diff --git a/mm/guestmem.c b/mm/guestmem.c
new file mode 100644
index 0000000000000000000000000000000000000000..19dd7e5d498f07577ec5cec5b52055f7435980f4
--- /dev/null
+++ b/mm/guestmem.c
@@ -0,0 +1,196 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * guestmem library
+ *
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/fs.h>
+#include <linux/guestmem.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+
+struct guestmem {
+ const struct guestmem_ops *ops;
+};
+
+static inline struct guestmem *folio_to_guestmem(struct folio *folio)
+{
+ struct address_space *mapping = folio->mapping;
+
+ return mapping->i_private_data;
+}
+
+static inline bool __guestmem_release_folio(struct address_space *mapping,
+ struct folio *folio)
+{
+ struct guestmem *gmem = mapping->i_private_data;
+ struct list_head *entry;
+
+ if (gmem->ops->release_folio) {
+ list_for_each(entry, &mapping->i_private_list) {
+ if (!gmem->ops->release_folio(entry, folio))
+ return false;
+ }
+ }
+
+ return true;
+}
+
+static inline int
+__guestmem_invalidate_begin(struct address_space *const mapping, pgoff_t start,
+ pgoff_t end)
+{
+ struct guestmem *gmem = mapping->i_private_data;
+ struct list_head *entry;
+ int ret = 0;
+
+ list_for_each(entry, &mapping->i_private_list) {
+ ret = gmem->ops->invalidate_begin(entry, start, end);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static inline void
+__guestmem_invalidate_end(struct address_space *const mapping, pgoff_t start,
+ pgoff_t end)
+{
+ struct guestmem *gmem = mapping->i_private_data;
+ struct list_head *entry;
+
+ if (gmem->ops->invalidate_end) {
+ list_for_each(entry, &mapping->i_private_list)
+ gmem->ops->invalidate_end(entry, start, end);
+ }
+}
+
+static void guestmem_free_folio(struct address_space *mapping,
+ struct folio *folio)
+{
+ WARN_ON_ONCE(!__guestmem_release_folio(mapping, folio));
+}
+
+static int guestmem_error_folio(struct address_space *mapping,
+ struct folio *folio)
+{
+ pgoff_t start, end;
+ int ret;
+
+ filemap_invalidate_lock_shared(mapping);
+
+ start = folio->index;
+ end = start + folio_nr_pages(folio);
+
+ ret = __guestmem_invalidate_begin(mapping, start, end);
+ if (ret)
+ goto out;
+
+ /*
+ * Do not truncate the range, what action is taken in response to the
+ * error is userspace's decision (assuming the architecture supports
+ * gracefully handling memory errors). If/when the guest attempts to
+ * access a poisoned page, kvm_gmem_get_pfn() will return -EHWPOISON,
+ * at which point KVM can either terminate the VM or propagate the
+ * error to userspace.
+ */
+
+ __guestmem_invalidate_end(mapping, start, end);
+
+out:
+ filemap_invalidate_unlock_shared(mapping);
+ return ret ? MF_DELAYED : MF_FAILED;
+}
+
+static int guestmem_migrate_folio(struct address_space *mapping,
+ struct folio *dst, struct folio *src,
+ enum migrate_mode mode)
+{
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+}
+
+static const struct address_space_operations guestmem_aops = {
+ .dirty_folio = noop_dirty_folio,
+ .free_folio = guestmem_free_folio,
+ .error_remove_folio = guestmem_error_folio,
+ .migrate_folio = guestmem_migrate_folio,
+};
+
+int guestmem_attach_mapping(struct address_space *mapping,
+ const struct guestmem_ops *const ops,
+ struct list_head *data)
+{
+ struct guestmem *gmem;
+
+ if (mapping->a_ops == &guestmem_aops) {
+ gmem = mapping->i_private_data;
+ if (gmem->ops != ops)
+ return -EINVAL;
+
+ goto add;
+ }
+
+ gmem = kzalloc(sizeof(*gmem), GFP_KERNEL);
+ if (!gmem)
+ return -ENOMEM;
+
+ gmem->ops = ops;
+
+ mapping->a_ops = &guestmem_aops;
+ mapping->i_private_data = gmem;
+
+ mapping_set_gfp_mask(mapping, GFP_HIGHUSER);
+ mapping_set_inaccessible(mapping);
+ /* Unmovable mappings are supposed to be marked unevictable as well. */
+ WARN_ON_ONCE(!mapping_unevictable(mapping));
+
+add:
+ list_add(data, &mapping->i_private_list);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(guestmem_attach_mapping);
+
+void guestmem_detach_mapping(struct address_space *mapping,
+ struct list_head *data)
+{
+ list_del(data);
+
+ if (list_empty(&mapping->i_private_list)) {
+ kfree(mapping->i_private_data);
