPL(iommu_sva_bind_device); */ void iommu_sva_unbind_device(struct iommu_sva *handle) { - struct iommu_domain *domain = handle->domain; + struct iommu_domain *domain = handle->handle.domain; struct iommu_mm_data *iommu_mm = domain->mm->iommu_mm; struct device *dev = handle->dev;
@@ -170,7 +173,7 @@ EXPORT_SYMBOL_GPL(iommu_sva_unbind_device);
u32 iommu_sva_get_pasid(struct iommu_sva *handle) { - struct iommu_domain *domain = handle->domain; + struct iommu_domain *domain = handle->handle.domain;
return mm_get_enqcmd_pasid(domain->mm); } diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index ddcf0a3c03d3..463eba849495 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -3564,16 +3564,17 @@ static void __iommu_remove_group_pasid(struct iommu_group *group, * @domain: the iommu domain. * @dev: the attached device. * @pasid: the pasid of the device. + * @handle: the attach handle. * * Return: 0 on success, or an error. */ int iommu_attach_device_pasid(struct iommu_domain *domain, - struct device *dev, ioasid_t pasid) + struct device *dev, ioasid_t pasid, + struct iommu_attach_handle *handle) { /* Caller must be a probed driver on dev */ struct iommu_group *group = dev->iommu_group; struct group_device *device; - void *curr; int ret;
if (!domain->ops->set_dev_pasid) @@ -3594,11 +3595,12 @@ int iommu_attach_device_pasid(struct iommu_domain *domain, } }
- curr = xa_cmpxchg(&group->pasid_array, pasid, NULL, domain, GFP_KERNEL); - if (curr) { - ret = xa_err(curr) ? : -EBUSY; + if (handle) + handle->domain = domain; + + ret = xa_insert(&group->pasid_array, pasid, handle, GFP_KERNEL); + if (ret) goto out_unlock; - }
ret = __iommu_set_group_pasid(domain, group, pasid); if (ret) @@ -3626,7 +3628,7 @@ void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev,
mutex_lock(&group->mutex); __iommu_remove_group_pasid(group, pasid, domain); - WARN_ON(xa_erase(&group->pasid_array, pasid) != domain); + xa_erase(&group->pasid_array, pasid); mutex_unlock(&group->mutex); } EXPORT_SYMBOL_GPL(iommu_detach_device_pasid); @@ -3651,15 +3653,19 @@ struct iommu_domain *iommu_get_domain_for_dev_pasid(struct device *dev, { /* Caller must be a probed driver on dev */ struct iommu_group *group = dev->iommu_group; - struct iommu_domain *domain; + struct iommu_attach_handle *handle; + struct iommu_domain *domain = NULL;
if (!group) return NULL;
xa_lock(&group->pasid_array); - domain = xa_load(&group->pasid_array, pasid); + handle = xa_load(&group->pasid_array, pasid); + if (handle) + domain = handle->domain; + if (type && domain && domain->type != type) - domain = ERR_PTR(-EBUSY); + domain = NULL; xa_unlock(&group->pasid_array);
return domain; diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 468e329da33f..4634e70ad699 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -1107,12 +1107,22 @@ struct iommu_fwspec { /* ATS is supported */ #define IOMMU_FWSPEC_PCI_RC_ATS (1 << 0)
+/* + * An iommu attach handle represents a relationship between an iommu domain + * and a PASID or RID of a device. It is allocated and managed by the component + * that manages the domain and is stored in the iommu group during the time the + * domain is attached. + */ +struct iommu_attach_handle { + struct iommu_domain *domain; +}; + /** * struct iommu_sva - handle to a device-mm bond */ struct iommu_sva { + struct iommu_attach_handle handle; struct device *dev; - struct iommu_domain *domain; struct list_head handle_item; refcount_t users; }; @@ -1170,7 +1180,8 @@ int iommu_device_claim_dma_owner(struct device *dev, void *owner); void iommu_device_release_dma_owner(struct device *dev);
int iommu_attach_device_pasid(struct iommu_domain *domain, - struct device *dev, ioasid_t pasid); + struct device *dev, ioasid_t pasid, + struct iommu_attach_handle *handle); void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev, ioasid_t pasid); struct iommu_domain * @@ -1536,7 +1547,8 @@ static inline int iommu_device_claim_dma_owner(struct device *dev, void *owner) }
static inline int iommu_attach_device_pasid(struct iommu_domain *domain, - struct device *dev, ioasid_t pasid) + struct device *dev, ioasid_t pasid, + struct iommu_attach_handle *handle) { return -ENODEV; }