From 0678138331f6de43aaee0b7fbacf8adb38e73ff0 Mon Sep 17 00:00:00 2001
From: Coiby Xu <coxu@redhat.com>
Date: Thu, 17 Jul 2025 17:25:38 +0800
Subject: [PATCH] Support dumping to NVMe/TCP configured using NVMe Boot
 Firmware Table

Resolves: https://issues.redhat.com/browse/RHEL-100907
Resolves: https://issues.redhat.com/browse/RHEL-33413

The dracut nvmf module can take care of all things. It can parse ACPI
NVMe Boot Firmware Table (NBFT) tables, generate NetworkManager profiles
and discover and connect all subsystems.

Currently, the dracut kdump module will try to bring up the same network
connections as in 1st kernel. But a different set of NVMe connections
and active network interfaces will be used for the case of multipathing.
So the dracut kdump module should let dracut nvmf module do everything.

Note connecting everything and having network redundancy may require extra
memory and the default crashkernel may not work. We'll document this
issue and ask users to increase the crashkernel.

Signed-off-by: Coiby Xu <coxu@redhat.com>
---
 dracut/99kdumpbase/module-setup.sh | 37 +++++++++++++++++++++++++-----
 supported-kdump-targets.txt        |  2 ++
 2 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/dracut/99kdumpbase/module-setup.sh b/dracut/99kdumpbase/module-setup.sh
index d71b28ce..f2a8a24f 100755
--- a/dracut/99kdumpbase/module-setup.sh
+++ b/dracut/99kdumpbase/module-setup.sh
@@ -360,11 +360,6 @@ kdump_install_nmconnections() {
             exit 1
         fi
     done <<< "$(nmcli -t -f device,filename connection show --active)"
-
-    # Stop dracut 35network-manger to calling nm-initrd-generator.
-    # Note this line of code can be removed after NetworkManager >= 1.35.2
-    # gets released.
-    echo > "${initdir}/usr/libexec/nm-initrd-generator"
 }
 
 kdump_install_nm_netif_allowlist() {
@@ -658,7 +653,7 @@ kdump_install_net() {
         kdump_install_nmconnections
         apply_nm_initrd_generator_timeouts
         kdump_setup_znet "$_netifs"
-        kdump_install_nm_netif_allowlist "$_netifs"
+        [[ $is_nvmf ]] || kdump_install_nm_netif_allowlist "$_netifs"
         kdump_install_nic_driver "$_netifs"
         kdump_install_resolv_conf
     fi
@@ -915,6 +910,33 @@ kdump_check_iscsi_targets() {
     }
 }
 
+# Callback function for for_each_host_dev_and_slaves_all
+#
+# Code adapted from the is_nvmf function of dracut nvmf module
+kdump_nvmf_callback() {
+    local _dev _d _trtype
+
+    _dev=$1
+
+    cd -P "/sys/dev/block/$_dev" || return 1
+    if [ -f partition ]; then
+        cd ..
+    fi
+
+    for _d in device/nvme*; do
+        [ -L "$_d" ] || continue
+        if readlink "$_d" | grep -q nvme-fabrics; then
+            read -r _trtype < "$_d"/transport
+            [[ $_trtype == "fc" || $_trtype == "tcp" || $_trtype == "rdma" ]] && return 0
+        fi
+    done
+    return 1
+}
+
+kdump_check_nvmf_target() {
+    for_each_host_dev_and_slaves_all kdump_nvmf_callback && is_nvmf=1
+}
+
 # hostname -a is deprecated, do it by ourself
 get_alias() {
     local ips
@@ -1074,6 +1096,7 @@ EOF
 
 install() {
     declare -A unique_netifs ovs_unique_netifs ipv4_usage ipv6_usage
+    local is_nvmf
 
     kdump_module_init
     kdump_install_conf
@@ -1121,6 +1144,8 @@ install() {
     # at some point of time.
     kdump_check_iscsi_targets
 
+    kdump_check_nvmf_target
+
     kdump_install_systemd_conf
 
     # nfs/ssh dump will need to get host ip in second kernel and need to call 'ip' tool, see get_host_ip for more detail
diff --git a/supported-kdump-targets.txt b/supported-kdump-targets.txt
index 936a42b6..0c7af107 100644
--- a/supported-kdump-targets.txt
+++ b/supported-kdump-targets.txt
@@ -47,6 +47,8 @@ storage:
         software FCoE (bnx2fc) (Extra configuration required,
             please read "Note on FCoE" section below)
         NVMe-FC (qla2xxx, lpfc)
+        NVMe/TCP configured by NVMe Boot Firmware Table (users may need to
+            increase the crashkernel value)
 
 network:
         Hardware using kernel modules: (igb, ixgbe, ice, i40e, e1000e, igc,
-- 
2.50.1