RE: Hang loading initrd since last Friday.

[Michael Kelley (LINUX)]

From: Ben Greear <greearb@xxxxxxxxxxxxxxx> Sent: Thursday, May 4, 2023 4:46 PM
> 
> On 5/4/23 10:59, Michael Kelley (LINUX) wrote:
> > From: Ben Greear <greearb@xxxxxxxxxxxxxxx> Sent: Thursday, May 4, 2023 10:23 AM
> >>
> >> On 5/3/23 16:49, Ben Greear wrote:
> >>> On 5/2/23 21:46, Linux regression tracking (Thorsten Leemhuis) wrote:
> >>>> On 03.05.23 04:31, Bagas Sanjaya wrote:
> >>>>> On Tue, May 02, 2023 at 02:03:33PM -0700, Ben Greear wrote:
> >>>>>>
> >>>>>> Pulling today's upstream 6.3+ tree, my system now hangs loading initrd.
> >>>>
> >>>> Just to understand this properly: you mean after the boot loader said it
> >>>> loaded the initramfs, not when the kernel starts using it?
> >>>
> >>> I am bisecting...it appears to be .config related.  If I skip enabling things
> >>> during bisect, then I do not see the problem.  But I copied my original buggy .config
> >>> into an otherwise good kernel commit, and now it fails.  I'm manually bisecting
> >>> the .config settings....
> >>
> >> I had enabled this option:  CONFIG_HYPERV_VTL_MODE
> >>
> >> And that makes it not boot.  Not sure that is expected or not, but
> >> I will simply un-select it and continue on, as I do not actually need that feature.
> >>
> >
> > What you observed is expected when CONFIG_HYPERV_VTL_MODE is selected,
> > which is why it defaults to N.  The comment for that option in the Kconfig file says:
> >
> > 	  Select this option to build a Linux kernel to run at a VTL other than
> > 	  the normal VTL0, which currently is only VTL2.  This option
> > 	  initializes the x86 platform for VTL2, and adds the ability to boot
> > 	  secondary CPUs directly into 64-bit context as required for VTLs other
> > 	  than 0.  A kernel built with this option must run at VTL2, and will
> > 	  not run as a normal guest.
> 
> I didn't read it close enough, but that is my fault.
> 

No problem. :-)   Just FYI, in the future if you are come across issues
specifically related to running Linux as a guest on Hyper-V, feel free
to copy the linux-hyperv@xxxxxxxxxxxxxxx mailing list.  That may
elicit faster help from someone with Hyper-V expertise and potentially
save you some trouble.

Michael