From: Dave Young <[email protected]> [ Upstream commit 2ecb7402cfc7f22764e7bbc80790e66eadb20560 ]
kexec reboot fails randomly in UEFI based KVM guest. The firmware just resets 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 the 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 a dummy object. Drop the efi_delete_dummy_variable so that kexec reboot can work. Signed-off-by: Dave Young <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Acked-by: Matthew Garrett <[email protected]> Cc: Ben Dooks <[email protected]> Cc: Jarkko Sakkinen <[email protected]> Cc: Jerry Snitselaar <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Lukas Wunner <[email protected]> Cc: Lyude Paul <[email protected]> Cc: Octavian Purdila <[email protected]> Cc: Peter Jones <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Scott Talbert <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- arch/x86/platform/efi/efi.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 9061babfbc83d..335a62e74a2e9 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -893,9 +893,6 @@ static void __init kexec_enter_virtual_mode(void) if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX)) runtime_code_page_mkexec(); - - /* clean DUMMY object */ - efi_delete_dummy_variable(); #endif } -- 2.20.1
