Add ability to select CPU type

builder/proxmox/config.go

@@ -40,6 +40,7 @@ type Config struct {
 	Memory  int          `mapstructure:"memory"`
 	Cores   int          `mapstructure:"cores"`
 	Sockets int          `mapstructure:"sockets"`
+	CPUType string       `mapstructure:"cpu_type"`
 	OS      string       `mapstructure:"os"`
 	NICs    []nicConfig  `mapstructure:"network_adapters"`
 	Disks   []diskConfig `mapstructure:"disks"`
@@ -129,6 +130,10 @@ func NewConfig(raws ...interface{}) (*Config, []string, error) {
 		log.Printf("Number of sockets %d is too small, using default: 1", c.Sockets)
 		c.Sockets = 1
 	}
+	if c.CPUType == "" {
+		log.Printf("CPU type not set, using default 'kvm64'")
+		c.CPUType = "kvm64"
+	}
 	if c.OS == "" {
 		log.Printf("OS not set, using default 'other'")
 		c.OS = "other"

builder/proxmox/config_test.go

@@ -90,6 +90,7 @@ func TestBasicExampleFromDocsIsValid(t *testing.T) {
 	// Memory 0 is too small, using default: 512
 	// Number of cores 0 is too small, using default: 1
 	// Number of sockets 0 is too small, using default: 1
+	// CPU type not set, using default 'kvm64'
 	// OS not set, using default 'other'
 	// NIC 0 model not set, using default 'e1000'
 	// Disk 0 cache mode not set, using default 'none'
@@ -104,6 +105,9 @@ func TestBasicExampleFromDocsIsValid(t *testing.T) {
 	if b.config.Sockets != 1 {
 		t.Errorf("Expected Sockets to be 1, got %d", b.config.Sockets)
 	}
+	if b.config.CPUType != "kvm64" {
+		t.Errorf("Expected CPU type to be 'kvm64', got %s", b.config.CPUType)
+	}
 	if b.config.OS != "other" {
 		t.Errorf("Expected OS to be 'other', got %s", b.config.OS)
 	}

builder/proxmox/step_start_vm.go

@@ -31,7 +31,7 @@ func (s *stepStartVM) Run(ctx context.Context, state multistep.StateBag) multist
 		Name:         c.VMName,
 		Agent:        agent,
 		Boot:         "cdn", // Boot priority, c:CDROM -> d:Disk -> n:Network
-		QemuCpu:      "host",
+		QemuCpu:      c.CPUType,
 		Description:  "Packer ephemeral build VM",
 		Memory:       c.Memory,
 		QemuCores:    c.Cores,

website/source/docs/builders/proxmox.html.md

@@ -73,6 +73,10 @@ builder.
 -   `sockets` (int) - How many CPU sockets to give the virtual machine.
     Defaults to `1`
 
+-   `cpu_type` (string) - The CPU type to emulate. See the Proxmox API
+    documentation for the complete list of accepted values. For best
+    performance, set this to `host`. Defaults to `kvm64`.
+
 -   `os` (string) - The operating system. Can be `wxp`, `w2k`, `w2k3`, `w2k8`,
     `wvista`, `win7`, `win8`, `win10`, `l24` (Linux 2.4), `l26` (Linux 2.6+),
     `solaris` or `other`. Defaults to `other`.