linux-kernel - Re: [PATCH 05/13] efi/x86: don't map the entire kernel text RW for mixed mode

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Message-ID: <CAMj1kXFJ3WvtTKejKFwY-JKsTBjANdM8+Mae8+Yvfsu15ke+zg@mail.gmail.com>
Date:   Thu, 9 Apr 2020 13:25:18 +0200
From:   Ard Biesheuvel <ardb@...nel.org>
To:     Jiri Slaby <jslaby@...e.cz>
Cc:     Gary Lin <glin@...e.com>, linux-efi <linux-efi@...r.kernel.org>,
        Ingo Molnar <mingo@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Anshuman Khandual <anshuman.khandual@....com>,
        Arnd Bergmann <arnd@...db.de>,
        Dan Williams <dan.j.williams@...el.com>,
        Dave Young <dyoung@...hat.com>,
        Saravana Kannan <saravanak@...gle.com>
Subject: Re: [PATCH 05/13] efi/x86: don't map the entire kernel text RW for
 mixed mode

On Thu, 9 Apr 2020 at 13:08, Ard Biesheuvel <ardb@...nel.org> wrote:
>
> On Thu, 9 Apr 2020 at 12:45, Ard Biesheuvel <ardb@...nel.org> wrote:
> >
> > On Thu, 9 Apr 2020 at 12:09, Jiri Slaby <jslaby@...e.cz> wrote:
> > >
> > > On 09. 04. 20, 11:09, Ard Biesheuvel wrote:
> > > > On Thu, 9 Apr 2020 at 10:36, Jiri Slaby <jslaby@...e.cz> wrote:
> > > >>
> > > >> On 09. 04. 20, 10:19, Ard Biesheuvel wrote:
> > > >>>>>> $ rpm -qlp ~/Downloads/ovmf-202002-1.1.i586.rpm
> > > >>>>>> warning: /home/ardbie01/Downloads/ovmf-202002-1.1.i586.rpm: Header V3
> > > >>>>>> RSA/SHA256 Signature, key ID 3dbdc284: NOKEY
> > > >>>>>> /usr/share/doc/packages/ovmf
> > > >>>>>> /usr/share/doc/packages/ovmf/README
> > > >>>>>
> > > >>>>> Hmmm, it's weird that OBS doesn't list all derived files.
> > > >>>>> Anyway, the ia32 ovmf is available in
> > > >>>>> http://download.opensuse.org/tumbleweed/repo/oss/noarch/qemu-ovmf-ia32-202002-1.1.noarch.rpm
> > > >>>>
> > > >>>> It indeed does:
> > > >>>> https://build.opensuse.org/package/binaries/openSUSE:Factory/ovmf/standard
> > > >>>>
> > > >>>> Note that the ia32 version is noarch, built on i586.
> > > >>>>
> > > >>>
> > > >>> I am not able to reproduce this issue using the linked firmware image
> > > >>> and a 5.6 x86_64_defconfig with efivarfs built in.
> > > >>
> > > >> Yeah, I had to use the distro config too. Not sure what the trigger is.
> > > >> Maybe some NUMA configs or something.
> > > >>
> > > >>> Could anyone share the full log, please, along with the kernel config
> > > >>> that was used?
> > > >>
> > > >> Both uploaded:
> > > >> http://decibel.fi.muni.cz/~xslaby/err/
> > > >>
> > > >
> > > > With the same config, I am still not seeing the issue.
> > > >
> > > >
> > > >> Note that I switched the for-me-necessary =m configs to =y. So that it
> > > >> is enough to build bzImage, w/o modules...
> > > >>
> > > >
> > > > Could you please try running it again with CONFIG_EFI_PGT_DUMP=y enabled?
> > >
> > > No problem:
> > > http://decibel.fi.muni.cz/~xslaby/err/dmesg2.txt
> > >
> > > > In the mean time, I will try to install Tumbleweed from scratch. Do
> > > > you have any steps I could follow to reproduce your setup?
> > >
> > > Not really, just installed TW 64-bit and used efi and grub 32 bit.
> > >
> >
> > OK, so you installed using a 64-bit EFI, and then switched to a 32-bit
> > one? Or is there a special mixed-mode capable installer?
> >
> > (The ones I found are x86_64 only)
>
> OK, I have managed to install tumbleweed into a 64-bit VM with 64-bit GRUB.
>
> Could you give any instructions how to convert to 32-bit GRUB please?

Never mind - I managed to switch. I still don't see the issue though :-(