On Friday, 4 December 2020 9:18:41 PM AEDT Bharata B Rao wrote: > > Reviewed-by: Bharata B Rao <bhar...@linux.ibm.com> > > Did you actually hit this scenario with secure VMs where a UV-paged-in > page was later found to be not migratable?
No, this was found by inspection. I have no way of testing this but we had a similar issue in Nouveau and I think you would have a similar issue here although it might be hard to hit. migrate_vma_pages() will fail a page migration if a CPU thread has raced and established a non-zero page PTE for the address. See migrate_vma_insert_page() for the implementation. It will also fail if something else has taken a reference on the page after calling migrate_vma_setup(), but that is less likely as any existing pages will have been isolated. - Alistair > Regards, > Bharata. >
