Re: Subject: Re: port-xen/45975: panic: HYPERVISOR_mmu_update failed, ret: -22 on -current MP domU (amd64)

[Greg Oster <oster%cs.usask.ca@localhost>]

I just saw this panic with today's -current.  Relevant(?) bits look
like:

...
pmap_kenter_pa: mapping already present
evtchn_do_event: handler 0xffffffff80121b77 didn't lower ipl 8 7
evtchn_do_event: handler 0xffffffff80121b77 didn't lower ipl 8 7
xpq_flush_queue: 1 entries (0 successful)
0x000000017e476de0: 0x0000000190e00007
panic: HYPERVISOR_mmu_update failed, ret: -22

fatal breakpoint trap in supervisor mode
trap type 1 code 0 rip ffffffff80134575 cs e030 rflags 246 cr2
7f7ff78002b4 cpl 6 rsp ffffa0005f9ff710 Stopped in pid 19481.1 (sh) at
netbsd:breakpoint+0x5:  leave breakpoint() at netbsd:breakpoint+0x5
vpanic() at netbsd:vpanic+0x1f2
printf_nolog() at netbsd:printf_nolog
xpq_queue_machphys_update() at netbsd:xpq_queue_machphys_update
pmap_enter_ma() at netbsd:pmap_enter_ma+0xb74
pmap_enter() at netbsd:pmap_enter+0x35
uvm_fault_internal() at netbsd:uvm_fault_internal+0xf17
trap() at netbsd:trap+0x5f5
--- trap (number 1600061548) ---
65736961720034:
ds          ffea
es          f750
fs          100
gs          e180
rdi         0
rsi         d
rbp         ffffa0005f9ff710
rbx         104
rdx         0
rcx         8
rax         1
r8          ffffa00004559000
r9          1
r10         0
r11         ffffa0000c761380
r12         ffffffff804b7350    copyright+0x40090
r13         ffffa0005f9ff750
r14         ffffffea
r15         2
rip         ffffffff80134575    breakpoint+0x5
cs          e030
rflags      246
rsp         ffffa0005f9ff710
ss          e02b
netbsd:breakpoint+0x5:  leave
db{2}> 
db{2}> 

relevant bits of 'xm dmesg' looks like:

(XEN) domain.c:509:d9 Attempt to change CR4 flags 00002620 -> 00000620
(XEN) domain.c:509:d9 Attempt to change CR4 flags 00002620 -> 00000620
(XEN) domain.c:509:d9 Attempt to change CR4 flags 00002620 -> 00000620
(XEN) mm.c:2012:d9 Bad type (saw 00000000e8000001 != exp
0000000020000000) for mfn 190e00 (pfn 59a5b) 
(XEN) mm.c:745:d9 Attempt to create linear p.t. with write perms

If you need more info, just let me know... (this is a test vm, so can
be killed at will/on demand..)

Later...

Greg Oster