Commit 2b8bb1d7 authored Dec 06, 2016 by Kirti Wankhede Committed by Alex Williamson Dec 06, 2016

vfio iommu type1: Fix size argument to vfio_find_dma() in pin_pages/unpin_pages



Passing zero for the size to vfio_find_dma() isn't compatible with
matching the start address of an existing vfio_dma. Doing so triggers a
corner case. In vfio_find_dma(), when the start address is equal to
dma->iova and size is 0, check for the end of search range makes it to
take wrong side of RB-tree. That fails the search even though the address
is present in mapped dma ranges.
In functions pin_pages and unpin_pages, the iova which is being searched
is base address of page to be pinned or unpinned. So here size should be
set to PAGE_SIZE, as argument to vfio_find_dma().

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Neo Jia <cjia@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

parent 7c03f428

drivers/vfio/vfio_iommu_type1.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -581,7 +581,7 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data,
		struct vfio_pfn *vpfn;

		iova = user_pfn[i] << PAGE_SHIFT;
		dma = vfio_find_dma(iommu, iova, 0);
		dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
		if (!dma) {
		ret = -EINVAL;
		goto pin_unwind;
		@@ -622,7 +622,7 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data,
		dma_addr_t iova;

		iova = user_pfn[j] << PAGE_SHIFT;
		dma = vfio_find_dma(iommu, iova, 0);
		dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
		vfio_unpin_page_external(dma, iova, do_accounting);
		phys_pfn[j] = 0;
		}
		@@ -659,7 +659,7 @@ static int vfio_iommu_type1_unpin_pages(void *iommu_data,
		dma_addr_t iova;

		iova = user_pfn[i] << PAGE_SHIFT;
		dma = vfio_find_dma(iommu, iova, 0);
		dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
		if (!dma)
		goto unpin_exit;
		vfio_unpin_page_external(dma, iova, do_accounting);