From 4bb4211e48fbfb392bb07168b75b1a92832b62f5 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 31 Oct 2022 08:59:16 +0800 Subject: [PATCH] iommu: Per-domain I/O page fault handling Tweak the I/O page fault handling framework to route the page faults to the domain and call the page fault handler retrieved from the domain. This makes the I/O page fault handling framework possible to serve more usage scenarios as long as they have an IOMMU domain and install a page fault handler in it. Some unused functions are also removed to avoid dead code. The iommu_get_domain_for_dev_pasid() which retrieves attached domain for a {device, PASID} pair is used. It will be used by the page fault handling framework which knows {device, PASID} reported from the iommu driver. We have a guarantee that the SVA domain doesn't go away during IOPF handling, because unbind() won't free the domain until all the pending page requests have been flushed from the pipeline. The drivers either call iopf_queue_flush_dev() explicitly, or in stall case, the device driver is required to flush all DMAs including stalled transactions before calling unbind(). This also renames iopf_handle_group() to iopf_handler() to avoid confusing. 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/20221031005917.45690-13-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/io-pgfault.c | 68 ++++++---------------------------------------- 1 file changed, 9 insertions(+), 59 deletions(-) diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c index aee9e03..d046d89 100644 --- a/drivers/iommu/io-pgfault.c +++ b/drivers/iommu/io-pgfault.c @@ -69,69 +69,18 @@ static int iopf_complete_group(struct device *dev, struct iopf_fault *iopf, return iommu_page_response(dev, &resp); } -static enum iommu_page_response_code -iopf_handle_single(struct iopf_fault *iopf) -{ - vm_fault_t ret; - struct mm_struct *mm; - struct vm_area_struct *vma; - unsigned int access_flags = 0; - unsigned int fault_flags = FAULT_FLAG_REMOTE; - struct iommu_fault_page_request *prm = &iopf->fault.prm; - enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID; - - if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID)) - return status; - - mm = iommu_sva_find(prm->pasid); - if (IS_ERR_OR_NULL(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; -} - -static void iopf_handle_group(struct work_struct *work) +static void iopf_handler(struct work_struct *work) { struct iopf_group *group; + struct iommu_domain *domain; struct iopf_fault *iopf, *next; enum iommu_page_response_code status = IOMMU_PAGE_RESP_SUCCESS; group = container_of(work, struct iopf_group, work); + domain = iommu_get_domain_for_dev_pasid(group->dev, + group->last_fault.fault.prm.pasid, 0); + if (!domain || !domain->iopf_handler) + status = IOMMU_PAGE_RESP_INVALID; list_for_each_entry_safe(iopf, next, &group->faults, list) { /* @@ -139,7 +88,8 @@ static void iopf_handle_group(struct work_struct *work) * faults in the group if there is an error. */ if (status == IOMMU_PAGE_RESP_SUCCESS) - status = iopf_handle_single(iopf); + status = domain->iopf_handler(&iopf->fault, + domain->fault_data); if (!(iopf->fault.prm.flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE)) @@ -242,7 +192,7 @@ int iommu_queue_iopf(struct iommu_fault *fault, void *cookie) group->last_fault.fault = *fault; INIT_LIST_HEAD(&group->faults); list_add(&group->last_fault.list, &group->faults); - INIT_WORK(&group->work, iopf_handle_group); + INIT_WORK(&group->work, iopf_handler); /* See if we have partial faults for this group */ list_for_each_entry_safe(iopf, next, &iopf_param->partial, list) { -- 2.7.4