On Fri, Jul 22, 2022 at 04:11:29PM -0600, Alex Williamson wrote: > GVT-g explodes for me with this series on my Broadwell test system, > continuously spewing the following: Thank you for running additional tests. > [ 47.348778] WARNING: CPU: 3 PID: 501 at drivers/vfio/vfio_iommu_type1.c:978 vfio_iommu_type1_unpin_pages+0x7b/0x100 [vfio_iommu_type1] > Line 978 is the WARN_ON(i != npage) line. For the cases where we don't > find a matching vfio_dma, I'm seeing addresses that look maybe like > we're shifting a value that's already an iova by PAGE_SHIFT somewhere. Hmm..I don't understand the PAGE_SHIFT part. Do you mind clarifying? And GVT code initiated an unpin request from gvt_unpin_guest_pag() that is currently unpinning one page at a time on a contiguous IOVA range, prior to this series. After this series, it leaves the per- page routine to the internal loop of vfio_iommu_type1_unpin_pages(), which is supposed to do the same. So, either resulted from the npage input being wrong or some other factor weighed in that invoked a vfio_remove_dma on those iovas? Thanks Nic