From 3395484105defc2a59eff846c8d15108972fe48f Mon Sep 17 00:00:00 2001
From: keerthivasan86 <keerthivassan86@gmail.com>
Date: Tue, 6 Feb 2024 13:25:30 -0800
Subject: [PATCH] Adding sysctl changes for post-copy migration

Related-Bug: 2052473
Change-Id: If9efdecbf3bfcb3390ec080b3e2f9cfc7b838459
---
 doc/source/admin/configuring-migrations.rst | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/doc/source/admin/configuring-migrations.rst b/doc/source/admin/configuring-migrations.rst
index 357189b3b18d..79a38cf24b4e 100644
--- a/doc/source/admin/configuring-migrations.rst
+++ b/doc/source/admin/configuring-migrations.rst
@@ -314,6 +314,15 @@ memory-intensive instances succeed.
       interrupted, page faults cannot be resolved anymore and the instance is
       rebooted.
 
+   .. important::
+
+      You may need to enable ``unprivileged_userfaultfd`` on newer kernels in
+      order for post-copy to work.
+
+      .. code-block:: console
+
+         sysctl vm.unprivileged_userfaultfd=1
+
 .. TODO Bernd: I *believe* that it is certain to succeed,
 .. but perhaps I am missing something.