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.
[hch@xxxxxx: rebased on previous cleanups, split the two checks]
Link: https://lkml.kernel.org/r/20220210072828.2930359-18-hch@xxxxxx
Signed-off-by: Alex Sierra <alex.sierra@xxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Acked-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
Reviewed-by: Alistair Poppple <apopple@xxxxxxxxxx>
Tested-by: "Sierra Guiza, Alejandro (Alex)" <alex.sierra@xxxxxxx>
Cc: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: Ben Skeggs <bskeggs@xxxxxxxxxx>
Cc: Chaitanya Kulkarni <kch@xxxxxxxxxx>
Cc: Christian Knig <christian.koenig@xxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>
Cc: Karol Herbst <kherbst@xxxxxxxxxx>
Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Cc: Lyude Paul <lyude@xxxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: "Pan, Xinhui" <Xinhui.Pan@xxxxxxx>
Cc: Ralph Campbell <rcampbell@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/mm/gup.c~mm-gup-fail-get_user_pages-for-longterm-dev-coherent-type
+++ a/mm/gup.c
@@ -1857,6 +1857,19 @@ static long check_and_migrate_movable_pa
continue;
prev_head = head;
+ /*
+ * Device private pages will get faulted in during gup so it
+ * shouldn't be possible to see one here.
+ */
+ if (WARN_ON_ONCE(is_device_private_page(head))) {
+ ret = -EFAULT;
+ goto unpin_pages;
+ }
+ if (is_device_coherent_page(head)) {
+ ret = -EFAULT;
+ goto unpin_pages;
+ }
+
if (is_pinnable_page(head))
continue;
@@ -1901,7 +1914,7 @@ unpin_pages:
put_page(pages[i]);
}
- if (!list_empty(&movable_page_list)) {
+ if (!ret && !list_empty(&movable_page_list)) {
struct migration_target_control mtc = {
.nid = NUMA_NO_NODE,
.gfp_mask = GFP_USER | __GFP_NOWARN,
_
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
