@@ -383,7 +383,7 @@ static void tce_iommu_unuse_page(struct tce_container *container,
struct page *page;
page = pfn_to_page(hpa >> PAGE_SHIFT);
- put_page(page);
+ unpin_user_page(page);
}
static int tce_iommu_prereg_ua_to_hpa(struct tce_container *container,
@@ -486,7 +486,7 @@ static int tce_iommu_use_page(unsigned long tce, unsigned long *hpa)
struct page *page = NULL;
enum dma_data_direction direction = iommu_tce_direction(tce);
- if (get_user_pages_fast(tce & PAGE_MASK, 1,
+ if (pin_user_pages_fast(tce & PAGE_MASK, 1,
direction != DMA_TO_DEVICE ? FOLL_WRITE : 0,
&page) != 1)
return -EFAULT;
This code was using get_user_pages*(), in a "Case 2" scenario (DMA/RDMA), using the categorization from [1]. That means that it's time to convert the get_user_pages*() + put_page() calls to pin_user_pages*() + unpin_user_pages() calls. There is some helpful background in [2]: basically, this is a small part of fixing a long-standing disconnect between pinning pages, and file systems' use of those pages. [1] Documentation/core-api/pin_user_pages.rst [2] "Explicit pinning of user-space pages": https://lwn.net/Articles/807108/ Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Cornelia Huck <cohuck@redhat.com> Cc: kvm@vger.kernel.org Signed-off-by: John Hubbard <jhubbard@nvidia.com> --- Hi, Changes since v1: rebased onto Linux-5.8-rc2. thanks, John Hubbard drivers/vfio/vfio_iommu_spapr_tce.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)