xen413 vs HVM disk?? (was Re: reliable panic with NetBSD 8.0/xen 4.8.3 and problems upgrading)

[Jeff Rizzo <riz%tastylime.net@localhost>]

OK.  I have solved my original problem (new HVM domU caused dom0 to 
crash when rebooting) by upgrading from Xen 4.8.3 with NetBSD 8.0 dom0 
to Xen 4.11 with NetBSD 9.2 dom0 - I can now reboot my HVM Ubuntu Server 
20.04 domU without crashing the whole dom0. Progress.

However, I originally tried going to Xen 4.13 - and everything worked 
great, EXCEPT the disk for the domU above didn't show up! The other 
domUs (all NetBSD PVM) were fine.

Anyone know what this is about?

Here's the config file for the domU in question:

builder = 'hvm'
memory = 8192
name = "nvr"
vif = ['mac=02:02:02:97:97:45, bridge=bridge0, type=ioemu, model=e1000',
    'mac=02:02:02:97:97:82, bridge=bridge82, type=ioemu, model=e1000']
disk = [ 'phy:/dev/mapper/vg0-nvr,hda,rw',
         #'file:/tmp/NetBSD-7.0-amd64.iso,ioemu:hdc:cdrom,r'
#'file:/home/riz/ubuntu-20.04.2-live-server-amd64.iso,ioemu:hdc:cdrom,r'
]
boot = 'c'
vcpus = 4
serial = 'pty'
sdl=0
vnc = 1
#device_model_version = 'qemu-xen'
acpi = 1


...it seems to work fine under Xen 4.11 .

+j

On 8/23/21 7:34 PM, Jeff Rizzo wrote:
> I tried to send the original report of this problem a couple weeks 
> ago, and a new copy earlier tonight - I suspect I'm hitting a filter?  
> anyway, trying again, but with new information.
>
>
> I just set up an HVM domU on a dom0 running NetBSD 8.0 (and Xen 4.8) - 
> the dom0 has been running stably for a couple of years, but once I 
> started installing this new domU (which is running Ubuntu Server 
> 20.04, if it matters), on four separate occasions (though I believe it 
> did *not* happen once) when I reboot the domU, the dom0 reboots as well.
>
>
> On serial console, I get this:
>
> fatal page fault in supervisor mode
> trap type 6 code 0 rip 0xffffffff80239626 cs 0xe030 rflags 0x10206 cr2 
> 0xffffa0004f910000 ilevel 0x6 rsp 0xffffa0004e49bb88
> curlwp 0xffffa00002f1b2a0 pid 499.1 lowest kstack 0xffffa0004e4982c0
> panic: trap
> cpu0: Begin traceback...
> vpanic() at netbsd:vpanic+0x140
> snprintf() at netbsd:snprintf
> trap() at netbsd:trap+0x953
> --- trap (number 6) ---
> xennetback_evthandler() at netbsd:xennetback_evthandler+0x4e
> Xresume_xenev6() at netbsd:Xresume_xenev6+0x47
> --- interrupt ---
> Xspllower() at netbsd:Xspllower+0xe
> sys_ioctl() at netbsd:sys_ioctl+0x101
> syscall() at netbsd:syscall+0x9c
> --- syscall (number 54) ---
> 75cdeeafedfa:
> cpu0: End traceback...
>
> dumping to dev 18,17 (offset=50151423, size=0): not possible
> rebooting...
> (XEN) Hardware Dom0 shutdown: rebooting machine
> (XEN) Resetting with ACPI MEMORY or I/O RESET_REG.
>
>
> So... I figured, maybe an 8.2 kernel will fix it?  So I tried booting 
> Xen 4.8.3 (which I am currently running) with a new kernel (yes, I 
> remembered to unpack modules!), but it panics before even getting to 
> single-user:
>
> (messages trimmed, available on request)
>
> (XEN) Brought up 4 CPUs
> (XEN) Dom0 has maximum 600 PIRQs
> (XEN) ELF: shdr overflow (off eefae8 > size eef9b0)
> (XEN)
> (XEN) ****************************************
> (XEN) Panic on CPU 0:
> (XEN) Could not set up DOM0 guest OS
> (XEN) ****************************************
> (XEN)
> (XEN) Reboot in five seconds...
>
>
> I also tried a xen 4.11 kernel with the same 8.2 NetBSD, no dice.
>
> Any suggestions?  Meanwhile, I'm back to running 8.0 with xen 4.8.3 
> and avoiding rebooting that domU  :)