The patch titled Subject: migrate.c: remove vma check in migrate_vma_setup() has been added to the -mm tree. Its filename is migratec-remove-vma-check-in-migrate_vma_setup.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/migratec-remove-vma-check-in-migrate_vma_setup.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/migratec-remove-vma-check-in-migrate_vma_setup.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Alistair Popple <apopple@xxxxxxxxxx> Subject: migrate.c: remove vma check in migrate_vma_setup() Patch series "Migrate device coherent pages on get_user_pages()", v2. Device coherent pages represent memory on a coherently attached device such as a GPU which is usually under the control of a driver. These pages should not be pinned as the driver needs to be able to move pages as required. Currently this is enforced by failing any attempt to pin a device coherent page. A similar problem exists for ZONE_MOVABLE pages. In that case though the pages are migrated instead of causing failure. There is no reason the kernel can't migrate device coherent pages so this series implements migration for device coherent pages so the same strategy of migrate and pin can be used. This series depends on the series "Add MEMORY_DEVICE_COHERENT for coherent device memory mapping"[1] which is in linux-next-20220204 and should apply cleanly to that. [1] - https://lore.kernel.org/linux-mm/20220128200825.8623-1-alex.sierra@xxxxxxx/ This patch (of 2): migrate_vma_setup() checks that a valid vma is passed so that the page tables can be walked to find the pfns associated with a given address range. However in some cases the pfns are already known, such as when migrating device coherent pages during pin_user_pages() meaning a valid vma isn't required. Link: https://lkml.kernel.org/r/cover.0d3c846b1c6c294e055ff7ebe221fab9964c1436.1644207242.git-series.apopple@xxxxxxxxxx Link: https://lkml.kernel.org/r/6831bf69f7c7699be83b31c9c56212b5fb07f873.1644207242.git-series.apopple@xxxxxxxxxx Signed-off-by: Alistair Popple <apopple@xxxxxxxxxx> Acked-by: Felix Kuehling <Felix.Kuehling@xxxxxxx> Cc: Ralph Campbell <rcampbell@xxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Jason Gunthorpe <jgg@xxxxxxxxxx> Cc: Jerome Glisse <jglisse@xxxxxxxxxx> Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Alex Sierra <Alex.Sierra@xxxxxxx> Cc: John Hubbard <jhubbard@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/migrate.c | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) --- a/mm/migrate.c~migratec-remove-vma-check-in-migrate_vma_setup +++ a/mm/migrate.c @@ -2609,24 +2609,24 @@ int migrate_vma_setup(struct migrate_vma args->start &= PAGE_MASK; args->end &= PAGE_MASK; - if (!args->vma || is_vm_hugetlb_page(args->vma) || - (args->vma->vm_flags & VM_SPECIAL) || vma_is_dax(args->vma)) - return -EINVAL; - if (nr_pages <= 0) - return -EINVAL; - if (args->start < args->vma->vm_start || - args->start >= args->vma->vm_end) - return -EINVAL; - if (args->end <= args->vma->vm_start || args->end > args->vma->vm_end) - return -EINVAL; if (!args->src || !args->dst) return -EINVAL; + if (args->vma) { + if (is_vm_hugetlb_page(args->vma) || + (args->vma->vm_flags & VM_SPECIAL) || vma_is_dax(args->vma)) + return -EINVAL; + if (args->start < args->vma->vm_start || + args->start >= args->vma->vm_end) + return -EINVAL; + if (args->end <= args->vma->vm_start || args->end > args->vma->vm_end) + return -EINVAL; + + memset(args->src, 0, sizeof(*args->src) * nr_pages); + args->cpages = 0; + args->npages = 0; - memset(args->src, 0, sizeof(*args->src) * nr_pages); - args->cpages = 0; - args->npages = 0; - - migrate_vma_collect(args); + migrate_vma_collect(args); + } if (args->cpages) migrate_vma_unmap(args); @@ -2811,7 +2811,7 @@ void migrate_vma_pages(struct migrate_vm continue; } - if (!page) { + if (!page && migrate->vma) { if (!(migrate->src[i] & MIGRATE_PFN_MIGRATE)) continue; if (!notified) { _ Patches currently in -mm which might be from apopple@xxxxxxxxxx are migratec-remove-vma-check-in-migrate_vma_setup.patch mm-gupc-migrate-device-coherent-pages-when-pinning-instead-of-failing.patch