On Sun, 02 Jun, at 02:56:10PM, Borislav Petkov wrote: > From: Borislav Petkov <bp@xxxxxxx> > > Due to the braindead design of EFI, we cannot map runtime services more > than once for the duration of a booted system. Thus, if we want to use > EFI runtime services in a kexec'ed kernel, maybe the only possible and > sensible approach would be to map them 1:1 so that when the kexec kernel > loads, it can simply call those addresses without the need for remapping > (which doesn't work anyway). > > Furthermore, this mapping approach could be of help with b0rked EFI > implementations for a different set of reasons. > > This implementation is 64-bit only for now and it boots fine in kvm with > OVMF BIOS. > > Signed-off-by: Borislav Petkov <bp@xxxxxxx> > --- > arch/x86/include/asm/efi.h | 2 + > arch/x86/platform/efi/efi.c | 161 +++++++++++++++++++++++++++++------- > arch/x86/platform/efi/efi_stub_64.S | 48 +++++++++++ > 3 files changed, 180 insertions(+), 31 deletions(-) This patch makes my TunnelMountain machine spin in handle_pte_fault() when triggering one of the "firmware makes references to physical addresses" code paths. I'll try and dig into this tomorrow to figure out what's going on. -- Matt Fleming, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
