• Dave Young's avatar
    efi/x86: Do not clean dummy variable in kexec path · 2ecb7402
    Dave Young authored
    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: default avatarDave Young <dyoung@redhat.com>
    Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
    Acked-by: default avatarMatthew Garrett <mjg59@google.com>
    Cc: Ben Dooks <ben.dooks@codethink.co.uk>
    Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
    Cc: Jerry Snitselaar <jsnitsel@redhat.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Lukas Wunner <lukas@wunner.de>
    Cc: Lyude Paul <lyude@redhat.com>
    Cc: Octavian Purdila <octavian.purdila@intel.com>
    Cc: Peter Jones <pjones@redhat.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Scott Talbert <swt@techie.net>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: linux-efi@vger.kernel.org
    Cc: linux-integrity@vger.kernel.org
    Link: https://lkml.kernel.org/r/20191002165904.8819-8-ard.biesheuvel@linaro.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
    2ecb7402
efi.c 27.1 KB