From:   Pingfan Liu <kernelfans@gmail.com>
To:     linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Cc:     Pingfan Liu <kernelfans@gmail.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Ard Biesheuvel <ardb@kernel.org>, kexec@lists.infradead.org
Subject: [PATCH 0/6] arm64: make kexec_file able to load zboot image
Date:   Mon,  6 Mar 2023 11:02:59 +0800
Message-Id: <20230306030305.15595-1-kernelfans@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

After introducing zboot image, kexec_file can not load and jump to the
new style image. Hence it demands a method to load the new kernel.

The crux of the problem lies in when and how to decompress the Image.gz.
There are three possible courses to take: -1. in user space, but hard to
achieve due to the signature verification inside the kernel.  -2. at the
boot time, let the efi_zboot_entry() handles it, which means a simulated
EFI service should be provided to that entry, especially about how to be
aware of the memory layout.  -3. in kernel space, during the file load
of the zboot image. At that point, the kernel masters the whole memory
information, and easily allocates a suitable memory for the decompressed
kernel image. (I think this is similar to what grub does today).

The core of this series is [5/6].  [3,6/6] handles the config option.
The assumption of [3/6] is kexec_file_load is independent of zboot,
especially it can load kernel images compressed with different
compression method.  [6/6] is if EFI_ZBOOT, the corresponding
decompression method should be included.


Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: kexec@lists.infradead.org
To: linux-arm-kernel@lists.infradead.org
To: linux-kernel@vger.kernel.org

Pingfan Liu (6):
  arm64: kexec: Rename kexec_image.c to kexec_raw_image.c
  lib/decompress: Introduce decompress_method_by_name()
  arm64: Kconfig: Pick decompressing method for kexec file load
  lib/decompress: Keep decompress routines based on selection
  arm64: kexec: Introduce zboot image loader
  init/Kconfig: Select decompressing method if compressing kernel

 arch/arm64/Kconfig                            |  59 ++++++
 arch/arm64/include/asm/kexec.h                |   4 +-
 arch/arm64/kernel/Makefile                    |   2 +-
 .../{kexec_image.c => kexec_raw_image.c}      |   2 +-
 arch/arm64/kernel/kexec_zboot_image.c         | 186 ++++++++++++++++++
 arch/arm64/kernel/machine_kexec.c             |   1 +
 arch/arm64/kernel/machine_kexec_file.c        |   3 +-
 include/linux/decompress/generic.h            |   2 +
 include/linux/decompress/mm.h                 |   9 +-
 include/linux/zboot.h                         |  26 +++
 init/Kconfig                                  |   7 +
 lib/Kconfig                                   |   3 +
 lib/decompress.c                              |  17 +-
 13 files changed, 314 insertions(+), 7 deletions(-)
 rename arch/arm64/kernel/{kexec_image.c => kexec_raw_image.c} (98%)
 create mode 100644 arch/arm64/kernel/kexec_zboot_image.c
 create mode 100644 include/linux/zboot.h

-- 
2.31.1