Re: NetBSD v70/amd64 and XEN v45 troubles

[Tobias Nygren <tnn%NetBSD.org@localhost>]

On Fri, 16 Oct 2015 12:23:27 +0200
Ib-Michael Martinsen <i.m.martinsen%gmail.com@localhost> wrote:

> uvm_fault(0xffffffff80cacf60, 0x0, 2) -> e
> fatal page fault in supervisor mode
> trap type 6 code 2 rip ffffffff80554752 cs e030 rflags 10246 cr2 ilevel 8 rsp ffffffff81001f00
> curlwp 0xffffffff80c606a0 pid 0.1 lowest kstack 0xffffffff810012c0
> kernel: page fault trap, code=0

The uvm_fault comes from the system dropping into the kernel debugger
or the root device prompt, attempting to read keyboard input from pckbc
which for some reason does not work with xen dom0 pre multi user,
generating a fault within ddb. To capture the actual error message,
build a kernel with this config:

include "arch/amd64/conf/XEN3_DOM0"
no pckbc* at acpi?
no pckbc0 at isa?
no agp* at pchb? # XXX i810 bug?
no options DDB_COMMANDONENTER
options DDB_COMMANDONENTER="bt"
options DEBUG
options DIAGNOSTIC
no config netbsd
config netbsd root on wd0a type ffs # adjust as appropriate

-Tobias