psoftware / kvm-endlessfault

Virtual Machine Monitor with keyboard and video text mode emulation. Support for ELF loading and gdb connection for debugging purposes.

README

Build

make

kvm.cpp and every other cpp file in frontend, backend, elf, debug-server and gdbserver folders will be compiled to generate the kvm executable file. Example sources of target/ folder will be compiled but not linked to kvm.

Run

The emulator needs an elf file to execute. The executable runs directly in long paged mode.

./kvm elfpath

Log output goes automatically into console.log file.

You can start the emulator in a new (xterm) console using

./run elfpath

The main console will be used as a log output.

Elf examples can be found in the build/ directory after building with make. There are also some precompiled and more complex examples in esempi-io/ folder

Parameters

./kvm -logfile file # -> to set the log file path

Other parameters can be set into the main folder .ini file.

IO Emulation

Actually there are only a few emulated devices: video card (text-mode only), keyboard and serial ports. The emulation is very basic.

GDB Server

This supervisor includes an almost complete implementation of a gdbstub. You can debug the program running on the VM using a gdb client and all the common commands like step, next, continue, memory commands and many others. The server must be enabled using the config.ini file. It's possible to attach a gdb client to a running supervisor instance using this set of commands:

(gdb) set architecture i386:x86-64
(gdb) file elfpath
(gdb) target remote address:port

You can also use the custom gdb command

(gdb) monitor regs

to get the content of some low level registers (not listed with the standard register command) like CR4, CR3, CR2, CR0 and EFER.

Developers

This project is developed by
Antonio Le Caldare (kvm skeleton code, gdbstub, keyboard emulation, elf execution)
Vincent Della Corte (video card text-mode emulation, code polish, comment review)
Vincenzo Consales (elf loader, bootloader code, custom memory debug server)

as a project for Virtualization university course (prof. @giuseppelettieri).

References

Part of kvm bootloading code (for protected, long and paged mode) is took from:
https://github.com/dpw/kvm-hello-world

The INI reader class code is took from:
https://github.com/benhoyt/inih

Notes

Some variable names, comments and commit messages are written in Italian language due to the purpose of the project. Just open an issue instance if you find unreadable code or comments.