Re: port-xen/53965: XEN DomU fails to poweroff in new HEAD kernels

[Greg Oster <oster%netbsd.org@localhost>]

The following reply was made to PR port-xen/53965; it has been noted by GNATS.

From: Greg Oster <oster%netbsd.org@localhost>
To: Manuel Bouyer <bouyer%antioche.eu.org@localhost>
Cc: gnats-bugs%NetBSD.org@localhost, port-xen-maintainer%netbsd.org@localhost,
 gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Subject: Re: port-xen/53965: XEN DomU fails to poweroff in new HEAD kernels
Date: Sat, 9 Feb 2019 11:37:31 -0600

 On Sat, 9 Feb 2019 17:36:37 +0100
 Manuel Bouyer <bouyer%antioche.eu.org@localhost> wrote:
 
 > On Sat, Feb 09, 2019 at 02:20:00PM +0000, kre%munnari.OZ.AU@localhost wrote:
 > > >Description:  
 > > 	Sometime in the recent past, my XEN DomU kernels lost the
 > > 	ability to power off the (virtual) machine (and cause the
 > > 	XEN hypervisor to let go.)
 > > 
 > > 	It was working with 8.99.32 (of some vintage, the last
 > > kernel update I did was probably a couple of weeks ago) and failed
 > > 	with the first update to a 8.99.34 kernel I attempted
 > > (though the first time I just assumed I left the "-p" off the
 > > shutdown command by accident, and didn't think any more of it.)
 > > 
 > > 	Note I am running a very old (by current standards) Xen
 > > kernel and Dom0 system, however they are (and have been) working
 > > well, and as (ignoring my uses for testing up to date current
 > > kernels, and particularly, shells) this is a production system I'm
 > > in no great hurry to update it.
 > > 
 > > 	pkg_info on the Dom0 tells me:
 > > 
 > > 	onyx$ pkg_info | grep xen
 > > 	xentools42-4.2.5nb15 Userland Tools for Xen 4.2.x
 > > 	xenkernel42-4.2.2   Xen 4.2.x Kernel
 > > 
 > > 	(with some other noise that just happened to match.)  
 > 
 > I'm not seeing this with the Daily ATF runs:
 > http://www-soc.lip6.fr/~bouyer/NetBSD-tests/xen/HEAD/
 > but the server is running Xen 4.11
 > 
 > I wonder if it could be related to the recent Xen API version bump in
 > our source tree
 
 I'm seeing this with an 8.0_STABLE DOM0... I instrumented cpu_reset()
 with printfs before/after the call to HYPERVISOR_reboot():
 
 #ifdef XEN
         printf("calling HYPERVISOR_reboot()\n");
 	HYPERVISOR_reboot();
         printf("done HYPERVISOR_reboot()\n");
 #else
 
 and both are printed:
 [ 119.1643554] xbd1: detached
 [ 119.3838479] rebooting...
 [ 119.3838479] calling x86_disable_intr()
 [ 119.3838479] calling HYPERVISOR_reboot()
 [ 119.3838479] done HYPERVISOR_reboot()
 
 I note that if I do a 'shutdown -h' I can enter 5 "+"'s to get to ddb,
 but once it hits the "done HYPERVISOR_reboot()" I can no longer get to
 ddb on the DOMU.
 
 Is HYPERVISOR_reboot() expected to return?  The next line in
 cpu_reset() is effectively: 
 
  for (;;);
 
 so I'm thinking not...
 
 Later...
 
 Greg Oster