baremetal: use q35 machine type with EFI firmware for bootstrap VM

The bootstrap VM domain definition did not set a machine type,
causing libvirt to default to the deprecated pc-i440fx-rhel7.6.0
chipset on CentOS Stream 9 hosts. This has been correlated with
intermittent bootstrap VM startup failures in CI where the VM
becomes unreachable after QEMU starts.

Explicitly set the machine type to q35 with EFI firmware for
x86_64, matching the pattern already used for aarch64 and
aligning with how dev-scripts provisions master/worker VMs.

The arch-specific domain configuration is extracted into a
separate configureDomainArch() function with unit tests.

Assisted-By: Claude 4.6 Opus High

Author: elfosardo

pkg/infrastructure/baremetal/bootstrap.go

@@ -290,28 +290,36 @@ func getHostCapabilities(virConn *libvirt.Libvirt) (libvirtxml.Caps, error) {
 	return caps, nil
 }
 
-func createBootstrapDomain(virConn *libvirt.Libvirt, config baremetalConfig, pool libvirt.StoragePool, volume libvirt.StorageVol) error {
-	bootstrapDom := newDomain(fmt.Sprintf("%s-bootstrap", config.ClusterID))
+func configureDomainArch(dom *libvirtxml.Domain, arch string) {
+	dom.OS.Type.Arch = arch
 
-	capabilities, err := getHostCapabilities(virConn)
-	if err != nil {
-		return fmt.Errorf("failed to get libvirt capabilities: %w", err)
+	if arch == "x86_64" {
+		dom.OS.Type.Machine = "q35"
+		dom.OS.Firmware = "efi"
 	}
 
-	arch := capabilities.Host.CPU.Arch
-	bootstrapDom.OS.Type.Arch = arch
-
 	if arch == "aarch64" {
-		// for aarch64 speciffying this will automatically select the firmware and NVRAM file
 		// reference: https://libvirt.org/formatdomain.html#bios-bootloader
-		bootstrapDom.OS.Firmware = "efi"
+		dom.OS.Firmware = "efi"
 	}
 
 	// For aarch64, s390x, ppc64 and ppc64le spice is not supported
 	if arch == "aarch64" || arch == "s390x" || strings.HasPrefix(arch, "ppc64") {
-		bootstrapDom.Devices.Graphics = nil
+		dom.Devices.Graphics = nil
+	}
+}
+
+func createBootstrapDomain(virConn *libvirt.Libvirt, config baremetalConfig, pool libvirt.StoragePool, volume libvirt.StorageVol) error {
+	bootstrapDom := newDomain(fmt.Sprintf("%s-bootstrap", config.ClusterID))
+
+	capabilities, err := getHostCapabilities(virConn)
+	if err != nil {
+		return fmt.Errorf("failed to get libvirt capabilities: %w", err)
 	}
 
+	arch := capabilities.Host.CPU.Arch
+	configureDomainArch(&bootstrapDom, arch)
+
 	for _, bridge := range config.Bridges {
 		netIface := libvirtxml.DomainInterface{
 			Model: &libvirtxml.DomainInterfaceModel{

pkg/infrastructure/baremetal/bootstrap_test.go

@@ -0,0 +1,97 @@
+package baremetal
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"libvirt.org/go/libvirtxml"
+)
+
+func TestNewDomain(t *testing.T) {
+	dom := newDomain("test-bootstrap")
+
+	assert.Equal(t, "test-bootstrap", dom.Name)
+	assert.Equal(t, "kvm", dom.Type)
+	assert.Equal(t, "hvm", dom.OS.Type.Type)
+	assert.Empty(t, dom.OS.Type.Arch, "arch should not be set by newDomain")
+	assert.Empty(t, dom.OS.Type.Machine, "machine should not be set by newDomain")
+	assert.Equal(t, uint(6144), dom.Memory.Value)
+	assert.Equal(t, "MiB", dom.Memory.Unit)
+	assert.Equal(t, uint(4), dom.VCPU.Value)
+	assert.Equal(t, "host-passthrough", dom.CPU.Mode)
+	assert.NotEmpty(t, dom.Devices.RNGs, "RNG device should be configured")
+	assert.NotEmpty(t, dom.Devices.Graphics, "graphics should be configured")
+	assert.NotEmpty(t, dom.Devices.Consoles, "console should be configured")
+}
+
+func TestConfigureDomainArch(t *testing.T) {
+	tests := []struct {
+		name            string
+		arch            string
+		expectMachine   string
+		expectFirmware  string
+		expectGraphics  bool
+	}{
+		{
+			name:           "x86_64 sets q35 and efi",
+			arch:           "x86_64",
+			expectMachine:  "q35",
+			expectFirmware: "efi",
+			expectGraphics: true,
+		},
+		{
+			name:           "aarch64 sets efi and removes graphics",
+			arch:           "aarch64",
+			expectMachine:  "",
+			expectFirmware: "efi",
+			expectGraphics: false,
+		},
+		{
+			name:           "s390x removes graphics",
+			arch:           "s390x",
+			expectMachine:  "",
+			expectFirmware: "",
+			expectGraphics: false,
+		},
+		{
+			name:           "ppc64le removes graphics",
+			arch:           "ppc64le",
+			expectMachine:  "",
+			expectFirmware: "",
+			expectGraphics: false,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			dom := newDomain("test-bootstrap")
+			configureDomainArch(&dom, tc.arch)
+
+			assert.Equal(t, tc.arch, dom.OS.Type.Arch)
+			assert.Equal(t, tc.expectMachine, dom.OS.Type.Machine)
+			assert.Equal(t, tc.expectFirmware, dom.OS.Firmware)
+
+			if tc.expectGraphics {
+				assert.NotNil(t, dom.Devices.Graphics, "graphics should be present for %s", tc.arch)
+			} else {
+				assert.Nil(t, dom.Devices.Graphics, "graphics should be removed for %s", tc.arch)
+			}
+		})
+	}
+}
+
+func TestConfigureDomainArchPreservesOtherFields(t *testing.T) {
+	dom := newDomain("test-bootstrap")
+
+	dom.Devices.Interfaces = []libvirtxml.DomainInterface{
+		{
+			Model: &libvirtxml.DomainInterfaceModel{Type: "virtio"},
+		},
+	}
+
+	configureDomainArch(&dom, "x86_64")
+
+	assert.Len(t, dom.Devices.Interfaces, 1, "interfaces should not be modified")
+	assert.Equal(t, "hvm", dom.OS.Type.Type, "OS type should remain hvm")
+	assert.Equal(t, "kvm", dom.Type, "domain type should remain kvm")
+}