diff --git a/pkg/compute/models/guests.go b/pkg/compute/models/guests.go
index ebb2f7a74d..7cbca100cb 100644
--- a/pkg/compute/models/guests.go
+++ b/pkg/compute/models/guests.go
@@ -976,6 +976,38 @@ func (self *SGuest) ValidateUpdateData(ctx context.Context, userCred mcclient.To
 		return input, httperrors.NewInputParameterError("name is too short")
 	}
 
+	if input.Vdi != nil {
+		if !utils.IsInStringArray(*input.Vdi, []string{"vnc", "spice"}) {
+			return input, httperrors.NewInputParameterError("unsupported vdi protocol")
+		}
+	}
+
+	if input.Vga != nil || input.Vdi != nil {
+		vdi := self.Vdi
+		if input.Vdi != nil {
+			vdi = *input.Vdi
+		}
+		if vdi != "vnc" && vdi != "spice" {
+			vdi = "vnc"
+			input.Vdi = &vdi
+		}
+		var candidateVga []string
+		switch vdi {
+		case "vnc":
+			candidateVga = []string{"std", "qxl", "virtio"}
+		case "spice":
+			candidateVga = []string{"qxl", "virtio"}
+		}
+		vga := self.Vga
+		if input.Vga != nil {
+			vga = *input.Vga
+		}
+		if !utils.IsInStringArray(vga, candidateVga) {
+			vga = candidateVga[0]
+			input.Vga = &vga
+		}
+	}
+
 	var err error
 	input.VirtualResourceBaseUpdateInput, err = self.SVirtualResourceBase.ValidateUpdateData(ctx, userCred, query, input.VirtualResourceBaseUpdateInput)
 	if err != nil {