diff options
Diffstat (limited to 'drivers/vfio/vfio_iommu_spapr_tce.c')
-rw-r--r-- | drivers/vfio/vfio_iommu_spapr_tce.c | 312 |
1 files changed, 222 insertions, 90 deletions
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c index 80378ddadc5c..85d3e648bdea 100644 --- a/drivers/vfio/vfio_iommu_spapr_tce.c +++ b/drivers/vfio/vfio_iommu_spapr_tce.c @@ -31,49 +31,49 @@ static void tce_iommu_detach_group(void *iommu_data, struct iommu_group *iommu_group); -static long try_increment_locked_vm(long npages) +static long try_increment_locked_vm(struct mm_struct *mm, long npages) { long ret = 0, locked, lock_limit; - if (!current || !current->mm) - return -ESRCH; /* process exited */ + if (WARN_ON_ONCE(!mm)) + return -EPERM; if (!npages) return 0; - down_write(¤t->mm->mmap_sem); - locked = current->mm->locked_vm + npages; + down_write(&mm->mmap_sem); + locked = mm->locked_vm + npages; lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; if (locked > lock_limit && !capable(CAP_IPC_LOCK)) ret = -ENOMEM; else - current->mm->locked_vm += npages; + mm->locked_vm += npages; pr_debug("[%d] RLIMIT_MEMLOCK +%ld %ld/%ld%s\n", current->pid, npages << PAGE_SHIFT, - current->mm->locked_vm << PAGE_SHIFT, + mm->locked_vm << PAGE_SHIFT, rlimit(RLIMIT_MEMLOCK), ret ? " - exceeded" : ""); - up_write(¤t->mm->mmap_sem); + up_write(&mm->mmap_sem); return ret; } -static void decrement_locked_vm(long npages) +static void decrement_locked_vm(struct mm_struct *mm, long npages) { - if (!current || !current->mm || !npages) - return; /* process exited */ + if (!mm || !npages) + return; - down_write(¤t->mm->mmap_sem); - if (WARN_ON_ONCE(npages > current->mm->locked_vm)) - npages = current->mm->locked_vm; - current->mm->locked_vm -= npages; + down_write(&mm->mmap_sem); + if (WARN_ON_ONCE(npages > mm->locked_vm)) + npages = mm->locked_vm; + mm->locked_vm -= npages; pr_debug("[%d] RLIMIT_MEMLOCK -%ld %ld/%ld\n", current->pid, npages << PAGE_SHIFT, - current->mm->locked_vm << PAGE_SHIFT, + mm->locked_vm << PAGE_SHIFT, rlimit(RLIMIT_MEMLOCK)); - up_write(¤t->mm->mmap_sem); + up_write(&mm->mmap_sem); } /* @@ -89,6 +89,15 @@ struct tce_iommu_group { }; /* + * A container needs to remember which preregistered region it has + * referenced to do proper cleanup at the userspace process exit. + */ +struct tce_iommu_prereg { + struct list_head next; + struct mm_iommu_table_group_mem_t *mem; +}; + +/* * The container descriptor supports only a single group per container. * Required by the API as the container is not supplied with the IOMMU group * at the moment of initialization. @@ -97,24 +106,68 @@ struct tce_container { struct mutex lock; bool enabled; bool v2; + bool def_window_pending; unsigned long locked_pages; + struct mm_struct *mm; struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES]; struct list_head group_list; + struct list_head prereg_list; }; +static long tce_iommu_mm_set(struct tce_container *container) +{ + if (container->mm) { + if (container->mm == current->mm) + return 0; + return -EPERM; + } + BUG_ON(!current->mm); + container->mm = current->mm; + atomic_inc(&container->mm->mm_count); + + return 0; +} + +static long tce_iommu_prereg_free(struct tce_container *container, + struct tce_iommu_prereg *tcemem) +{ + long ret; + + ret = mm_iommu_put(container->mm, tcemem->mem); + if (ret) + return ret; + + list_del(&tcemem->next); + kfree(tcemem); + + return 0; +} + static long tce_iommu_unregister_pages(struct tce_container *container, __u64 vaddr, __u64 size) { struct mm_iommu_table_group_mem_t *mem; + struct tce_iommu_prereg *tcemem; + bool found = false; if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK)) return -EINVAL; - mem = mm_iommu_find(vaddr, size >> PAGE_SHIFT); + mem = mm_iommu_find(container->mm, vaddr, size >> PAGE_SHIFT); if (!mem) return -ENOENT; - return mm_iommu_put(mem); + list_for_each_entry(tcemem, &container->prereg_list, next) { + if (tcemem->mem == mem) { + found = true; + break; + } + } + + if (!found) + return -ENOENT; + + return tce_iommu_prereg_free(container, tcemem); } static long tce_iommu_register_pages(struct tce_container *container, @@ -122,22 +175,36 @@ static long tce_iommu_register_pages(struct tce_container *container, { long ret = 0; struct mm_iommu_table_group_mem_t *mem = NULL; + struct tce_iommu_prereg *tcemem; unsigned long entries = size >> PAGE_SHIFT; if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK) || ((vaddr + size) < vaddr)) return -EINVAL; - ret = mm_iommu_get(vaddr, entries, &mem); + mem = mm_iommu_find(container->mm, vaddr, entries); + if (mem) { + list_for_each_entry(tcemem, &container->prereg_list, next) { + if (tcemem->mem == mem) + return -EBUSY; + } + } + + ret = mm_iommu_get(container->mm, vaddr, entries, &mem); if (ret) return ret; + tcemem = kzalloc(sizeof(*tcemem), GFP_KERNEL); + tcemem->mem = mem; + list_add(&tcemem->next, &container->prereg_list); + container->enabled = true; return 0; } -static long tce_iommu_userspace_view_alloc(struct iommu_table *tbl) +static long tce_iommu_userspace_view_alloc(struct iommu_table *tbl, + struct mm_struct *mm) { unsigned long cb = _ALIGN_UP(sizeof(tbl->it_userspace[0]) * tbl->it_size, PAGE_SIZE); @@ -146,13 +213,13 @@ static long tce_iommu_userspace_view_alloc(struct iommu_table *tbl) BUG_ON(tbl->it_userspace); - ret = try_increment_locked_vm(cb >> PAGE_SHIFT); + ret = try_increment_locked_vm(mm, cb >> PAGE_SHIFT); if (ret) return ret; uas = vzalloc(cb); if (!uas) { - decrement_locked_vm(cb >> PAGE_SHIFT); + decrement_locked_vm(mm, cb >> PAGE_SHIFT); return -ENOMEM; } tbl->it_userspace = uas; @@ -160,7 +227,8 @@ static long tce_iommu_userspace_view_alloc(struct iommu_table *tbl) return 0; } -static void tce_iommu_userspace_view_free(struct iommu_table *tbl) +static void tce_iommu_userspace_view_free(struct iommu_table *tbl, + struct mm_struct *mm) { unsigned long cb = _ALIGN_UP(sizeof(tbl->it_userspace[0]) * tbl->it_size, PAGE_SIZE); @@ -170,7 +238,7 @@ static void tce_iommu_userspace_view_free(struct iommu_table *tbl) vfree(tbl->it_userspace); tbl->it_userspace = NULL; - decrement_locked_vm(cb >> PAGE_SHIFT); + decrement_locked_vm(mm, cb >> PAGE_SHIFT); } static bool tce_page_is_contained(struct page *page, unsigned page_shift) @@ -230,9 +298,6 @@ static int tce_iommu_enable(struct tce_container *container) struct iommu_table_group *table_group; struct tce_iommu_group *tcegrp; - if (!current->mm) - return -ESRCH; /* process exited */ - if (container->enabled) return -EBUSY; @@ -277,8 +342,12 @@ static int tce_iommu_enable(struct tce_container *container) if (!table_group->tce32_size) return -EPERM; + ret = tce_iommu_mm_set(container); + if (ret) + return ret; + locked = table_group->tce32_size >> PAGE_SHIFT; - ret = try_increment_locked_vm(locked); + ret = try_increment_locked_vm(container->mm, locked); if (ret) return ret; @@ -296,10 +365,8 @@ static void tce_iommu_disable(struct tce_container *container) container->enabled = false; - if (!current->mm) - return; - - decrement_locked_vm(container->locked_pages); + BUG_ON(!container->mm); + decrement_locked_vm(container->mm, container->locked_pages); } static void *tce_iommu_open(unsigned long arg) @@ -317,6 +384,7 @@ static void *tce_iommu_open(unsigned long arg) mutex_init(&container->lock); INIT_LIST_HEAD_RCU(&container->group_list); + INIT_LIST_HEAD_RCU(&container->prereg_list); container->v2 = arg == VFIO_SPAPR_TCE_v2_IOMMU; @@ -326,7 +394,8 @@ static void *tce_iommu_open(unsigned long arg) static int tce_iommu_clear(struct tce_container *container, struct iommu_table *tbl, unsigned long entry, unsigned long pages); -static void tce_iommu_free_table(struct iommu_table *tbl); +static void tce_iommu_free_table(struct tce_container *container, + struct iommu_table *tbl); static void tce_iommu_release(void *iommu_data) { @@ -351,10 +420,20 @@ static void tce_iommu_release(void *iommu_data) continue; tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size); - tce_iommu_free_table(tbl); + tce_iommu_free_table(container, tbl); + } + + while (!list_empty(&container->prereg_list)) { + struct tce_iommu_prereg *tcemem; + + tcemem = list_first_entry(&container->prereg_list, + struct tce_iommu_prereg, next); + WARN_ON_ONCE(tce_iommu_prereg_free(container, tcemem)); } tce_iommu_disable(container); + if (container->mm) + mmdrop(container->mm); mutex_destroy(&container->lock); kfree(container); @@ -369,13 +448,14 @@ static void tce_iommu_unuse_page(struct tce_container *container, put_page(page); } -static int tce_iommu_prereg_ua_to_hpa(unsigned long tce, unsigned long size, +static int tce_iommu_prereg_ua_to_hpa(struct tce_container *container, + unsigned long tce, unsigned long size, unsigned long *phpa, struct mm_iommu_table_group_mem_t **pmem) { long ret = 0; struct mm_iommu_table_group_mem_t *mem; - mem = mm_iommu_lookup(tce, size); + mem = mm_iommu_lookup(container->mm, tce, size); if (!mem) return -EINVAL; @@ -388,18 +468,18 @@ static int tce_iommu_prereg_ua_to_hpa(unsigned long tce, unsigned long size, return 0; } -static void tce_iommu_unuse_page_v2(struct iommu_table *tbl, - unsigned long entry) +static void tce_iommu_unuse_page_v2(struct tce_container *container, + struct iommu_table *tbl, unsigned long entry) { struct mm_iommu_table_group_mem_t *mem = NULL; int ret; unsigned long hpa = 0; unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry); - if (!pua || !current || !current->mm) + if (!pua) return; - ret = tce_iommu_prereg_ua_to_hpa(*pua, IOMMU_PAGE_SIZE(tbl), + ret = tce_iommu_prereg_ua_to_hpa(container, *pua, IOMMU_PAGE_SIZE(tbl), &hpa, &mem); if (ret) pr_debug("%s: tce %lx at #%lx was not cached, ret=%d\n", @@ -429,7 +509,7 @@ static int tce_iommu_clear(struct tce_container *container, continue; if (container->v2) { - tce_iommu_unuse_page_v2(tbl, entry); + tce_iommu_unuse_page_v2(container, tbl, entry); continue; } @@ -509,13 +589,19 @@ static long tce_iommu_build_v2(struct tce_container *container, unsigned long hpa; enum dma_data_direction dirtmp; + if (!tbl->it_userspace) { + ret = tce_iommu_userspace_view_alloc(tbl, container->mm); + if (ret) + return ret; + } + for (i = 0; i < pages; ++i) { struct mm_iommu_table_group_mem_t *mem = NULL; unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry + i); - ret = tce_iommu_prereg_ua_to_hpa(tce, IOMMU_PAGE_SIZE(tbl), - &hpa, &mem); + ret = tce_iommu_prereg_ua_to_hpa(container, + tce, IOMMU_PAGE_SIZE(tbl), &hpa, &mem); if (ret) break; @@ -536,7 +622,7 @@ static long tce_iommu_build_v2(struct tce_container *container, ret = iommu_tce_xchg(tbl, entry + i, &hpa, &dirtmp); if (ret) { /* dirtmp cannot be DMA_NONE here */ - tce_iommu_unuse_page_v2(tbl, entry + i); + tce_iommu_unuse_page_v2(container, tbl, entry + i); pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n", __func__, entry << tbl->it_page_shift, tce, ret); @@ -544,7 +630,7 @@ static long tce_iommu_build_v2(struct tce_container *container, } if (dirtmp != DMA_NONE) - tce_iommu_unuse_page_v2(tbl, entry + i); + tce_iommu_unuse_page_v2(container, tbl, entry + i); *pua = tce; @@ -572,7 +658,7 @@ static long tce_iommu_create_table(struct tce_container *container, if (!table_size) return -EINVAL; - ret = try_increment_locked_vm(table_size >> PAGE_SHIFT); + ret = try_increment_locked_vm(container->mm, table_size >> PAGE_SHIFT); if (ret) return ret; @@ -582,25 +668,17 @@ static long tce_iommu_create_table(struct tce_container *container, WARN_ON(!ret && !(*ptbl)->it_ops->free); WARN_ON(!ret && ((*ptbl)->it_allocated_size != table_size)); - if (!ret && container->v2) { - ret = tce_iommu_userspace_view_alloc(*ptbl); - if (ret) - (*ptbl)->it_ops->free(*ptbl); - } - - if (ret) - decrement_locked_vm(table_size >> PAGE_SHIFT); - return ret; } -static void tce_iommu_free_table(struct iommu_table *tbl) +static void tce_iommu_free_table(struct tce_container *container, + struct iommu_table *tbl) { unsigned long pages = tbl->it_allocated_size >> PAGE_SHIFT; - tce_iommu_userspace_view_free(tbl); + tce_iommu_userspace_view_free(tbl, container->mm); tbl->it_ops->free(tbl); - decrement_locked_vm(pages); + decrement_locked_vm(container->mm, pages); } static long tce_iommu_create_window(struct tce_container *container, @@ -663,7 +741,7 @@ unset_exit: table_group = iommu_group_get_iommudata(tcegrp->grp); table_group->ops->unset_window(table_group, num); } - tce_iommu_free_table(tbl); + tce_iommu_free_table(container, tbl); return ret; } @@ -701,12 +779,41 @@ static long tce_iommu_remove_window(struct tce_container *container, /* Free table */ tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size); - tce_iommu_free_table(tbl); + tce_iommu_free_table(container, tbl); container->tables[num] = NULL; return 0; } +static long tce_iommu_create_default_window(struct tce_container *container) +{ + long ret; + __u64 start_addr = 0; + struct tce_iommu_group *tcegrp; + struct iommu_table_group *table_group; + + if (!container->def_window_pending) + return 0; + + if (!tce_groups_attached(container)) + return -ENODEV; + + tcegrp = list_first_entry(&container->group_list, + struct tce_iommu_group, next); + table_group = iommu_group_get_iommudata(tcegrp->grp); + if (!table_group) + return -ENODEV; + + ret = tce_iommu_create_window(container, IOMMU_PAGE_SHIFT_4K, + table_group->tce32_size, 1, &start_addr); + WARN_ON_ONCE(!ret && start_addr); + + if (!ret) + container->def_window_pending = false; + + return ret; +} + static long tce_iommu_ioctl(void *iommu_data, unsigned int cmd, unsigned long arg) { @@ -727,7 +834,17 @@ static long tce_iommu_ioctl(void *iommu_data, } return (ret < 0) ? 0 : ret; + } + + /* + * Sanity check to prevent one userspace from manipulating + * another userspace mm. + */ + BUG_ON(!container); + if (container->mm && container->mm != current->mm) + return -EPERM; + switch (cmd) { case VFIO_IOMMU_SPAPR_TCE_GET_INFO: { struct vfio_iommu_spapr_tce_info info; struct tce_iommu_group *tcegrp; @@ -797,6 +914,10 @@ static long tce_iommu_ioctl(void *iommu_data, VFIO_DMA_MAP_FLAG_WRITE)) return -EINVAL; + ret = tce_iommu_create_default_window(container); + if (ret) + return ret; + num = tce_iommu_find_table(container, param.iova, &tbl); if (num < 0) return -ENXIO; @@ -860,6 +981,10 @@ static long tce_iommu_ioctl(void *iommu_data, if (param.flags) return -EINVAL; + ret = tce_iommu_create_default_window(container); + if (ret) + return ret; + num = tce_iommu_find_table(container, param.iova, &tbl); if (num < 0) return -ENXIO; @@ -888,6 +1013,10 @@ static long tce_iommu_ioctl(void *iommu_data, minsz = offsetofend(struct vfio_iommu_spapr_register_memory, size); + ret = tce_iommu_mm_set(container); + if (ret) + return ret; + if (copy_from_user(¶m, (void __user *)arg, minsz)) return -EFAULT; @@ -911,6 +1040,9 @@ static long tce_iommu_ioctl(void *iommu_data, if (!container->v2) break; + if (!container->mm) + return -EPERM; + minsz = offsetofend(struct vfio_iommu_spapr_register_memory, size); @@ -969,6 +1101,10 @@ static long tce_iommu_ioctl(void *iommu_data, if (!container->v2) break; + ret = tce_iommu_mm_set(container); + if (ret) + return ret; + if (!tce_groups_attached(container)) return -ENXIO; @@ -986,6 +1122,10 @@ static long tce_iommu_ioctl(void *iommu_data, mutex_lock(&container->lock); + ret = tce_iommu_create_default_window(container); + if (ret) + return ret; + ret = tce_iommu_create_window(container, create.page_shift, create.window_size, create.levels, &create.start_addr); @@ -1003,6 +1143,10 @@ static long tce_iommu_ioctl(void *iommu_data, if (!container->v2) break; + ret = tce_iommu_mm_set(container); + if (ret) + return ret; + if (!tce_groups_attached(container)) return -ENXIO; @@ -1018,6 +1162,11 @@ static long tce_iommu_ioctl(void *iommu_data, if (remove.flags) return -EINVAL; + if (container->def_window_pending && !remove.start_addr) { + container->def_window_pending = false; + return 0; + } + mutex_lock(&container->lock); ret = tce_iommu_remove_window(container, remove.start_addr); @@ -1043,7 +1192,7 @@ static void tce_iommu_release_ownership(struct tce_container *container, continue; tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size); - tce_iommu_userspace_view_free(tbl); + tce_iommu_userspace_view_free(tbl, container->mm); if (tbl->it_map) iommu_release_ownership(tbl); @@ -1062,10 +1211,7 @@ static int tce_iommu_take_ownership(struct tce_container *container, if (!tbl || !tbl->it_map) continue; - rc = tce_iommu_userspace_view_alloc(tbl); - if (!rc) - rc = iommu_take_ownership(tbl); - + rc = iommu_take_ownership(tbl); if (rc) { for (j = 0; j < i; ++j) iommu_release_ownership( @@ -1101,7 +1247,6 @@ static long tce_iommu_take_ownership_ddw(struct tce_container *container, struct iommu_table_group *table_group) { long i, ret = 0; - struct iommu_table *tbl = NULL; if (!table_group->ops->create_table || !table_group->ops->set_window || !table_group->ops->release_ownership) { @@ -1111,33 +1256,13 @@ static long tce_iommu_take_ownership_ddw(struct tce_container *container, table_group->ops->take_ownership(table_group); - /* - * If it the first group attached, check if there is - * a default DMA window and create one if none as - * the userspace expects it to exist. - */ - if (!tce_groups_attached(container) && !container->tables[0]) { - ret = tce_iommu_create_table(container, - table_group, - 0, /* window number */ - IOMMU_PAGE_SHIFT_4K, - table_group->tce32_size, - 1, /* default levels */ - &tbl); - if (ret) - goto release_exit; - else - container->tables[0] = tbl; - } - /* Set all windows to the new group */ for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { - tbl = container->tables[i]; + struct iommu_table *tbl = container->tables[i]; if (!tbl) continue; - /* Set the default window to a new group */ ret = table_group->ops->set_window(table_group, i, tbl); if (ret) goto release_exit; @@ -1167,6 +1292,10 @@ static int tce_iommu_attach_group(void *iommu_data, /* pr_debug("tce_vfio: Attaching group #%u to iommu %p\n", iommu_group_id(iommu_group), iommu_group); */ table_group = iommu_group_get_iommudata(iommu_group); + if (!table_group) { + ret = -ENODEV; + goto unlock_exit; + } if (tce_groups_attached(container) && (!table_group->ops || !table_group->ops->take_ownership || @@ -1203,10 +1332,13 @@ static int tce_iommu_attach_group(void *iommu_data, } if (!table_group->ops || !table_group->ops->take_ownership || - !table_group->ops->release_ownership) + !table_group->ops->release_ownership) { ret = tce_iommu_take_ownership(container, table_group); - else + } else { ret = tce_iommu_take_ownership_ddw(container, table_group); + if (!tce_groups_attached(container) && !container->tables[0]) + container->def_window_pending = true; + } if (!ret) { tcegrp->grp = iommu_group; |