| /* |
| * VFIO: IOMMU DMA mapping support for Type1 IOMMU |
| * |
| * Copyright (C) 2012 Red Hat, Inc. All rights reserved. |
| * Author: Alex Williamson <alex.williamson@redhat.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * Derived from original vfio: |
| * Copyright 2010 Cisco Systems, Inc. All rights reserved. |
| * Author: Tom Lyon, pugs@cisco.com |
| * |
| * We arbitrarily define a Type1 IOMMU as one matching the below code. |
| * It could be called the x86 IOMMU as it's designed for AMD-Vi & Intel |
| * VT-d, but that makes it harder to re-use as theoretically anyone |
| * implementing a similar IOMMU could make use of this. We expect the |
| * IOMMU to support the IOMMU API and have few to no restrictions around |
| * the IOVA range that can be mapped. The Type1 IOMMU is currently |
| * optimized for relatively static mappings of a userspace process with |
| * userpsace pages pinned into memory. We also assume devices and IOMMU |
| * domains are PCI based as the IOMMU API is still centered around a |
| * device/bus interface rather than a group interface. |
| */ |
| |
| #include <linux/compat.h> |
| #include <linux/device.h> |
| #include <linux/fs.h> |
| #include <linux/iommu.h> |
| #include <linux/module.h> |
| #include <linux/mm.h> |
| #include <linux/pci.h> /* pci_bus_type */ |
| #include <linux/rbtree.h> |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include <linux/uaccess.h> |
| #include <linux/vfio.h> |
| #include <linux/workqueue.h> |
| |
| #define DRIVER_VERSION "0.2" |
| #define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>" |
| #define DRIVER_DESC "Type1 IOMMU driver for VFIO" |
| |
| static bool allow_unsafe_interrupts; |
| module_param_named(allow_unsafe_interrupts, |
| allow_unsafe_interrupts, bool, S_IRUGO | S_IWUSR); |
| MODULE_PARM_DESC(allow_unsafe_interrupts, |
| "Enable VFIO IOMMU support for on platforms without interrupt remapping support."); |
| |
| static bool disable_hugepages; |
| module_param_named(disable_hugepages, |
| disable_hugepages, bool, S_IRUGO | S_IWUSR); |
| MODULE_PARM_DESC(disable_hugepages, |
| "Disable VFIO IOMMU support for IOMMU hugepages."); |
| |
| struct vfio_iommu { |
| struct iommu_domain *domain; |
| struct mutex lock; |
| struct rb_root dma_list; |
| struct list_head group_list; |
| bool cache; |
| }; |
| |
| struct vfio_dma { |
| struct rb_node node; |
| dma_addr_t iova; /* Device address */ |
| unsigned long vaddr; /* Process virtual addr */ |
| size_t size; /* Map size (bytes) */ |
| int prot; /* IOMMU_READ/WRITE */ |
| }; |
| |
| struct vfio_group { |
| struct iommu_group *iommu_group; |
| struct list_head next; |
| }; |
| |
| /* |
| * This code handles mapping and unmapping of user data buffers |
| * into DMA'ble space using the IOMMU |
| */ |
| |
| static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu, |
| dma_addr_t start, size_t size) |
| { |
| struct rb_node *node = iommu->dma_list.rb_node; |
| |
| while (node) { |
| struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node); |
| |
| if (start + size <= dma->iova) |
| node = node->rb_left; |
| else if (start >= dma->iova + dma->size) |
| node = node->rb_right; |
| else |
| return dma; |
| } |
| |
| return NULL; |
| } |
| |
| static void vfio_insert_dma(struct vfio_iommu *iommu, struct vfio_dma *new) |
| { |
| struct rb_node **link = &iommu->dma_list.rb_node, *parent = NULL; |
| struct vfio_dma *dma; |
| |
| while (*link) { |
| parent = *link; |
| dma = rb_entry(parent, struct vfio_dma, node); |
| |
| if (new->iova + new->size <= dma->iova) |
| link = &(*link)->rb_left; |
| else |
| link = &(*link)->rb_right; |
| } |
| |
| rb_link_node(&new->node, parent, link); |
| rb_insert_color(&new->node, &iommu->dma_list); |
| } |
| |
| static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *old) |
| { |
| rb_erase(&old->node, &iommu->dma_list); |
| } |
| |
| struct vwork { |
| struct mm_struct *mm; |
| long npage; |
| struct work_struct work; |
| }; |
| |
| /* delayed decrement/increment for locked_vm */ |
| static void vfio_lock_acct_bg(struct work_struct *work) |
| { |
| struct vwork *vwork = container_of(work, struct vwork, work); |
| struct mm_struct *mm; |
| |
| mm = vwork->mm; |
| down_write(&mm->mmap_sem); |
| mm->locked_vm += vwork->npage; |
| up_write(&mm->mmap_sem); |
| mmput(mm); |
| kfree(vwork); |
| } |
| |
| static void vfio_lock_acct(long npage) |
| { |
| struct vwork *vwork; |
| struct mm_struct *mm; |
| |
| if (!current->mm || !npage) |
| return; /* process exited or nothing to do */ |
| |
| if (down_write_trylock(¤t->mm->mmap_sem)) { |
| current->mm->locked_vm += npage; |
| up_write(¤t->mm->mmap_sem); |
| return; |
| } |
| |
| /* |
| * Couldn't get mmap_sem lock, so must setup to update |
| * mm->locked_vm later. If locked_vm were atomic, we |
| * wouldn't need this silliness |
| */ |
| vwork = kmalloc(sizeof(struct vwork), GFP_KERNEL); |
| if (!vwork) |
| return; |
| mm = get_task_mm(current); |
| if (!mm) { |
| kfree(vwork); |
| return; |
| } |
| INIT_WORK(&vwork->work, vfio_lock_acct_bg); |
| vwork->mm = mm; |
| vwork->npage = npage; |
| schedule_work(&vwork->work); |
| } |
| |
| /* |
| * Some mappings aren't backed by a struct page, for example an mmap'd |
| * MMIO range for our own or another device. These use a different |
| * pfn conversion and shouldn't be tracked as locked pages. |
| */ |
| static bool is_invalid_reserved_pfn(unsigned long pfn) |
| { |
| if (pfn_valid(pfn)) { |
| bool reserved; |
| struct page *tail = pfn_to_page(pfn); |
| struct page *head = compound_trans_head(tail); |
| reserved = !!(PageReserved(head)); |
| if (head != tail) { |
| /* |
| * "head" is not a dangling pointer |
| * (compound_trans_head takes care of that) |
| * but the hugepage may have been split |
| * from under us (and we may not hold a |
| * reference count on the head page so it can |
| * be reused before we run PageReferenced), so |
| * we've to check PageTail before returning |
| * what we just read. |
| */ |
| smp_rmb(); |
| if (PageTail(tail)) |
| return reserved; |
| } |
| return PageReserved(tail); |
| } |
| |
| return true; |
| } |
| |
| static int put_pfn(unsigned long pfn, int prot) |
| { |
| if (!is_invalid_reserved_pfn(pfn)) { |
| struct page *page = pfn_to_page(pfn); |
| if (prot & IOMMU_WRITE) |
| SetPageDirty(page); |
| put_page(page); |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int vaddr_get_pfn(unsigned long vaddr, int prot, unsigned long *pfn) |
| { |
| struct page *page[1]; |
| struct vm_area_struct *vma; |
| int ret = -EFAULT; |
| |
| if (get_user_pages_fast(vaddr, 1, !!(prot & IOMMU_WRITE), page) == 1) { |
| *pfn = page_to_pfn(page[0]); |
| return 0; |
| } |
| |
| down_read(¤t->mm->mmap_sem); |
| |
| vma = find_vma_intersection(current->mm, vaddr, vaddr + 1); |
| |
| if (vma && vma->vm_flags & VM_PFNMAP) { |
| *pfn = ((vaddr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; |
| if (is_invalid_reserved_pfn(*pfn)) |
| ret = 0; |
| } |
| |
| up_read(¤t->mm->mmap_sem); |
| |
| return ret; |
| } |
| |
| /* |
| * Attempt to pin pages. We really don't want to track all the pfns and |
| * the iommu can only map chunks of consecutive pfns anyway, so get the |
| * first page and all consecutive pages with the same locking. |
| */ |
| static long vfio_pin_pages(unsigned long vaddr, long npage, |
| int prot, unsigned long *pfn_base) |
| { |
| unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; |
| bool lock_cap = capable(CAP_IPC_LOCK); |
| long ret, i; |
| |
| if (!current->mm) |
| return -ENODEV; |
| |
| ret = vaddr_get_pfn(vaddr, prot, pfn_base); |
| if (ret) |
| return ret; |
| |
| if (is_invalid_reserved_pfn(*pfn_base)) |
| return 1; |
| |
| if (!lock_cap && current->mm->locked_vm + 1 > limit) { |
| put_pfn(*pfn_base, prot); |
| pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__, |
| limit << PAGE_SHIFT); |
| return -ENOMEM; |
| } |
| |
| if (unlikely(disable_hugepages)) { |
| vfio_lock_acct(1); |
| return 1; |
| } |
| |
| /* Lock all the consecutive pages from pfn_base */ |
| for (i = 1, vaddr += PAGE_SIZE; i < npage; i++, vaddr += PAGE_SIZE) { |
| unsigned long pfn = 0; |
| |
| ret = vaddr_get_pfn(vaddr, prot, &pfn); |
| if (ret) |
| break; |
| |
| if (pfn != *pfn_base + i || is_invalid_reserved_pfn(pfn)) { |
| put_pfn(pfn, prot); |
| break; |
| } |
| |
| if (!lock_cap && current->mm->locked_vm + i + 1 > limit) { |
| put_pfn(pfn, prot); |
| pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", |
| __func__, limit << PAGE_SHIFT); |
| break; |
| } |
| } |
| |
| vfio_lock_acct(i); |
| |
| return i; |
| } |
| |
| static long vfio_unpin_pages(unsigned long pfn, long npage, |
| int prot, bool do_accounting) |
| { |
| unsigned long unlocked = 0; |
| long i; |
| |
| for (i = 0; i < npage; i++) |
| unlocked += put_pfn(pfn++, prot); |
| |
| if (do_accounting) |
| vfio_lock_acct(-unlocked); |
| |
| return unlocked; |
| } |
| |
| static int vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma, |
| dma_addr_t iova, size_t *size) |
| { |
| dma_addr_t start = iova, end = iova + *size; |
| long unlocked = 0; |
| |
| while (iova < end) { |
| size_t unmapped; |
| phys_addr_t phys; |
| |
| /* |
| * We use the IOMMU to track the physical address. This |
| * saves us from having a lot more entries in our mapping |
| * tree. The downside is that we don't track the size |
| * used to do the mapping. We request unmap of a single |
| * page, but expect IOMMUs that support large pages to |
| * unmap a larger chunk. |
| */ |
| phys = iommu_iova_to_phys(iommu->domain, iova); |
| if (WARN_ON(!phys)) { |
| iova += PAGE_SIZE; |
| continue; |
| } |
| |
| unmapped = iommu_unmap(iommu->domain, iova, PAGE_SIZE); |
| if (!unmapped) |
| break; |
| |
| unlocked += vfio_unpin_pages(phys >> PAGE_SHIFT, |
| unmapped >> PAGE_SHIFT, |
| dma->prot, false); |
| iova += unmapped; |
| } |
| |
| vfio_lock_acct(-unlocked); |
| |
| *size = iova - start; |
| |
| return 0; |
| } |
| |
| static int vfio_remove_dma_overlap(struct vfio_iommu *iommu, dma_addr_t start, |
| size_t *size, struct vfio_dma *dma) |
| { |
| size_t offset, overlap, tmp; |
| struct vfio_dma *split; |
| int ret; |
| |
| if (!*size) |
| return 0; |
| |
| /* |
| * Existing dma region is completely covered, unmap all. This is |
| * the likely case since userspace tends to map and unmap buffers |
| * in one shot rather than multiple mappings within a buffer. |
| */ |
| if (likely(start <= dma->iova && |
| start + *size >= dma->iova + dma->size)) { |
| *size = dma->size; |
| ret = vfio_unmap_unpin(iommu, dma, dma->iova, size); |
| if (ret) |
| return ret; |
| |
| /* |
| * Did we remove more than we have? Should never happen |
| * since a vfio_dma is contiguous in iova and vaddr. |
| */ |
| WARN_ON(*size != dma->size); |
| |
| vfio_remove_dma(iommu, dma); |
| kfree(dma); |
| return 0; |
| } |
| |
| /* Overlap low address of existing range */ |
| if (start <= dma->iova) { |
| overlap = start + *size - dma->iova; |
| ret = vfio_unmap_unpin(iommu, dma, dma->iova, &overlap); |
| if (ret) |
| return ret; |
| |
| vfio_remove_dma(iommu, dma); |
| |
| /* |
| * Check, we may have removed to whole vfio_dma. If not |
| * fixup and re-insert. |
| */ |
| if (overlap < dma->size) { |
| dma->iova += overlap; |
| dma->vaddr += overlap; |
| dma->size -= overlap; |
| vfio_insert_dma(iommu, dma); |
| } else |
| kfree(dma); |
| |
| *size = overlap; |
| return 0; |
| } |
| |
| /* Overlap high address of existing range */ |
| if (start + *size >= dma->iova + dma->size) { |
| offset = start - dma->iova; |
| overlap = dma->size - offset; |
| |
| ret = vfio_unmap_unpin(iommu, dma, start, &overlap); |
| if (ret) |
| return ret; |
| |
| dma->size -= overlap; |
| *size = overlap; |
| return 0; |
| } |
| |
| /* Split existing */ |
| |
| /* |
| * Allocate our tracking structure early even though it may not |
| * be used. An Allocation failure later loses track of pages and |
| * is more difficult to unwind. |
| */ |
| split = kzalloc(sizeof(*split), GFP_KERNEL); |
| if (!split) |
| return -ENOMEM; |
| |
| offset = start - dma->iova; |
| |
| ret = vfio_unmap_unpin(iommu, dma, start, size); |
| if (ret || !*size) { |
| kfree(split); |
| return ret; |
| } |
| |
| tmp = dma->size; |
| |
| /* Resize the lower vfio_dma in place, before the below insert */ |
| dma->size = offset; |
| |
| /* Insert new for remainder, assuming it didn't all get unmapped */ |
| if (likely(offset + *size < tmp)) { |
| split->size = tmp - offset - *size; |
| split->iova = dma->iova + offset + *size; |
| split->vaddr = dma->vaddr + offset + *size; |
| split->prot = dma->prot; |
| vfio_insert_dma(iommu, split); |
| } else |
| kfree(split); |
| |
| return 0; |
| } |
| |
| static int vfio_dma_do_unmap(struct vfio_iommu *iommu, |
| struct vfio_iommu_type1_dma_unmap *unmap) |
| { |
| uint64_t mask; |
| struct vfio_dma *dma; |
| size_t unmapped = 0, size; |
| int ret = 0; |
| |
| mask = ((uint64_t)1 << __ffs(iommu->domain->ops->pgsize_bitmap)) - 1; |
| |
| if (unmap->iova & mask) |
| return -EINVAL; |
| if (!unmap->size || unmap->size & mask) |
| return -EINVAL; |
| |
| WARN_ON(mask & PAGE_MASK); |
| |
| mutex_lock(&iommu->lock); |
| |
| while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size))) { |
| size = unmap->size; |
| ret = vfio_remove_dma_overlap(iommu, unmap->iova, &size, dma); |
| if (ret || !size) |
| break; |
| unmapped += size; |
| } |
| |
| mutex_unlock(&iommu->lock); |
| |
| /* |
| * We may unmap more than requested, update the unmap struct so |
| * userspace can know. |
| */ |
| unmap->size = unmapped; |
| |
| return ret; |
| } |
| |
| /* |
| * Turns out AMD IOMMU has a page table bug where it won't map large pages |
| * to a region that previously mapped smaller pages. This should be fixed |
| * soon, so this is just a temporary workaround to break mappings down into |
| * PAGE_SIZE. Better to map smaller pages than nothing. |
| */ |
| static int map_try_harder(struct vfio_iommu *iommu, dma_addr_t iova, |
| unsigned long pfn, long npage, int prot) |
| { |
| long i; |
| int ret; |
| |
| for (i = 0; i < npage; i++, pfn++, iova += PAGE_SIZE) { |
| ret = iommu_map(iommu->domain, iova, |
| (phys_addr_t)pfn << PAGE_SHIFT, |
| PAGE_SIZE, prot); |
| if (ret) |
| break; |
| } |
| |
| for (; i < npage && i > 0; i--, iova -= PAGE_SIZE) |
| iommu_unmap(iommu->domain, iova, PAGE_SIZE); |
| |
| return ret; |
| } |
| |
| static int vfio_dma_do_map(struct vfio_iommu *iommu, |
| struct vfio_iommu_type1_dma_map *map) |
| { |
| dma_addr_t end, iova; |
| unsigned long vaddr = map->vaddr; |
| size_t size = map->size; |
| long npage; |
| int ret = 0, prot = 0; |
| uint64_t mask; |
| |
| end = map->iova + map->size; |
| |
| mask = ((uint64_t)1 << __ffs(iommu->domain->ops->pgsize_bitmap)) - 1; |
| |
| /* READ/WRITE from device perspective */ |
| if (map->flags & VFIO_DMA_MAP_FLAG_WRITE) |
| prot |= IOMMU_WRITE; |
| if (map->flags & VFIO_DMA_MAP_FLAG_READ) |
| prot |= IOMMU_READ; |
| |
| if (!prot) |
| return -EINVAL; /* No READ/WRITE? */ |
| |
| if (iommu->cache) |
| prot |= IOMMU_CACHE; |
| |
| if (vaddr & mask) |
| return -EINVAL; |
| if (map->iova & mask) |
| return -EINVAL; |
| if (!map->size || map->size & mask) |
| return -EINVAL; |
| |
| WARN_ON(mask & PAGE_MASK); |
| |
| /* Don't allow IOVA wrap */ |
| if (end && end < map->iova) |
| return -EINVAL; |
| |
| /* Don't allow virtual address wrap */ |
| if (vaddr + map->size && vaddr + map->size < vaddr) |
| return -EINVAL; |
| |
| mutex_lock(&iommu->lock); |
| |
| if (vfio_find_dma(iommu, map->iova, map->size)) { |
| mutex_unlock(&iommu->lock); |
| return -EEXIST; |
| } |
| |
| for (iova = map->iova; iova < end; iova += size, vaddr += size) { |
| struct vfio_dma *dma = NULL; |
| unsigned long pfn; |
| long i; |
| |
| /* Pin a contiguous chunk of memory */ |
| npage = vfio_pin_pages(vaddr, (end - iova) >> PAGE_SHIFT, |
| prot, &pfn); |
| if (npage <= 0) { |
| WARN_ON(!npage); |
| ret = (int)npage; |
| break; |
| } |
| |
| /* Verify pages are not already mapped */ |
| for (i = 0; i < npage; i++) { |
| if (iommu_iova_to_phys(iommu->domain, |
| iova + (i << PAGE_SHIFT))) { |
| vfio_unpin_pages(pfn, npage, prot, true); |
| ret = -EBUSY; |
| break; |
| } |
| } |
| |
| ret = iommu_map(iommu->domain, iova, |
| (phys_addr_t)pfn << PAGE_SHIFT, |
| npage << PAGE_SHIFT, prot); |
| if (ret) { |
| if (ret != -EBUSY || |
| map_try_harder(iommu, iova, pfn, npage, prot)) { |
| vfio_unpin_pages(pfn, npage, prot, true); |
| break; |
| } |
| } |
| |
| size = npage << PAGE_SHIFT; |
| |
| /* |
| * Check if we abut a region below - nothing below 0. |
| * This is the most likely case when mapping chunks of |
| * physically contiguous regions within a virtual address |
| * range. Update the abutting entry in place since iova |
| * doesn't change. |
| */ |
| if (likely(iova)) { |
| struct vfio_dma *tmp; |
| tmp = vfio_find_dma(iommu, iova - 1, 1); |
| if (tmp && tmp->prot == prot && |
| tmp->vaddr + tmp->size == vaddr) { |
| tmp->size += size; |
| iova = tmp->iova; |
| size = tmp->size; |
| vaddr = tmp->vaddr; |
| dma = tmp; |
| } |
| } |
| |
| /* |
| * Check if we abut a region above - nothing above ~0 + 1. |
| * If we abut above and below, remove and free. If only |
| * abut above, remove, modify, reinsert. |
| */ |
| if (likely(iova + size)) { |
| struct vfio_dma *tmp; |
| tmp = vfio_find_dma(iommu, iova + size, 1); |
| if (tmp && tmp->prot == prot && |
| tmp->vaddr == vaddr + size) { |
| vfio_remove_dma(iommu, tmp); |
| if (dma) { |
| dma->size += tmp->size; |
| kfree(tmp); |
| } else { |
| size += tmp->size; |
| tmp->size = size; |
| tmp->iova = iova; |
| tmp->vaddr = vaddr; |
| vfio_insert_dma(iommu, tmp); |
| dma = tmp; |
| } |
| } |
| } |
| |
| if (!dma) { |
| dma = kzalloc(sizeof(*dma), GFP_KERNEL); |
| if (!dma) { |
| iommu_unmap(iommu->domain, iova, size); |
| vfio_unpin_pages(pfn, npage, prot, true); |
| ret = -ENOMEM; |
| break; |
| } |
| |
| dma->size = size; |
| dma->iova = iova; |
| dma->vaddr = vaddr; |
| dma->prot = prot; |
| vfio_insert_dma(iommu, dma); |
| } |
| } |
| |
| if (ret) { |
| struct vfio_dma *tmp; |
| iova = map->iova; |
| size = map->size; |
| while ((tmp = vfio_find_dma(iommu, iova, size))) { |
| int r = vfio_remove_dma_overlap(iommu, iova, |
| &size, tmp); |
| if (WARN_ON(r || !size)) |
| break; |
| } |
| } |
| |
| mutex_unlock(&iommu->lock); |
| return ret; |
| } |
| |
| static int vfio_iommu_type1_attach_group(void *iommu_data, |
| struct iommu_group *iommu_group) |
| { |
| struct vfio_iommu *iommu = iommu_data; |
| struct vfio_group *group, *tmp; |
| int ret; |
| |
| group = kzalloc(sizeof(*group), GFP_KERNEL); |
| if (!group) |
| return -ENOMEM; |
| |
| mutex_lock(&iommu->lock); |
| |
| list_for_each_entry(tmp, &iommu->group_list, next) { |
| if (tmp->iommu_group == iommu_group) { |
| mutex_unlock(&iommu->lock); |
| kfree(group); |
| return -EINVAL; |
| } |
| } |
| |
| /* |
| * TODO: Domain have capabilities that might change as we add |
| * groups (see iommu->cache, currently never set). Check for |
| * them and potentially disallow groups to be attached when it |
| * would change capabilities (ugh). |
| */ |
| ret = iommu_attach_group(iommu->domain, iommu_group); |
| if (ret) { |
| mutex_unlock(&iommu->lock); |
| kfree(group); |
| return ret; |
| } |
| |
| group->iommu_group = iommu_group; |
| list_add(&group->next, &iommu->group_list); |
| |
| mutex_unlock(&iommu->lock); |
| |
| return 0; |
| } |
| |
| static void vfio_iommu_type1_detach_group(void *iommu_data, |
| struct iommu_group *iommu_group) |
| { |
| struct vfio_iommu *iommu = iommu_data; |
| struct vfio_group *group; |
| |
| mutex_lock(&iommu->lock); |
| |
| list_for_each_entry(group, &iommu->group_list, next) { |
| if (group->iommu_group == iommu_group) { |
| iommu_detach_group(iommu->domain, iommu_group); |
| list_del(&group->next); |
| kfree(group); |
| break; |
| } |
| } |
| |
| mutex_unlock(&iommu->lock); |
| } |
| |
| static void *vfio_iommu_type1_open(unsigned long arg) |
| { |
| struct vfio_iommu *iommu; |
| |
| if (arg != VFIO_TYPE1_IOMMU) |
| return ERR_PTR(-EINVAL); |
| |
| iommu = kzalloc(sizeof(*iommu), GFP_KERNEL); |
| if (!iommu) |
| return ERR_PTR(-ENOMEM); |
| |
| INIT_LIST_HEAD(&iommu->group_list); |
| iommu->dma_list = RB_ROOT; |
| mutex_init(&iommu->lock); |
| |
| /* |
| * Wish we didn't have to know about bus_type here. |
| */ |
| iommu->domain = iommu_domain_alloc(&pci_bus_type); |
| if (!iommu->domain) { |
| kfree(iommu); |
| return ERR_PTR(-EIO); |
| } |
| |
| /* |
| * Wish we could specify required capabilities rather than create |
| * a domain, see what comes out and hope it doesn't change along |
| * the way. Fortunately we know interrupt remapping is global for |
| * our iommus. |
| */ |
| if (!allow_unsafe_interrupts && |
| !iommu_domain_has_cap(iommu->domain, IOMMU_CAP_INTR_REMAP)) { |
| pr_warn("%s: No interrupt remapping support. Use the module param \"allow_unsafe_interrupts\" to enable VFIO IOMMU support on this platform\n", |
| __func__); |
| iommu_domain_free(iommu->domain); |
| kfree(iommu); |
| return ERR_PTR(-EPERM); |
| } |
| |
| return iommu; |
| } |
| |
| static void vfio_iommu_type1_release(void *iommu_data) |
| { |
| struct vfio_iommu *iommu = iommu_data; |
| struct vfio_group *group, *group_tmp; |
| struct rb_node *node; |
| |
| list_for_each_entry_safe(group, group_tmp, &iommu->group_list, next) { |
| iommu_detach_group(iommu->domain, group->iommu_group); |
| list_del(&group->next); |
| kfree(group); |
| } |
| |
| while ((node = rb_first(&iommu->dma_list))) { |
| struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node); |
| size_t size = dma->size; |
| vfio_remove_dma_overlap(iommu, dma->iova, &size, dma); |
| if (WARN_ON(!size)) |
| break; |
| } |
| |
| iommu_domain_free(iommu->domain); |
| iommu->domain = NULL; |
| kfree(iommu); |
| } |
| |
| static long vfio_iommu_type1_ioctl(void *iommu_data, |
| unsigned int cmd, unsigned long arg) |
| { |
| struct vfio_iommu *iommu = iommu_data; |
| unsigned long minsz; |
| |
| if (cmd == VFIO_CHECK_EXTENSION) { |
| switch (arg) { |
| case VFIO_TYPE1_IOMMU: |
| return 1; |
| default: |
| return 0; |
| } |
| } else if (cmd == VFIO_IOMMU_GET_INFO) { |
| struct vfio_iommu_type1_info info; |
| |
| minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes); |
| |
| if (copy_from_user(&info, (void __user *)arg, minsz)) |
| return -EFAULT; |
| |
| if (info.argsz < minsz) |
| return -EINVAL; |
| |
| info.flags = 0; |
| |
| info.iova_pgsizes = iommu->domain->ops->pgsize_bitmap; |
| |
| return copy_to_user((void __user *)arg, &info, minsz); |
| |
| } else if (cmd == VFIO_IOMMU_MAP_DMA) { |
| struct vfio_iommu_type1_dma_map map; |
| uint32_t mask = VFIO_DMA_MAP_FLAG_READ | |
| VFIO_DMA_MAP_FLAG_WRITE; |
| |
| minsz = offsetofend(struct vfio_iommu_type1_dma_map, size); |
| |
| if (copy_from_user(&map, (void __user *)arg, minsz)) |
| return -EFAULT; |
| |
| if (map.argsz < minsz || map.flags & ~mask) |
| return -EINVAL; |
| |
| return vfio_dma_do_map(iommu, &map); |
| |
| } else if (cmd == VFIO_IOMMU_UNMAP_DMA) { |
| struct vfio_iommu_type1_dma_unmap unmap; |
| long ret; |
| |
| minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size); |
| |
| if (copy_from_user(&unmap, (void __user *)arg, minsz)) |
| return -EFAULT; |
| |
| if (unmap.argsz < minsz || unmap.flags) |
| return -EINVAL; |
| |
| ret = vfio_dma_do_unmap(iommu, &unmap); |
| if (ret) |
| return ret; |
| |
| return copy_to_user((void __user *)arg, &unmap, minsz); |
| } |
| |
| return -ENOTTY; |
| } |
| |
| static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = { |
| .name = "vfio-iommu-type1", |
| .owner = THIS_MODULE, |
| .open = vfio_iommu_type1_open, |
| .release = vfio_iommu_type1_release, |
| .ioctl = vfio_iommu_type1_ioctl, |
| .attach_group = vfio_iommu_type1_attach_group, |
| .detach_group = vfio_iommu_type1_detach_group, |
| }; |
| |
| static int __init vfio_iommu_type1_init(void) |
| { |
| if (!iommu_present(&pci_bus_type)) |
| return -ENODEV; |
| |
| return vfio_register_iommu_driver(&vfio_iommu_driver_ops_type1); |
| } |
| |
| static void __exit vfio_iommu_type1_cleanup(void) |
| { |
| vfio_unregister_iommu_driver(&vfio_iommu_driver_ops_type1); |
| } |
| |
| module_init(vfio_iommu_type1_init); |
| module_exit(vfio_iommu_type1_cleanup); |
| |
| MODULE_VERSION(DRIVER_VERSION); |
| MODULE_LICENSE("GPL v2"); |
| MODULE_AUTHOR(DRIVER_AUTHOR); |
| MODULE_DESCRIPTION(DRIVER_DESC); |