kexec reboot fails randomly in UEFI based kvm guest. The firmware just reset while calling efi_delete_dummy_variable(); Unfortunately I don't know how to debug the firmware, it is also possible a potential problem on real hardware as well although nobody reproduced it.
The intention of efi_delete_dummy_variable is to trigger garbage collection when entering virtual mode. But SetVirtualAddressMap can only run once for each physical reboot, thus kexec_enter_virtual_mode is not necessarily a good place to clean dummy object. Drop efi_delete_dummy_variable so that kexec reboot can work. Signed-off-by: Dave Young <[email protected]> --- arch/x86/platform/efi/efi.c | 3 --- 1 file changed, 3 deletions(-) --- linux-x86.orig/arch/x86/platform/efi/efi.c +++ linux-x86/arch/x86/platform/efi/efi.c @@ -894,9 +894,6 @@ static void __init kexec_enter_virtual_m if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX)) runtime_code_page_mkexec(); - - /* clean DUMMY object */ - efi_delete_dummy_variable(); #endif }
