On Tue, Feb 01, 2022 at 12:44:09PM +0000, Dov Murik wrote: > Confidential computing (coco) hardware such as AMD SEV (Secure Encrypted > Virtualization) allows a guest owner to inject secrets into the VMs > memory without the host/hypervisor being able to read them. > > Firmware support for secret injection is available in OVMF, which > reserves a memory area for secret injection and includes a pointer to it > the in EFI config table entry LINUX_EFI_COCO_SECRET_TABLE_GUID. > > If EFI exposes such a table entry, uefi_init() will keep a pointer to > the EFI config table entry in efi.coco_secret, so it can be used later > by the kernel (specifically drivers/virt/coco/efi_secret). It will also > appear in the kernel log as "CocoSecret=ADDRESS"; for example: > > [ 0.000000] efi: EFI v2.70 by EDK II > [ 0.000000] efi: CocoSecret=0x7f22e680 SMBIOS=0x7f541000 ACPI=0x7f77e000 ACPI 2.0=0x7f77e014 MEMATTR=0x7ea0c018 > > The new functionality can be enabled with CONFIG_EFI_COCO_SECRET=y. > > Signed-off-by: Dov Murik <dovmurik@xxxxxxxxxxxxx> Reviewed-by: Gerd Hoffmann <kraxel@xxxxxxxxxx> take care, Gerd
