On Tue, 29 Nov 2022 13:12:35 +0000
Joao Martins <joao.m.martins@xxxxxxxxxx> wrote:
> Commit f38044e5ef58 ("vfio/iova_bitmap: Fix PAGE_SIZE unaligned bitmaps")
> had fixed the unaligned bitmaps by capping the remaining iterable set at
> the start of the bitmap. Although, that mistakenly worked around
> iova_bitmap_set() incorrectly setting bits across page boundary.
>
> Fix this by reworking the loop inside iova_bitmap_set() to iterate over a
> range of bits to set (cur_bit .. last_bit) which may span different pinned
> pages, thus updating @page_idx and @offset as it sets the bits. The
> previous cap to the first page is now adjusted to be always accounted
> rather than when there's only a non-zero pgoff.
>
> While at it, make @page_idx , @offset and @nbits to be unsigned int given
> that it won't be more than 512 and 4096 respectively (even a bigger
> PAGE_SIZE or a smaller struct page size won't make this bigger than the
> above 32-bit max). Also, delete the stale kdoc on Return type.
>
> Cc: Avihai Horon <avihaih@xxxxxxxxxx>
> Fixes: f38044e5ef58 ("vfio/iova_bitmap: Fix PAGE_SIZE unaligned bitmaps")
> Co-developed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> ---
> Changes since v1:
> * Add Reviewed-by by Jason Gunthorpe
> * Add Fixes tag (Alex Williamson)
>
> It passes my tests but to be extra sure: Avihai could you take this
> patch a spin in your rig/tests as well? Thanks!
> ---
> drivers/vfio/iova_bitmap.c | 30 +++++++++++++-----------------
> 1 file changed, 13 insertions(+), 17 deletions(-)
Applied to vfio next branch for v6.2 with Avihai's tested-by. Thanks,
Alex
