Re: [Qemu-ppc] qemu-ppc crashing on x86

[Cedric Le Goater]

On 02/04/2014 12:08 AM, Cedric Le Goater wrote:
> On 02/03/2014 11:48 PM, Alexander Graf wrote:
>>
>> On 03.02.2014, at 23:31, Cedric Le Goater <address@hidden> wrote:
>>
>>> Hi,
>>>
>>> The "latest" qemu-ppc is crashing when running a ppc guest on x86. I was 
>>> using a 
>>> relatively old version until recently, when Tom Musta's patches were merged 
>>> a few 
>>> days ago. 
>>>
>>> Anyhow, here are some info on the crash. 
>>>
>>> qemu-system-ppc64: /home/legoater/work/linux/qemu-agraf.git/tcg/tcg.c:515: 
>>> tcg_temp_new_internal: Assertion `ts->base_type == type' failed.
>>> Aborted (core dumped)
>>>
>>> and the core stack trace :
>>>
>>> #0  0xb7173424 in __kernel_vsyscall ()
>>> #1  0xb6d73941 in raise () from /lib/i386-linux-gnu/i686/cmov/libc.so.6
>>> #2  0xb6d76d72 in abort () from /lib/i386-linux-gnu/i686/cmov/libc.so.6
>>> #3  0xb6d6cb58 in __assert_fail () from 
>>> /lib/i386-linux-gnu/i686/cmov/libc.so.6
>>> #4  0xb75c4a4a in tcg_temp_new_internal (type=TCG_TYPE_I32, temp_local=0)
>>>    at /home/legoater/work/linux/qemu-agraf.git/tcg/tcg.c:515
>>> #5  0xb75c4c70 in tcg_temp_new_internal_i32 (temp_local=0)
>>>    at /home/legoater/work/linux/qemu-agraf.git/tcg/tcg.c:559
>>> #6  0xb75beb03 in tcg_temp_new_i32 () at 
>>> /home/legoater/work/linux/qemu-agraf.git/tcg/tcg.h:569
>>> #7  0xb75c4efb in tcg_const_i32 (val=25) at 
>>> /home/legoater/work/linux/qemu-agraf.git/tcg/tcg.c:606
>>> #8  0xb75bf0a4 in tcg_gen_shli_i32 (ret=..., arg1=..., arg2=25)
>>>    at /home/legoater/work/linux/qemu-agraf.git/tcg/tcg-op.h:612
>>> #9  0xb75c5517 in tcg_gen_shifti_i64 (ret=..., arg1=..., c=7, right=1, 
>>> arith=0)
>>>    at /home/legoater/work/linux/qemu-agraf.git/tcg/tcg.c:790
>>> #10 0xb7543d21 in tcg_gen_shri_i64 (ret=..., arg1=..., arg2=7)
>>>    at /home/legoater/work/linux/qemu-agraf.git/tcg/tcg-op.h:985
>>> #11 0xb755ff4f in gen_rlwinm (ctx=0x9c7c9e3c)
>>>    at /home/legoater/work/linux/qemu-agraf.git/target-ppc/translate.c:1636
>>> #12 0xb75ba884 in gen_intermediate_code_internal (cpu=0xb964e210, 
>>> tb=0x9d5065b4, search_pc=false)
>>>    at /home/legoater/work/linux/qemu-agraf.git/target-ppc/translate.c:11001
>>> #13 0xb75bac50 in gen_intermediate_code (env=0xb964e2cc, tb=0x9d5065b4)
>>>    at /home/legoater/work/linux/qemu-agraf.git/target-ppc/translate.c:11058
>>> #14 0xb75caec3 in cpu_ppc_gen_code (env=0xb964e2cc, tb=0x9d5065b4, 
>>> gen_code_size_ptr=0x9c7c9f7c)
>>>    at /home/legoater/work/linux/qemu-agraf.git/translate-all.c:159
>>> #15 0xb75cc28b in tb_gen_code (env=0xb964e2cc, pc=19524, cs_base=0, 
>>> flags=0, cflags=0)
>>>    at /home/legoater/work/linux/qemu-agraf.git/translate-all.c:967
>>> #16 0xb7431fa4 in tb_find_slow (env=0xb964e2cc, pc=19524, cs_base=0, 
>>> flags=0)
>>>    at /home/legoater/work/linux/qemu-agraf.git/cpu-exec.c:163
>>> #17 0xb743219d in tb_find_fast (env=0xb964e2cc) at 
>>> /home/legoater/work/linux/qemu-agraf.git/cpu-exec.c:190
>>> #18 0xb74325cf in cpu_ppc_exec (env=0xb964e2cc) at 
>>> /home/legoater/work/linux/qemu-agraf.git/cpu-exec.c:604
>>> #19 0xb7435bb8 in tcg_cpu_exec (env=0xb964e2cc) at 
>>> /home/legoater/work/linux/qemu-agraf.git/cpus.c:1255
>>> #20 0xb7435cfc in tcg_exec_all () at 
>>> /home/legoater/work/linux/qemu-agraf.git/cpus.c:1288
>>> #21 0xb7435061 in qemu_tcg_cpu_thread_fn (arg=0xb964e210) at 
>>> /home/legoater/work/linux/qemu-agraf.git/cpus.c:954
>>> #22 0xb6eb1c39 in start_thread () from 
>>> /lib/i386-linux-gnu/i686/cmov/libpthread.so.0
>>> #23 0xb6e1e78e in clone () from /lib/i386-linux-gnu/i686/cmov/libc.so.6
>>> (gdb) up
>>> #1  0xb6d73941 in raise () from /lib/i386-linux-gnu/i686/cmov/libc.so.6
>>> (gdb) up
>>> #2  0xb6d76d72 in abort () from /lib/i386-linux-gnu/i686/cmov/libc.so.6
>>> (gdb) up
>>> #3  0xb6d6cb58 in __assert_fail () from 
>>> /lib/i386-linux-gnu/i686/cmov/libc.so.6
>>> (gdb) up
>>> #4  0xb75c4a4a in tcg_temp_new_internal (type=TCG_TYPE_I32, temp_local=0)
>>>    at /home/legoater/work/linux/qemu-agraf.git/tcg/tcg.c:515
>>> 515         assert(ts->base_type == type);
>>> (gdb) p type
>>> $1 = TCG_TYPE_I32
>>> (gdb) p *ts
>>> $2 = {base_type = TCG_TYPE_I64, type = TCG_TYPE_I32, val_type = 0, reg = 6, 
>>> val = 0, mem_reg = 4, 
>>>  mem_offset = 128, fixed_reg = 0, mem_coherent = 0, mem_allocated = 0, 
>>> temp_local = 0, temp_allocated = 1, 
>>>  name = 0x0}
>>>
>>>
>>> It might be related to commit 0ec9eabc7f6020418e1f3b3273d1dd701f7f87f9
>>> (tcg: Use bitmaps for free temporaries). I tried a few possible fixes 
>>> but I did not have much success. Any idea ? 
>>
>> You're running on a 32bit host (which is a pretty bad idea when running  
>> qemu-system-ppc64 
>> since it'll split all 64bit registers into two 32bit ones) OS. 
> 
> Yes. I need to reinstall. I have a few 32bit legacy applications ... 
> 
>> There was a bug with TCG there which I fixed a while ago (TCG: Fix 
>> I64-on-32bit-host temporaries).
>>
>> I just rebased my tree against current upstream and checked - the fix is 
>> definitely in now. So 
>> you should be able to get a working system through a more recent checkout. 
>> Except for the VGA 
>> problem discussed earlier on this list of course.
> 
> This is working much better ! 

This is not true. I had to revert commit 
ccfb53ed6360cac0d5f6f7915ca9ae7eed866412 
(target-ppc: fix Authority Mask Register init value) to have a working qemu when
emulation is on. The symptom is the one described in the changelog : the guest 
is 
hanging right after switching from the real to protected mode. That is right 
after
early_setup()

Reverting this patch does not seem to have any impact with kvm, but I did not 
dig
further for the moment.

C.