Messages in this thread | | | Date | Wed, 13 Aug 2014 15:27:48 +0100 | From | Matt Fleming <> | Subject | Re: [PATCH 4/5] efi x86: clear EFI_RUNTIME_SERVICES bit in case failures other than SetVirtualAddressMap |
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On Tue, 12 Aug, at 02:10:21PM, Dave Young wrote: > If enter virtual mode failed due to some reason other than the efi call > the EFI_RUNTIME_SERVICES bit in efi.flags should be cleared thus users > of efi runtime services can check the bit and handle the case instead of > assume efi runtime is ok. > > Per Matt, if efi call SetVirtualAddressMap fails we will be not sure it's safe > to make any assumptions about the state of the system. so kernel panics instead > of clears EFI_RUNTIME_SERVICES bit. > > Signed-off-by: Dave Young <dyoung@redhat.com> > --- > arch/x86/platform/efi/efi.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-)
[...]
> @@ -882,8 +886,10 @@ static void __init __efi_enter_virtual_mode(void) > > void __init efi_enter_virtual_mode(void) > { > - if (efi_enabled(EFI_PARAVIRT)) > + if (efi_enabled(EFI_PARAVIRT)) { > + clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); > return; > + }
The EFI_PARAVIRT folks purposely do not set this bit, so there should be no reason to clear it here.
-- Matt Fleming, Intel Open Source Technology Center
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