From: Dave Young <dyo...@redhat.com> [ 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 <dyo...@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org> Acked-by: Matthew Garrett <mj...@google.com> Cc: Ben Dooks <ben.do...@codethink.co.uk> Cc: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com> Cc: Jerry Snitselaar <jsnit...@redhat.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Lukas Wunner <lu...@wunner.de> Cc: Lyude Paul <ly...@redhat.com> Cc: Octavian Purdila <octavian.purd...@intel.com> Cc: Peter Jones <pjo...@redhat.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Scott Talbert <s...@techie.net> Cc: Thomas Gleixner <t...@linutronix.de> Cc: linux-efi@vger.kernel.org Cc: linux-integr...@vger.kernel.org Link: https://lkml.kernel.org/r/20191002165904.8819-8-ard.biesheu...@linaro.org Signed-off-by: Ingo Molnar <mi...@kernel.org> Signed-off-by: Sasha Levin <sas...@kernel.org> --- 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 ad285404ea7f5..4bc352fc08f19 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -859,9 +859,6 @@ 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
