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From:   "Jason A. Donenfeld" <Jason@zx2c4.com>
Date:   Wed, 8 Feb 2023 15:14:38 -0300
Message-ID: <CAHmME9rMnbGDZ+Rq8ao=gZd10kBp5ni=73HcPpFC58ChoKZObA@mail.gmail.com>
Subject: Re: [PATCH] x86: temporarily remove all attempts to provide setup_data
To:     "Michael S. Tsirkin" <mst@redhat.com>
Cc:     qemu-devel@nongnu.org, x86@kernel.org,
        linux-kernel@vger.kernel.org, Dov Murik <dovmurik@linux.ibm.com>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        Gerd Hoffmann <kraxel@redhat.com>,
        =?UTF-8?Q?Daniel_P_=2E_Berrang=C3=A9?= <berrange@redhat.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Richard Henderson <richard.henderson@linaro.org>,
        "H . Peter Anvin" <hpa@zytor.com>,
        =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= <philmd@linaro.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Borislav Petkov <bp@alien8.de>,
        Eric Biggers <ebiggers@kernel.org>
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On Wed, Feb 8, 2023 at 3:13 PM Michael S. Tsirkin <mst@redhat.com> wrote:
>
> On Wed, Feb 08, 2023 at 03:08:35PM -0300, Jason A. Donenfeld wrote:
> > All attempts at providing setup_data have been made as an iteration on
> > whatever was there before, stretching back to the original
> > implementation used for DTBs that [mis]used the kernel image itself.
> > We've now had a dozen rounds of bugs and hacks, and the result is
> > turning into a pile of unmaintainable and increasingly brittle hacks.
> >
> > Let's just rip out all the madness and start over. We can re-architect
> > this based on having a separate standalone setup_data file, which is ho=
w
> > it should have been done in the first place. This is a larger project
> > with a few things to coordinate, but we can't really begin thinking
> > about that while trying to play whack-a-mole with the current buggy
> > implementation.
> >
> > So this commit removes the setup_data setting from x86_load_linux(),
> > while leaving intact the infrastructure we'll need in the future to try
> > again.
> >
> > Cc: Michael S. Tsirkin <mst@redhat.com>
> > Cc: Dov Murik <dovmurik@linux.ibm.com>
> > Cc: Tom Lendacky <thomas.lendacky@amd.com>
> > Cc: Gerd Hoffmann <kraxel@redhat.com>
> > Cc: Daniel P. Berrang=C3=A9 <berrange@redhat.com>
> > Cc: Paolo Bonzini <pbonzini@redhat.com>
> > Cc: Richard Henderson <richard.henderson@linaro.org>
> > Cc: H. Peter Anvin <hpa@zytor.com>
> > Cc: Philippe Mathieu-Daud=C3=A9 <philmd@linaro.org>
> > Cc: Nathan Chancellor <nathan@kernel.org>
> > Cc: Borislav Petkov <bp@alien8.de>
> > Cc: Eric Biggers <ebiggers@kernel.org>
> > Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
>
> I think I'll be happier if this is just a revert of
> the relevant commits in reverse order to make life easier
> for backporters.
> Unless that's too much work as we made other changes around
> this code?

I think that's going to be messy. And it won't handle the dtb stuff
either straightforwardly.