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 syscall.ENOMEM/"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

@@ -2,6 +2,7 @@ package generic
 
 import (
 	"bytes"
+	"errors"
 	"os/exec"
 	"reflect"
 	"strconv"
@@ -173,6 +174,10 @@ 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{}

pkg/utils/utils.go

@@ -48,6 +48,7 @@ const (
 	udevDisableNM   = "/bindata/scripts/udev-find-sriov-pf.sh"
 	nmUdevRule      = "SUBSYSTEM==\"net\", ACTION==\"add|change|move\", ATTRS{device}==\"%s\", IMPORT{program}=\"/etc/udev/disable-nm-sriov.sh $env{INTERFACE} %s\""
 
+	KernelArgPciRealloc = "pci=realloc"
 	KernelArgIntelIommu = "intel_iommu=on"
 	KernelArgIommuPt    = "iommu=pt"
 )