device: 0.586 virtual: 0.586 semantic: 0.548 performance: 0.472 PID: 0.462 architecture: 0.442 mistranslation: 0.390 register: 0.387 hypervisor: 0.349 graphic: 0.346 vnc: 0.335 ppc: 0.333 arm: 0.304 permissions: 0.292 boot: 0.281 files: 0.280 risc-v: 0.272 socket: 0.265 x86: 0.258 KVM: 0.247 network: 0.244 TCG: 0.241 user-level: 0.233 VMM: 0.230 debug: 0.204 kernel: 0.202 i386: 0.184 assembly: 0.122 peripherals: 0.120 [Feature Request] Battery Status / Virtual Battery When using virtualization on notebooks heavily then virtual machines do not realize that they're running on a notebook device causing high power consumption because they're not switching into a optimized "laptop mode". This leads to the circumstance that they are trying to do things like defragmentation / virtus scan / etc. while the host is still running on batteries. So it would be great if QEMU / KVM would have support for emulating "Virtual Batteries" to guests causing them to enable power-saving options like disabling specific services / devices / file operations automatically by OS. Optionally a great feature would be to set virtual battery's status manually. For example: Current charge rate / charging / discharging / ... I'm trying to add virtual battery to QEMU. More specifically, if the HOST is running on battery power [laptop] I want to pass this knowledge to GUEST. I have looked at ACPI folder within QEMU source code, however was unable to find the specific place where I can add this functionality. Can someone provide me with general roadmap of what should I do and where I should start? I suspect that changing the QEMU source code will not be enough and I will also have to implement a driver for the GUEST. I've started working on this issue and have some progress. Fedora 31 guest is already able to see a battery device but its state currently hardcoded. I think i will finish this in a few weeks. Has there been any progress? I'm using KVM for ubuntu 20.04 and would love to have this feature. The implementation could be similar to the temperature sensor interface proposed here: https://