acrn: use the new follow_pfnmap API

Use the new API that can understand huge pfn mappings.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Peter Xu <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Alex Williamson <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Gavin Shan <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Niklas Schnelle <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Sean Christopherson <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: xzpeter

drivers/virt/acrn/mm.c

@@ -177,26 +177,28 @@ int acrn_vm_ram_map(struct acrn_vm *vm, struct acrn_vm_memmap *memmap)
 	vma = vma_lookup(current->mm, memmap->vma_base);
 	if (vma && ((vma->vm_flags & VM_PFNMAP) != 0)) {
 		unsigned long start_pfn, cur_pfn;
-		spinlock_t *ptl;
 		bool writable;
-		pte_t *ptep;
 
 		if ((memmap->vma_base + memmap->len) > vma->vm_end) {
 			mmap_read_unlock(current->mm);
 			return -EINVAL;
 		}
 
 		for (i = 0; i < nr_pages; i++) {
-			ret = follow_pte(vma, memmap->vma_base + i * PAGE_SIZE,
-					 &ptep, &ptl);
+			struct follow_pfnmap_args args = {
+				.vma = vma,
+				.address = memmap->vma_base + i * PAGE_SIZE,
+			};
+
+			ret = follow_pfnmap_start(&args);
 			if (ret)
 				break;
 
-			cur_pfn = pte_pfn(ptep_get(ptep));
+			cur_pfn = args.pfn;
 			if (i == 0)
 				start_pfn = cur_pfn;
-			writable = !!pte_write(ptep_get(ptep));
-			pte_unmap_unlock(ptep, ptl);
+			writable = args.writable;
+			follow_pfnmap_end(&args);
 
 			/* Disallow write access if the PTE is not writable. */
 			if (!writable &&