Re: [PATCH v2] x86/vm86: Remove deprecated VM86 support

[Brian Gerst]

On Wed, May 27, 2026 at 3:33 AM Ashwin Gundarapu
<linuxuser509@xxxxxxxxxxx> wrote:
>
> VM86 support allows 16-bit DOS programs to run in virtual 8086 mode
> on 32-bit x86 kernels. This feature has been deprecated and the Kconfig
> help text itself states that any recent software works without it.
>
> Remove the vm86 subsystem entirely including the main driver source,
> Kconfig options, header file, and all references in thread_info,
> processor, and processor-flags headers.
>
> Signed-off-by: Ashwin Gundarapu <linuxuser509@xxxxxxxxxxx>
> ---
> v2: Also remove arch/x86/include/asm/vm86.h and arch/x86/kernel/vm86_32.c
>     as pointed out by Christophe JAILLET.
> ---
>  arch/x86/Kconfig                       |  30 -
>  arch/x86/include/asm/processor-flags.h |   6 +-
>  arch/x86/include/asm/processor.h       |   5 +-
>  arch/x86/include/asm/thread_info.h     |   6 +-
>  arch/x86/include/asm/vm86.h            |  91 ---
>  arch/x86/kernel/Makefile               |   1 -
>  arch/x86/kernel/process.c              |   5 -
>  arch/x86/kernel/vm86_32.c              | 831 -------------------------
>  8 files changed, 3 insertions(+), 972 deletions(-)
>  delete mode 100644 arch/x86/include/asm/vm86.h
>  delete mode 100644 arch/x86/kernel/vm86_32.c

An additional cleanup is to remove the code to switch
MSR_IA32_SYSENTER_CS, which is only needed when entering VM86 mode.