Re: freedos under qemu failure with nvmm

[Vitaly Shevtsov <shev.vt1984%gmail.com@localhost>]

Hello, Ramiro.

I don't know the reason. It looks like FreeDOS uses something that
other OSes don't use causing QEMU to crash.
But for me it happens only when FreeDOS is being installed. Once it's
installed I never face this issue. I'm pretty sure it's a bug in NVMM.
Maybe it's worth trying dosbox instead?

On Thu, Nov 13, 2025 at 11:29 PM Ramiro Aceves <ea1abz%gmail.com@localhost> wrote:
>
>
>
> El 13/11/25 a las 19:19, Vitaly Shevtsov escribió:
> > Hello. I faced the same issue with qemu, nvmm and freedos. Tried to
> > debug with no luck. I found a workaround - run qemu with no
> > acceleration, install freedos, then run it with acceleration turned on.
> > This issue only happens when is it is being installed.
> >
> > чт, 13 нояб. 2025 г., 23:15 Ramiro Aceves <ea1abz%gmail.com@localhost
> > <mailto:ea1abz%gmail.com@localhost>>:
> >
> >
> >     Hello,
> >
> >     I tried to install FreeDOS under Qemu in NetBSD 10.1 using nvmm
> >     acceleration driver.
> >
> >
> >     I get an error like this when almost installed on the virtual disk:
> >
> >     qemu-system-i386: NVMM: Unexpected VM exit code 0xffffffffffffffff
> >     [hw=0x9]
> >     qemu-system-i386: NVMM: Failed to execute a VCPU.
> >     [1]   Abort trap (core dumped) qemu-system-i386 -m 64 -accel nvmm -
> >     smp 1
> >     -dri...
> >
> >
> >     I removed nvmm acceleration and I was able to end the installation
> >     without acceleration but it was painly slow.
> >
> >     I have been able to virtualize a full Debian GNU/Linux system using
> >     nvmm, no problems at all. Why nvmm fails with FreeDOS?
> >
> >     Thanks so much.
> >     Ramiro.
> >
>
> Hello Vitaly,
>
> I have started the virtual FreeDOS with nvmm, it starts fast and well.
>
>
> c:\dir (file listing works fine)
>
> But when I start an editor:
>
>
> c:\EDIT
>
> qemu-system-i386: NVMM: Failed to execute a VCPU.
> [1]   Abort trap (core dumped) qemu-system-i386 -m 64 -accel nvmm -smp 1
> -dri...
> netbsd-nuc$
>
>
> Regards.
> Ramiro.
>
>
> >
> >
>