I am working to get Opteron IOMMU support for Xen. I have progressed to the point where the system boots, finds and sizes the aperture, and mostly seems to work. However, my NIC is not working (it works with the same kernel without IOMMU support) and I see the following message in the kernel log after the IOMMU is set up: clear_kernel_mapping: mapping has been split. will leak memory arch/xen/x86_64/mm/init.c:724 bad pmd <address>(<reg>). Line 724 of init.c has a comment saying "could handle this, but it should not happen currently.*/ How should I be handling the split mapping? internal dmesg log attached. -Mark Langsdorf AMD, Inc. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On 5 Oct 2005, at 22:20, Langsdorf, Mark wrote:> Line 724 of init.c has a comment saying > "could handle this, but it should not happen currently.*/ > > How should I be handling the split mapping? > > internal dmesg log attached.The code assumes kernel space is mapped with 2MB superpages. This isn;t the case on Xen, hence the warning. In a perfect world we should free up the pagetable page pointed at by the pmd entry. However, in practise not doing this will not burn much memory. The best fix is probably to wrap that check and warning in #ifndef CONFIG_XEN. -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel