diff options
Diffstat (limited to 'drivers/iommu/intel/svm.c')
| -rw-r--r-- | drivers/iommu/intel/svm.c | 1223 |
1 files changed, 1223 insertions, 0 deletions
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c new file mode 100644 index 000000000..aabf56272 --- /dev/null +++ b/drivers/iommu/intel/svm.c @@ -0,0 +1,1223 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright © 2015 Intel Corporation. + * + * Authors: David Woodhouse <dwmw2@infradead.org> + */ + +#include <linux/intel-iommu.h> +#include <linux/mmu_notifier.h> +#include <linux/sched.h> +#include <linux/sched/mm.h> +#include <linux/slab.h> +#include <linux/intel-svm.h> +#include <linux/rculist.h> +#include <linux/pci.h> +#include <linux/pci-ats.h> +#include <linux/dmar.h> +#include <linux/interrupt.h> +#include <linux/mm_types.h> +#include <linux/ioasid.h> +#include <asm/page.h> +#include <asm/fpu/api.h> + +#include "pasid.h" + +static irqreturn_t prq_event_thread(int irq, void *d); +static void intel_svm_drain_prq(struct device *dev, u32 pasid); + +#define PRQ_ORDER 0 + +int intel_svm_enable_prq(struct intel_iommu *iommu) +{ + struct page *pages; + int irq, ret; + + pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, PRQ_ORDER); + if (!pages) { + pr_warn("IOMMU: %s: Failed to allocate page request queue\n", + iommu->name); + return -ENOMEM; + } + iommu->prq = page_address(pages); + + irq = dmar_alloc_hwirq(DMAR_UNITS_SUPPORTED + iommu->seq_id, iommu->node, iommu); + if (irq <= 0) { + pr_err("IOMMU: %s: Failed to create IRQ vector for page request queue\n", + iommu->name); + ret = -EINVAL; + err: + free_pages((unsigned long)iommu->prq, PRQ_ORDER); + iommu->prq = NULL; + return ret; + } + iommu->pr_irq = irq; + + snprintf(iommu->prq_name, sizeof(iommu->prq_name), "dmar%d-prq", iommu->seq_id); + + ret = request_threaded_irq(irq, NULL, prq_event_thread, IRQF_ONESHOT, + iommu->prq_name, iommu); + if (ret) { + pr_err("IOMMU: %s: Failed to request IRQ for page request queue\n", + iommu->name); + dmar_free_hwirq(irq); + iommu->pr_irq = 0; + goto err; + } + dmar_writeq(iommu->reg + DMAR_PQH_REG, 0ULL); + dmar_writeq(iommu->reg + DMAR_PQT_REG, 0ULL); + dmar_writeq(iommu->reg + DMAR_PQA_REG, virt_to_phys(iommu->prq) | PRQ_ORDER); + + init_completion(&iommu->prq_complete); + + return 0; +} + +int intel_svm_finish_prq(struct intel_iommu *iommu) +{ + dmar_writeq(iommu->reg + DMAR_PQH_REG, 0ULL); + dmar_writeq(iommu->reg + DMAR_PQT_REG, 0ULL); + dmar_writeq(iommu->reg + DMAR_PQA_REG, 0ULL); + + if (iommu->pr_irq) { + free_irq(iommu->pr_irq, iommu); + dmar_free_hwirq(iommu->pr_irq); + iommu->pr_irq = 0; + } + + free_pages((unsigned long)iommu->prq, PRQ_ORDER); + iommu->prq = NULL; + + return 0; +} + +static inline bool intel_svm_capable(struct intel_iommu *iommu) +{ + return iommu->flags & VTD_FLAG_SVM_CAPABLE; +} + +void intel_svm_check(struct intel_iommu *iommu) +{ + if (!pasid_supported(iommu)) + return; + + if (cpu_feature_enabled(X86_FEATURE_GBPAGES) && + !cap_fl1gp_support(iommu->cap)) { + pr_err("%s SVM disabled, incompatible 1GB page capability\n", + iommu->name); + return; + } + + if (cpu_feature_enabled(X86_FEATURE_LA57) && + !cap_5lp_support(iommu->cap)) { + pr_err("%s SVM disabled, incompatible paging mode\n", + iommu->name); + return; + } + + iommu->flags |= VTD_FLAG_SVM_CAPABLE; +} + +static void __flush_svm_range_dev(struct intel_svm *svm, + struct intel_svm_dev *sdev, + unsigned long address, + unsigned long pages, int ih) +{ + struct device_domain_info *info = get_domain_info(sdev->dev); + + if (WARN_ON(!pages)) + return; + + qi_flush_piotlb(sdev->iommu, sdev->did, svm->pasid, address, pages, ih); + if (info->ats_enabled) + qi_flush_dev_iotlb_pasid(sdev->iommu, sdev->sid, info->pfsid, + svm->pasid, sdev->qdep, address, + order_base_2(pages)); +} + +static void intel_flush_svm_range_dev(struct intel_svm *svm, + struct intel_svm_dev *sdev, + unsigned long address, + unsigned long pages, int ih) +{ + unsigned long shift = ilog2(__roundup_pow_of_two(pages)); + unsigned long align = (1ULL << (VTD_PAGE_SHIFT + shift)); + unsigned long start = ALIGN_DOWN(address, align); + unsigned long end = ALIGN(address + (pages << VTD_PAGE_SHIFT), align); + + while (start < end) { + __flush_svm_range_dev(svm, sdev, start, align >> VTD_PAGE_SHIFT, ih); + start += align; + } +} + +static void intel_flush_svm_range(struct intel_svm *svm, unsigned long address, + unsigned long pages, int ih) +{ + struct intel_svm_dev *sdev; + + rcu_read_lock(); + list_for_each_entry_rcu(sdev, &svm->devs, list) + intel_flush_svm_range_dev(svm, sdev, address, pages, ih); + rcu_read_unlock(); +} + +/* Pages have been freed at this point */ +static void intel_invalidate_range(struct mmu_notifier *mn, + struct mm_struct *mm, + unsigned long start, unsigned long end) +{ + struct intel_svm *svm = container_of(mn, struct intel_svm, notifier); + + intel_flush_svm_range(svm, start, + (end - start + PAGE_SIZE - 1) >> VTD_PAGE_SHIFT, 0); +} + +static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm) +{ + struct intel_svm *svm = container_of(mn, struct intel_svm, notifier); + struct intel_svm_dev *sdev; + + /* This might end up being called from exit_mmap(), *before* the page + * tables are cleared. And __mmu_notifier_release() will delete us from + * the list of notifiers so that our invalidate_range() callback doesn't + * get called when the page tables are cleared. So we need to protect + * against hardware accessing those page tables. + * + * We do it by clearing the entry in the PASID table and then flushing + * the IOTLB and the PASID table caches. This might upset hardware; + * perhaps we'll want to point the PASID to a dummy PGD (like the zero + * page) so that we end up taking a fault that the hardware really + * *has* to handle gracefully without affecting other processes. + */ + rcu_read_lock(); + list_for_each_entry_rcu(sdev, &svm->devs, list) + intel_pasid_tear_down_entry(sdev->iommu, sdev->dev, + svm->pasid, true); + rcu_read_unlock(); + +} + +static const struct mmu_notifier_ops intel_mmuops = { + .release = intel_mm_release, + .invalidate_range = intel_invalidate_range, +}; + +static DEFINE_MUTEX(pasid_mutex); +static LIST_HEAD(global_svm_list); + +#define for_each_svm_dev(sdev, svm, d) \ + list_for_each_entry((sdev), &(svm)->devs, list) \ + if ((d) != (sdev)->dev) {} else + +static int pasid_to_svm_sdev(struct device *dev, unsigned int pasid, + struct intel_svm **rsvm, + struct intel_svm_dev **rsdev) +{ + struct intel_svm_dev *d, *sdev = NULL; + struct intel_svm *svm; + + /* The caller should hold the pasid_mutex lock */ + if (WARN_ON(!mutex_is_locked(&pasid_mutex))) + return -EINVAL; + + if (pasid == INVALID_IOASID || pasid >= PASID_MAX) + return -EINVAL; + + svm = ioasid_find(NULL, pasid, NULL); + if (IS_ERR(svm)) + return PTR_ERR(svm); + + if (!svm) + goto out; + + /* + * If we found svm for the PASID, there must be at least one device + * bond. + */ + if (WARN_ON(list_empty(&svm->devs))) + return -EINVAL; + + rcu_read_lock(); + list_for_each_entry_rcu(d, &svm->devs, list) { + if (d->dev == dev) { + sdev = d; + break; + } + } + rcu_read_unlock(); + +out: + *rsvm = svm; + *rsdev = sdev; + + return 0; +} + +int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev, + struct iommu_gpasid_bind_data *data) +{ + struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL); + struct intel_svm_dev *sdev = NULL; + struct dmar_domain *dmar_domain; + struct device_domain_info *info; + struct intel_svm *svm = NULL; + unsigned long iflags; + int ret = 0; + + if (WARN_ON(!iommu) || !data) + return -EINVAL; + + if (data->format != IOMMU_PASID_FORMAT_INTEL_VTD) + return -EINVAL; + + /* IOMMU core ensures argsz is more than the start of the union */ + if (data->argsz < offsetofend(struct iommu_gpasid_bind_data, vendor.vtd)) + return -EINVAL; + + /* Make sure no undefined flags are used in vendor data */ + if (data->vendor.vtd.flags & ~(IOMMU_SVA_VTD_GPASID_LAST - 1)) + return -EINVAL; + + if (!dev_is_pci(dev)) + return -ENOTSUPP; + + /* VT-d supports devices with full 20 bit PASIDs only */ + if (pci_max_pasids(to_pci_dev(dev)) != PASID_MAX) + return -EINVAL; + + /* + * We only check host PASID range, we have no knowledge to check + * guest PASID range. + */ + if (data->hpasid <= 0 || data->hpasid >= PASID_MAX) + return -EINVAL; + + info = get_domain_info(dev); + if (!info) + return -EINVAL; + + dmar_domain = to_dmar_domain(domain); + + mutex_lock(&pasid_mutex); + ret = pasid_to_svm_sdev(dev, data->hpasid, &svm, &sdev); + if (ret) + goto out; + + if (sdev) { + /* + * Do not allow multiple bindings of the same device-PASID since + * there is only one SL page tables per PASID. We may revisit + * once sharing PGD across domains are supported. + */ + dev_warn_ratelimited(dev, "Already bound with PASID %u\n", + svm->pasid); + ret = -EBUSY; + goto out; + } + + if (!svm) { + /* We come here when PASID has never been bond to a device. */ + svm = kzalloc(sizeof(*svm), GFP_KERNEL); + if (!svm) { + ret = -ENOMEM; + goto out; + } + /* REVISIT: upper layer/VFIO can track host process that bind + * the PASID. ioasid_set = mm might be sufficient for vfio to + * check pasid VMM ownership. We can drop the following line + * once VFIO and IOASID set check is in place. + */ + svm->mm = get_task_mm(current); + svm->pasid = data->hpasid; + if (data->flags & IOMMU_SVA_GPASID_VAL) { + svm->gpasid = data->gpasid; + svm->flags |= SVM_FLAG_GUEST_PASID; + } + ioasid_set_data(data->hpasid, svm); + INIT_LIST_HEAD_RCU(&svm->devs); + mmput(svm->mm); + } + sdev = kzalloc(sizeof(*sdev), GFP_KERNEL); + if (!sdev) { + ret = -ENOMEM; + goto out; + } + sdev->dev = dev; + sdev->sid = PCI_DEVID(info->bus, info->devfn); + sdev->iommu = iommu; + + /* Only count users if device has aux domains */ + if (iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX)) + sdev->users = 1; + + /* Set up device context entry for PASID if not enabled already */ + ret = intel_iommu_enable_pasid(iommu, sdev->dev); + if (ret) { + dev_err_ratelimited(dev, "Failed to enable PASID capability\n"); + kfree(sdev); + goto out; + } + + /* + * PASID table is per device for better security. Therefore, for + * each bind of a new device even with an existing PASID, we need to + * call the nested mode setup function here. + */ + spin_lock_irqsave(&iommu->lock, iflags); + ret = intel_pasid_setup_nested(iommu, dev, + (pgd_t *)(uintptr_t)data->gpgd, + data->hpasid, &data->vendor.vtd, dmar_domain, + data->addr_width); + spin_unlock_irqrestore(&iommu->lock, iflags); + if (ret) { + dev_err_ratelimited(dev, "Failed to set up PASID %llu in nested mode, Err %d\n", + data->hpasid, ret); + /* + * PASID entry should be in cleared state if nested mode + * set up failed. So we only need to clear IOASID tracking + * data such that free call will succeed. + */ + kfree(sdev); + goto out; + } + + svm->flags |= SVM_FLAG_GUEST_MODE; + + init_rcu_head(&sdev->rcu); + list_add_rcu(&sdev->list, &svm->devs); + out: + if (!IS_ERR_OR_NULL(svm) && list_empty(&svm->devs)) { + ioasid_set_data(data->hpasid, NULL); + kfree(svm); + } + + mutex_unlock(&pasid_mutex); + return ret; +} + +int intel_svm_unbind_gpasid(struct device *dev, u32 pasid) +{ + struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL); + struct intel_svm_dev *sdev; + struct intel_svm *svm; + int ret; + + if (WARN_ON(!iommu)) + return -EINVAL; + + mutex_lock(&pasid_mutex); + ret = pasid_to_svm_sdev(dev, pasid, &svm, &sdev); + if (ret) + goto out; + + if (sdev) { + if (iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX)) + sdev->users--; + if (!sdev->users) { + list_del_rcu(&sdev->list); + intel_pasid_tear_down_entry(iommu, dev, + svm->pasid, false); + intel_svm_drain_prq(dev, svm->pasid); + kfree_rcu(sdev, rcu); + + if (list_empty(&svm->devs)) { + /* + * We do not free the IOASID here in that + * IOMMU driver did not allocate it. + * Unlike native SVM, IOASID for guest use was + * allocated prior to the bind call. + * In any case, if the free call comes before + * the unbind, IOMMU driver will get notified + * and perform cleanup. + */ + ioasid_set_data(pasid, NULL); + kfree(svm); + } + } + } +out: + mutex_unlock(&pasid_mutex); + return ret; +} + +static void _load_pasid(void *unused) +{ + update_pasid(); +} + +static void load_pasid(struct mm_struct *mm, u32 pasid) +{ + mutex_lock(&mm->context.lock); + + /* Synchronize with READ_ONCE in update_pasid(). */ + smp_store_release(&mm->pasid, pasid); + + /* Update PASID MSR on all CPUs running the mm's tasks. */ + on_each_cpu_mask(mm_cpumask(mm), _load_pasid, NULL, true); + + mutex_unlock(&mm->context.lock); +} + +/* Caller must hold pasid_mutex, mm reference */ +static int +intel_svm_bind_mm(struct device *dev, unsigned int flags, + struct svm_dev_ops *ops, + struct mm_struct *mm, struct intel_svm_dev **sd) +{ + struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL); + struct device_domain_info *info; + struct intel_svm_dev *sdev; + struct intel_svm *svm = NULL; + unsigned long iflags; + int pasid_max; + int ret; + + if (!iommu || dmar_disabled) + return -EINVAL; + + if (!intel_svm_capable(iommu)) + return -ENOTSUPP; + + if (dev_is_pci(dev)) { + pasid_max = pci_max_pasids(to_pci_dev(dev)); + if (pasid_max < 0) + return -EINVAL; + } else + pasid_max = 1 << 20; + + /* Bind supervisor PASID shuld have mm = NULL */ + if (flags & SVM_FLAG_SUPERVISOR_MODE) { + if (!ecap_srs(iommu->ecap) || mm) { + pr_err("Supervisor PASID with user provided mm.\n"); + return -EINVAL; + } + } + + if (!(flags & SVM_FLAG_PRIVATE_PASID)) { + struct intel_svm *t; + + list_for_each_entry(t, &global_svm_list, list) { + if (t->mm != mm || (t->flags & SVM_FLAG_PRIVATE_PASID)) + continue; + + svm = t; + if (svm->pasid >= pasid_max) { + dev_warn(dev, + "Limited PASID width. Cannot use existing PASID %d\n", + svm->pasid); + ret = -ENOSPC; + goto out; + } + + /* Find the matching device in svm list */ + for_each_svm_dev(sdev, svm, dev) { + if (sdev->ops != ops) { + ret = -EBUSY; + goto out; + } + sdev->users++; + goto success; + } + + break; + } + } + + sdev = kzalloc(sizeof(*sdev), GFP_KERNEL); + if (!sdev) { + ret = -ENOMEM; + goto out; + } + sdev->dev = dev; + sdev->iommu = iommu; + + ret = intel_iommu_enable_pasid(iommu, dev); + if (ret) { + kfree(sdev); + goto out; + } + + info = get_domain_info(dev); + sdev->did = FLPT_DEFAULT_DID; + sdev->sid = PCI_DEVID(info->bus, info->devfn); + if (info->ats_enabled) { + sdev->dev_iotlb = 1; + sdev->qdep = info->ats_qdep; + if (sdev->qdep >= QI_DEV_EIOTLB_MAX_INVS) + sdev->qdep = 0; + } + + /* Finish the setup now we know we're keeping it */ + sdev->users = 1; + sdev->ops = ops; + init_rcu_head(&sdev->rcu); + + if (!svm) { + svm = kzalloc(sizeof(*svm), GFP_KERNEL); + if (!svm) { + ret = -ENOMEM; + kfree(sdev); + goto out; + } + + if (pasid_max > intel_pasid_max_id) + pasid_max = intel_pasid_max_id; + + /* Do not use PASID 0, reserved for RID to PASID */ + svm->pasid = ioasid_alloc(NULL, PASID_MIN, + pasid_max - 1, svm); + if (svm->pasid == INVALID_IOASID) { + kfree(svm); + kfree(sdev); + ret = -ENOSPC; + goto out; + } + svm->notifier.ops = &intel_mmuops; + svm->mm = mm; + svm->flags = flags; + INIT_LIST_HEAD_RCU(&svm->devs); + INIT_LIST_HEAD(&svm->list); + ret = -ENOMEM; + if (mm) { + ret = mmu_notifier_register(&svm->notifier, mm); + if (ret) { + ioasid_free(svm->pasid); + kfree(svm); + kfree(sdev); + goto out; + } + } + + spin_lock_irqsave(&iommu->lock, iflags); + ret = intel_pasid_setup_first_level(iommu, dev, + mm ? mm->pgd : init_mm.pgd, + svm->pasid, FLPT_DEFAULT_DID, + (mm ? 0 : PASID_FLAG_SUPERVISOR_MODE) | + (cpu_feature_enabled(X86_FEATURE_LA57) ? + PASID_FLAG_FL5LP : 0)); + spin_unlock_irqrestore(&iommu->lock, iflags); + if (ret) { + if (mm) + mmu_notifier_unregister(&svm->notifier, mm); + ioasid_free(svm->pasid); + kfree(svm); + kfree(sdev); + goto out; + } + + list_add_tail(&svm->list, &global_svm_list); + if (mm) { + /* The newly allocated pasid is loaded to the mm. */ + load_pasid(mm, svm->pasid); + } + } else { + /* + * Binding a new device with existing PASID, need to setup + * the PASID entry. + */ + spin_lock_irqsave(&iommu->lock, iflags); + ret = intel_pasid_setup_first_level(iommu, dev, + mm ? mm->pgd : init_mm.pgd, + svm->pasid, FLPT_DEFAULT_DID, + (mm ? 0 : PASID_FLAG_SUPERVISOR_MODE) | + (cpu_feature_enabled(X86_FEATURE_LA57) ? + PASID_FLAG_FL5LP : 0)); + spin_unlock_irqrestore(&iommu->lock, iflags); + if (ret) { + kfree(sdev); + goto out; + } + } + list_add_rcu(&sdev->list, &svm->devs); +success: + sdev->pasid = svm->pasid; + sdev->sva.dev = dev; + if (sd) + *sd = sdev; + ret = 0; +out: + return ret; +} + +/* Caller must hold pasid_mutex */ +static int intel_svm_unbind_mm(struct device *dev, u32 pasid) +{ + struct intel_svm_dev *sdev; + struct intel_iommu *iommu; + struct intel_svm *svm; + int ret = -EINVAL; + + iommu = device_to_iommu(dev, NULL, NULL); + if (!iommu) + goto out; + + ret = pasid_to_svm_sdev(dev, pasid, &svm, &sdev); + if (ret) + goto out; + + if (sdev) { + sdev->users--; + if (!sdev->users) { + list_del_rcu(&sdev->list); + /* Flush the PASID cache and IOTLB for this device. + * Note that we do depend on the hardware *not* using + * the PASID any more. Just as we depend on other + * devices never using PASIDs that they have no right + * to use. We have a *shared* PASID table, because it's + * large and has to be physically contiguous. So it's + * hard to be as defensive as we might like. */ + intel_pasid_tear_down_entry(iommu, dev, + svm->pasid, false); + intel_svm_drain_prq(dev, svm->pasid); + kfree_rcu(sdev, rcu); + + if (list_empty(&svm->devs)) { + ioasid_free(svm->pasid); + if (svm->mm) { + mmu_notifier_unregister(&svm->notifier, svm->mm); + /* Clear mm's pasid. */ + load_pasid(svm->mm, PASID_DISABLED); + } + list_del(&svm->list); + /* We mandate that no page faults may be outstanding + * for the PASID when intel_svm_unbind_mm() is called. + * If that is not obeyed, subtle errors will happen. + * Let's make them less subtle... */ + memset(svm, 0x6b, sizeof(*svm)); + kfree(svm); + } + } + } +out: + return ret; +} + +/* Page request queue descriptor */ +struct page_req_dsc { + union { + struct { + u64 type:8; + u64 pasid_present:1; + u64 priv_data_present:1; + u64 rsvd:6; + u64 rid:16; + u64 pasid:20; + u64 exe_req:1; + u64 pm_req:1; + u64 rsvd2:10; + }; + u64 qw_0; + }; + union { + struct { + u64 rd_req:1; + u64 wr_req:1; + u64 lpig:1; + u64 prg_index:9; + u64 addr:52; + }; + u64 qw_1; + }; + u64 priv_data[2]; +}; + +#define PRQ_RING_MASK ((0x1000 << PRQ_ORDER) - 0x20) + +static bool access_error(struct vm_area_struct *vma, struct page_req_dsc *req) +{ + unsigned long requested = 0; + + if (req->exe_req) + requested |= VM_EXEC; + + if (req->rd_req) + requested |= VM_READ; + + if (req->wr_req) + requested |= VM_WRITE; + + return (requested & ~vma->vm_flags) != 0; +} + +static bool is_canonical_address(u64 addr) +{ + int shift = 64 - (__VIRTUAL_MASK_SHIFT + 1); + long saddr = (long) addr; + + return (((saddr << shift) >> shift) == saddr); +} + +/** + * intel_svm_drain_prq - Drain page requests and responses for a pasid + * @dev: target device + * @pasid: pasid for draining + * + * Drain all pending page requests and responses related to @pasid in both + * software and hardware. This is supposed to be called after the device + * driver has stopped DMA, the pasid entry has been cleared, and both IOTLB + * and DevTLB have been invalidated. + * + * It waits until all pending page requests for @pasid in the page fault + * queue are completed by the prq handling thread. Then follow the steps + * described in VT-d spec CH7.10 to drain all page requests and page + * responses pending in the hardware. + */ +static void intel_svm_drain_prq(struct device *dev, u32 pasid) +{ + struct device_domain_info *info; + struct dmar_domain *domain; + struct intel_iommu *iommu; + struct qi_desc desc[3]; + struct pci_dev *pdev; + int head, tail; + u16 sid, did; + int qdep; + + info = get_domain_info(dev); + if (WARN_ON(!info || !dev_is_pci(dev))) + return; + + if (!info->pri_enabled) + return; + + iommu = info->iommu; + domain = info->domain; + pdev = to_pci_dev(dev); + sid = PCI_DEVID(info->bus, info->devfn); + did = domain->iommu_did[iommu->seq_id]; + qdep = pci_ats_queue_depth(pdev); + + /* + * Check and wait until all pending page requests in the queue are + * handled by the prq handling thread. + */ +prq_retry: + reinit_completion(&iommu->prq_complete); + tail = dmar_readq(iommu->reg + DMAR_PQT_REG) & PRQ_RING_MASK; + head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK; + while (head != tail) { + struct page_req_dsc *req; + + req = &iommu->prq[head / sizeof(*req)]; + if (!req->pasid_present || req->pasid != pasid) { + head = (head + sizeof(*req)) & PRQ_RING_MASK; + continue; + } + + wait_for_completion(&iommu->prq_complete); + goto prq_retry; + } + + /* + * Perform steps described in VT-d spec CH7.10 to drain page + * requests and responses in hardware. + */ + memset(desc, 0, sizeof(desc)); + desc[0].qw0 = QI_IWD_STATUS_DATA(QI_DONE) | + QI_IWD_FENCE | + QI_IWD_TYPE; + desc[1].qw0 = QI_EIOTLB_PASID(pasid) | + QI_EIOTLB_DID(did) | + QI_EIOTLB_GRAN(QI_GRAN_NONG_PASID) | + QI_EIOTLB_TYPE; + desc[2].qw0 = QI_DEV_EIOTLB_PASID(pasid) | + QI_DEV_EIOTLB_SID(sid) | + QI_DEV_EIOTLB_QDEP(qdep) | + QI_DEIOTLB_TYPE | + QI_DEV_IOTLB_PFSID(info->pfsid); +qi_retry: + reinit_completion(&iommu->prq_complete); + qi_submit_sync(iommu, desc, 3, QI_OPT_WAIT_DRAIN); + if (readl(iommu->reg + DMAR_PRS_REG) & DMA_PRS_PRO) { + wait_for_completion(&iommu->prq_complete); + goto qi_retry; + } +} + +static int prq_to_iommu_prot(struct page_req_dsc *req) +{ + int prot = 0; + + if (req->rd_req) + prot |= IOMMU_FAULT_PERM_READ; + if (req->wr_req) + prot |= IOMMU_FAULT_PERM_WRITE; + if (req->exe_req) + prot |= IOMMU_FAULT_PERM_EXEC; + if (req->pm_req) + prot |= IOMMU_FAULT_PERM_PRIV; + + return prot; +} + +static int +intel_svm_prq_report(struct device *dev, struct page_req_dsc *desc) +{ + struct iommu_fault_event event; + + if (!dev || !dev_is_pci(dev)) + return -ENODEV; + + /* Fill in event data for device specific processing */ + memset(&event, 0, sizeof(struct iommu_fault_event)); + event.fault.type = IOMMU_FAULT_PAGE_REQ; + event.fault.prm.addr = (u64)desc->addr << VTD_PAGE_SHIFT; + event.fault.prm.pasid = desc->pasid; + event.fault.prm.grpid = desc->prg_index; + event.fault.prm.perm = prq_to_iommu_prot(desc); + + if (desc->lpig) + event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE; + if (desc->pasid_present) { + event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PASID_VALID; + event.fault.prm.flags |= IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID; + } + if (desc->priv_data_present) { + /* + * Set last page in group bit if private data is present, + * page response is required as it does for LPIG. + * iommu_report_device_fault() doesn't understand this vendor + * specific requirement thus we set last_page as a workaround. + */ + event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE; + event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA; + memcpy(event.fault.prm.private_data, desc->priv_data, + sizeof(desc->priv_data)); + } + + return iommu_report_device_fault(dev, &event); +} + +static irqreturn_t prq_event_thread(int irq, void *d) +{ + struct intel_svm_dev *sdev = NULL; + struct intel_iommu *iommu = d; + struct intel_svm *svm = NULL; + int head, tail, handled = 0; + + /* Clear PPR bit before reading head/tail registers, to + * ensure that we get a new interrupt if needed. */ + writel(DMA_PRS_PPR, iommu->reg + DMAR_PRS_REG); + + tail = dmar_readq(iommu->reg + DMAR_PQT_REG) & PRQ_RING_MASK; + head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK; + while (head != tail) { + struct vm_area_struct *vma; + struct page_req_dsc *req; + struct qi_desc resp; + int result; + vm_fault_t ret; + u64 address; + + handled = 1; + + req = &iommu->prq[head / sizeof(*req)]; + + result = QI_RESP_FAILURE; + address = (u64)req->addr << VTD_PAGE_SHIFT; + if (!req->pasid_present) { + pr_err("%s: Page request without PASID: %08llx %08llx\n", + iommu->name, ((unsigned long long *)req)[0], + ((unsigned long long *)req)[1]); + goto no_pasid; + } + /* We shall not receive page request for supervisor SVM */ + if (req->pm_req && (req->rd_req | req->wr_req)) { + pr_err("Unexpected page request in Privilege Mode"); + /* No need to find the matching sdev as for bad_req */ + goto no_pasid; + } + /* DMA read with exec requeset is not supported. */ + if (req->exe_req && req->rd_req) { + pr_err("Execution request not supported\n"); + goto no_pasid; + } + if (!svm || svm->pasid != req->pasid) { + rcu_read_lock(); + svm = ioasid_find(NULL, req->pasid, NULL); + /* It *can't* go away, because the driver is not permitted + * to unbind the mm while any page faults are outstanding. + * So we only need RCU to protect the internal idr code. */ + rcu_read_unlock(); + if (IS_ERR_OR_NULL(svm)) { + pr_err("%s: Page request for invalid PASID %d: %08llx %08llx\n", + iommu->name, req->pasid, ((unsigned long long *)req)[0], + ((unsigned long long *)req)[1]); + goto no_pasid; + } + } + + if (!sdev || sdev->sid != req->rid) { + struct intel_svm_dev *t; + + sdev = NULL; + rcu_read_lock(); + list_for_each_entry_rcu(t, &svm->devs, list) { + if (t->sid == req->rid) { + sdev = t; + break; + } + } + rcu_read_unlock(); + } + + result = QI_RESP_INVALID; + /* Since we're using init_mm.pgd directly, we should never take + * any faults on kernel addresses. */ + if (!svm->mm) + goto bad_req; + + /* If address is not canonical, return invalid response */ + if (!is_canonical_address(address)) + goto bad_req; + + /* + * If prq is to be handled outside iommu driver via receiver of + * the fault notifiers, we skip the page response here. + */ + if (svm->flags & SVM_FLAG_GUEST_MODE) { + if (sdev && !intel_svm_prq_report(sdev->dev, req)) + goto prq_advance; + else + goto bad_req; + } + + /* If the mm is already defunct, don't handle faults. */ + if (!mmget_not_zero(svm->mm)) + goto bad_req; + + mmap_read_lock(svm->mm); + vma = find_extend_vma(svm->mm, address); + if (!vma || address < vma->vm_start) + goto invalid; + + if (access_error(vma, req)) + goto invalid; + + ret = handle_mm_fault(vma, address, + req->wr_req ? FAULT_FLAG_WRITE : 0, + NULL); + if (ret & VM_FAULT_ERROR) + goto invalid; + + result = QI_RESP_SUCCESS; +invalid: + mmap_read_unlock(svm->mm); + mmput(svm->mm); +bad_req: + WARN_ON(!sdev); + if (sdev && sdev->ops && sdev->ops->fault_cb) { + int rwxp = (req->rd_req << 3) | (req->wr_req << 2) | + (req->exe_req << 1) | (req->pm_req); + sdev->ops->fault_cb(sdev->dev, req->pasid, req->addr, + req->priv_data, rwxp, result); + } + /* We get here in the error case where the PASID lookup failed, + and these can be NULL. Do not use them below this point! */ + sdev = NULL; + svm = NULL; +no_pasid: + if (req->lpig || req->priv_data_present) { + /* + * Per VT-d spec. v3.0 ch7.7, system software must + * respond with page group response if private data + * is present (PDP) or last page in group (LPIG) bit + * is set. This is an additional VT-d feature beyond + * PCI ATS spec. + */ + resp.qw0 = QI_PGRP_PASID(req->pasid) | + QI_PGRP_DID(req->rid) | + QI_PGRP_PASID_P(req->pasid_present) | + QI_PGRP_PDP(req->priv_data_present) | + QI_PGRP_RESP_CODE(result) | + QI_PGRP_RESP_TYPE; + resp.qw1 = QI_PGRP_IDX(req->prg_index) | + QI_PGRP_LPIG(req->lpig); + resp.qw2 = 0; + resp.qw3 = 0; + + if (req->priv_data_present) + memcpy(&resp.qw2, req->priv_data, + sizeof(req->priv_data)); + qi_submit_sync(iommu, &resp, 1, 0); + } +prq_advance: + head = (head + sizeof(*req)) & PRQ_RING_MASK; + } + + dmar_writeq(iommu->reg + DMAR_PQH_REG, tail); + + /* + * Clear the page request overflow bit and wake up all threads that + * are waiting for the completion of this handling. + */ + if (readl(iommu->reg + DMAR_PRS_REG) & DMA_PRS_PRO) { + pr_info_ratelimited("IOMMU: %s: PRQ overflow detected\n", + iommu->name); + head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK; + tail = dmar_readq(iommu->reg + DMAR_PQT_REG) & PRQ_RING_MASK; + if (head == tail) { + writel(DMA_PRS_PRO, iommu->reg + DMAR_PRS_REG); + pr_info_ratelimited("IOMMU: %s: PRQ overflow cleared", + iommu->name); + } + } + + if (!completion_done(&iommu->prq_complete)) + complete(&iommu->prq_complete); + + return IRQ_RETVAL(handled); +} + +#define to_intel_svm_dev(handle) container_of(handle, struct intel_svm_dev, sva) +struct iommu_sva * +intel_svm_bind(struct device *dev, struct mm_struct *mm, void *drvdata) +{ + struct iommu_sva *sva = ERR_PTR(-EINVAL); + struct intel_svm_dev *sdev = NULL; + unsigned int flags = 0; + int ret; + + /* + * TODO: Consolidate with generic iommu-sva bind after it is merged. + * It will require shared SVM data structures, i.e. combine io_mm + * and intel_svm etc. + */ + if (drvdata) + flags = *(unsigned int *)drvdata; + mutex_lock(&pasid_mutex); + ret = intel_svm_bind_mm(dev, flags, NULL, mm, &sdev); + if (ret) + sva = ERR_PTR(ret); + else if (sdev) + sva = &sdev->sva; + else + WARN(!sdev, "SVM bind succeeded with no sdev!\n"); + + mutex_unlock(&pasid_mutex); + + return sva; +} + +void intel_svm_unbind(struct iommu_sva *sva) +{ + struct intel_svm_dev *sdev; + + mutex_lock(&pasid_mutex); + sdev = to_intel_svm_dev(sva); + intel_svm_unbind_mm(sdev->dev, sdev->pasid); + mutex_unlock(&pasid_mutex); +} + +u32 intel_svm_get_pasid(struct iommu_sva *sva) +{ + struct intel_svm_dev *sdev; + u32 pasid; + + mutex_lock(&pasid_mutex); + sdev = to_intel_svm_dev(sva); + pasid = sdev->pasid; + mutex_unlock(&pasid_mutex); + + return pasid; +} + +int intel_svm_page_response(struct device *dev, + struct iommu_fault_event *evt, + struct iommu_page_response *msg) +{ + struct iommu_fault_page_request *prm; + struct intel_svm_dev *sdev = NULL; + struct intel_svm *svm = NULL; + struct intel_iommu *iommu; + bool private_present; + bool pasid_present; + bool last_page; + u8 bus, devfn; + int ret = 0; + u16 sid; + + if (!dev || !dev_is_pci(dev)) + return -ENODEV; + + iommu = device_to_iommu(dev, &bus, &devfn); + if (!iommu) + return -ENODEV; + + if (!msg || !evt) + return -EINVAL; + + mutex_lock(&pasid_mutex); + + prm = &evt->fault.prm; + sid = PCI_DEVID(bus, devfn); + pasid_present = prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID; + private_present = prm->flags & IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA; + last_page = prm->flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE; + + if (!pasid_present) { + ret = -EINVAL; + goto out; + } + + if (prm->pasid == 0 || prm->pasid >= PASID_MAX) { + ret = -EINVAL; + goto out; + } + + ret = pasid_to_svm_sdev(dev, prm->pasid, &svm, &sdev); + if (ret || !sdev) { + ret = -ENODEV; + goto out; + } + + /* + * For responses from userspace, need to make sure that the + * pasid has been bound to its mm. + */ + if (svm->flags & SVM_FLAG_GUEST_MODE) { + struct mm_struct *mm; + + mm = get_task_mm(current); + if (!mm) { + ret = -EINVAL; + goto out; + } + + if (mm != svm->mm) { + ret = -ENODEV; + mmput(mm); + goto out; + } + + mmput(mm); + } + + /* + * Per VT-d spec. v3.0 ch7.7, system software must respond + * with page group response if private data is present (PDP) + * or last page in group (LPIG) bit is set. This is an + * additional VT-d requirement beyond PCI ATS spec. + */ + if (last_page || private_present) { + struct qi_desc desc; + + desc.qw0 = QI_PGRP_PASID(prm->pasid) | QI_PGRP_DID(sid) | + QI_PGRP_PASID_P(pasid_present) | + QI_PGRP_PDP(private_present) | + QI_PGRP_RESP_CODE(msg->code) | + QI_PGRP_RESP_TYPE; + desc.qw1 = QI_PGRP_IDX(prm->grpid) | QI_PGRP_LPIG(last_page); + desc.qw2 = 0; + desc.qw3 = 0; + if (private_present) + memcpy(&desc.qw2, prm->private_data, + sizeof(prm->private_data)); + + qi_submit_sync(iommu, &desc, 1, 0); + } +out: + mutex_unlock(&pasid_mutex); + return ret; +} |