Commit 7ef32e52 authored Sep 16, 2020 by Yan Zhao Committed by Alex Williamson Sep 21, 2020

vfio: add a singleton check for vfio_group_pin_pages



Page pinning is used both to translate and pin device mappings for DMA
purpose, as well as to indicate to the IOMMU backend to limit the dirty
page scope to those pages that have been pinned, in the case of an IOMMU
backed device.
To support this, the vfio_pin_pages() interface limits itself to only
singleton groups such that the IOMMU backend can consider dirty page
scope only at the group level.  Implement the same requirement for the
vfio_group_pin_pages() interface.

Fixes: 95fc87b4 ("vfio: Selective dirty page tracking if IOMMU backed device pins pages")
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

parent ba4f184e

drivers/vfio/vfio.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -2051,6 +2051,9 @@ int vfio_group_pin_pages(struct vfio_group *group,
		if (!group \|\| !user_iova_pfn \|\| !phys_pfn \|\| !npage)
		return -EINVAL;

		if (group->dev_counter > 1)
		return -EINVAL;

		if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
		return -E2BIG;

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