hypervisor_debugger

Bare-metal x86-64 kernel for bringing up an AMD SVM (SVM) hypervisor from scratch. Boots via Multiboot + GRUB, enters long mode, then works toward VMRUN / VMEXIT handling.

Status

Done:

• 32-bit boot → long mode, GDT + 64-bit TSS
• IDT + exception handlers
• Physical bump allocator from the Multiboot memory map

Next (see NOTES.md):

• SVM detection / enable, VMCB + host-save area, minimal guest, VMRUN, VMEXIT handling, NPT

Requirements

• AMD CPU with SVM + KVM enabled (Makefile runs QEMU with -cpu host -enable-kvm)
• Linux — tested on:
  • AMD Ryzen 5 2600
  • Linux phanteks-desktop 7.0.0-28-generic #28~24.04.1-Ubuntu SMP PREEMPT_DYNAMIC x86_64 GNU/Linux
• Packages:

  sudo apt install grub-pc-bin qemu-system-x86 nasm gdb git cmake ninja-build mtools

Toolchain

Builds a -fbounds-safety Clang into ~/toolchain/x86_64-bounds-safety:

chmod +x os/scripts/get_and_build_llvm.sh
./os/scripts/get_and_build_llvm.sh

Build / Run / Debug

All commands run from os/:

make          # build .output/hypervisor_debugger.iso
make run      # QEMU with KVM, serial to stdio (-nographic)
make debug    # QEMU with -s -S (waits for GDB on :1234)
make clean

Attach GDB in another terminal:

./os/scripts/start_gdb.sh    # or start_gdb.fish

QEMU exposes its monitor on telnet 127.0.0.1:1235.

Layout

os/
  Makefile          # kernel -> ISO, run/debug targets
  linker.ld         # kernel loaded at 1 MiB
  scripts/          # LLVM toolchain build, GDB helpers
  x64/src/boot/     # Multiboot, serial, page tables, long-mode entry
  x64/src/cpu/      # TSS, SVM (stub)
  x64/src/irq/      # IDT + ISRs
  x64/src/mm/       # Multiboot parsing, bump allocator
  x64/src/util/     # printf, panic