From 2e8e92930e9ea3fefb85cae40042b01aab79a35e Mon Sep 17 00:00:00 2001
From: Javier Martinez Canillas <javierm@redhat.com>
Date: Oct 16 2019 09:55:32 +0000
Subject: 99-grub-mkconfig: Also disable BLS usage for Xen Dom0 hosts


A previous patch disabled BLS usage for Xen Dom0 guests but it turns out
that Xen Dom0 hosts also need to regenerate a GRUB config file since the
menuentries used aren't the generated by 10_linux but by 20_linux_xen.

Resolves: rhbz#1761799

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Steven Haigh <netwiz@crc.id.au>

---

diff --git a/99-grub-mkconfig.install b/99-grub-mkconfig.install
index d29de21..339b3c7 100755
--- a/99-grub-mkconfig.install
+++ b/99-grub-mkconfig.install
@@ -4,24 +4,29 @@ if ! [[ $KERNEL_INSTALL_MACHINE_ID ]]; then
     exit 0
 fi
 
-# A "control_d" string in /proc/xen/capabilities indicates that is a Xen Dom0 host.
-[[ -e /sys/hypervisor/type ]] && read HV_TYPE < /sys/hypervisor/type
-[[ -e /proc/xen/capabilities ]] && grep -q "control_d" /proc/xen/capabilities && XEN_DOM0=true
-
-if [[ $HV_TYPE = "xen" && $XEN_DOM0 != "true" ]]; then
+# PV and PVH Xen DomU guests boot with pygrub that doesn't have BLS support,
+# also Xen Dom0 use the menuentries from 20_linux_xen and not the ones from
+# 10_linux. So BLS support needs to be disabled for both Xen Dom0 and DomU.
+if [[ -e /sys/hypervisor/type ]] && grep -q "^xen$" /sys/hypervisor/type; then
     RUN_MKCONFIG=true
-    if grep -q '^GRUB_ENABLE_BLSCFG="*true"*\s*$' /etc/default/grub; then
-	sed -i 's/^GRUB_ENABLE_BLSCFG=.*/GRUB_ENABLE_BLSCFG=false/' /etc/default/grub
-    fi
+    DISABLE_BLS=true
 fi
 
 ARCH=$(uname -m)
+# Older ppc64le OPAL firmware don't have BLS support so grub2-mkconfig has to
+# be run to generate a GRUB config file that contains menuentry commands.
 if [[ $ARCH = "ppc64le" ]]; then
     RUN_MKCONFIG=true
 fi
 
-# A traditional grub configuration file needs to be generated only for ppc64le and
-# Xen DomU guests since we can't assume that bootloaders will be BLS capable there.
+if [[ $DISABLE_BLS = "true" ]]; then
+    if grep -q '^GRUB_ENABLE_BLSCFG="*true"*\s*$' /etc/default/grub; then
+	sed -i 's/^GRUB_ENABLE_BLSCFG=.*/GRUB_ENABLE_BLSCFG=false/' /etc/default/grub
+    fi
+fi
+
+# A traditional grub configuration file needs to be generated only in the case when
+# the bootloaders are not capable of populating a menu entry from the BLS fragments.
 if [[ $RUN_MKCONFIG != "true" ]]; then
     exit 0
 fi