> > > I think we should make it obvious from a kernel image if it supports > > > unaccepted memory (with UTS_VERSION or other way). > > > > > Something I didn't address in my previous email: how would the UEFI > know where the kernel is to parse this UTS_VERSION out when it's > booting a bootloader before Linux gets booted? > How about instead of the limited resource of UTS_VERSION, we add a SETUP_BOOT_FEATURES enum for setup_data in the boot header? That would be easier to parse out and more extensible in the future. https://www.kernel.org/doc/html/latest/x86/boot.html?highlight=boot This can contain a bitmap of a number of features that we currently need manual tagging for, such as SEV guest support, SEV-SNP guest support, TDX guest support, and (CONFIG_UNACCEPTED_MEMORY, TDX) or (CONFIG_UNACCEPTED_MEMORY, SEV-SNP). The VMM, UEFI, or boot loader can read these from the images/kernels and have the appropriate behavior. -- -Dionna Glaze, PhD (she/her)
