Commit 2c5af985 authored Sep 16, 2020 by Yan Zhao Committed by Alex Williamson Sep 22, 2020

vfio/type1: fix dirty bitmap calculation in vfio_dma_rw



The count of dirtied pages is not only determined by count of copied
pages, but also by the start offset.

e.g. if offset = PAGE_SIZE - 1, and *copied=2, the dirty pages count
is 2, instead of 1 or 0.

Fixes: d6a4c185 ("vfio iommu: Implementation of ioctl for dirty pages tracking")
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

parent 28b13024

drivers/vfio/vfio_iommu_type1.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -2933,7 +2933,8 @@ static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu,
		* size
		*/
		bitmap_set(dma->bitmap, offset >> pgshift,
		*copied >> pgshift);
		((offset + *copied - 1) >> pgshift) -
		(offset >> pgshift) + 1);
		}
		} else
		copied = copy_from_user(data, (void __user )vaddr,

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