From 29e7b1ff8235009706338ea9c9853a24ec329b02 Mon Sep 17 00:00:00 2001
From: Jonathan Teh <30538043+jonathan-teh@users.noreply.github.com>
Date: Wed, 10 Mar 2021 17:40:30 +0000
Subject: [PATCH] linux: enable NVMe Multipath

Enable NVME_MULTIPATH so that a single /dev/nvmeXnY device will show
up for each NVMe namespaces, even if it is accessible through multiple
controllers. Can be disabled at boot with `nvme_core.multipath=0`.

This is default enabled in Debian [1], Ubuntu 20.04 [2] , Arch [3] and
Fedora 33 [4].

[1]: https://salsa.debian.org/kernel-team/linux/-/blob/debian/5.10.19-1/debian/config/config#L4362
[2]: https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/tree/debian.master/config/config.common.ubuntu?h=Ubuntu-5.4.0-67.75#n6722
[3]: https://git.archlinux.org/svntogit/packages.git/tree/trunk/config?h=packages/linux#n2423
[4]: https://src.fedoraproject.org/rpms/kernel/blob/f33/f/kernel-x86_64-fedora.config#_4338
---
 pkgs/os-specific/linux/kernel/common-config.nix | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pkgs/os-specific/linux/kernel/common-config.nix b/pkgs/os-specific/linux/kernel/common-config.nix
index 5e749ed3fcf2..4fef56077c01 100644
--- a/pkgs/os-specific/linux/kernel/common-config.nix
+++ b/pkgs/os-specific/linux/kernel/common-config.nix
@@ -772,6 +772,8 @@ let
       MLX4_EN_VXLAN = whenOlder "4.8" yes;
       MLX5_CORE_EN       = option yes;
 
+      NVME_MULTIPATH = whenAtLeast "4.15" yes;
+
       PSI = whenAtLeast "4.20" yes;
 
       MODVERSIONS        = whenOlder "4.9" yes;