Re: [PATCH v2] efi: Check the number of EFI configuration tables entries

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On Tue, 21 May 2019 at 14:20, Bradford, Robert
<robert.bradford@intel.com> wrote:
>
> On Tue, 2019-04-16 at 10:59 +0100, Rob Bradford wrote:
> > Only try and access the EFI configuration tables if there there are
> > any
> > reported. This allows EFI to be continued to used on systems where
> > there
> > are no configuration table entries.
> >
> > v2: Move return on nr_tables==0 earlier
> >
> > Signed-off-by: Rob Bradford <robert.bradford@intel.com>
> > ---
> >  arch/x86/platform/efi/quirks.c | 3 +++
> >  drivers/firmware/efi/efi.c     | 3 +++
> >  2 files changed, 6 insertions(+)
> >
> > diff --git a/arch/x86/platform/efi/quirks.c
> > b/arch/x86/platform/efi/quirks.c
> > index 95e77a667ba5..6b9a4792242b 100644
> > --- a/arch/x86/platform/efi/quirks.c
> > +++ b/arch/x86/platform/efi/quirks.c
> > @@ -471,6 +471,9 @@ int __init efi_reuse_config(u64 tables, int
> > nr_tables)
> >       void *p, *tablep;
> >       struct efi_setup_data *data;
> >
> > +     if (nr_tables == 0)
> > +             return 0;
> > +
> >       if (!efi_setup)
> >               return 0;
> >
> > diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> > index 415849bab233..185424a8b879 100644
> > --- a/drivers/firmware/efi/efi.c
> > +++ b/drivers/firmware/efi/efi.c
> > @@ -628,6 +628,9 @@ int __init
> > efi_config_init(efi_config_table_type_t *arch_tables)
> >       void *config_tables;
> >       int sz, ret;
> >
> > +     if (efi.systab->nr_tables == 0)
> > +             return 0;
> > +
> >       if (efi_enabled(EFI_64BIT))
> >               sz = sizeof(efi_config_table_64_t);
> >       else
>
> Any chance of getting this into the tree? Without this we can't boot
> the kernel in EFI mode on our KVM based hypervisor[1] & firmware[2] as
> it does not provide any tables, nor does it need to.
>

Apologies for the delay. I will pick it up today.