VirtualMachine

2023-02-04 305 words 2 minutes

Contents

KVM

bridge

NOTE: start dhcpcd.service

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nmcli connection add type bridge ifname br0 stp no
nmcli connection add type bridge-slave ifname enp7s0 master br0

nmcli connection show --active
nmcli connection down bridge-br0
nmcli connection down Wired\ connection\ 1

nmcli connection show
nmcli connection up bridge-br0
nmcli connection up bridge-slave-enp7s0

kernel

compilation

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make -j24 && \
sudo make -j24 modules_install headers_install install && \
sudo cp arch/x86_64/boot/bzImage /boot/vmlinuz-6.0-ebpf-x86_64 && \
sudo mkinitcpio -p linux60-ebpf && \
sudo update-grub

Cannot find LILO

manually update boot loader

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sudo pacman -S grub

install

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sudo make -j24 modules_install headers_install install

mkinitcpio

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sudo mkinitcpio -p linux60

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# /etc/mkinitcpio.d/linux60.preset
# mkinitcpio preset file for the '6.0-x86_64' package

ALL_config="/etc/mkinitcpio.conf"
ALL_kver="/boot/vmlinuz-6.0-x86_64"

PRESETS=('default' 'fallback')

#default_config="/etc/mkinitcpio.conf"
default_image="/boot/initramfs-6.0-x86_64.img"
#default_options=""

#fallback_config="/etc/mkinitcpio.conf"
fallback_image="/boot/initramfs-6.0-x86_64-fallback.img"
fallback_options="-S autodetect"

serial console

change the grub config

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# /etc/default/grub
GRUB_TERMINAL="serial console"
GRUB_CMDLINE_LINUX_DEFAULT="console=ttyS0,115200n8"
GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"

systemctl enable serial-getty@ttyS0.service
systemctl start serial-getty@ttyS0.service

gdb

kernel config

Build the kernel with CONFIG_GDB_SCRIPTS enabled, but leave CONFIG_DEBUG_INFO_REDUCED off.
Turn off KASLR if necessary by adding “nokaslr” to the kernel command line.
If your architecture supports CONFIG_FRAME_POINTER, Enable FRAME_POINTER!!!

QEMU/KVM

Add qemu commandline
-s stands for -gdb & tcp:1234

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<domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
  <qemu:commandline>
    <qemu:arg value='-s'/>
  </qemu:commandline>
  <!-- or -->
  <qemu:commandline>
    <qemu:arg value="-gdb"/>
    <qemu:arg value="tcp::1235"/>
  </qemu:commandline>
</domain>

Attach

Copy vmlinux from Linux kernel root directory first

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gdb ./vmlinux
target remote :1234
lx-symbols

Edit ~/.config/gdb/gdbinit

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add-auto-load-safe-path /PATH/linux/scripts/gdb/vmlinux-gdb.py

Image

qemu	qcow2
virtual box	vmdk
vmware	vmdk

unzip OVA →

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tar -xf ova-file.ova
qemu-img convert -O qcow2 vmdk-file.vmdk qcow2-file.qcow2

boot from disk

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qemu-system-x86_64 -drive format=qcow2,file=fact.qcow2