vfio: Replace phys_pfn with pages for vfio_pin_pages()

Most of the callers of vfio_pin_pages() want "struct page *" and the
low-level mm code to pin pages returns a list of "struct page *" too.
So there's no gain in converting "struct page *" to PFN in between.

Replace the output parameter "phys_pfn" list with a "pages" list, to
simplify callers. This also allows us to replace the vfio_iommu_type1
implementation with a more efficient one.

And drop the pfn_valid check in the gvt code, as there is no need to
do such a check at a page-backed struct page pointer.

For now, also update vfio_iommu_type1 to fit this new parameter too.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-11-nicolinc@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index acefd663e63b..e05ddc6fe6a5 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -162,7 +162,7 @@ bool vfio_file_has_dev(struct file *file, struct vfio_device *device);
 #define VFIO_PIN_PAGES_MAX_ENTRIES	(PAGE_SIZE/sizeof(unsigned long))
 
 int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova,
-		   int npage, int prot, unsigned long *phys_pfn);
+		   int npage, int prot, struct page **pages);
 void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage);
 int vfio_dma_rw(struct vfio_device *device, dma_addr_t iova,
 		void *data, size_t len, bool write);