Re: KVM guest crashes

[Alexander Graf <agraf@suse.de>]

Alexander Graf wrote:
> Alexander Graf wrote:
>
> [...]
>   
>> Also after two days of permanent stress testing I also got the Intel
>> machine w/ current git down:
>>
>> + sudo -u contain1 env -i /usr/local/bin/qemu-system-x86_64 -localtime
>> -kernel virtio-kernel -initrd virtio-initrd -nographic -append 'quiet
>> clocksource=acpi_pm cifsuser=contain1 cifspass=contain1
>> root=cifs://contain1:contain1@172.16.1.1/contain1
>> realroot=//172.16.1.1/users/contain1
>> ip=172.16.1.2:172.16.1.1::255.255.255.0::eth0:none console=ttyS0
>> dhcp=off builder=1' -net nic,model=virtio,macaddr=52:54:00:12:34:1 -net
>> tap,ifname=tap1,script=/bin/true -m 2000 -nographic -smp 8 /dev/null
>> qemu: loading initrd (0x1daf359 bytes) at 0x000000007b240000
>> Stuck ??
>>
>> No backtrace here though. That's all I got from the serial console.
>>   
>>     
>
> + sudo -u contain1 env -i /usr/local/bin/qemu-system-x86_64 -localtime
> -kernel virtio-kernel -initrd virtio-initrd -nographic -append 'quiet
> clocksource=acpi_pm cifsuser=contain1 cifspass=contain1
> root=cifs://contain1:contain1@172.16.1.1/contain1
> realroot=//172.16.1.1/users/contain1
> ip=172.16.1.2:172.16.1.1::255.255.255.0::eth0:none console=ttyS0
> dhcp=off builder=1' -net nic,model=virtio,macaddr=52:54:00:12:34:1 -net
> tap,ifname=tap1,script=/bin/true -m 2000 -nographic -smp 8 /dev/null
> qemu: loading initrd (0x1daf359 bytes) at 0x000000007b240000
> Stuck ??
>
> (qemu) info cpus
> * CPU #0: pc=0xffffffff80221f1d thread_id=15211
>   CPU #1: pc=0xffffffff80221f1d thread_id=15212
>   CPU #2: pc=0xffffffff80221f1d thread_id=15213
>   CPU #3: pc=0xffffffff80221f1d thread_id=15214
>   CPU #4: pc=0xffffffff8049f7d0 thread_id=15215
>   CPU #5: pc=0xffffffff80221f1d thread_id=15216
>   CPU #6: pc=0xffffffff80221f1d thread_id=15217
>   CPU #7: pc=0x000000000009f02c thread_id=15218
>
> (qemu) cpu 7
> (qemu) info registers
> EAX=00000c06 EBX=000005b8 ECX=00000000 EDX=00000000
> ESI=00000000 EDI=00000000 EBP=00000000 ESP=00000000
> EIP=0000002c EFL=00033002 [-------] CPL=3 II=0 A20=1 SMM=0 HLT=0
> ES =0000 00000000 0000ffff 0000f300
> CS =9f00 0009f000 0000ffff 0000f300
> SS =0000 00000000 0000ffff 0000f300
> DS =0000 00000000 0000ffff 0000f300
> FS =0000 00000000 0000ffff 0000f300
> GS =0000 00000000 0000ffff 0000f300
> LDT=0000 00000000 0000ffff 00008200
> TR =0000 fffbd000 00002088 00008b00
> GDT=     00000000 0000ffff
> IDT=     00000000 0000ffff
> CR0=60000010 CR2=00000000 CR3=00000000 CR4=00000000
> DR0=00000000 DR1=00000000 DR2=00000000 DR3=00000000
> DR6=ffff0ff0 DR7=00000400
> FCW=037f FSW=0000 [ST=0] FTW=00 MXCSR=00000000
> FPR0=0000000000000000 0000 FPR1=0000000000000000 0000
> FPR2=0000000000000000 0000 FPR3=0000000000000000 0000
> FPR4=0000000000000000 0000 FPR5=0000000000000000 0000
> FPR6=0000000000000000 0000 FPR7=0000000000000000 0000
> XMM00=00000000000000000000000000000000
> XMM01=00000000000000000000000000000000
> XMM02=00000000000000000000000000000000
> XMM03=00000000000000000000000000000000
> XMM04=00000000000000000000000000000000
> XMM05=00000000000000000000000000000000
> XMM06=00000000000000000000000000000000
> XMM07=00000000000000000000000000000000
>
> Is that guest really seriously in BIOS code? After booting Linux?
>
> (qemu) x /2i $pc-1
> 0x000000000009f02b:  hlt   
> 0x000000000009f02c:  jmp    0x9f02b
>
> Where is this? Looks like panic code to me.
>   
0x000000000009f000:  cli   
0x000000000009f001:  xor    %ax,%ax
0x000000000009f003:  mov    %ax,%ds
0x000000000009f005:  mov    $0x510,%ebx
0x000000000009f00b:  addr32 mov (%ebx),%ecx
0x000000000009f00f:  test   %ecx,%ecx
0x000000000009f012:  je     0x9f026
0x000000000009f014:  addr32 mov 0x4(%ebx),%eax
0x000000000009f019:  addr32 mov 0x8(%ebx),%edx
0x000000000009f01e:  wrmsr 
0x000000000009f020:  add    $0xc,%ebx
0x000000000009f024:  jmp    0x9f00b
0x000000000009f026:  lock incw 1856
0x000000000009f02b:  hlt   
0x000000000009f02c:  jmp    0x9f02b

Looks a lot like this:

smp_ap_boot_code_start:
  cli
  xor %ax, %ax
  mov %ax, %ds

  mov $SMP_MSR_ADDR, %ebx
11:
  mov 0(%ebx), %ecx
  test %ecx, %ecx
  jz 12f
  mov 4(%ebx), %eax
  mov 8(%ebx), %edx
  wrmsr
  add $12, %ebx
  jmp 11b
12:

  lock incw smp_cpus
1:
  hlt
  jmp 1b


But that code shouldn't run after Linux booted, right? And without at
least a "Power Off" message I'd expect Linux to still be up.
The only thing the host's dmesg was saying is this:

Ignoring delivery mode 3 (repeated often)

Alex