gentoo-overlay/app-emulation/xen/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
	<herd>xen</herd>
	<use>
		<flag name='flask'>Enable the Flask XSM module from NSA</flag>
		<flag name='pae'>Enable support for PAE kernels (usually x86-32 with >4GB memory)</flag>
		<flag name='xsm'>Enable the Xen Security Modules (XSM)</flag>
		<flag name='efi'>Adds efi boot support, requires LDFLAG -melf_x86_64 for amd64</flag>
	</use>
</pkgmetadata>