Hi,

Just tried to upgrade my netbsd domU kernel to newer (because of 
occasional crashes) and got another crash at startup

Domain0 is netbsd and base netbsd is upgraded to 3.1:

NetBSD xenbsd.prolosoft.com 4.99.3 NetBSD 4.99.3 (XEN3_DOM0) #0: Thu Oct 
26 05:44:33 UTC 2006  
builds@pb:/home/builds/ab/HEAD/i386/200610250000Z-obj/home/builds/ab/HEAD/src/sys/arch/i386/compile/XEN3_DOM0 
i386

I dont know how to debug this further, but here is the output that I got:

NetBSD 4.99.7 (XEN3_DOMU) #30: Mon Jan  8 18:00:33 CET 2007
        
zafer@mia2:/home/zafer/netbsd/usr/objdir/sys/arch/i386/compile/XEN3_DOMU
total memory = 128 MB
avail memory = 121 MB
mainbus0 (root)
hypervisor0 at mainbus0
vcpu0 at hypervisor0: (uniprocessor)
vcpu0: AMD Athlon XP 2200+ (686-class), 1800.06 MHz, id 0x680
vcpu0: features c3c3fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR>
vcpu0: features c3c3fbff<PGE,MCA,CMOV,PAT,PSE36,MMXX,MMX>
vcpu0: features c3c3fbff<FXSR,SSE,3DNOW2,3DNOW>
vcpu0: I-cache 64 KB 64B/line 2-way, D-cache 64 KB 64B/line 2-way
vcpu0: L2 cache 256 KB 64B/line 16-way
vcpu0: ITLB 16 4 KB entries fully associative, 8 4 MB entries fully 
associative
vcpu0: DTLB 32 4 KB entries fully associative, 8 4 MB entries 4-way
vcpu0: 8 page colors
debug virtual interrupt using event channel 3
xenbus0 at hypervisor0: Xen Virtual Bus Interface
xencons0 at hypervisor0: Xen Virtual Console Driver
xencons0: console major 143, unit 0
xencons0: using event channel 2
npx0 at hypervisor0: using exception 16
Xen clock: using event channel 4
crypto: assign driver 0, flags 2
crypto: driver 0 registers alg 1 flags 0 maxoplen 0
crypto: driver 0 registers alg 2 flags 0 maxoplen 0
crypto: driver 0 registers alg 3 flags 0 maxoplen 0
crypto: driver 0 registers alg 4 flags 0 maxoplen 0
crypto: driver 0 registers alg 5 flags 0 maxoplen 0
crypto: driver 0 registers alg 17 flags 0 maxoplen 0
crypto: driver 0 registers alg 6 flags 0 maxoplen 0
crypto: driver 0 registers alg 7 flags 0 maxoplen 0
crypto: driver 0 registers alg 15 flags 0 maxoplen 0
crypto: driver 0 registers alg 8 flags 0 maxoplen 0
crypto: driver 0 registers alg 16 flags 0 maxoplen 0
crypto: driver 0 registers alg 9 flags 0 maxoplen 0
crypto: driver 0 registers alg 10 flags 0 maxoplen 0
crypto: driver 0 registers alg 13 flags 0 maxoplen 0
crypto: driver 0 registers alg 14 flags 0 maxoplen 0
crypto: driver 0 registers alg 11 flags 0 maxoplen 0
crypto: driver 0 registers alg 18 flags 0 maxoplen 0
raidattach: Asked for 8 units
Kernelized RAIDframe activated
xenbus0: using event channel 1
xbd0 at xenbus0 id 0: Xen Virtual Block Device Interface
xbd0: using event channel 5
xbd1 at xenbus0 id 1: Xen Virtual Block Device Interface
xbd1: using event channel 6
xbd2 at xenbus0 id 2: Xen Virtual Block Device Interface
xbd2: using event channel 7
xennet0 at xenbus0 id 0: Xen Virtual Network Interface
xennet0: MAC address 00:16:3e:00:00:11
xennet0: using event channel 8
kernel: supervisor trap page fault, code=0
Stopped at      netbsd:bufq_get+0x15:   call    *0x4(%eax)

db> show reg
ds          0x11
es          0x11
fs          0x31
gs          0x11
edi         0xc043b990  dkintf_esdi
esi         0xc086e03c
ebp         0xca1e6f8c
ebx         0xc086e000
edx         0x1
ecx         0xc086e000
eax         0
eip         0xc02eb3e5  bufq_get+0x15
cs          0x9
eflags      0x10286
esp         0xca1e6f84
ss          0x11
netbsd:bufq_get+0x15:   call    *0x4(%eax)

db> bt
bufq_get(0,ca1e6fb8,c0102135,c086e000,0) at netbsd:bufq_get+0x15
dk_start(c043b990,c086e03c,c038dcbc,10,0) at netbsd:dk_start+0x2e
xbd_handler(c086e000,c0507b50,0,1,2) at netbsd:xbd_handler+0x2d6
DDB lost frame for netbsd:Xresume_xenev4+0x3e, trying 0xca1e6ff4
Xresume_xenev4() at netbsd:Xresume_xenev4+0x3e
--- interrupt ---
0:
db>