帶有 lz4 壓縮核心的 Xen pvgrub

我正在使用 pvgrub 在 xen 4.11 上執行 PV 來賓。最近發布的 ubuntu (>19.04) 看起來已經切換到 lz4 壓縮核心。這些核心在直接引導下工作正常，但在 pvgrub 和 pvgrub2 下它們似乎不可引導。

最新版本的 ubuntu 焦點 20.04。來賓核心 5.4.0-28。

error: not xen image.                [ vmlinuz-5.4.0-28-gen  10B  0%  0.17B/s ]
error: you need to load the kernel first.

Press any key to continue...

相同的設置適用於較舊的核心（例如 4.19）

我注意到這個更新檔到 xen 本身有一個問題，有沒有人讓這些核心與 pvgrub 一起工作？

感謝 Andy 在 xen-users 郵件列表上的一些建議，我有一個臨時工作。從它的聲音來看，lz4 尚不支持。

特定於 Ubuntu PV 來賓，我編寫了以下內容作為 apt 鉤子，使用 extract-vmlinux 在安裝期間解壓縮核心。 https://raw.githubusercontent.com/torvalds/linux/master/scripts/extract-vmlinux

該鉤子在某處需要extract-linux（我使用了/usr/local/bin）並進入/etc/kernel/postinst.d/

#!/bin/bash

KERNEL_VERSION="$1"
KERNEL_PATH="$2"

# extract-vmlinux is in /usr/local/bin
PATH="${PATH}:/usr/local/bin"

# Ensure we have the extract-linux tool
if ! command -v extract-vmlinux > /dev/null; then
       echo >&2 "Command 'extract-vmlinux' is not available (https://raw.githubusercontent.com/torvalds/linux/master/scripts/extract-vmlinux),  Aborting"
       exit 1
fi

# The KERNEL_PATH must be valid
if [ ! -f "${KERNEL_PATH}" ]; then
       echo >&2 "Kernel file '${KERNEL_PATH}' not found. Aborting"
       exit 1
fi

# Create a temp file
TEMP_FILE=$(mktemp /tmp/decompress-kernel-XXXXX)
trap "rm -f ${TEMP_FILE}" 0

# If the given kernel file is still a bzimage see if its needs decompression
if echo "$(file -b "${KERNEL_PATH}")" | grep -q "^Linux kernel x86 boot executable bzImage"; then

       # Kernel is probably lz4 if there are lz4 headers in it
       LZ4_HEADER="$(printf '\002!L\030')"
       if ! grep -aqo "${LZ4_HEADER}" ${KERNEL_PATH}; then
               echo "No lz4 compression headers found, skipping..."
               exit 0
       fi

       echo "Decompressing '${KERNEL_PATH}'..."
       # Extract the kernel and replace existing if successful
       if extract-vmlinux ${KERNEL_PATH} > ${TEMP_FILE}; then

               # Double check the kernel is a valid ELF image
               if ! readelf -h ${TEMP_FILE} > /dev/null; then
                       echo >&2 "Decompression of kernel file '${KERNEL_PATH}' failed!, not a valid ELF image"
                       exit 1
               fi

               echo "Decompression of kernel file '${KERNEL_PATH}' successful"
               cp -v ${TEMP_FILE} ${KERNEL_PATH}

       else
               echo >&2 "Decompression of kernel file '${KERNEL_PATH}' failed!"
               exit 1
       fi

# Perhaps its already been decompressed
elif echo "$(file -b "${KERNEL_PATH}")" | grep -q "^ELF 64-bit LSB executable"; then
       echo "Kernel file '${KERNEL_PATH}' appears to be decompressed already. skipping"

else
       echo >&2 "Unable to determine the state of kernel file '${KERNEL_PATH}'"
       exit 1
fi

引用自：https://unix.stackexchange.com/questions/583714