xen: add pages parameter to xen_remap_domain_mfn_range

Also introduce xen_unmap_domain_mfn_range. These are the parts of
Mukesh's "xen/pvh: Implement MMU changes for PVH" which are also
needed as a baseline for ARM privcmd support.

The original patch was:

Signed-off-by: Mukesh Rathor <[e-mail]>
Signed-off-by: Konrad Rzeszutek Wilk <[e-mail]>

This derivative is also:

Signed-off-by: Ian Campbell <[e-mail]>

arch/x86/xen/mmu.c

···
 int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
 			       unsigned long addr,
 			       unsigned long mfn, int nr,
-			       pgprot_t prot, unsigned domid)
+			       pgprot_t prot, unsigned domid,
+			       struct page **pages)
+
 {
 	struct remap_data rmd;
 	struct mmu_update mmu_update[REMAP_BATCH_SIZE];
···
 	return err;
 }
 EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
+
+/* Returns: 0 success */
+int xen_unmap_domain_mfn_range(struct vm_area_struct *vma,
+			       int numpgs, struct page **pages)
+{
+	if (!pages || !xen_feature(XENFEAT_auto_translated_physmap))
+		return 0;
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(xen_unmap_domain_mfn_range);

drivers/xen/privcmd.c

···
 					msg->va & PAGE_MASK,
 					msg->mfn, msg->npages,
 					vma->vm_page_prot,
-					st->domain);
+					st->domain, NULL);
 	if (rc < 0)
 		return rc;
 
···
 	int ret;
 
 	ret = xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1,
-					 st->vma->vm_page_prot, st->domain);
+					 st->vma->vm_page_prot, st->domain,
+					 NULL);
 
 	/* Store error code for second pass. */
 	*(st->err++) = ret;

include/xen/xen-ops.h

···
 int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
 			       unsigned long addr,
 			       unsigned long mfn, int nr,
-			       pgprot_t prot, unsigned domid);
+			       pgprot_t prot, unsigned domid,
+			       struct page **pages);
+int xen_unmap_domain_mfn_range(struct vm_area_struct *vma,
+			       int numpgs, struct page **pages);
 
 #endif /* INCLUDE_XEN_OPS_H */