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

[Alexey Kardashevskiy]

On 02/05/2014 12:33 AM, Cedric Le Goater wrote:
> 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.


It does break KVM. The whole patch came up because KVM got broken once I
enabled actual set/put of SPR registers.



-- 
Alexey