Support both kinds of provider config options for disk config

plugins/kernel_v2/config/disk.rb

@@ -66,18 +66,30 @@ module VagrantPlugins
         @id = SecureRandom.uuid
       end
 
+      # Helper method for storing provider specific config options
+      #
+      # Expected format is:
+      #
+      # - `provider__diskoption: value`
+      # - `{provider: {diskoption: value, otherdiskoption: value, ...}`
+      #
+      # Duplicates will be overriden
+      #
+      # @param [Hash] options
       def add_provider_config(**options, &block)
         current = {}
         options.each do |k,v|
           opts = k.to_s.split("__")
+
           if opts.size == 2
-            current[opts[0]] = opts[1]
+            current[opts[0].to_sym] = {opts[1].to_sym => v}
+          elsif v.is_a?(Hash)
+            current[k] = v
           else
-            @logger.warn("Disk option '#{k}' found that does not match expected schema")
+            @logger.warn("Disk option '#{k}' found that does not match expected provider disk config schema.")
           end
         end
 
-        #block.call(current) if block
         current = @provider_config.merge(current) if !@provider_config.empty?
         @provider_config = current
       end

plugins/kernel_v2/config/vm.rb

@@ -409,23 +409,27 @@ module VagrantPlugins
         @__defined_vms[name].config_procs << [options[:config_version], block] if block
       end
 
+      # Stores disk config options from Vagrantfile
+      #
+      # @param [Symbol] type
+      # @param [Hash]   options
+      # @param [Block]  block
       def disk(type, **options, &block)
         disk_config = VagrantConfigDisk.new(type)
 
         # Remove provider__option options before set_options, otherwise will
         # show up as missing setting
-        #
-        # We can probably combine this into a single method call...?
-        provider_options = options.select { |k,v| k.to_s.include?("__") }
-        options.delete_if { |k,v| k.to_s.include?("__") }
+        # Extract provider hash options as well
+        provider_options = {}
+        options.delete_if do |p,o|
+          if o.is_a?(Hash) || p.to_s.include?("__")
+            provider_options[p] = o
+            true
+          end
+        end
 
         disk_config.set_options(options)
 
-        # Can't use blocks if we use provider__option
-        #if block_given?
-        #  block.call(disk, VagrantConfigDisk)
-        #end
-
         # Add provider config
         disk_config.add_provider_config(provider_options, &block)