[libvirt] [RFC] passing standard input to host bootloaders

Hello list, Some host boot loaders, e.g. grub-bhyve when using the bhyve driver, take commands on stdin. While there is the <bootloader_args> tag to set arbitrary command line tags, there is no <bootloader_stdin> or similar to provide standard input to the boot loader. Typical input could be something along the lines of e.g. the following grub commands: kernel (cd)/path/to/vmlinuz some-cmdline initrd (root)/path/to/host/initrd boot Using e.g. the (root) device is especially useful on the bhyve driver when creating diskless VMs. Before I start implementing this, I’d appreciate some feedback on the following two points: 1) should this be an attr on the <bootloader> tag, e.g. <bootloader_stdin=“/path/to/file”>/path/to/bootloader</bootloader> or rather, as there already exists a <bootloader_args> tag a separate <bootloader_stdin> tag? 2) should the input be passed verbatim in the domain def, e.g. using a CDATA block or from a file? Should this be user-specified, e.g. in an attr? <bootloader_stdin from=“/path/to/file”/> <bootloader_stdin> <![CDATA[ kernel (host)/path/to/kernel with cmdline initrd (host)/path/to/ramdisk boot ]]> </bootloader_stdin> Regards, Fabian