Re: [Qemu-devel] Bug AioContext polling is not implemented on Windows with qemu-system-ppc.exe

[Paolo Bonzini <pbonzini@redhat.com>]

On 21/03/2018 17:31, Howard Spoelstra wrote:
> On Wed, Mar 21, 2018 at 5:25 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>> On 21/03/2018 17:23, Howard Spoelstra wrote:
>>> warning: FTH: (10844): *** Fault tolerant heap shim applied to current
>>> process. This is usually due to previous crashes. ***
>>> [New Thread 10844.0x1224]
>>> [New Thread 10844.0x2a30]
>>> [New Thread 10844.0x2594]
>>> [New Thread 10844.0x32a8]
>>>
>>> Thread 1 hit Breakpoint 1, aio_context_set_poll_params (ctx=0xc14a9b0,
>>> max_ns=32768, grow=0, shrink=0, errp=0x362f968)
>>>     at util/aio-win32.c:413
>>> 413     in util/aio-win32.c
>>> (gdb) s
>>> error_setg_internal (errp=0x362f968, src=0xe166e0 <__func__.58569+32>
>>> "util/aio-win32.c", line=413,
>>>     func=0xe16740 <__func__.59050> "aio_context_set_poll_params",
>>>     fmt=0xe16708 <__func__.58569+72> "AioContext polling is not
>>> implemented on Windows") at util/error.c:91
>>> 91      util/error.c: No such file or directory.
>>> (gdb) s
>>> 94      in util/error.c
>>
>> Great!  Now do "bt".
>>
>> Paolo
> 
> (gdb) bt full
> #0  aio_context_set_poll_params (ctx=0xc16a9b0, max_ns=32768, grow=0,
> shrink=0, errp=0x362f968) at util/aio-win32.c:413
>         __func__ = "aio_context_set_poll_params"
> #1  0x00000000005f7563 in iothread_complete (obj=0xc16a290,
> errp=0x362fa50) at iothread.c:143
>         local_error = 0x0
>         iothread = 0xc16a290
>         __func__ = "iothread_complete"
>         name = 0xde8be9 <container_info+265> "user-creatable"
>         thread_name = 0x400000000 <error: Cannot access memory at
> address 0x400000000>
> #2  0x0000000000831716 in user_creatable_complete (obj=0xc16a290,
> errp=0x362fa50) at qom/object_interfaces.c:24
>         ucc = 0x7fec650
>         uc = 0xc16a290
>         __func__ = "user_creatable_complete"
> #3  0x000000000082cde1 in object_new_with_propv (typename=0xc4b14b
> <__func__.56984+43> "iothread", parent=0xc169e50,
>     id=0xc12494 <__emutls_t.iothread_locked+19167> "mon_iothread",
> errp=0x14ae260 <error_abort>, vargs=0x362fb20 "")
>     at qom/object.c:555
>         obj = 0xc16a290
>         klass = 0x7fec020
>         local_err = 0x0
>         __func__ = "object_new_with_propv"
> #4  0x000000000082cc67 in object_new_with_props (typename=0xc4b14b
> <__func__.56984+43> "iothread", parent=0xc169e50,
>     id=0xc12494 <__emutls_t.iothread_locked+19167> "mon_iothread",
> errp=0x14ae260 <error_abort>) at qom/object.c:516
>         vargs = 0x362fb20 ""
>         obj = 0xd34e26fdf887
> #5  0x00000000005f7ced in iothread_create (id=0xc12494
> <__emutls_t.iothread_locked+19167> "mon_iothread",
> ---Type <return> to continue, or q <return> to quit---
>     errp=0x14ae260 <error_abort>) at iothread.c:352
>         obj = 0x45bef7 <sortcmdlist+137>
>         __func__ = "iothread_create"
> #6  0x000000000045bf53 in monitor_iothread_init () at
> /home/hsp/src/qemu-master/monitor.c:4436
> No locals.
> #7  0x000000000045bfcb in monitor_init_globals () at
> /home/hsp/src/qemu-master/monitor.c:4464
> No locals.
> #8  0x00000000006064d5 in qemu_main (argc=28, argv=0x5679620,
> envp=0x0) at vl.c:4545
>         i = 1
>         snapshot = 0
>         linux_boot = 0
>         initrd_filename = 0x0
>         kernel_filename = 0x0
>         kernel_cmdline = 0xc4e286 <runstate_transitions_def+6918> ""
>         boot_order = 0x57052c0 "d"
>         boot_once = 0x0
>         ds = 0x7ff94aced24c
>         opts = 0x5705100
>         machine_opts = 0x5705560
>         icount_opts = 0x0
>         accel_opts = 0x0
>         olist = 0xa6e000 <qemu_machine_opts>
>         optind = 28
>         optarg = 0x56793dd "file=c:\\Mac-disks\\9.2.img,format=raw,media=disk"
> ---Type <return> to continue, or q <return> to quit---
>         loadvm = 0x0
>         machine_class = 0x7fb28f0
>         cpu_model = 0x0
>         vga_model = 0x0
>         qtest_chrdev = 0x0
>         qtest_log = 0x0
>         pid_file = 0x0
>         incoming = 0x0
>         userconfig = true
>         nographic = false
>         display_remote = 0
>         log_mask = 0x0
>         log_file = 0x0
>         trace_file = 0x0
>         maxram_size = 268435456
>         ram_slots = 0
>         vmstate_dump_file = 0x0
>         main_loop_err = 0x0
>         err = 0x0
>         list_data_dirs = false
>         dir = 0x8026a80 "c:\\qemu-master"
>         dirs = 0x8026980
>         bdo_queue = {sqh_first = 0x0, sqh_last = 0x362fda0}
>         __func__ = "qemu_main"
> ---Type <return> to continue, or q <return> to quit---
> #9  0x00000000005fc507 in SDL_main (argc=28, argv=0x5679620) at vl.c:43
> No locals.
> #10 0x000000000096e4e8 in main_getcmdline ()
> No symbol table info available.
> #11 0x00000000004013f7 in __tmainCRTStartup () at ../crt/crtexe.c:334
>         lock_free = <optimized out>
>         fiberid = <optimized out>
>         nested = <optimized out>
>         lpszCommandLine = <optimized out>
>         StartupInfo = {cb = 104, lpReserved = 0x5787680 "", lpDesktop
> = 0x57881f0 "Winsta0\\Default",
>           lpTitle = 0x578c000 "c:\\qemu-master\\qemu-system-ppc.exe",
> dwX = 0, dwY = 0, dwXSize = 0, dwYSize = 0,
>           dwXCountChars = 0, dwYCountChars = 0, dwFillAttribute = 0,
> dwFlags = 0, wShowWindow = 0, cbReserved2 = 0,
>           lpReserved2 = 0x0, hStdInput = 0xffffffffffffffff,
> hStdOutput = 0xffffffffffffffff,
>           hStdError = 0xffffffffffffffff}
>         inDoubleQuote = <optimized out>
> #12 0x00000000004014fb in WinMainCRTStartup () at ../crt/crtexe.c:184
>         ret = 255
> (gdb)
> 
> Finally ;-)

Great, thanks.  Peter, can you look at it?  I think we should:

1) make aio_context_set_poll_params succeed in aio-win32.c if
poll_max_ns is zero

2) set IOTHREAD_POLL_MAX_NS_DEFAULT to zero on windows.

Paolo