[PATCH v2 13/14] vfio_iommu_type1: specify FOLL_HINT_BULK to pin_user_pages()

[Ankur Arora]

Specify FOLL_HINT_BULK to pin_user_pages() so it is aware that
this pin is part of a larger region being pinned, so it can
optimize based on that expectation.

Cc: alex.williamson@xxxxxxxxxx
Signed-off-by: Ankur Arora <ankur.a.arora@xxxxxxxxxx>
---
 drivers/vfio/vfio_iommu_type1.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 0e9217687f5c..0d45b0c6464d 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -557,6 +557,9 @@ static int vaddr_get_pfns(struct mm_struct *mm, unsigned long vaddr,
 	if (prot & IOMMU_WRITE)
 		flags |= FOLL_WRITE;
 
+	/* Tell gup that this iterations is part of larger set of pins. */
+	flags |= FOLL_HINT_BULK;
+
 	mmap_read_lock(mm);
 	ret = pin_user_pages_remote(mm, vaddr, npages, flags | FOLL_LONGTERM,
 				    pages, NULL, NULL);
-- 
2.29.2