Kevin Wolf <[email protected]> writes:
> Am 12.10.2020 um 13:53 hat Philippe Mathieu-Daudé geschrieben: >> On 10/12/20 1:25 PM, Kevin Wolf wrote: >> > Am 12.10.2020 um 12:47 hat Alex Bennée geschrieben: >> > > >> > > Markus Armbruster <[email protected]> writes: >> > > >> > > > From: Kevin Wolf <[email protected]> >> > > > >> > > > This moves the QMP dispatcher to a coroutine and runs all QMP command >> > > > handlers that declare 'coroutine': true in coroutine context so they >> > > > can avoid blocking the main loop while doing I/O or waiting for other >> > > > events. >> > > >> > > This subtly changes the replay behaviour leading to a hang in: >> > > >> > > 10:55:18 [alex.bennee@hackbox2:~/l/q/b/bisect] (625581c2…)|✚1(+1/-1) >> > > + ./tests/venv/bin/avocado run >> > > tests/acceptance/replay_kernel.py:ReplayKernel.test_arm_virt >> > > Fetching asset from >> > > tests/acceptance/replay_kernel.py:ReplayKernel.test_arm_virt >> > > JOB ID : ec11fd2544f06e6c0d421f16afa757b49f7ed734 >> > > JOB LOG : >> > > /home/alex.bennee/avocado/job-results/job-2020-10-12T11.40-ec11fd2/job.log >> > > (1/1) tests/acceptance/replay_kernel.py:ReplayKernel.test_arm_virt: >> > > ERROR: Could not perform graceful shutdown (26.27 s) >> > > RESULTS : PASS 0 | ERROR 1 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT >> > > 0 | CANCEL 0 >> > > JOB TIME : 27.77 s >> > > >> > > Looking at the log: >> > > >> > > 2020-10-12 11:40:31,426 __init__ L0085 DEBUG| [ 3.887411] >> > > rtc-pl031 9010000.pl031: setting system clock to 2020-10-12 10:40:31 UTC >> > > (1602499231) >> > > 2020-10-12 11:40:31,428 __init__ L0085 DEBUG| [ 3.887431] >> > > sr_init: No PMIC hook to init smartreflex >> > > 2020-10-12 11:40:31,447 __init__ L0085 DEBUG| [ 3.897193] >> > > uart-pl011 9000000.pl011: no DMA platform data >> > > 2020-10-12 11:40:31,460 __init__ L0085 DEBUG| [ 3.897242] >> > > md: Waiting for all devices to be available before autodetect >> > > 2020-10-12 11:40:31,462 __init__ L0085 DEBUG| [ 3.897259] >> > > md: If you don't use raid, use raid=noautodetect >> > > 2020-10-12 11:40:31,475 __init__ L0085 DEBUG| [ 3.897819] >> > > md: Autodetecting RAID arrays. >> > > 2020-10-12 11:40:31,476 __init__ L0085 DEBUG| [ 3.897832] >> > > md: autorun ... >> > > 2020-10-12 11:40:31,477 __init__ L0085 DEBUG| [ 3.897842] >> > > md: ... autorun DONE. >> > > 2020-10-12 11:40:31,483 __init__ L0085 DEBUG| [ 3.897962] >> > > VFS: Cannot open root device "(null)" or unknown-block(0,0): error -6 >> > > 2020-10-12 11:40:31,483 qmp L0245 DEBUG| >>> {'execute': >> > > 'quit'} >> > > 2020-10-12 11:40:31,495 qmp L0145 DEBUG| <<< >> > > {'timestamp': {'seconds': 1602499231, 'microseconds': 493379}, 'event': >> > > 'SHUTDOWN', 'data': {'guest': True, 'reason': 'guest-reset'}} >> > > 2020-10-12 11:40:31,733 machine L0325 WARNI| qemu received >> > > signal 6; command: "./qemu-system-arm -display none -vga none -chardev >> > > socket,id=mon,path=/var/tmp/tmpzls53khe/qemu-8487-monitor.sock -mon >> > > chardev=mon,mode=control -machine virt -chardev >> > > socket,id=console,path=/var/tmp/tmpzls53khe/qemu-8487-console.sock,server,nowait >> > > -serial chardev:console -icount >> > > shift=1,rr=record,rrfile=/var/tmp/avocado_n00stdrf/avocado_job_aw60qdul/1-tests_acceptance_replay_kernel.py_ReplayKernel.test_arm_virt/replay.bin >> > > -kernel >> > > /home/alex.bennee/avocado/data/cache/by_location/62750ce9e069e69e6a7ff04ff54c382ee660b92a/vmlinuz >> > > -append printk.time=1 panic=-1 console=ttyAMA0 -net none -no-reboot" >> > >> > This looks like a crash (SIGABRT) rather than a hang. Do you have a >> > stack trace for the crashed process? >> >> No crash, exit(0): > > Why does the log say "qemu received signal 6" then? > >> VFS: Cannot open root device "(null)" or unknown-block(0,0): error -6 > > Alex has this error in the logs before this commit, so I assume this is > expected. All of the following is then probably expected, too, because > it follows directly from this error: > >> Please append a correct "root=" boot option; here are the available >> partitions: >> Kernel panic - not syncing: VFS: Unable to mount root fs on >> unknown-block(0,0) >> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.18.16-300.fc29.armv7hl #1 >> Hardware name: Generic DT based system >> [<c0313f7c>] (unwind_backtrace) from [<c030dc64>] (show_stack+0x20/0x24) >> [<c030dc64>] (show_stack) from [<c0b50ec4>] (dump_stack+0x88/0xa8) >> [<c0b50ec4>] (dump_stack) from [<c03592f8>] (panic+0xd4/0x26c) >> [<c03592f8>] (panic) from [<c110183c>] (mount_block_root+0x250/0x2ec) >> [<c110183c>] (mount_block_root) from [<c1101950>] (mount_root+0x78/0x90) >> [<c1101950>] (mount_root) from [<c1101ac4>] (prepare_namespace+0x15c/0x19c) >> [<c1101ac4>] (prepare_namespace) from [<c11012e8>] >> (kernel_init_freeable+0x2c0/0x370) >> [<c11012e8>] (kernel_init_freeable) from [<c0b63914>] >> (kernel_init+0x18/0x128) >> [<c0b63914>] (kernel_init) from [<c03010e8>] (ret_from_fork+0x14/0x2c) >> Exception stack(0xc790bfb0 to 0xc790bff8) >> bfa0: 00000000 00000000 00000000 >> 00000000 >> bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 >> 00000000 >> bfe0: 00000000 00000000 00000000 00000000 00000013 00000000 >> >> -> PSCI call >> -> QEMU_PSCI_0_2_FN_SYSTEM_RESET >> -> SHUTDOWN_CAUSE_GUEST_RESET >> -> exit(0) Yes - the test is recording the kernel up until the point it gives up. > Hm... So you're saying that the test sends a 'quit' QMP command, but > before it could be processed, the guest causes QEMU to exit, so the test > will never receive a reply to its request? > > If commit 9ce44e2ce2 changes anything about this, it seems to me that it > would be that more QMP commands are processed during monitor_cleanup() > because it doesn't just delete the dispatcher BH, but waits until it's > not busy any more. > > Looking at this code again, however, the order in monitor_cleanup() is > probably wrong. We should first shut down the dispatcher (which may > still be using Monitor objects) and then destroy the monitors. This > could possibly explain a crash, but probably not wrong results with a > successful shutdown. I suspect this is a race between QEMU shutting down because the guest shut it down and the acceptance test trying to shut things down via QMP. I think the proper fix is either to: - s/panic=-1/panic=0/ in the command line (and probably drop --no-reboot) which would let the acceptance test cleanly shutdown via QMP. Or: - modify the test to declare that qemu will shutdown itself and therefor no "quit" needs to be sent WDYT? -- Alex Bennée
