vfio_pin_pages() and vfio_group_pin_pages() are used purely to mark dirty pages to devices with IOMMU backend as they already have all VM pages pinned at VM startup. when there're multiple devices in the vfio group, the dirty pages marked through pin_pages interface by one device is not useful as the other devices may access and dirty any VM pages. So added a check such that only singleton IOMMU groups can pin pages in vfio_group_pin_pages. for mdevs, there's always only one dev in a vfio group. This is a fix to the commit below that added a singleton IOMMU group check in vfio_pin_pages. Fixes: 95fc87b44104 (vfio: Selective dirty page tracking if IOMMU backed device pins pages) Signed-off-by: Yan Zhao <yan.y.zhao@xxxxxxxxx> --- drivers/vfio/vfio.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 5e6e0511b5aa..2f0fa272ebf2 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -2053,6 +2053,9 @@ 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; -- 2.17.1
