From: Lu Baolu Date: Mon, 31 Oct 2022 00:59:15 +0000 (+0800) Subject: iommu: Prepare IOMMU domain for IOPF X-Git-Tag: v6.2-rc1~96^2~12 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=8cc93159f91960b4812ea48887e9e7501babc95a;p=linux-2.6-block.git iommu: Prepare IOMMU domain for IOPF This adds some mechanisms around the iommu_domain so that the I/O page fault handling framework could route a page fault to the domain and call the fault handler from it. Add pointers to the page fault handler and its private data in struct iommu_domain. The fault handler will be called with the private data as a parameter once a page fault is routed to the domain. Any kernel component which owns an iommu domain could install handler and its private parameter so that the page fault could be further routed and handled. This also prepares the SVA implementation to be the first consumer of the per-domain page fault handling model. The I/O page fault handler for SVA is copied to the SVA file with mmget_not_zero() added before mmap_read_lock(). Suggested-by: Jean-Philippe Brucker Signed-off-by: Lu Baolu Reviewed-by: Jean-Philippe Brucker Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Tested-by: Zhangfei Gao Tested-by: Tony Zhu Link: https://lore.kernel.org/r/20221031005917.45690-12-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c index 1df8c1dcae77..aee9e033012f 100644 --- a/drivers/iommu/io-pgfault.c +++ b/drivers/iommu/io-pgfault.c @@ -181,6 +181,13 @@ static void iopf_handle_group(struct work_struct *work) * request completes, outstanding faults will have been dealt with by the time * the PASID is freed. * + * Any valid page fault will be eventually routed to an iommu domain and the + * page fault handler installed there will get called. The users of this + * handling framework should guarantee that the iommu domain could only be + * freed after the device has stopped generating page faults (or the iommu + * hardware has been set to block the page faults) and the pending page faults + * have been flushed. + * * Return: 0 on success and <0 on error. */ int iommu_queue_iopf(struct iommu_fault *fault, void *cookie) diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c index e425573a1787..089fd61ff453 100644 --- a/drivers/iommu/iommu-sva-lib.c +++ b/drivers/iommu/iommu-sva-lib.c @@ -180,3 +180,61 @@ u32 iommu_sva_get_pasid(struct iommu_sva *handle) return domain->mm->pasid; } EXPORT_SYMBOL_GPL(iommu_sva_get_pasid); + +/* + * I/O page fault handler for SVA + */ +enum iommu_page_response_code +iommu_sva_handle_iopf(struct iommu_fault *fault, void *data) +{ + vm_fault_t ret; + struct vm_area_struct *vma; + struct mm_struct *mm = data; + unsigned int access_flags = 0; + unsigned int fault_flags = FAULT_FLAG_REMOTE; + struct iommu_fault_page_request *prm = &fault->prm; + enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID; + + if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID)) + return status; + + if (!mmget_not_zero(mm)) + return status; + + mmap_read_lock(mm); + + vma = find_extend_vma(mm, prm->addr); + if (!vma) + /* Unmapped area */ + goto out_put_mm; + + if (prm->perm & IOMMU_FAULT_PERM_READ) + access_flags |= VM_READ; + + if (prm->perm & IOMMU_FAULT_PERM_WRITE) { + access_flags |= VM_WRITE; + fault_flags |= FAULT_FLAG_WRITE; + } + + if (prm->perm & IOMMU_FAULT_PERM_EXEC) { + access_flags |= VM_EXEC; + fault_flags |= FAULT_FLAG_INSTRUCTION; + } + + if (!(prm->perm & IOMMU_FAULT_PERM_PRIV)) + fault_flags |= FAULT_FLAG_USER; + + if (access_flags & ~vma->vm_flags) + /* Access fault */ + goto out_put_mm; + + ret = handle_mm_fault(vma, prm->addr, fault_flags, NULL); + status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID : + IOMMU_PAGE_RESP_SUCCESS; + +out_put_mm: + mmap_read_unlock(mm); + mmput(mm); + + return status; +} diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva-lib.h index 8909ea1094e3..1b3ace4b5863 100644 --- a/drivers/iommu/iommu-sva-lib.h +++ b/drivers/iommu/iommu-sva-lib.h @@ -26,6 +26,8 @@ int iopf_queue_flush_dev(struct device *dev); struct iopf_queue *iopf_queue_alloc(const char *name); void iopf_queue_free(struct iopf_queue *queue); int iopf_queue_discard_partial(struct iopf_queue *queue); +enum iommu_page_response_code +iommu_sva_handle_iopf(struct iommu_fault *fault, void *data); #else /* CONFIG_IOMMU_SVA */ static inline int iommu_queue_iopf(struct iommu_fault *fault, void *cookie) @@ -63,5 +65,11 @@ static inline int iopf_queue_discard_partial(struct iopf_queue *queue) { return -ENODEV; } + +static inline enum iommu_page_response_code +iommu_sva_handle_iopf(struct iommu_fault *fault, void *data) +{ + return IOMMU_PAGE_RESP_INVALID; +} #endif /* CONFIG_IOMMU_SVA */ #endif /* _IOMMU_SVA_LIB_H */ diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index c9da0a1bb3b8..9e0fb18e1b34 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -33,6 +33,8 @@ #include "dma-iommu.h" +#include "iommu-sva-lib.h" + static struct kset *iommu_group_kset; static DEFINE_IDA(iommu_group_ida); @@ -3309,6 +3311,8 @@ struct iommu_domain *iommu_sva_domain_alloc(struct device *dev, domain->type = IOMMU_DOMAIN_SVA; mmgrab(mm); domain->mm = mm; + domain->iopf_handler = iommu_sva_handle_iopf; + domain->fault_data = mm; return domain; } diff --git a/include/linux/iommu.h b/include/linux/iommu.h index c337ef1c97bc..7d2648058e43 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -98,6 +98,9 @@ struct iommu_domain { unsigned long pgsize_bitmap; /* Bitmap of page sizes in use */ struct iommu_domain_geometry geometry; struct iommu_dma_cookie *iova_cookie; + enum iommu_page_response_code (*iopf_handler)(struct iommu_fault *fault, + void *data); + void *fault_data; union { struct { iommu_fault_handler_t handler;