| Message ID | 1591113090-23640-1-git-send-email-kwankhede@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | None | expand |
On Tue, 2 Jun 2020 21:21:30 +0530 Kirti Wankhede <kwankhede@nvidia.com> wrote: > VFIO_IOMMU_DIRTY_PAGES ioctl performs three operations: > - Start dirty pages tracking while migration is active > - Stop dirty pages tracking. > - Get dirty pages bitmap. Its user space application's responsibility to > copy content of dirty pages from source to destination during migration. > > To prevent DoS attack, memory for bitmap is allocated per vfio_dma > structure. Bitmap size is calculated considering smallest supported page > size. Bitmap is allocated for all vfio_dmas when dirty logging is enabled > > Bitmap is populated for already pinned pages when bitmap is allocated for > a vfio_dma with the smallest supported page size. Update bitmap from > pinning functions when tracking is enabled. When user application queries > bitmap, check if requested page size is same as page size used to > populated bitmap. If it is equal, copy bitmap, but if not equal, return > error. > > Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> > Reviewed-by: Neo Jia <cjia@nvidia.com> > Reviewed-by: Yan Zhao <yan.y.zhao@intel.com> > > Fixed error reported by build bot by changing pgsize type from uint64_t > to size_t. > Reported-by: kbuild test robot <lkp@intel.com> > --- > > Fixed errors and sparse warnings reported by kbuild test robot > Reported-by: kbuild test robot <lkp@intel.com> > > ld: drivers/vfio/vfio_iommu_type1.o: in function `vfio_dma_populate_bitmap': > >> vfio_iommu_type1.c:(.text+0x666): undefined reference to `__udivdi3' Hi Kirti, This is already in linux-next, could you please send just the incremental fix with a Fixes: tag? Thanks, Alex > drivers/vfio/vfio_iommu_type1.c | 315 +++++++++++++++++++++++++++++++++++++++- > 1 file changed, 309 insertions(+), 6 deletions(-) > > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index 814c795a2543..8362a36c0de4 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -72,6 +72,7 @@ struct vfio_iommu { > uint64_t pgsize_bitmap; > bool v2; > bool nesting; > + bool dirty_page_tracking; > }; > > struct vfio_domain { > @@ -92,6 +93,7 @@ struct vfio_dma { > bool lock_cap; /* capable(CAP_IPC_LOCK) */ > struct task_struct *task; > struct rb_root pfn_list; /* Ex-user pinned pfn list */ > + unsigned long *bitmap; > }; > > struct vfio_group { > @@ -126,6 +128,19 @@ struct vfio_regions { > #define IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu) \ > (!list_empty(&iommu->domain_list)) > > +#define DIRTY_BITMAP_BYTES(n) (ALIGN(n, BITS_PER_TYPE(u64)) / BITS_PER_BYTE) > + > +/* > + * Input argument of number of bits to bitmap_set() is unsigned integer, which > + * further casts to signed integer for unaligned multi-bit operation, > + * __bitmap_set(). > + * Then maximum bitmap size supported is 2^31 bits divided by 2^3 bits/byte, > + * that is 2^28 (256 MB) which maps to 2^31 * 2^12 = 2^43 (8TB) on 4K page > + * system. > + */ > +#define DIRTY_BITMAP_PAGES_MAX ((u64)INT_MAX) > +#define DIRTY_BITMAP_SIZE_MAX DIRTY_BITMAP_BYTES(DIRTY_BITMAP_PAGES_MAX) > + > static int put_pfn(unsigned long pfn, int prot); > > /* > @@ -176,6 +191,81 @@ static void vfio_unlink_dma(struct vfio_iommu *iommu, struct vfio_dma *old) > rb_erase(&old->node, &iommu->dma_list); > } > > + > +static int vfio_dma_bitmap_alloc(struct vfio_dma *dma, size_t pgsize) > +{ > + uint64_t npages = dma->size / pgsize; > + > + if (npages > DIRTY_BITMAP_PAGES_MAX) > + return -EINVAL; > + > + /* > + * Allocate extra 64 bits that are used to calculate shift required for > + * bitmap_shift_left() to manipulate and club unaligned number of pages > + * in adjacent vfio_dma ranges. > + */ > + dma->bitmap = kvzalloc(DIRTY_BITMAP_BYTES(npages) + sizeof(u64), > + GFP_KERNEL); > + if (!dma->bitmap) > + return -ENOMEM; > + > + return 0; > +} > + > +static void vfio_dma_bitmap_free(struct vfio_dma *dma) > +{ > + kfree(dma->bitmap); > + dma->bitmap = NULL; > +} > + > +static void vfio_dma_populate_bitmap(struct vfio_dma *dma, size_t pgsize) > +{ > + struct rb_node *p; > + unsigned long pgshift = __ffs(pgsize); > + > + for (p = rb_first(&dma->pfn_list); p; p = rb_next(p)) { > + struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn, node); > + > + bitmap_set(dma->bitmap, (vpfn->iova - dma->iova) >> pgshift, 1); > + } > +} > + > +static int vfio_dma_bitmap_alloc_all(struct vfio_iommu *iommu, size_t pgsize) > +{ > + struct rb_node *n; > + > + for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) { > + struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); > + int ret; > + > + ret = vfio_dma_bitmap_alloc(dma, pgsize); > + if (ret) { > + struct rb_node *p; > + > + for (p = rb_prev(n); p; p = rb_prev(p)) { > + struct vfio_dma *dma = rb_entry(n, > + struct vfio_dma, node); > + > + vfio_dma_bitmap_free(dma); > + } > + return ret; > + } > + vfio_dma_populate_bitmap(dma, pgsize); > + } > + return 0; > +} > + > +static void vfio_dma_bitmap_free_all(struct vfio_iommu *iommu) > +{ > + struct rb_node *n; > + > + for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) { > + struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); > + > + vfio_dma_bitmap_free(dma); > + } > +} > + > /* > * Helper Functions for host iova-pfn list > */ > @@ -598,6 +688,17 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data, > vfio_unpin_page_external(dma, iova, do_accounting); > goto pin_unwind; > } > + > + if (iommu->dirty_page_tracking) { > + unsigned long pgshift = __ffs(iommu->pgsize_bitmap); > + > + /* > + * Bitmap populated with the smallest supported page > + * size > + */ > + bitmap_set(dma->bitmap, > + (iova - dma->iova) >> pgshift, 1); > + } > } > > ret = i; > @@ -832,6 +933,7 @@ static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma) > vfio_unmap_unpin(iommu, dma, true); > vfio_unlink_dma(iommu, dma); > put_task_struct(dma->task); > + vfio_dma_bitmap_free(dma); > kfree(dma); > iommu->dma_avail++; > } > @@ -859,6 +961,94 @@ static void vfio_update_pgsize_bitmap(struct vfio_iommu *iommu) > } > } > > +static int update_user_bitmap(u64 __user *bitmap, struct vfio_dma *dma, > + dma_addr_t base_iova, size_t pgsize) > +{ > + unsigned long pgshift = __ffs(pgsize); > + unsigned long nbits = dma->size >> pgshift; > + unsigned long bit_offset = (dma->iova - base_iova) >> pgshift; > + unsigned long copy_offset = bit_offset / BITS_PER_LONG; > + unsigned long shift = bit_offset % BITS_PER_LONG; > + unsigned long leftover; > + > + /* mark all pages dirty if all pages are pinned and mapped. */ > + if (dma->iommu_mapped) > + bitmap_set(dma->bitmap, 0, nbits); > + > + if (shift) { > + bitmap_shift_left(dma->bitmap, dma->bitmap, shift, > + nbits + shift); > + > + if (copy_from_user(&leftover, > + (void __user *)(bitmap + copy_offset), > + sizeof(leftover))) > + return -EFAULT; > + > + bitmap_or(dma->bitmap, dma->bitmap, &leftover, shift); > + } > + > + if (copy_to_user((void __user *)(bitmap + copy_offset), dma->bitmap, > + DIRTY_BITMAP_BYTES(nbits + shift))) > + return -EFAULT; > + > + return 0; > +} > + > +static int vfio_iova_dirty_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu, > + dma_addr_t iova, size_t size, size_t pgsize) > +{ > + struct vfio_dma *dma; > + struct rb_node *n; > + unsigned long pgshift = __ffs(pgsize); > + int ret; > + > + /* > + * GET_BITMAP request must fully cover vfio_dma mappings. Multiple > + * vfio_dma mappings may be clubbed by specifying large ranges, but > + * there must not be any previous mappings bisected by the range. > + * An error will be returned if these conditions are not met. > + */ > + dma = vfio_find_dma(iommu, iova, 1); > + if (dma && dma->iova != iova) > + return -EINVAL; > + > + dma = vfio_find_dma(iommu, iova + size - 1, 0); > + if (dma && dma->iova + dma->size != iova + size) > + return -EINVAL; > + > + for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) { > + struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); > + > + if (dma->iova < iova) > + continue; > + > + if (dma->iova > iova + size - 1) > + break; > + > + ret = update_user_bitmap(bitmap, dma, iova, pgsize); > + if (ret) > + return ret; > + > + /* > + * Re-populate bitmap to include all pinned pages which are > + * considered as dirty but exclude pages which are unpinned and > + * pages which are marked dirty by vfio_dma_rw() > + */ > + bitmap_clear(dma->bitmap, 0, dma->size >> pgshift); > + vfio_dma_populate_bitmap(dma, pgsize); > + } > + return 0; > +} > + > +static int verify_bitmap_size(uint64_t npages, uint64_t bitmap_size) > +{ > + if (!npages || !bitmap_size || (bitmap_size > DIRTY_BITMAP_SIZE_MAX) || > + (bitmap_size < DIRTY_BITMAP_BYTES(npages))) > + return -EINVAL; > + > + return 0; > +} > + > static int vfio_dma_do_unmap(struct vfio_iommu *iommu, > struct vfio_iommu_type1_dma_unmap *unmap) > { > @@ -1076,7 +1266,7 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, > unsigned long vaddr = map->vaddr; > size_t size = map->size; > int ret = 0, prot = 0; > - uint64_t mask; > + size_t pgsize; > struct vfio_dma *dma; > > /* Verify that none of our __u64 fields overflow */ > @@ -1091,11 +1281,11 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, > > mutex_lock(&iommu->lock); > > - mask = ((uint64_t)1 << __ffs(iommu->pgsize_bitmap)) - 1; > + pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap); > > - WARN_ON(mask & PAGE_MASK); > + WARN_ON((pgsize - 1) & PAGE_MASK); > > - if (!prot || !size || (size | iova | vaddr) & mask) { > + if (!prot || !size || (size | iova | vaddr) & (pgsize - 1)) { > ret = -EINVAL; > goto out_unlock; > } > @@ -1172,6 +1362,12 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, > else > ret = vfio_pin_map_dma(iommu, dma, size); > > + if (!ret && iommu->dirty_page_tracking) { > + ret = vfio_dma_bitmap_alloc(dma, pgsize); > + if (ret) > + vfio_remove_dma(iommu, dma); > + } > + > out_unlock: > mutex_unlock(&iommu->lock); > return ret; > @@ -2318,6 +2514,104 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, > > return copy_to_user((void __user *)arg, &unmap, minsz) ? > -EFAULT : 0; > + } else if (cmd == VFIO_IOMMU_DIRTY_PAGES) { > + struct vfio_iommu_type1_dirty_bitmap dirty; > + uint32_t mask = VFIO_IOMMU_DIRTY_PAGES_FLAG_START | > + VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP | > + VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP; > + int ret = 0; > + > + if (!iommu->v2) > + return -EACCES; > + > + minsz = offsetofend(struct vfio_iommu_type1_dirty_bitmap, > + flags); > + > + if (copy_from_user(&dirty, (void __user *)arg, minsz)) > + return -EFAULT; > + > + if (dirty.argsz < minsz || dirty.flags & ~mask) > + return -EINVAL; > + > + /* only one flag should be set at a time */ > + if (__ffs(dirty.flags) != __fls(dirty.flags)) > + return -EINVAL; > + > + if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_START) { > + size_t pgsize; > + > + mutex_lock(&iommu->lock); > + pgsize = 1 << __ffs(iommu->pgsize_bitmap); > + if (!iommu->dirty_page_tracking) { > + ret = vfio_dma_bitmap_alloc_all(iommu, pgsize); > + if (!ret) > + iommu->dirty_page_tracking = true; > + } > + mutex_unlock(&iommu->lock); > + return ret; > + } else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP) { > + mutex_lock(&iommu->lock); > + if (iommu->dirty_page_tracking) { > + iommu->dirty_page_tracking = false; > + vfio_dma_bitmap_free_all(iommu); > + } > + mutex_unlock(&iommu->lock); > + return 0; > + } else if (dirty.flags & > + VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP) { > + struct vfio_iommu_type1_dirty_bitmap_get range; > + unsigned long pgshift; > + size_t data_size = dirty.argsz - minsz; > + size_t iommu_pgsize; > + > + if (!data_size || data_size < sizeof(range)) > + return -EINVAL; > + > + if (copy_from_user(&range, (void __user *)(arg + minsz), > + sizeof(range))) > + return -EFAULT; > + > + if (range.iova + range.size < range.iova) > + return -EINVAL; > + if (!access_ok((void __user *)range.bitmap.data, > + range.bitmap.size)) > + return -EINVAL; > + > + pgshift = __ffs(range.bitmap.pgsize); > + ret = verify_bitmap_size(range.size >> pgshift, > + range.bitmap.size); > + if (ret) > + return ret; > + > + mutex_lock(&iommu->lock); > + > + iommu_pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap); > + > + /* allow only smallest supported pgsize */ > + if (range.bitmap.pgsize != iommu_pgsize) { > + ret = -EINVAL; > + goto out_unlock; > + } > + if (range.iova & (iommu_pgsize - 1)) { > + ret = -EINVAL; > + goto out_unlock; > + } > + if (!range.size || range.size & (iommu_pgsize - 1)) { > + ret = -EINVAL; > + goto out_unlock; > + } > + > + if (iommu->dirty_page_tracking) > + ret = vfio_iova_dirty_bitmap(range.bitmap.data, > + iommu, range.iova, range.size, > + range.bitmap.pgsize); > + else > + ret = -EINVAL; > +out_unlock: > + mutex_unlock(&iommu->lock); > + > + return ret; > + } > } > > return -ENOTTY; > @@ -2385,10 +2679,19 @@ static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu, > > vaddr = dma->vaddr + offset; > > - if (write) > + if (write) { > *copied = copy_to_user((void __user *)vaddr, data, > count) ? 0 : count; > - else > + if (*copied && iommu->dirty_page_tracking) { > + unsigned long pgshift = __ffs(iommu->pgsize_bitmap); > + /* > + * Bitmap populated with the smallest supported page > + * size > + */ > + bitmap_set(dma->bitmap, offset >> pgshift, > + *copied >> pgshift); > + } > + } else > *copied = copy_from_user(data, (void __user *)vaddr, > count) ? 0 : count; > if (kthread)
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 814c795a2543..8362a36c0de4 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -72,6 +72,7 @@ struct vfio_iommu { uint64_t pgsize_bitmap; bool v2; bool nesting; + bool dirty_page_tracking; }; struct vfio_domain { @@ -92,6 +93,7 @@ struct vfio_dma { bool lock_cap; /* capable(CAP_IPC_LOCK) */ struct task_struct *task; struct rb_root pfn_list; /* Ex-user pinned pfn list */ + unsigned long *bitmap; }; struct vfio_group { @@ -126,6 +128,19 @@ struct vfio_regions { #define IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu) \ (!list_empty(&iommu->domain_list)) +#define DIRTY_BITMAP_BYTES(n) (ALIGN(n, BITS_PER_TYPE(u64)) / BITS_PER_BYTE) + +/* + * Input argument of number of bits to bitmap_set() is unsigned integer, which + * further casts to signed integer for unaligned multi-bit operation, + * __bitmap_set(). + * Then maximum bitmap size supported is 2^31 bits divided by 2^3 bits/byte, + * that is 2^28 (256 MB) which maps to 2^31 * 2^12 = 2^43 (8TB) on 4K page + * system. + */ +#define DIRTY_BITMAP_PAGES_MAX ((u64)INT_MAX) +#define DIRTY_BITMAP_SIZE_MAX DIRTY_BITMAP_BYTES(DIRTY_BITMAP_PAGES_MAX) + static int put_pfn(unsigned long pfn, int prot); /* @@ -176,6 +191,81 @@ static void vfio_unlink_dma(struct vfio_iommu *iommu, struct vfio_dma *old) rb_erase(&old->node, &iommu->dma_list); } + +static int vfio_dma_bitmap_alloc(struct vfio_dma *dma, size_t pgsize) +{ + uint64_t npages = dma->size / pgsize; + + if (npages > DIRTY_BITMAP_PAGES_MAX) + return -EINVAL; + + /* + * Allocate extra 64 bits that are used to calculate shift required for + * bitmap_shift_left() to manipulate and club unaligned number of pages + * in adjacent vfio_dma ranges. + */ + dma->bitmap = kvzalloc(DIRTY_BITMAP_BYTES(npages) + sizeof(u64), + GFP_KERNEL); + if (!dma->bitmap) + return -ENOMEM; + + return 0; +} + +static void vfio_dma_bitmap_free(struct vfio_dma *dma) +{ + kfree(dma->bitmap); + dma->bitmap = NULL; +} + +static void vfio_dma_populate_bitmap(struct vfio_dma *dma, size_t pgsize) +{ + struct rb_node *p; + unsigned long pgshift = __ffs(pgsize); + + for (p = rb_first(&dma->pfn_list); p; p = rb_next(p)) { + struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn, node); + + bitmap_set(dma->bitmap, (vpfn->iova - dma->iova) >> pgshift, 1); + } +} + +static int vfio_dma_bitmap_alloc_all(struct vfio_iommu *iommu, size_t pgsize) +{ + struct rb_node *n; + + for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) { + struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); + int ret; + + ret = vfio_dma_bitmap_alloc(dma, pgsize); + if (ret) { + struct rb_node *p; + + for (p = rb_prev(n); p; p = rb_prev(p)) { + struct vfio_dma *dma = rb_entry(n, + struct vfio_dma, node); + + vfio_dma_bitmap_free(dma); + } + return ret; + } + vfio_dma_populate_bitmap(dma, pgsize); + } + return 0; +} + +static void vfio_dma_bitmap_free_all(struct vfio_iommu *iommu) +{ + struct rb_node *n; + + for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) { + struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); + + vfio_dma_bitmap_free(dma); + } +} + /* * Helper Functions for host iova-pfn list */ @@ -598,6 +688,17 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data, vfio_unpin_page_external(dma, iova, do_accounting); goto pin_unwind; } + + if (iommu->dirty_page_tracking) { + unsigned long pgshift = __ffs(iommu->pgsize_bitmap); + + /* + * Bitmap populated with the smallest supported page + * size + */ + bitmap_set(dma->bitmap, + (iova - dma->iova) >> pgshift, 1); + } } ret = i; @@ -832,6 +933,7 @@ static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma) vfio_unmap_unpin(iommu, dma, true); vfio_unlink_dma(iommu, dma); put_task_struct(dma->task); + vfio_dma_bitmap_free(dma); kfree(dma); iommu->dma_avail++; } @@ -859,6 +961,94 @@ static void vfio_update_pgsize_bitmap(struct vfio_iommu *iommu) } } +static int update_user_bitmap(u64 __user *bitmap, struct vfio_dma *dma, + dma_addr_t base_iova, size_t pgsize) +{ + unsigned long pgshift = __ffs(pgsize); + unsigned long nbits = dma->size >> pgshift; + unsigned long bit_offset = (dma->iova - base_iova) >> pgshift; + unsigned long copy_offset = bit_offset / BITS_PER_LONG; + unsigned long shift = bit_offset % BITS_PER_LONG; + unsigned long leftover; + + /* mark all pages dirty if all pages are pinned and mapped. */ + if (dma->iommu_mapped) + bitmap_set(dma->bitmap, 0, nbits); + + if (shift) { + bitmap_shift_left(dma->bitmap, dma->bitmap, shift, + nbits + shift); + + if (copy_from_user(&leftover, + (void __user *)(bitmap + copy_offset), + sizeof(leftover))) + return -EFAULT; + + bitmap_or(dma->bitmap, dma->bitmap, &leftover, shift); + } + + if (copy_to_user((void __user *)(bitmap + copy_offset), dma->bitmap, + DIRTY_BITMAP_BYTES(nbits + shift))) + return -EFAULT; + + return 0; +} + +static int vfio_iova_dirty_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu, + dma_addr_t iova, size_t size, size_t pgsize) +{ + struct vfio_dma *dma; + struct rb_node *n; + unsigned long pgshift = __ffs(pgsize); + int ret; + + /* + * GET_BITMAP request must fully cover vfio_dma mappings. Multiple + * vfio_dma mappings may be clubbed by specifying large ranges, but + * there must not be any previous mappings bisected by the range. + * An error will be returned if these conditions are not met. + */ + dma = vfio_find_dma(iommu, iova, 1); + if (dma && dma->iova != iova) + return -EINVAL; + + dma = vfio_find_dma(iommu, iova + size - 1, 0); + if (dma && dma->iova + dma->size != iova + size) + return -EINVAL; + + for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) { + struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); + + if (dma->iova < iova) + continue; + + if (dma->iova > iova + size - 1) + break; + + ret = update_user_bitmap(bitmap, dma, iova, pgsize); + if (ret) + return ret; + + /* + * Re-populate bitmap to include all pinned pages which are + * considered as dirty but exclude pages which are unpinned and + * pages which are marked dirty by vfio_dma_rw() + */ + bitmap_clear(dma->bitmap, 0, dma->size >> pgshift); + vfio_dma_populate_bitmap(dma, pgsize); + } + return 0; +} + +static int verify_bitmap_size(uint64_t npages, uint64_t bitmap_size) +{ + if (!npages || !bitmap_size || (bitmap_size > DIRTY_BITMAP_SIZE_MAX) || + (bitmap_size < DIRTY_BITMAP_BYTES(npages))) + return -EINVAL; + + return 0; +} + static int vfio_dma_do_unmap(struct vfio_iommu *iommu, struct vfio_iommu_type1_dma_unmap *unmap) { @@ -1076,7 +1266,7 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, unsigned long vaddr = map->vaddr; size_t size = map->size; int ret = 0, prot = 0; - uint64_t mask; + size_t pgsize; struct vfio_dma *dma; /* Verify that none of our __u64 fields overflow */ @@ -1091,11 +1281,11 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, mutex_lock(&iommu->lock); - mask = ((uint64_t)1 << __ffs(iommu->pgsize_bitmap)) - 1; + pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap); - WARN_ON(mask & PAGE_MASK); + WARN_ON((pgsize - 1) & PAGE_MASK); - if (!prot || !size || (size | iova | vaddr) & mask) { + if (!prot || !size || (size | iova | vaddr) & (pgsize - 1)) { ret = -EINVAL; goto out_unlock; } @@ -1172,6 +1362,12 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, else ret = vfio_pin_map_dma(iommu, dma, size); + if (!ret && iommu->dirty_page_tracking) { + ret = vfio_dma_bitmap_alloc(dma, pgsize); + if (ret) + vfio_remove_dma(iommu, dma); + } + out_unlock: mutex_unlock(&iommu->lock); return ret; @@ -2318,6 +2514,104 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, return copy_to_user((void __user *)arg, &unmap, minsz) ? -EFAULT : 0; + } else if (cmd == VFIO_IOMMU_DIRTY_PAGES) { + struct vfio_iommu_type1_dirty_bitmap dirty; + uint32_t mask = VFIO_IOMMU_DIRTY_PAGES_FLAG_START | + VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP | + VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP; + int ret = 0; + + if (!iommu->v2) + return -EACCES; + + minsz = offsetofend(struct vfio_iommu_type1_dirty_bitmap, + flags); + + if (copy_from_user(&dirty, (void __user *)arg, minsz)) + return -EFAULT; + + if (dirty.argsz < minsz || dirty.flags & ~mask) + return -EINVAL; + + /* only one flag should be set at a time */ + if (__ffs(dirty.flags) != __fls(dirty.flags)) + return -EINVAL; + + if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_START) { + size_t pgsize; + + mutex_lock(&iommu->lock); + pgsize = 1 << __ffs(iommu->pgsize_bitmap); + if (!iommu->dirty_page_tracking) { + ret = vfio_dma_bitmap_alloc_all(iommu, pgsize); + if (!ret) + iommu->dirty_page_tracking = true; + } + mutex_unlock(&iommu->lock); + return ret; + } else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP) { + mutex_lock(&iommu->lock); + if (iommu->dirty_page_tracking) { + iommu->dirty_page_tracking = false; + vfio_dma_bitmap_free_all(iommu); + } + mutex_unlock(&iommu->lock); + return 0; + } else if (dirty.flags & + VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP) { + struct vfio_iommu_type1_dirty_bitmap_get range; + unsigned long pgshift; + size_t data_size = dirty.argsz - minsz; + size_t iommu_pgsize; + + if (!data_size || data_size < sizeof(range)) + return -EINVAL; + + if (copy_from_user(&range, (void __user *)(arg + minsz), + sizeof(range))) + return -EFAULT; + + if (range.iova + range.size < range.iova) + return -EINVAL; + if (!access_ok((void __user *)range.bitmap.data, + range.bitmap.size)) + return -EINVAL; + + pgshift = __ffs(range.bitmap.pgsize); + ret = verify_bitmap_size(range.size >> pgshift, + range.bitmap.size); + if (ret) + return ret; + + mutex_lock(&iommu->lock); + + iommu_pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap); + + /* allow only smallest supported pgsize */ + if (range.bitmap.pgsize != iommu_pgsize) { + ret = -EINVAL; + goto out_unlock; + } + if (range.iova & (iommu_pgsize - 1)) { + ret = -EINVAL; + goto out_unlock; + } + if (!range.size || range.size & (iommu_pgsize - 1)) { + ret = -EINVAL; + goto out_unlock; + } + + if (iommu->dirty_page_tracking) + ret = vfio_iova_dirty_bitmap(range.bitmap.data, + iommu, range.iova, range.size, + range.bitmap.pgsize); + else + ret = -EINVAL; +out_unlock: + mutex_unlock(&iommu->lock); + + return ret; + } } return -ENOTTY; @@ -2385,10 +2679,19 @@ static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu, vaddr = dma->vaddr + offset; - if (write) + if (write) { *copied = copy_to_user((void __user *)vaddr, data, count) ? 0 : count; - else + if (*copied && iommu->dirty_page_tracking) { + unsigned long pgshift = __ffs(iommu->pgsize_bitmap); + /* + * Bitmap populated with the smallest supported page + * size + */ + bitmap_set(dma->bitmap, offset >> pgshift, + *copied >> pgshift); + } + } else *copied = copy_from_user(data, (void __user *)vaddr, count) ? 0 : count; if (kthread)