diff --git a/builder/proxmox/config.go b/builder/proxmox/config.go
index 22cb6786d..41288cb7a 100644
--- a/builder/proxmox/config.go
+++ b/builder/proxmox/config.go
@@ -53,6 +53,7 @@ type Config struct {
 	Agent          bool         `mapstructure:"qemu_agent"`
 	SCSIController string       `mapstructure:"scsi_controller"`
 	Onboot         bool         `mapstructure:"onboot"`
+	DisableKVM     bool         `mapstructure:"disable_kvm"`
 
 	TemplateName        string `mapstructure:"template_name"`
 	TemplateDescription string `mapstructure:"template_description"`
diff --git a/builder/proxmox/config.hcl2spec.go b/builder/proxmox/config.hcl2spec.go
index 73a70b6a1..5136e933f 100644
--- a/builder/proxmox/config.hcl2spec.go
+++ b/builder/proxmox/config.hcl2spec.go
@@ -96,6 +96,7 @@ type FlatConfig struct {
 	Agent                     *bool             `mapstructure:"qemu_agent" cty:"qemu_agent" hcl:"qemu_agent"`
 	SCSIController            *string           `mapstructure:"scsi_controller" cty:"scsi_controller" hcl:"scsi_controller"`
 	Onboot                    *bool             `mapstructure:"onboot" cty:"onboot" hcl:"onboot"`
+	DisableKVM                *bool             `mapstructure:"disable_kvm" cty:"disable_kvm" hcl:"disable_kvm"`
 	TemplateName              *string           `mapstructure:"template_name" cty:"template_name" hcl:"template_name"`
 	TemplateDescription       *string           `mapstructure:"template_description" cty:"template_description" hcl:"template_description"`
 	UnmountISO                *bool             `mapstructure:"unmount_iso" cty:"unmount_iso" hcl:"unmount_iso"`
@@ -202,6 +203,7 @@ func (*FlatConfig) HCL2Spec() map[string]hcldec.Spec {
 		"qemu_agent":                   &hcldec.AttrSpec{Name: "qemu_agent", Type: cty.Bool, Required: false},
 		"scsi_controller":              &hcldec.AttrSpec{Name: "scsi_controller", Type: cty.String, Required: false},
 		"onboot":                       &hcldec.AttrSpec{Name: "onboot", Type: cty.Bool, Required: false},
+		"disable_kvm":                  &hcldec.AttrSpec{Name: "disable_kvm", Type: cty.Bool, Required: false},
 		"template_name":                &hcldec.AttrSpec{Name: "template_name", Type: cty.String, Required: false},
 		"template_description":         &hcldec.AttrSpec{Name: "template_description", Type: cty.String, Required: false},
 		"unmount_iso":                  &hcldec.AttrSpec{Name: "unmount_iso", Type: cty.Bool, Required: false},
diff --git a/builder/proxmox/config_test.go b/builder/proxmox/config_test.go
index e9889ba38..1c4f03552 100644
--- a/builder/proxmox/config_test.go
+++ b/builder/proxmox/config_test.go
@@ -98,6 +98,7 @@ func TestBasicExampleFromDocsIsValid(t *testing.T) {
 	// Agent not set, default is true
 	// SCSI controller not set, using default 'lsi'
 	// Firewall toggle not set, using default: 0
+	// Disable KVM not set, using default: 0
 
 	if b.config.Memory != 512 {
 		t.Errorf("Expected Memory to be 512, got %d", b.config.Memory)
@@ -126,6 +127,9 @@ func TestBasicExampleFromDocsIsValid(t *testing.T) {
 	if b.config.Agent != true {
 		t.Errorf("Expected Agent to be true, got %t", b.config.Agent)
 	}
+	if b.config.DisableKVM != false {
+		t.Errorf("Expected Disable KVM toggle to be false, got %t", b.config.DisableKVM)
+	}
 	if b.config.SCSIController != "lsi" {
 		t.Errorf("Expected SCSI controller to be 'lsi', got %s", b.config.SCSIController)
 	}
diff --git a/builder/proxmox/step_start_vm.go b/builder/proxmox/step_start_vm.go
index 63d961125..132c383d4 100644
--- a/builder/proxmox/step_start_vm.go
+++ b/builder/proxmox/step_start_vm.go
@@ -27,12 +27,18 @@ func (s *stepStartVM) Run(ctx context.Context, state multistep.StateBag) multist
 		agent = 0
 	}
 
+	kvm := true
+	if c.DisableKVM {
+		kvm = false
+	}
+
 	isoFile := state.Get("iso_file").(string)
 
 	ui.Say("Creating VM")
 	config := proxmox.ConfigQemu{
 		Name:         c.VMName,
 		Agent:        agent,
+		QemuKVM:      kvm,
 		Boot:         "cdn", // Boot priority, c:CDROM -> d:Disk -> n:Network
 		QemuCpu:      c.CPUType,
 		Description:  "Packer ephemeral build VM",
diff --git a/go.mod b/go.mod
index 4c3a3e66f..6e67f6c77 100644
--- a/go.mod
+++ b/go.mod
@@ -14,7 +14,7 @@ require (
 	github.com/NaverCloudPlatform/ncloud-sdk-go-v2 v1.1.0
 	github.com/PuerkitoBio/goquery v1.5.0 // indirect
 	github.com/StackExchange/wmi v0.0.0-20190523213315-cbe66965904d // indirect
-	github.com/Telmate/proxmox-api-go v0.0.0-20200225212220-a29566462efd
+	github.com/Telmate/proxmox-api-go v0.0.0-20200715182505-ec97c70ba887
 	github.com/abdullin/seq v0.0.0-20160510034733-d5467c17e7af // indirect
 	github.com/aliyun/alibaba-cloud-sdk-go v0.0.0-20190418113227-25233c783f4e
 	github.com/aliyun/aliyun-oss-go-sdk v0.0.0-20170113022742-e6dbea820a9f
diff --git a/go.sum b/go.sum
index bb506bb41..a11563e17 100644
--- a/go.sum
+++ b/go.sum
@@ -77,8 +77,8 @@ github.com/PuerkitoBio/goquery v1.5.0 h1:uGvmFXOA73IKluu/F84Xd1tt/z07GYm8X49XKHP
 github.com/PuerkitoBio/goquery v1.5.0/go.mod h1:qD2PgZ9lccMbQlc7eEOjaeRlFQON7xY8kdmcsrnKqMg=
 github.com/StackExchange/wmi v0.0.0-20190523213315-cbe66965904d h1:G0m3OIz70MZUWq3EgK3CesDbo8upS2Vm9/P3FtgI+Jk=
 github.com/StackExchange/wmi v0.0.0-20190523213315-cbe66965904d/go.mod h1:3eOhrUMpNV+6aFIbp5/iudMxNCF27Vw2OZgy4xEx0Fg=
-github.com/Telmate/proxmox-api-go v0.0.0-20200225212220-a29566462efd h1:Moss3RtB00h4omKW+leNGIGIfmHcnkZPTJ5d0A0fY14=
-github.com/Telmate/proxmox-api-go v0.0.0-20200225212220-a29566462efd/go.mod h1:OGWyIMJ87/k/GCz8CGiWB2HOXsOVDM6Lpe/nFPkC4IQ=
+github.com/Telmate/proxmox-api-go v0.0.0-20200715182505-ec97c70ba887 h1:Q65o4V0g/KR1sSUZIMf4m1rShb7f1tVHuEt30hfnh2A=
+github.com/Telmate/proxmox-api-go v0.0.0-20200715182505-ec97c70ba887/go.mod h1:OGWyIMJ87/k/GCz8CGiWB2HOXsOVDM6Lpe/nFPkC4IQ=
 github.com/abdullin/seq v0.0.0-20160510034733-d5467c17e7af h1:DBNMBMuMiWYu0b+8KMJuWmfCkcxl09JwdlqwDZZ6U14=
 github.com/abdullin/seq v0.0.0-20160510034733-d5467c17e7af/go.mod h1:5Jv4cbFiHJMsVxt52+i0Ha45fjshj6wxYr1r19tB9bw=
 github.com/agext/levenshtein v1.2.1 h1:QmvMAjj2aEICytGiWzmxoE0x2KZvE0fvmqMOfy2tjT8=
diff --git a/vendor/github.com/Telmate/proxmox-api-go/proxmox/client.go b/vendor/github.com/Telmate/proxmox-api-go/proxmox/client.go
index 787e7497f..f7fa27da5 100644
--- a/vendor/github.com/Telmate/proxmox-api-go/proxmox/client.go
+++ b/vendor/github.com/Telmate/proxmox-api-go/proxmox/client.go
@@ -13,6 +13,7 @@ import (
 	"mime/multipart"
 	"net"
 	"net/http"
+	"os"
 	"regexp"
 	"strconv"
 	"strings"
@@ -722,7 +723,28 @@ func (c *Client) DeleteVMDisks(
 }
 
 func (c *Client) Upload(node string, storage string, contentType string, filename string, file io.Reader) error {
-	body, mimetype, err := createUploadBody(contentType, filename, file)
+	var doStreamingIO bool
+	var fileSize int64
+	var contentLength int64
+
+	if f, ok := file.(*os.File); ok {
+		doStreamingIO = true
+		fileInfo, err := f.Stat()
+		if err != nil {
+			return err
+		}
+		fileSize = fileInfo.Size()
+	}
+
+	var body io.Reader
+	var mimetype string
+	var err error
+
+	if doStreamingIO {
+		body, mimetype, contentLength, err = createStreamedUploadBody(contentType, filename, fileSize, file)
+	} else {
+		body, mimetype, err = createUploadBody(contentType, filename, file)
+	}
 	if err != nil {
 		return err
 	}
@@ -735,6 +757,10 @@ func (c *Client) Upload(node string, storage string, contentType string, filenam
 	req.Header.Add("Content-Type", mimetype)
 	req.Header.Add("Accept", "application/json")
 
+	if doStreamingIO {
+		req.ContentLength = contentLength
+	}
+
 	resp, err := c.session.Do(req)
 	if err != nil {
 		return err
@@ -780,6 +806,38 @@ func createUploadBody(contentType string, filename string, r io.Reader) (io.Read
 	return &buf, w.FormDataContentType(), nil
 }
 
+// createStreamedUploadBody - Use MultiReader to create the multipart body from the file reader,
+// avoiding allocation of large files in memory before upload (useful e.g. for Windows ISOs).
+func createStreamedUploadBody(contentType string, filename string, fileSize int64, r io.Reader) (io.Reader, string, int64, error) {
+	var buf bytes.Buffer
+	w := multipart.NewWriter(&buf)
+
+	err := w.WriteField("content", contentType)
+	if err != nil {
+		return nil, "", 0, err
+	}
+
+	_, err = w.CreateFormFile("filename", filename)
+	if err != nil {
+		return nil, "", 0, err
+	}
+
+	headerSize := buf.Len()
+
+	err = w.Close()
+	if err != nil {
+		return nil, "", 0, err
+	}
+
+	mr := io.MultiReader(bytes.NewReader(buf.Bytes()[:headerSize]),
+		r,
+		bytes.NewReader(buf.Bytes()[headerSize:]))
+
+	contentLength := int64(buf.Len()) + fileSize
+
+	return mr, w.FormDataContentType(), contentLength, nil
+}
+
 // getStorageAndVolumeName - Extract disk storage and disk volume, since disk name is saved
 // in Proxmox with its storage.
 func getStorageAndVolumeName(
diff --git a/vendor/github.com/Telmate/proxmox-api-go/proxmox/config_lxc.go b/vendor/github.com/Telmate/proxmox-api-go/proxmox/config_lxc.go
index e0138690e..5060d64ee 100644
--- a/vendor/github.com/Telmate/proxmox-api-go/proxmox/config_lxc.go
+++ b/vendor/github.com/Telmate/proxmox-api-go/proxmox/config_lxc.go
@@ -313,7 +313,9 @@ func (config configLxc) CreateLxc(vmr *VmRef, client *Client) (err error) {
 	// comma separated list of "key=value" pairs
 	featuresParam := QemuDeviceParam{}
 	featuresParam = featuresParam.createDeviceParam(config.Features, nil)
-	paramMap["features"] = strings.Join(featuresParam, ",")
+	if len(featuresParam) > 0 {
+		paramMap["features"] = strings.Join(featuresParam, ",")
+	}
 
 	// build list of mountpoints
 	// this does the same as for the feature list
diff --git a/vendor/github.com/Telmate/proxmox-api-go/proxmox/config_qemu.go b/vendor/github.com/Telmate/proxmox-api-go/proxmox/config_qemu.go
index 43f0a1920..e57ee6bdf 100644
--- a/vendor/github.com/Telmate/proxmox-api-go/proxmox/config_qemu.go
+++ b/vendor/github.com/Telmate/proxmox-api-go/proxmox/config_qemu.go
@@ -38,6 +38,7 @@ type ConfigQemu struct {
 	QemuVcpus    int         `json:"vcpus"`
 	QemuCpu      string      `json:"cpu"`
 	QemuNuma     bool        `json:"numa"`
+	QemuKVM      bool        `json:"kvm"`
 	Hotplug      string      `json:"hotplug"`
 	QemuIso      string      `json:"iso"`
 	FullClone    *int        `json:"fullclone"`
@@ -94,6 +95,7 @@ func (config ConfigQemu) CreateVm(vmr *VmRef, client *Client) (err error) {
 		"cores":       config.QemuCores,
 		"cpu":         config.QemuCpu,
 		"numa":        config.QemuNuma,
+		"kvm":         config.QemuKVM,
 		"hotplug":     config.Hotplug,
 		"memory":      config.Memory,
 		"boot":        config.Boot,
@@ -107,11 +109,11 @@ func (config ConfigQemu) CreateVm(vmr *VmRef, client *Client) (err error) {
 	if config.Balloon >= 1 {
 		params["balloon"] = config.Balloon
 	}
-	
+
 	if config.QemuVcpus >= 1 {
 		params["vcpus"] = config.QemuVcpus
 	}
-	
+
 	if vmr.pool != "" {
 		params["pool"] = vmr.pool
 	}
@@ -214,6 +216,7 @@ func (config ConfigQemu) UpdateConfig(vmr *VmRef, client *Client) (err error) {
 		"cores":       config.QemuCores,
 		"cpu":         config.QemuCpu,
 		"numa":        config.QemuNuma,
+		"kvm":         config.QemuKVM,
 		"hotplug":     config.Hotplug,
 		"memory":      config.Memory,
 		"boot":        config.Boot,
@@ -231,13 +234,13 @@ func (config ConfigQemu) UpdateConfig(vmr *VmRef, client *Client) (err error) {
 	} else {
 		deleteParams = append(deleteParams, "balloon")
 	}
-	
+
 	if config.QemuVcpus >= 1 {
 		configParams["vcpus"] = config.QemuVcpus
 	} else {
 		deleteParams = append(deleteParams, "vcpus")
 	}
-	
+
 	if config.BootDisk != "" {
 		configParams["bootdisk"] = config.BootDisk
 	}
@@ -307,11 +310,11 @@ func (config ConfigQemu) UpdateConfig(vmr *VmRef, client *Client) (err error) {
 	if config.Ipconfig2 != "" {
 		configParams["ipconfig2"] = config.Ipconfig2
 	}
-	
+
 	if len(deleteParams) > 0 {
 		configParams["delete"] = strings.Join(deleteParams, ", ")
 	}
-	
+
 	_, err = client.SetVmConfig(vmr, configParams)
 	if err != nil {
 		log.Print(err)
@@ -326,7 +329,7 @@ func (config ConfigQemu) UpdateConfig(vmr *VmRef, client *Client) (err error) {
 }
 
 func NewConfigQemuFromJson(io io.Reader) (config *ConfigQemu, err error) {
-	config = &ConfigQemu{QemuVlanTag: -1}
+	config = &ConfigQemu{QemuVlanTag: -1, QemuKVM: true}
 	err = json.NewDecoder(io).Decode(config)
 	if err != nil {
 		log.Fatal(err)
@@ -449,6 +452,10 @@ func NewConfigQemuFromApi(vmr *VmRef, client *Client) (config *ConfigQemu, err e
 	if _, isSet := vmConfig["bootdisk"]; isSet {
 		bootdisk = vmConfig["bootdisk"].(string)
 	}
+	kvm := true
+	if _, isSet := vmConfig["kvm"]; isSet {
+		kvm = Itob(int(vmConfig["kvm"].(float64)))
+	}
 	scsihw := "lsi"
 	if _, isSet := vmConfig["scsihw"]; isSet {
 		scsihw = vmConfig["scsihw"].(string)
@@ -470,6 +477,7 @@ func NewConfigQemuFromApi(vmr *VmRef, client *Client) (config *ConfigQemu, err e
 		QemuSockets:  int(sockets),
 		QemuCpu:      cpu,
 		QemuNuma:     numa,
+		QemuKVM:      kvm,
 		Hotplug:      hotplug,
 		QemuVlanTag:  -1,
 		Boot:         boot,
@@ -481,12 +489,12 @@ func NewConfigQemuFromApi(vmr *VmRef, client *Client) (config *ConfigQemu, err e
 		QemuNetworks: QemuDevices{},
 		QemuSerials:  QemuDevices{},
 	}
-	
+
 	if balloon >= 1 {
-		config.Balloon = int(balloon);
+		config.Balloon = int(balloon)
 	}
 	if vcpus >= 1 {
-		config.QemuVcpus = int(vcpus);
+		config.QemuVcpus = int(vcpus)
 	}
 
 	if vmConfig["ide2"] != nil {
diff --git a/vendor/github.com/Telmate/proxmox-api-go/proxmox/session.go b/vendor/github.com/Telmate/proxmox-api-go/proxmox/session.go
index 819bc6903..2b6f58c44 100644
--- a/vendor/github.com/Telmate/proxmox-api-go/proxmox/session.go
+++ b/vendor/github.com/Telmate/proxmox-api-go/proxmox/session.go
@@ -65,7 +65,9 @@ func ParamsToBody(params map[string]interface{}) (body []byte) {
 		default:
 			v = fmt.Sprintf("%v", intrV)
 		}
-		vals.Set(k, v)
+		if v != "" {
+			vals.Set(k, v)
+		}
 	}
 	body = bytes.NewBufferString(vals.Encode()).Bytes()
 	return
diff --git a/vendor/modules.txt b/vendor/modules.txt
index 29f67e2b9..38055e719 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -69,7 +69,7 @@ github.com/NaverCloudPlatform/ncloud-sdk-go-v2/services/server
 github.com/PuerkitoBio/goquery
 # github.com/StackExchange/wmi v0.0.0-20190523213315-cbe66965904d
 github.com/StackExchange/wmi
-# github.com/Telmate/proxmox-api-go v0.0.0-20200225212220-a29566462efd
+# github.com/Telmate/proxmox-api-go v0.0.0-20200715182505-ec97c70ba887
 github.com/Telmate/proxmox-api-go/proxmox
 # github.com/agext/levenshtein v1.2.1
 github.com/agext/levenshtein
diff --git a/website/pages/docs/builders/proxmox.mdx b/website/pages/docs/builders/proxmox.mdx
index 1dd34d189..3e6669923 100644
--- a/website/pages/docs/builders/proxmox.mdx
+++ b/website/pages/docs/builders/proxmox.mdx
@@ -193,6 +193,8 @@ builder.
   then `qemu-guest-agent` must be installed on the guest. When disabled, then
   `ssh_host` should be used. Defaults to `true`.
 
+- `disable_kvm` (boolean) - Disables KVM hardware virtualization. Defaults to `false`.
+
 - `scsi_controller` (string) - The SCSI controller model to emulate. Can be `lsi`,
   `lsi53c810`, `virtio-scsi-pci`, `virtio-scsi-single`, `megasas`, or `pvscsi`.
   Defaults to `lsi`.