From 3e71ce9ed6f0c57129e767f42d16fce5a3c7b1e9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
 <marmarek@invisiblethingslab.com>
Date: Mon, 8 Mar 2021 01:19:01 +0100
Subject: [PATCH] Enable xen balloon memory hotplug

Allow to not use otherwise usable RAM pages to map foreign
pages (including grant mappings). This is especially useful for dom0 (or
GUI domain) that maps a lot of foreign pages.

QubesOS/qubes-issues#6097
---
 config-qubes | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/config-qubes b/config-qubes
index 0d3aa1db..896afa48 100644
--- a/config-qubes
+++ b/config-qubes
@@ -123,6 +123,12 @@ CONFIG_USB_DUMMY_HCD=m
 
 CONFIG_SECURITY_APPARMOR=y
 
+################################################################################
+## Enable memory hotplug of Xen balloon driver. This is useful to map a lot of
+## grant tables, without using otherwise usable physical address space
+
+CONFIG_XEN_BALLOON_MEMORY_HOTPLUG=y
+CONFIG_XEN_UNPOPULATED_ALLOC=y
 
 ################################################################################
 ## TODO: from diff to old config