From 15a6f4a86111926a974d63cc61387f3ed8048d65 Mon Sep 17 00:00:00 2001
From: Ryan Yin <xiaoyin_c@qq.com>
Date: Mon, 29 Jul 2024 22:07:10 +0800
Subject: [PATCH] fix: allocate only hugepages with size 1Gi

---
 hosts/k8s/kubevirt-shoryu/default.nix  | 12 ++++++++++++
 hosts/k8s/kubevirt-shushou/default.nix | 12 ++++++++++++
 hosts/k8s/kubevirt-youko/default.nix   | 12 ++++++++++++
 3 files changed, 36 insertions(+)

diff --git a/hosts/k8s/kubevirt-shoryu/default.nix b/hosts/k8s/kubevirt-shoryu/default.nix
index cd198a925..f4ab5fe07 100644
--- a/hosts/k8s/kubevirt-shoryu/default.nix
+++ b/hosts/k8s/kubevirt-shoryu/default.nix
@@ -49,4 +49,16 @@ in {
       coreModule
       k3sModule
     ];
+
+  # https://kubernetes.io/docs/tasks/manage-hugepages/scheduling-hugepages/
+  boot.kernelParams = [
+    # disable transparent hugepage(allocate hugepages dynamically)
+    "transparent_hugepage=never"
+
+    # pre-allocate hugepages manually(for kubevirt guest vms)
+    # NOTE: the hugepages allocated here can not be used for other purposes!
+    # so we should left some memory for the host OS
+    "hugepagesz=1G"
+    "hugepages=56"
+  ];
 }
diff --git a/hosts/k8s/kubevirt-shushou/default.nix b/hosts/k8s/kubevirt-shushou/default.nix
index 75eb85458..b6f84020f 100644
--- a/hosts/k8s/kubevirt-shushou/default.nix
+++ b/hosts/k8s/kubevirt-shushou/default.nix
@@ -43,4 +43,16 @@ in {
       coreModule
       k3sModule
     ];
+
+  # https://kubernetes.io/docs/tasks/manage-hugepages/scheduling-hugepages/
+  boot.kernelParams = [
+    # disable transparent hugepage(allocate hugepages dynamically)
+    "transparent_hugepage=never"
+
+    # pre-allocate hugepages manually(for kubevirt guest vms)
+    # NOTE: the hugepages allocated here can not be used for other purposes!
+    # so we should left some memory for the host OS
+    "hugepagesz=1G"
+    "hugepages=56"
+  ];
 }
diff --git a/hosts/k8s/kubevirt-youko/default.nix b/hosts/k8s/kubevirt-youko/default.nix
index 00a5a0c23..2b2e3a292 100644
--- a/hosts/k8s/kubevirt-youko/default.nix
+++ b/hosts/k8s/kubevirt-youko/default.nix
@@ -43,4 +43,16 @@ in {
       coreModule
       k3sModule
     ];
+
+  # https://kubernetes.io/docs/tasks/manage-hugepages/scheduling-hugepages/
+  boot.kernelParams = [
+    # disable transparent hugepage(allocate hugepages dynamically)
+    "transparent_hugepage=never"
+
+    # pre-allocate hugepages manually(for kubevirt guest vms)
+    # NOTE: the hugepages allocated here can not be used for other purposes!
+    # so we should left some memory for the host OS
+    "hugepagesz=1G"
+    "hugepages=18"
+  ];
 }