The patch titled
Subject: mm/gup: fail get_user_pages for LONGTERM dev coherent type
has been added to the -mm tree. Its filename is
mm-gup-fail-get_user_pages-for-longterm-dev-coherent-type.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-gup-fail-get_user_pages-for-longterm-dev-coherent-type.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-gup-fail-get_user_pages-for-longterm-dev-coherent-type.patch
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------------------------------------------------------
From: Alex Sierra <alex.sierra@xxxxxxx>
Subject: mm/gup: fail get_user_pages for LONGTERM dev coherent type
Avoid long term pinning for Coherent device type pages. This could
interfere with their own device memory manager. For now, we are just
returning error for PIN_LONGTERM Coherent device type pages. Eventually,
these type of pages will get migrated to system memory, once the device
migration pages support is added.
Link: https://lkml.kernel.org/r/20220201154901.7921-4-alex.sierra@xxxxxxx
Signed-off-by: Alex Sierra <alex.sierra@xxxxxxx>
Acked-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
Reviewed-by: Alistair Poppple <apopple@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>
Cc: Jerome Glisse <jglisse@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Ralph Campbell <rcampbell@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/gup.c | 7 +++++++
1 file changed, 7 insertions(+)
--- a/mm/gup.c~mm-gup-fail-get_user_pages-for-longterm-dev-coherent-type
+++ a/mm/gup.c
@@ -1870,6 +1870,12 @@ static long check_and_migrate_movable_pa
* If we get a movable page, since we are going to be pinning
* these entries, try to move them out if possible.
*/
+ if (is_dev_private_or_coherent_page(head)) {
+ WARN_ON_ONCE(is_device_private_page(head));
+ ret = -EFAULT;
+ goto unpin_pages;
+ }
+
if (!is_pinnable_page(head)) {
if (PageHuge(head)) {
if (!isolate_huge_page(head, &movable_page_list))
@@ -1900,6 +1906,7 @@ static long check_and_migrate_movable_pa
if (list_empty(&movable_page_list) && !isolation_error_count)
return nr_pages;
+unpin_pages:
if (gup_flags & FOLL_PIN) {
unpin_user_pages(pages, nr_pages);
} else {
_
Patches currently in -mm which might be from alex.sierra@xxxxxxx are
mm-add-zone-device-coherent-type-memory-support.patch
mm-add-device-coherent-vma-selection-for-memory-migration.patch
mm-gup-fail-get_user_pages-for-longterm-dev-coherent-type.patch
drm-amdkfd-add-spm-support-for-svm.patch
drm-amdkfd-coherent-type-as-sys-mem-on-migration-to-ram.patch
lib-test_hmm-add-ioctl-to-get-zone-device-type.patch
lib-test_hmm-add-module-param-for-zone-device-type.patch
lib-add-support-for-device-coherent-type-in-test_hmm.patch
tools-update-hmm-test-to-support-device-coherent-type.patch
tools-update-test_hmm-script-to-support-sp-config.patch
