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| author |   John Hubbard <jhubbard@nvidia.com> | 2020-07-27 13:43:38 -0600 |
|---|---|---|
| committer |   Alex Williamson <alex.williamson@redhat.com> | 2020-07-27 13:43:38 -0600 |
| commit | 9d532f286914add61e02312881733a90355f153c (patch) | |
| tree | 7d077623eb2f6ddd653b05a494caa3a84af876b3 /drivers/vfio | |
| parent | vfio/type1: Add conditional rescheduling after iommu map failed (diff) | |
| download | linux-dev-9d532f286914add61e02312881733a90355f153c.tar.xz linux-dev-9d532f286914add61e02312881733a90355f153c.zip | |
vfio/spapr_tce: convert get_user_pages() --> pin_user_pages()
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>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio')
| -rw-r--r-- | drivers/vfio/vfio_iommu_spapr_tce.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c index 16b3adc508db..fe888b5dcc00 100644 --- a/drivers/vfio/vfio_iommu_spapr_tce.c +++ b/drivers/vfio/vfio_iommu_spapr_tce.c @@ -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; |