Qemu 5.2 - nothing shows up after VNC running - virtual-machine

i'm trying to use QEMU 5.x for research.
I got QEMU 5.2 source code from qemu.org and installed following instructions.
However, when i tried to run VM by this command:
qemu-system-x86_64 \
-monitor stdio \
--enable-kvm \
-m 4096 \
-cdrom ubuntu-20.04.iso \
-drive file=img.qcow,if=virtio \
-boot c
-rtc base=localtime \
-device virtio-keyboard-pci \
-vga virtio \
then the following texts are printed:
QEMU 5.2.0 monitor - type 'help' for more information
(qemu) VNC server running on 127.0.0.1:5900
then nothing shows up, while QEMU 4.x (used before) pops up a window showing guest ubuntu's GUI.
I'm using ubuntu 20.04. Hope anyone has breakthrough for this..

The message says that this QEMU is using the VNC protocol for graphics output. You can connect a VNC client to the 127.0.0.1:5900 port that it tells you about to see the graphics output.
If what you wanted was a native X11 window (GTK), then the problem is probably that you didn't have the necessary libraries installed to build the GTK support. QEMU's configure script's default behaviour is "build all the optional features that this host has the libraries installed for, and omit the features where the libraries aren't present". So if you don't have any of the GTK/SDL etc libraries when you build QEMU, the only thing you will get in the resulting QEMU binary is the lowest-common-denominator VNC support. If you want configure to report an error for a missing feature then you need to pass it the appropriate --enable-whatever option to force the feature to be enabled (in this case, --enable-gtk).
If you're running on Ubuntu and your apt sources.list file has deb-src lines in it, the easiest way to install all the dependencies that would get you the same feature list as the real Ubuntu QEMU package is to run "apt build-dep qemu". I recommend that you do that and then re-build QEMU, passing --enable-gtk to configure so you can confirm that the necessary dependencies were installed.

Related

Is it possible to run VM with ppc64le architecture on a host machine with x86_64 architecture?

I want to test some use-cases which need to run on 'ppc64le' architecture but I don't have a host machine with ppc64le architecture.
My host system is of x86_64 architecture. Is it possible to run VM with 'ppc64le' architecture on my host machine with x86_64 architecture?
Absolutely! The only caveat is that since you're not running natively, the virtual machine needs to emulate the target (ppc64le) instruction set. This can be much slower than running native instructions.
The way to do this will depend on which tools you're using to manage your virtual machine instances. For example, virt-manager allows you to select the architecture type when you're creating a new virtual machine. If you set this to ppc64el, you'll get a ppc64el machine. Other options (like disk and network devices) can be set just like native VMs.
If you're not using any specific VM management tools, the following invocation of qemu will get a ppc64el machine going easily:
qemu-system-ppc64le \
-M pseries # use the pseries machine model \
-m 4G # with 4G of RAM \
-hda ubuntu-18.04-server-ppc64el.iso # Ubuntu installer as a virtual disk
Depending on your usage, you may want to use the following options too:
-nographic -serial pty to use a text console instead of an emulated graphics device. qemu will print the console pty on startup - something like /dev/pts/X. Run screen /dev/pts/X to access it.
-M powernv -bios skiboot.lid to use the non-virtualised ppc64el machine model, which is closer to current OpenPOWER hardware. The skiboot.lid firmware may be included in your distro's install of qemu.
-drive, -device and -netdev to configure virtual disks and networking. These work in the same manner at x86 VMs on qemu.
I hosted centos7-ppc64le on my x86_64 machine(OS RHEL-7). I used qemu + virt-install for that. First install qemu as
wget https://download.qemu.org/qemu-3.1.0-rc1.tar.xz
tar xvJf qemu-3.1.0-rc1.tar.xz
cd qemu-3.1.0-rc1
./configure
make
make install
After installation check qemu-system-ppc64le is available from the command line. Then install virt-manager,virt-install,virt-viewer and libvirt for managing the VM's. Then I started the VM as
virt-install --name centos7-ppc64le \
--disk centos7-ppc64le.qcow2 \
--machine pseries \
--arch ppc64 \
--vcpus 2 \
--cdrom CentOS-7-ppc64le-Minimal-1804.iso \
--memory 2048 \
--network=bridge:virbr0 \
--graphics vnc

How can I develop in docker container with intellij?

I know intellij has a docker container plugin, however it doesn't seem to allow me to develop inside the container itself. The idea is simple, I don't want to configure my host to have the correct environment tools. I'd rather just a docker container setup and then use intellij to find libs, functionality and such with in the container itself.
This would be incredibly helpful for c++, java, and scala dev. Also it would be useful debugging as well.
So is it possible to develop within a docker container with intellij?
So you just want to work within a container just as you would within a full-blown VM, right? Then you should just run a container, attach a display (to run IDEA) and start configuring your development environment.
For the display part I'd test some answers given in Can you run GUI apps in a docker container?. There are some very cool answers in this topic showing various approaches to running GUI apps within a container.
Shouldn't the approach be rather:
Have local repository and local IDE. In the repository have docker file and eventually docker-compose.yml, which spins up environment required to run project.
Mount your local drive with sources into docker (volumes), so changes done in your local folder are reflected in docker, similar in other direction.
Please look at this example for Intellij IDEA CI and JDK8 based on Alpine Linux (taken here
https://raw.githubusercontent.com/shaharv/docker/master/alpine/dev/Dockerfile)
# Alpine 3.8 C++/Java Developer Image
#
# For IntelliJ and GUI (X11), run the image with:
# $ XSOCK=/tmp/.X11-unix && sudo docker run -i -v $XSOCK:$XSOCK -e DISPLAY -u developer -t [image-name]
#
# Then run IntelliJ with:
# /idea-IC-191.6707.61/bin/idea.sh
FROM alpine:3.8
ENV LANG C.UTF-8
RUN set -ex && \
apk add --no-cache --update \
# basic packages
bash bash-completion coreutils file grep openssl openssh nano sudo tar xz \
# debug tools
gdb musl-dbg strace \
# docs and man
bash-doc man man-pages less less-doc \
# GUI fonts
font-noto \
# user utils
shadow
RUN set -ex && \
apk add --no-cache --update \
# C++ build tools
cmake g++ git linux-headers libpthread-stubs make
RUN set -ex && \
apk add --no-cache --update \
# Java tools
gradle openjdk8 openjdk8-dbg
# Install IntelliJ Community
RUN set -ex && \
wget https://download-cf.jetbrains.com/idea/ideaIC-2019.1.1-no-jbr.tar.gz && \
tar -xf ideaIC-2019.1.1-no-jbr.tar.gz && \
rm ideaIC-2019.1.1-no-jbr.tar.gz
# Create a new user with no password
ENV USERNAME developer
RUN set -ex && \
useradd --create-home --key MAIL_DIR=/dev/null --shell /bin/bash $USERNAME && \
passwd -d $USERNAME
# Set additional environment variables
ENV JAVA_HOME /usr/lib/jvm/java-1.8-openjdk
ENV JDK_HOME /usr/lib/jvm/java-1.8-openjdk
ENV JAVA_EXE /usr/lib/jvm/java-1.8-openjdk/bin/java
There is a better way to do this now with Jetbrains Gateway. Just make sure you have OpenSSH server installed (latest Ubuntu containers have this already installed) in the container that you initially ran with exposed ports, i.e. -p 220:22 (I like 220) and the SSH service running, i.e. service ssh start, after modifying the /etc/ssh/sshd_config to enable root login and password authentication then service ssh restart. Make sure you set a password for the root user, i.e. passwd root, (or go through other steps to setup a new user). Then all you need to do is open Jetbrains Gateway, and SSH to the container with the fields set thus: user=root, host=localhost, and port=220 (or whatever you chose); note, you will also need to specify a project location, which in my use case is a Java application repository root directory -- this means you will need to have Java and Maven or whatever other tools installed in the container at some point, but doesn't affect ability to connect. Assuming you connect with no issues you will see activity whereby Gateway installs an IDE backend inside the container (takes about 10 minutes) and then starts up a IDE client which is a light version of IntelliJ (or whatever other IDE version you selected) that is honestly a bit buggy at time of writing. But it works and has unblocked some of my colleagues stuck with Windows machines and not many options to upgrade to Macs in the current chip shortage environment. Note that any time you restart the container you also need to restart the SSH service unless you script it to automatically start up when the container does.

Found unknown Linux distribution on /dev/sdb2: grub configuration dual boot Arch Linux and NetBSD-7.0

I have Arch Linux on /dev/sdb1 and NetBSD-7.0 on /dev/sdb2.
On Arch Linux when I run sudo grub-mkconfig -o /boot/grub/grub.cfg I get a message like Found unknown Linux distribution on /dev/sdb2 but when I reboot, there is no grub option for that unknown Linux distribution which I know it is NetBSD-7.0.
How can I add NetBSD-7.0 to my grub menu option when rebooting.
There is a similar post, currently looking into it.
UPDATE: I mounted NetBSD partition with sudo mount -t ufs -o ro,ufstype=ufs2 /dev/sdb2 /mnt/ (ufstype=44bsd did not work) and then ran grub-mkconfig -o /boot/grub/grub.cfg but yet the issue persists.
UPDATE: Rebooted and pressed c to get the grub command line. Following commands booted the NetBSD-7.0:
ls
Ran ls to see the correct name of disks and partitions, /dev/sdb2 on Linux was (hd0,gpt2) on Grub. Then ran the following:
insmod ufs2
set root=(hd0,gpt2)
knetbsd /netbsd
boot
And NetBSD-7.0 booted.
To add NetBSD option to Grub menu, modified file /etc/grub/40_custom on Arch Linux like below:
menuentry "NetBSD-7.0"{
insmod ufs2
set root=(hd0,gpt2)
knetbsd /netbsd
}
However, after modifying 40_custom like above, NetBSD option does not appear on Grub menu. I don't know why.
Unless you have a typo, it looks like the 40_custom file is in the wrong directory. it should be located at /etc/grub.d/40_custom, notice the .d.
If your /boot is located on a separate partition, make sure that it is mounted with mount /boot before generating the grub.cfg. Otherwise your new grub.cfg won't be used.
Check which partition grub is loading the configuration from by running echo ${prefix} within the grub command line. It's possible that grub is loading the configuration from a partition that you don't expect.
Verify that netbsd was added to the config with grep -i netbsd /boot/grub/grub.cfg before rebooting to avoid some frustration after generating grub.cfg

qemu emulated ARM machine fails to boot

I compiled the Linux kernel (version 2.6.32) using the Emdebian ARM toolchain. Downloaded the initrd from Aurel's personal FTP server hosted on Debian here.
The ran qemu like so:
qemu-system-arm -M versatilepb -kernel zImage -hda hda.img -initrd initrd_versatile.gz -append "root=/dev/ram" -m 1024
Yet it fails with qemu reporting:
mount: mouting none of /run failed invalid argument.
Keen to hear if someone has something to say about this. As I search for it, could someone also let me know if it is possible to use an off the shelf initrd or is it related to the kernel version being run?
I was able to run the machine by cross compiling busybox, creating a cpio archive image and then using it like so:
qemu-system-arm -M versatilepb -m 128M -kernel zImage -initrd rootfs.img -append "root=/dev/ram rdinit=/bin/sh console=tty1"
Now that Ive got it working Ill investigate what those arguments actually mean.

libvirt and VirtualBox / Getting Started

I'm trying to get started on libvirt with VirtualBox as a virtualization solution. I installed everything and VirtualBox itself is running when using their VBoxHeadless command.
However, libvirt fails to connect to VirtualBox:
# virsh -c vbox:///session
libvir: error : could not connect to vbox:///session
error: failed to connect to the hypervisor
I could not find any hints in the libvirt documentation that point to whether I have to make any domain specific configuration before using virsh.
Does anyone have a hint? Or even better, maybe a tutorial that works through the way of using libvirt, virsh or it's APIs (my later goal) from the ground up.
If you are doing this on Ubuntu, then the problem is their libvirt package is built without VirtualBox support.
You can rebuild the package with support very easily. Something like:
apt-get source -d libvirt
sudo apt-get build-dep libvirt
dpkg-source -x libvirt*dsc
Go into the libvirt directory and edit debian/rules so that instead of --without-vbox it says --with-vbox. You can add an entry to the top of debian/changelog so the package is compiled as a different version (e.g., append ~local1 to the version).
dpkg-buildpackage -us -uc -b -rfakeroot
You'll get new .debs built in the directory above. Use dpkg -i to install the relevant ones (libvirt0, libvirt0-bin, and whatever else you want).
Double-check whether or not you have write access to /var/run/libvirt/libvirt-sock.
The socket file should have permissions similar to:
$ sudo ls -la /var/run/libvirt/libvirt-sock
srwxrwx--- 1 root libvirtd 0 2010-08-24 14:54 /var/run/libvirt/libvirt-sock
I think it could be helpful also to increase the libvirt logging capabilities by running this in your shell:
export LIBVIRT_DEBUG=1
There is Ubuntu PPA for libvirt with VirtualBox support: https://launchpad.net/~cxl/+archive/ubuntu/libvirt