QEMU VS virt-manager

My most-wanted QEMU feature: https://github.com/qemu/qemu/commit/a2260983c6553

Using `gic-version=3` on macOS you can now use more than 8 cores on ARM chips.

A better solution is just to write a plain ass shell script that tests if various C snippets compile.

https://github.com/oilshell/oil/blob/master/configure

https://github.com/oilshell/oil/blob/master/build/detect-pwe...

Not an unholy mix of m4, shell, and C, all in the same file.

---

These are the same style as a the configure scripts that Fabrice Bellard wrote for tcc and QEMU.

They are plain ass shell scripts, because he actually understands the code he writes.

https://github.com/qemu/qemu/blob/master/configure

https://github.com/TinyCC/tinycc/blob/mob/configure

OCaml’s configure script is also “normal”.

You don’t have to copy and paste thousands of lines of GNU stuff that you don’t understand.

(copy of lobste.rs comment)

Related:

A fast Pascal (Delphi) WebAssembly interpreter:

https://github.com/marat1961/wasm

WASM-4:

https://github.com/aduros/wasm4

Curated list of awesome things regarding WebAssembly (wasm) ecosystem:

https://github.com/mbasso/awesome-wasm

Also, it would be nice if there was a WASM (soft) CPU for QEMU, which (if it existed!) would go here:

https://github.com/qemu/qemu/tree/master/target

> architectural registers are always updated

In tiny code, the guest registers (global TCG variables) are stored in the host's registers until you either call an helper which can access the CPU state or you return (`git grep la_global_sync`). This is the reason why QEMU is not so terribly slow.

But after a check, this also happens when you access the guest memory address space! https://github.com/qemu/qemu/blob/master/include/tcg/tcg-opc... (TCG_OPF_SIDE_EFFECTS is what matters)

But still, in the end, it's the same problem. What QEMU does, can be done in LLVM too. You could probably be more efficient in LLVM by using the exception handling mechanism (invoke and friends) to only serialize back to memory when there's an actual exception, at the cost of higher register pressure. More or less what we do here: https://rev.ng/downloads/bar-2019-paper.pdf

Um, in case you don't know, UTM (based on QEMU) is out for quite a while.

Some of these tools include Oracle VM VirtualBox (that I've used since before the acquisition of Sun Microsystems by Oracle), VMWare Workstation Player, and QEMU, but last year, I found out about Multipass.

For C/C++ projects that use meson as the build system, there is an excellent way to manage dependencies:

https://mesonbuild.com/Wrapdb-projects.html

https://mesonbuild.com/Wrap-dependency-system-manual.html

meson will download and build the libraries automatically and give you a variable which you pass as a regular dependency into the built target:

https://github.com/qemu/qemu/tree/005ad32358f12fe9313a4a0191...

https://github.com/harfbuzz/harfbuzz/tree/main/subprojects

https://github.com/harfbuzz/harfbuzz/blob/37457412b3212463c5...

Or, if you're using proper operating systems, they're managed by the usual package manager, just like everything else.

For all the users of the Linux platform, QEMU is the VM that you should go for. This software comes without any price tag and works as an emulator of various machines with utmost ease and completion; the software uses dynamic translations to emulate hardware peripherals and enhances its overall performance. If you are using QEMU as a virtualizer, then it will function exactly like the host system (provided you have the right set of hardware).

In this tutorial, we set up macOS and Windows virtual machines on UTM, a macOS application that provides a GUI wrapper for QEMU, a powerful open-source emulator and virtualizer. UTM allows you to easily manage and run virtual machines without memorizing complex commands. It also has special handling for macOS, making it simpler to install compared to other virtual machine software.

It's still being updated. I don't see anything on the virt-manager homepage or GitHub that would suggest it is deprecated.

https://virt-manager.org/

https://github.com/virt-manager/virt-manager

It can't do literally everything Qemu/libvirt can do using only the UI, but given that it has escape hatches to directly edit libvirt configurations, and libvirt has escape hatches to directly pass arguments to Qemu, there's very little you can't do with it.

I would love to see a serious comparison (features & performance) between VMWare ESXi, Proxmox VE and let's say a more stock RHEL or Ubuntu. And maybe even include FreeBSD/bhyve.

Because yes, in terms of core functionality it should be in the same ballpark. And in terms of UI, Virtual Machine Manager [0] was not that bad.

[0] https://virt-manager.org/

Shout out to https://virt-manager.org/ - works much better for me, supports running qemu on remote systems via ssh. I used to use this all the time for managing bunches of disparate vm hosts and local vms.

If not, I would just run a CentOS Stream 8 virtual machine using either GNOME Boxes or virt-manager, and set up networking and ssh so you can access the database from the host.

https://virt-manager.org/ <- Recommend this as Front-end

I'd say it is half-baked webmin. You can only use it with NetworkManager, and if you have an even remotely complex network setup for VMs, NetworkManager usually must be turned off, which makes Cockpit practically unusable. virt-manager [1] is way more powerful for those who like managing VMs with GUI.

[1] https://virt-manager.org/

$ apt build-dep libvirt $ git clone https://github.com/libvirt/libvirt.git Cloning into 'libvirt'... $ cd libvirt $ meson setup build $ ninja -C build $ ninja -C build install $ which virsh /usr/local/bin/virsh $ which libvirtd /usr/local/sbin/libvirtd $ apt install libgtk-3-dev libpulse-dev libgbm-dev libspice-protocol-dev \ libspice-server-dev libusb-1.0-0-dev libepoxy-dev libfdt-dev $ git clone -b v5.1.0 http://git.qemu.org/qemu.git $ cd qemu-v5.1.0 $ git submodule add -f https://git.kernel.org/pub/scm/utils/dtc/dtc.git dtc $ ./configure --disable-werror --target-list=arm-softmmu \ --enable-opengl --enable-gtk --enable-kvm --enable-guest-agent \ --enable-spice --audio-drv-list="oss pa" --enable-libusb \ --enable-trace-backend=simple --enable-debug $ make $ make install $ git clone https://github.com/virt-manager/virt-manager.git $ apt install gobject-introspection libosinfo-1.0-0 libosinfo-1.0-dev \ gir1.2-libosinfo-1.0 libvirt-glib-1.0-dev $ cd virt-manager $ ./setup.py configure --prefix=/usr/local $ sudo ./setup.py install $ sudo usermod -a -G libvirt root $ sudo usermod -a -G libvirtd root $ sudo usermod -a -G libvirt-qemu libvirt-qemu $ sudo usermod -a -G libvirt marietto $ sudo adduser libvirt-qemu $ sudo groupadd --system libvirt $ sudo groupadd --system libvirt-qemu $ sudo newgrp libvirt-qemu $ newgrp libvirt $ /usr/local/sbin# libvirtd & [1] 2875 $ /usr/local/sbin# virtqemud & info : libvirt version: 9.7.0 info : hostname: chromarietto error : virPidFileAcquirePathFull:409 Failed to acquire pid file : /var/local/run/libvirt/qemu/driver.pid Resource temporarily unavailable error : virStateInitialize:672 : Initialization of QEMU state driver failed Failed to acquire pid file : /var/local/run/libvirt/qemu/driver.pid Resource temporarily unavailable error : daemonRunStateInit:617 : Driver state initialization failed $ /usr/local/sbin# ps ax | grep libvirt 2875 pts/0 Sl 0:00 libvirtd $ /usr/local/sbin# ps ax | grep virtqemu nothing If I do the opposite way : $ /usr/local/sbin# virtqemud & $ /usr/local/sbin# ps ax | grep virtqemu 3041 pts/0 Sl 0:00 virtqemud $ /usr/local/sbin# libvirtd & info : libvirt version: 9.7.0 info : hostname: chromarietto error : virPidFileAcquirePathFull:409 Failed to acquire pid file : /var/local/run/libvirt/qemu/driver.pid Resource temporarily unavailable virStateInitialize:672 : Initialization of QEMU state driver failed Failed to acquire pid file : /var/local/run/libvirt/qemu/driver.pid Resource temporarily unavailable daemon RunStateInit:617 : Driver state initialization failed $ /usr/local/sbin# ps ax | grep virtqemu 3041 pts/0 Sl 0:00 virtqemud $ /usr/local/sbin# ps ax | grep libvirt nothing

I want to test Hyprland with NixOS in a VM using Virt-Manager (https://virt-manager.org/) on Arch Linux host before installing it on my machine.