Re: [PULL 21/50] block/block-backend.c: assertions for block-backend

["Philippe Mathieu-Daudé" <philippe.mathieu.daude@gmail.com>]

On 16/3/22 15:46, Emanuele Giuseppe Esposito wrote:
> Am 16/03/2022 um 13:53 schrieb Philippe Mathieu-Daudé:
>> On 16/3/22 13:44, Philippe Mathieu-Daudé wrote:
>>> Hi,
>>>
>>> On 4/3/22 17:46, Kevin Wolf wrote:
>>>> From: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>>>>
>>>> All the global state (GS) API functions will check that
>>>> qemu_in_main_thread() returns true. If not, it means
>>>> that the safety of BQL cannot be guaranteed, and
>>>> they need to be moved to I/O.
>>>
>>> I'm getting this crash:
>>>
>>> $ qemu-system-i386
>>> Assertion failed: (qemu_in_main_thread()), function blk_all_next, file
>>> block-backend.c, line 552.
>>> Abort trap: 6
>>>
>>> Assertion failed: (qemu_in_main_thread()), function blk_all_next, file
>>> block-backend.c, line 552.
>>> qemu-system-i386 was compiled with optimization - stepping may behave
>>> oddly; variables may not be available.
>>> Process 76914 stopped
>>> * thread #1, queue = 'com.apple.main-thread', stop reason = hit
>>> program assert
>>>       frame #4: 0x000000010057c2d4 qemu-system-i386`blk_all_next.cold.1
>>> at block-backend.c:552:5 [opt]
>>>      549    */
>>>      550   BlockBackend *blk_all_next(BlockBackend *blk)
>>>      551   {
>>> -> 552       GLOBAL_STATE_CODE();
>>>      553       return blk ? QTAILQ_NEXT(blk, link)
>>>      554                  : QTAILQ_FIRST(&block_backends);
>>>      555   }
>>> Target 1: (qemu-system-i386) stopped.
>>
>> Forgot to paste the backtrace:
>>
>> (lldb) bt
>> * thread #1, queue = 'com.apple.main-thread', stop reason = hit program
>> assert
>>      frame #0: 0x00000001908c99b8 libsystem_kernel.dylib`__pthread_kill + 8
>>      frame #1: 0x00000001908fceb0 libsystem_pthread.dylib`pthread_kill + 288
>>      frame #2: 0x000000019083a314 libsystem_c.dylib`abort + 164
>>      frame #3: 0x000000019083972c libsystem_c.dylib`__assert_rtn + 300
>>    * frame #4: 0x000000010057c2d4 qemu-system-i386`blk_all_next.cold.1 at
>> block-backend.c:552:5 [opt]
>>      frame #5: 0x00000001003c00b4
>> qemu-system-i386`blk_all_next(blk=<unavailable>) at
>> block-backend.c:552:5 [opt]
>>      frame #6: 0x00000001003d8f04
>> qemu-system-i386`qmp_query_block(errp=0x0000000000000000) at
>> qapi.c:591:16 [opt]
>>      frame #7: 0x000000010003ab0c qemu-system-i386`main [inlined]
>> addRemovableDevicesMenuItems at cocoa.m:1756:21 [opt]
>>      frame #8: 0x000000010003ab04
>> qemu-system-i386`main(argc=<unavailable>, argv=<unavailable>) at
>> cocoa.m:1980:5 [opt]
>>      frame #9: 0x00000001012690f4 dyld`start + 520
> 
> I think Paolo and Peter talked about this a couple of days ago on #qemu,
> and have already found a solution if I remember correctly.
> 
> Maybe it's worth to check with them first.

Maybe this discussion?

https://lore.kernel.org/qemu-devel/20220307151004.578069-1-pbonzini@redhat.com/

> 
> Emanuele
>>
>>> Bisected to this patch:
>>>
>>> 0439c5a4623d674efa0c72abd62ca6e98bb7cf87 is the first bad commit
>>>
>>>> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>>>> Message-Id: <20220303151616.325444-9-eesposit@redhat.com>
>>>> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
>>>> ---
>>>>    block/block-backend.c  | 78 ++++++++++++++++++++++++++++++++++++++++++
>>>>    softmmu/qdev-monitor.c |  2 ++
>>>>    2 files changed, 80 insertions(+)
>>
>