On Wed, Aug 20, 2025 at 04:23:12PM +0200, Hans-Jrg Hxer wrote:
> On Wed, Aug 20, 2025 at 02:23:45PM +0100, Crystal Kolipe wrote:
> > On Wed, Aug 20, 2025 at 02:24:34PM +0200, Hans-Jrg Hxer wrote:
> > > The diff can be tested with amd64 and i386 ramdisk kernels like this:
> > > 
> > > # vmctl start -c -b i386/bsd.rd myvm
> > > # vmctl start -c -b amd64/bsd.rd myvm
> > > 
> > > Using a BIOS boot image (eg. /etc/firmware/vmm-bios) is not affected by
> > > this change.
> > 
> > On a few of our systems this diff is throwing vm_resetcpu: failed, and the
> > corresponding vms don't start.
> > 
> > Does this change rely on any other recent commits?
> > 
> > If not, I suspect that some of our local changes are breaking it.
> > 
> > We have various production systems deployed with vms that boot directly in to
> > the kernel without using a bios image, including several custom kernel
> > configs, so I would like to test this on them, but unfortunately most of the
> > interesting systems are running a heavily modified 7.7-release rather than
> > -current.
> > 
> 
> First of all:  Thanks for testing!
> 
> This diff does rely on commits more recent than 7.7-release.  It won't
> apply cleanly on 7.7-release sources.  To understand what you are doing:
> You are running a currnet vmd with this patch on a 7.7-release based
> system?

Not exactly, the host systems are running 7.7-release with various local
changes, (unrelated to vmd).  I just updated loadfile_elf.c to HEAD, (one
commit by bluhm@), and then applied your patch.

When I first read the diff, I thought it was a no-op for booting i386 kernels,
so I was surprised that that broke.  Looking more closely, I see that you're
setting bits in CR0 that were not set before.  Reverting that makes i386 vms
boot again on this hacked up 7.7-release system, which is what I would expect.