On LLVM clang compiled Linux kernel host, VirtualBox hard-freezes the host when launching a Virtual Machine.

[dreieck]

Ahoj,

I am on Linux, kernel version 6.8.8, Virtual Box version 7.0.16 (EDIT: also with version 7.0.18 as tested later, see follow-up comment).

Virtual Box host module compiled via DKMS for all installed kernels.

When I want to run any VortualBox virtual machine with a Linux kernel compiled using the LLVM clang compiler, the system freezes immediately, only a hard reset helps (also the Linux' SysRq does not work anymore). A dmesg -w running in parallel in another window does not show anything (before system freeze).

When I instead use a kernel compiled with GCC (otherwise same kernel configuration), VirtualBox virtual machine runs as expected.

Note that using LLVM clang is a supported compiler for Linux.

Compiler versions:

• clang --version:

  clang version 17.0.6
  Target: x86_64-pc-linux-gnu
  Thread model: posix
  InstalledDir: /usr/bin
  

• ld.lld --version: LLD 17.0.6 (compatible with GNU linkers)
• gcc --version | head -n1: gcc (GCC) 13.2.1 20240417

I attach the following files for background information:

• Kernel config of the GCC compiled kernel: config_6.8.8-gcc.gz (compressed),
• Kernel config of the LLVM clang compiled kernel: config_6.8.8-clang.gz (compressed),
• diff between those two kernel configurations: config-diff_6.8.8-gcc-clang.txt,
• dmesg output after booting the system with the GCC compiled kernel: dmesg_6.8.8-gcc.log,
• dmesg output after booting the system with the LLVM clang compiled kernel: dmesg_6.8.8-clang.log,
• hwinfo output (captured with the LLVM clang compiled kernel): hwinfo_6.8.8-clang.log.zstd (compressed),
• inxi -F output (captured with the LLVM clang compiled kernel): inxi_6.8.8-clang.log,
• lspci -vvv output (captured with the LLVM clang compiled kernel): lspci_6.8.8-clang.log,
• The VirtualBox-logfile of sucessfully running a Virtual Machine from the host booted with the GCC compiled kernel: VirtualBox-machine-log_CD boot-2024-05-04-19-58-26_6.8.8-gcc.log. *(All occurances of <censored> in those logs are censorings of my username.)*

Regards!

[dreieck]

Linux kernel configuration of the GCC compiled kernel

[dreieck]

Linux kernel config of the clang compiled kernel

[dreieck]

diff between the two kernel configs (GCC and clang compiled kernel)

[dreieck]

dmesg output after booting the system with the GCC compiled kernel

[dreieck]

dmesg output after booting the system with the clang compiled kernel

[dreieck]

hwinfo output (captured with the LLVM clang compiled kernel)

[dreieck]

inxi -F output (captured with the LLVM clang compiled kernel)

[dreieck]

lspci -vvv output (captured with the LLVM clang compiled kernel)

[dreieck]

The VirtualBox-logfile of sucessfully running a Virtual Machine from the host booted with the GCC compiled kernel

[dreieck]

Also happens with VirtualBox version 7.0.18, and with "Enable 3D Acceleration" switched off and with USB 1.1 instead of USB 3.0.