diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 09967e030803..35d94c51cc56 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -6381,10 +6381,16 @@ mapping for userspace_addr is not required to be valid/populated at the time of
 KVM_SET_USER_MEMORY_REGION2, e.g. shared memory can be lazily mapped/allocated
 on-demand.
 
-When mapping a gfn into the guest, KVM selects shared vs. private, i.e. consumes
-userspace_addr vs. guest_memfd, based on the state in guest_memfd, which is the
-sole authority on private vs. shared memory.  See :ref:`KVM_CREATE_GUEST_MEMFD`
-to find out more about the creation-time shared/private status.
+When mapping a gfn into the guest, guest faults are always serviced from
+guest_memfd regardless of whether memory is shared or private.  KVM determines
+shared vs. private based on the state in guest_memfd, which is the sole
+authority on private vs. shared memory.  See :ref:`KVM_CREATE_GUEST_MEMFD` to
+find out more about the creation-time shared/private status.
+
+userspace_addr is expected to be the mmap()-ed address corresponding to the
+right offset within the guest_memfd. Any mismatch between userspace_addr and
+guest_memfd is not validated and is a user error. userspace_addr is only used
+for host-side guest accesses such as kvm_read_guest().
 
 If in-place conversion is disabled, KVM selects shared vs. private based on the
 gfn's KVM_MEMORY_ATTRIBUTE_PRIVATE state.  At VM creation time, all memory is
@@ -6490,10 +6496,10 @@ specified via KVM_CREATE_GUEST_MEMFD.  Currently defined flags:
                                page tables. Private memory cannot.
   ============================ ================================================
 
-When the KVM MMU performs a PFN lookup to service a guest fault and the backing
-guest_memfd has the GUEST_MEMFD_FLAG_MMAP set, then the fault will always be
-consumed from guest_memfd, regardless of whether it is a shared or a private
-fault.
+When the KVM MMU performs a PFN lookup to service a guest fault, the fault will
+always be consumed from guest_memfd, regardless of whether it is a shared or a
+private fault (unless in-place conversion is disabled and the backing
+guest_memfd does not have the GUEST_MEMFD_FLAG_MMAP flag set).
 
 See KVM_SET_USER_MEMORY_REGION2 for additional details.
 
diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
index 2af2b6f0ab61..10831f9d7ab0 100644
--- a/virt/kvm/guest_memfd.c
+++ b/virt/kvm/guest_memfd.c
@@ -775,7 +775,7 @@ int kvm_gmem_prepare_memory_region(struct kvm *kvm, struct kvm_memory_slot *slot
 	 */
 	slot->gmem.file = file;
 	slot->gmem.pgoff = offset >> PAGE_SHIFT;
-	if (kvm_gmem_supports_mmap(inode))
+	if (gmem_in_place_conversion || kvm_gmem_supports_mmap(inode))
 		slot->flags |= KVM_MEMSLOT_GMEM_ONLY;
 
 	/*