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Only rename the virtual Azure Hyper-V network interface

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Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1964822
Upstream: RHEL-only

Currently, vmcore dumping to remote fs gives a warning "eth0: Failed to
rename network interface 3 from 'eth0' to 'kdump-eth0': File exists" on
Azure Hyper-V VM with accelerated networking because it uses a physical
NIC for accelerated networking [1] and the backing physical NIC has the
same MAC address as the virtual NIC. In the kdump initrd, an udev rule
will try renaming NICs with the given MAC address and fails as expected
since there are two NICs having the same MAC address. This udev rule is
created automatically when specifying the dracut cmdline
"ifname=<interface>:<MAC>". For the case of Azure Hyper-V VM with
accelerated networking, only the virtual network interface need to be
renamed. So create an udev rule manually.

[1] https://learn.microsoft.com/en-us/azure/virtual-network/accelerated-networking-overview

Signed-off-by: Coiby Xu <coxu@redhat.com>
This commit is contained in:
Coiby Xu 2023-05-25 16:56:12 +08:00
parent 933ba930f7
commit c4a0ad47dd
1 changed files with 19 additions and 7 deletions
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22
dracut-module-setup.sh
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@ -303,10 +303,6 @@ kdump_get_perm_addr() {
fi
}
_get_nic_driver() {
ethtool -i "$1" | sed -n -E "s/driver: (.*)/\1/p"
}
# Prefix kernel assigned names with "kdump-". EX: eth0 -> kdump-eth0
# Because kernel assigned names are not persistent between 1st and 2nd
# kernel. We could probably end up with eth0 being eth1, eth0 being
@ -318,7 +314,7 @@ kdump_setup_ifname() {
# fadump to kdump. Skip prefixing 'kdump-' in this case as adding
# another prefix may truncate the ifname. Since an ifname with
# 'kdump-' is already persistent, this should be fine.
if [[ $1 =~ eth* ]] && [[ ! $1 =~ ^kdump-* ]] && [[ $(_get_nic_driver "$1") != hv_netvsc ]]; then
if [[ $1 =~ eth* ]] && [[ ! $1 =~ ^kdump-* ]]; then
_ifname="kdump-$1"
else
_ifname="$1"
@ -485,6 +481,18 @@ kdump_setup_znet() {
echo rd.znet=${NETTYPE},${SUBCHANNELS}${_options} rd.znet_ifname=$(kdump_setup_ifname $_netdev):${SUBCHANNELS} > ${initdir}/etc/cmdline.d/30znet.conf
}
_get_nic_driver() {
ethtool -i "$1" | sed -n -E "s/driver: (.*)/\1/p"
}
_rename_hypver_netdev() {
local _udev_rule_dir
_udev_rule_dir=${initdir}/etc/udev/rules.d
mkdir -p "$_udev_rule_dir"
printf 'SUBSYSTEM=="net", ACTION=="add", DRIVERS=="hv_netvsc", ATTR{address}=="%s", ATTR{type}=="1", NAME="%s"\n' "$2" "$1" > "${_udev_rule_dir}/80-hv_netvsc-ifname.rules"
}
# Setup dracut to bringup a given network interface
kdump_setup_netdev() {
local _netdev=$1 _srcaddr=$2
@ -533,8 +541,12 @@ kdump_setup_netdev() {
elif kdump_is_vlan "$_netdev"; then
kdump_setup_vlan "$_netdev"
else
if [[ $(_get_nic_driver "$1") != hv_netvsc ]]; then
_ifname_opts=" ifname=$kdumpnic:$_netmac"
echo "$_ifname_opts" >> $_ip_conf
else
_rename_hypver_netdev "$kdumpnic" "$_netmac"
fi
fi
_save_kdump_netifs "$_netdev" "$_kdumpdev"