On 28/11/2022 19:12, Alex Williamson wrote:
> On Fri, 25 Nov 2022 17:29:56 +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>
>> Co-developed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
>> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
>> Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
>
> Should this have:
>
> Fixes: f38044e5ef58 ("vfio/iova_bitmap: Fix PAGE_SIZE unaligned bitmaps")
>
> ?
I was at two minds with the Fixes tag.
The commit you referenced above is still a fix (or workaround), this patch is a
better fix that superseeds as opposed to fixing a bug that commit f38044e5ef58
introduced. So perhaps the right one ought to be:
Fixes: 58ccf0190d19 ("vfio: Add an IOVA bitmap support")
Joao
