From 163c02970e4ddcf238b2ac09eadf380744e01ba2 Mon Sep 17 00:00:00 2001
From: Pingfan Liu <piliu@redhat.com>
Date: Mon, 20 Dec 2021 09:29:02 +0800
Subject: [PATCH] ppc64/ppc64le: drop cpu online rule in 40-redhat.rules in
 kdump initramfs

Onlining secondary cpus breaks kdump completely on KVM on Power hosts
Though we use maxcpus=1 by default but 40-redhat.rules will bring up all
possible cpus by default.

Thus before we get the kernel fix and the systemd rule fix let's remove
the cpu rule in 40-redhat.rules for ppc64/ppc64le kdump initramfs.

This is back ported from RHEL, and original credit goes to Dave Young
<dyoung@redhat.com>

Signed-off-by: Pingfan Liu <piliu@redhat.com>
Acked-by: Tao Liu <ltao@redhat.com>
---
 dracut-module-setup.sh | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
index 1ea0d95..c319fc2 100755
--- a/dracut-module-setup.sh
+++ b/dracut-module-setup.sh
@@ -1010,11 +1010,29 @@ kdump_install_systemd_conf() {
     echo "ForwardToConsole=yes" >> "${initdir}/etc/systemd/journald.conf.d/kdump.conf"
 }
 
+remove_cpu_online_rule() {
+    local file=${initdir}/usr/lib/udev/rules.d/40-redhat.rules
+
+    sed -i '/SUBSYSTEM=="cpu"/d' "$file"
+}
+
 install() {
+    local arch
+
     kdump_module_init
     kdump_install_conf
     remove_sysctl_conf
 
+    # Onlining secondary cpus breaks kdump completely on KVM on Power hosts
+    # Though we use maxcpus=1 by default but 40-redhat.rules will bring up all
+    # possible cpus by default. (rhbz1270174 rhbz1266322)
+    # Thus before we get the kernel fix and the systemd rule fix let's remove
+    # the cpu online rule in kdump initramfs.
+    arch=$(uname -m)
+    if [[ "$arch" = "ppc64le" ]] || [[ "$arch" = "ppc64" ]]; then
+        remove_cpu_online_rule
+    fi
+
     if is_ssh_dump_target; then
         kdump_install_random_seed
     fi