From 27b878546fd148adb4cb214c14a7ade9b0d7b2c4 Mon Sep 17 00:00:00 2001
From: William Zhao <wizhao@redhat.com>
Date: Thu, 3 Aug 2023 18:23:20 -0400
Subject: [PATCH] Set kernel arg PCI realloc on "cannot allocate memory" on VF
 creation

When creating VFs via sysfs sriov_numvfs, there is a chance of getting
the error "cannot allocate memory". This could occur when the BIOS is
not providing enough MMIO space for VFs. A solution is to reallocate
the MMIO space via "pci=realloc".

Signed-off-by: William Zhao <wizhao@redhat.com>
---
 pkg/plugins/generic/generic_plugin.go | 5 +++++
 pkg/utils/utils.go                    | 1 +
 2 files changed, 6 insertions(+)

diff --git a/pkg/plugins/generic/generic_plugin.go b/pkg/plugins/generic/generic_plugin.go
index 5ed34fde3..8e0c5f82f 100644
--- a/pkg/plugins/generic/generic_plugin.go
+++ b/pkg/plugins/generic/generic_plugin.go
@@ -2,6 +2,7 @@ package generic
 
 import (
 	"bytes"
+	"errors"
 	"os/exec"
 	"reflect"
 	"strconv"
@@ -172,6 +173,10 @@ func (p *GenericPlugin) Apply() error {
 	}
 
 	if err := utils.SyncNodeState(p.DesireState, pfsToSkip); err != nil {
+		// Catch the "cannot allocate memory" error and try to use PCI realloc
+		if errors.Is(err, syscall.ENOMEM) {
+			p.addToDesiredKernelArgs(utils.KernelArgPciRealloc)
+		}
 		return err
 	}
 	p.LastState = &sriovnetworkv1.SriovNetworkNodeState{}
diff --git a/pkg/utils/utils.go b/pkg/utils/utils.go
index 635ca054b..a63c67587 100644
--- a/pkg/utils/utils.go
+++ b/pkg/utils/utils.go
@@ -42,6 +42,7 @@ const (
 	DeviceBF2             = "a2d6"
 	DeviceBF3             = "a2dc"
 
+	KernelArgPciRealloc = "pci=realloc"
 	KernelArgIntelIommu = "intel_iommu=on"
 	KernelArgIommuPt    = "iommu=pt"
 )