Bug 2033626
| Summary: | Qemu core dump when start guest with nbd node or do block jobs to nbd node | |||
|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 9 | Reporter: | aihua liang <aliang> | |
| Component: | qemu-kvm | Assignee: | Hanna Czenczek <hreitz> | |
| qemu-kvm sub component: | NBD | QA Contact: | aihua liang <aliang> | |
| Status: | CLOSED ERRATA | Docs Contact: | ||
| Severity: | high | |||
| Priority: | urgent | CC: | coli, hreitz, jinzhao, juzhang, kkiwi, mrezanin, timao, virt-maint | |
| Version: | 9.0 | Keywords: | Regression, Triaged | |
| Target Milestone: | rc | |||
| Target Release: | --- | |||
| Hardware: | Unspecified | |||
| OS: | Unspecified | |||
| Whiteboard: | ||||
| Fixed In Version: | qemu-kvm-6.2.0-9.el9 | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | ||
| Clone Of: | ||||
| : | 2035185 (view as bug list) | Environment: | ||
| Last Closed: | 2022-05-17 12:25:11 UTC | Type: | Bug | |
| Regression: | --- | Mount Type: | --- | |
| Documentation: | --- | CRM: | ||
| Verified Versions: | Category: | --- | ||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | ||
| Cloudforms Team: | --- | Target Upstream Version: | ||
| Embargoed: | ||||
| Bug Depends On: | ||||
| Bug Blocks: | 1990835, 2035185 | |||
Eric, can you take this? I've classified it as high-priority as it's a crash in apparently a customer-exposed path, but let's discuss if you disagree. Aihua Liang, can you identify if this is a new testcase, or a regression? In case of the latter, set the regression keyword and identify the last working qemu-kvm version? Thanks (In reply to Klaus Heinrich Kiwi from comment #2) > Eric, can you take this? I've classified it as high-priority as it's a crash > in apparently a customer-exposed path, but let's discuss if you disagree. > > Aihua Liang, can you identify if this is a new testcase, or a regression? In > case of the latter, set the regression keyword and identify the last working > qemu-kvm version? > > Thanks Hi, Klaus It's not a new case and its a regression bug. emu-kvm-6.1.0-8.el9 don't hit it. BR, Aliang Won't hit this issue when iothread not set. I believe this is the bug I described in BZ 1990835 comment 7, and which I’ve sent an RFC for (currently working on writing tests for a proper v1): https://lists.nongnu.org/archive/html/qemu-block/2022-01/msg00765.html If you prefer, Eric, I could take this bug. (I was about to create a new one for this issue anyway, and the duplicate detector pointed me towards this one, which is how I found it.) (In reply to Hanna Reitz from comment #5) > I believe this is the bug I described in BZ 1990835 comment 7, and which > I’ve sent an RFC for (currently working on writing tests for a proper v1): > https://lists.nongnu.org/archive/html/qemu-block/2022-01/msg00765.html > > If you prefer, Eric, I could take this bug. (I was about to create a new > one for this issue anyway, and the duplicate detector pointed me towards > this one, which is how I found it.) Hanna, may I take you on your offer? If you have a scratch build that QE can test, please let us know. Thanks! As long as AArch64 isn’t needed (which seems kind of slow today), I can offer this: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=42850336 The x86-64 RPMs are here: http://download.eng.bos.redhat.com/brewroot/work/tasks/428/42850428/ (Sorry, I don’t have a repo yet, because the overall build won’t finish because of AArch64) Could you test whether those fix the crash, Aliang? Thanks! Test with qemu-kvm-6.2.0-7.el9.hreitz202202071714 by auto, don't hit this issue any more. (1/3) Host_RHEL.m9.u0.qcow2.virtio_scsi.up.virtio_net.Guest.RHEL.9.0.0.x86_64.io-github-autotest-qemu.blockdev_stream_remote_server_down.q35: PASS (144.42 s) (2/3) Host_RHEL.m9.u0.qcow2.virtio_scsi.up.virtio_net.Guest.RHEL.9.0.0.x86_64.io-github-autotest-qemu.blockdev_mirror_remote_server_down.q35: PASS (122.59 s) (3/3) Host_RHEL.m9.u0.qcow2.virtio_scsi.up.virtio_net.Guest.RHEL.9.0.0.x86_64.io-github-autotest-qemu.blockdev_commit_firewall.q35: PASS (321.08 s) Awesome, thanks! This fix has been merged upstream, and I’ve sent a backport for 8.6 (see BZ 2035185). I’d love to send a backport for this BZ, too, but can’t, because the Brew build server seems to have some subscription problems. If they persist, I suppose I’ll just send a backport without a Brew build. Hanna QE bot(pre verify): Set 'Verified:Tested,SanityOnly' as gating/tier1 test pass. Test with qemu-kvm-6.2.0-9.el9, not hit this issue any more. (1/3) Host_RHEL.m9.u0.qcow2.virtio_scsi.up.virtio_net.Guest.RHEL.9.0.0.x86_64.io-github-autotest-qemu.blockdev_stream_remote_server_down.q35: PASS (143.82 s) (2/3) Host_RHEL.m9.u0.qcow2.virtio_scsi.up.virtio_net.Guest.RHEL.9.0.0.x86_64.io-github-autotest-qemu.blockdev_mirror_remote_server_down.q35: PASS (119.67 s) (3/3) Host_RHEL.m9.u0.qcow2.virtio_scsi.up.virtio_net.Guest.RHEL.9.0.0.x86_64.io-github-autotest-qemu.blockdev_commit_firewall.q35: PASS (321.33 s) As comment 12 and comment 16, set bug's status to "VERIFIED". Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (new packages: qemu-kvm), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2022:2307 |
Description of problem: Qemu core dump when block jobs on nbd node were blocked by firewall or server down Version-Release number of selected component (if applicable): kernel version:5.14.0-30.el9.x86_64 qemu-kvm version:qemu-kvm-6.2.0-1.el9 How reproducible: 100% by auto Steps to Reproduce: 1.Create data disk image. #qemu-img create -f qcow2 /root/avocado/data/avocado-vt/data.qcow2 2G 2.Expose data image #/usr/bin/qemu-nbd -f qcow2 -t -p 10810 --fork --pid-file /tmp/avocado_0e1jqoko/data_nbd_server-20211217-075948-p12l.pid /root/avocado/data/avocado-vt/data.qcow2 3.Start guest with the exposed data disk: /usr/libexec/qemu-kvm \ -S \ -name 'avocado-vt-vm1' \ -sandbox on \ -machine q35,memory-backend=mem-machine_mem \ -device pcie-root-port,id=pcie-root-port-0,multifunction=on,bus=pcie.0,addr=0x1,chassis=1 \ -device pcie-pci-bridge,id=pcie-pci-bridge-0,addr=0x0,bus=pcie-root-port-0 \ -nodefaults \ -device VGA,bus=pcie.0,addr=0x2 \ -m 30720 \ -object memory-backend-ram,size=30720M,id=mem-machine_mem \ -smp 10,maxcpus=10,cores=5,threads=1,dies=1,sockets=2 \ -cpu 'Cascadelake-Server-noTSX',+kvm_pv_unhalt \ -chardev socket,wait=off,path=/tmp/avocado_0e1jqoko/monitor-qmpmonitor1-20211217-075949-ZwO9C7pE,server=on,id=qmp_id_qmpmonitor1 \ -mon chardev=qmp_id_qmpmonitor1,mode=control \ -chardev socket,wait=off,path=/tmp/avocado_0e1jqoko/monitor-catch_monitor-20211217-075949-ZwO9C7pE,server=on,id=qmp_id_catch_monitor \ -mon chardev=qmp_id_catch_monitor,mode=control \ -device pvpanic,ioport=0x505,id=id9Na7Yp \ -chardev socket,wait=off,path=/tmp/avocado_0e1jqoko/serial-serial0-20211217-075949-ZwO9C7pE,server=on,id=chardev_serial0 \ -device isa-serial,id=serial0,chardev=chardev_serial0 \ -chardev socket,id=seabioslog_id_20211217-075949-ZwO9C7pE,path=/tmp/avocado_0e1jqoko/seabios-20211217-075949-ZwO9C7pE,server=on,wait=off \ -device isa-debugcon,chardev=seabioslog_id_20211217-075949-ZwO9C7pE,iobase=0x402 \ -device pcie-root-port,id=pcie-root-port-1,port=0x1,addr=0x1.0x1,bus=pcie.0,chassis=2 \ -device qemu-xhci,id=usb1,bus=pcie-root-port-1,addr=0x0 \ -device usb-tablet,id=usb-tablet1,bus=usb1.0,port=1 \ -object iothread,id=iothread0 \ -device pcie-root-port,id=pcie-root-port-2,port=0x2,addr=0x1.0x2,bus=pcie.0,chassis=3 \ -device virtio-scsi-pci,id=virtio_scsi_pci0,bus=pcie-root-port-2,addr=0x0,iothread=iothread0 \ -blockdev node-name=file_image1,driver=file,auto-read-only=on,discard=unmap,aio=threads,filename=/home/kvm_autotest_root/images/rhel900-64-virtio-scsi.qcow2,cache.direct=on,cache.no-flush=off \ -blockdev node-name=drive_image1,driver=qcow2,read-only=off,cache.direct=on,cache.no-flush=off,file=file_image1 \ -device scsi-hd,id=image1,drive=drive_image1,write-cache=on \ -blockdev node-name=nbd_nbddata,driver=nbd,auto-read-only=on,discard=unmap,server.type=inet,server.host=dell-per440-09.lab.eng.pek2.redhat.com,server.port=10810,reconnect-delay=30,cache.direct=on,cache.no-flush=off \ -blockdev node-name=drive_nbddata,driver=raw,read-only=off,cache.direct=on,cache.no-flush=off,file=nbd_nbddata \ -device scsi-hd,id=nbddata,drive=drive_nbddata,write-cache=on \ -device pcie-root-port,id=pcie-root-port-3,port=0x3,addr=0x1.0x3,bus=pcie.0,chassis=4 \ -device virtio-net-pci,mac=9a:ed:fc:56:77:68,id=idY9yr3Q,netdev=id1qEUjK,bus=pcie-root-port-3,addr=0x0 \ -netdev tap,id=id1qEUjK,vhost=on,vhostfd=22,fd=19 \ -vnc :0 \ -rtc base=utc,clock=host,driftfix=slew \ -boot menu=off,order=cdn,once=c,strict=off \ -enable-kvm \ -device pcie-root-port,id=pcie_extra_root_port_0,multifunction=on,bus=pcie.0,addr=0x3,chassis=5 4. Continue vm {'execute': 'cont', 'id': 'CE1lLVef'} Actual results: After step4, qemu core dump with info: [qemu output] qemu-kvm: ../io/channel.c:484: void qio_channel_restart_read(void *): Assertion `qemu_get_current_aio_context() == qemu_coroutine_get_aio_context(co)' failed. [qemu output] /tmp/aexpect_SwITdppJ/aexpect-y1zy2kcy.sh: line 1: 236656 Aborted (core dumped) MALLOC_PERTURB_=1 /usr/libexec/qemu-kvm -S -name 'avocado-vt-vm1' -sandbox on -machine q35,memory-backend=mem-machine_mem -device pcie-root-port,id=pcie-root-port-0,multifunction=on,bus=pcie.0,addr=0x1,chassis=1 -device pcie-pci-bridge,id=pcie-pci-bridge-0,addr=0x0,bus=pcie-root-port-0 ... Detailed core dump info: coredumpctl debug 236656 PID: 236656 (qemu-kvm) UID: 0 (root) GID: 0 (root) Signal: 6 (ABRT) Timestamp: Fri 2021-12-17 08:00:02 EST (8min ago) Command Line: /usr/libexec/qemu-kvm -S -name avocado-vt-vm1 -sandbox on -machine q35,memory-backend=mem-machine_mem -device pcie-root-port,id=pcie-root-port-0,multifunction=on,bus=pcie.0,addr=0x1,chassis=1 -device pcie-pci-bridge,id=pcie-pci-bridge-0,addr=0x0,bus=pcie-root-port-0 -nodefaults -device VGA,bus=pcie.0,addr=0x2 -m 30720 -object memory-backend-ram,size=30720M,id=mem-machine_mem -smp 10,maxcpus=10,cores=5,threads=1,dies=1,sockets=2 -cpu Cascadelake-Server-noTSX,+kvm_pv_unhalt -chardev socket,wait=off,path=/tmp/avocado_0e1jqoko/monitor-qmpmonitor1-20211217-075949-ZwO9C7pE,server=on,id=qmp_id_qmpmonitor1 -mon chardev=qmp_id_qmpmonitor1,mode=control -chardev socket,wait=off,path=/tmp/avocado_0e1jqoko/monitor-catch_monitor-20211217-075949-ZwO9C7pE,server=on,id=qmp_id_catch_monitor -mon chardev=qmp_id_catch_monitor,mode=control -device pvpanic,ioport=0x505,id=id9Na7Yp -chardev socket,wait=off,path=/tmp/avocado_0e1jqoko/serial-serial0-20211217-075949-ZwO9C7pE,server=on,id=chardev_serial0 -device isa-serial,id=serial0,chardev=chardev_serial0 -chardev socket,id=seabioslog_id_20211217-075949-ZwO9C7pE,path=/tmp/avocado_0e1jqoko/seabios-20211217-075949-ZwO9C7pE,server=on,wait=off -device isa-debugcon,chardev=seabioslog_id_20211217-075949-ZwO9C7pE,iobase=0x402 -device pcie-root-port,id=pcie-root-port-1,port=0x1,addr=0x1.0x1,bus=pcie.0,chassis=2 -device qemu-xhci,id=usb1,bus=pcie-root-port-1,addr=0x0 -device usb-tablet,id=usb-tablet1,bus=usb1.0,port=1 -object iothread,id=iothread0 -device pcie-root-port,id=pcie-root-port-2,port=0x2,addr=0x1.0x2,bus=pcie.0,chassis=3 -device virtio-scsi-pci,id=virtio_scsi_pci0,bus=pcie-root-port-2,addr=0x0,iothread=iothread0 -blockdev node-name=file_image1,driver=file,auto-read-only=on,discard=unmap,aio=threads,filename=/home/kvm_autotest_root/images/rhel900-64-virtio-scsi.qcow2,cache.direct=on,cache.no-flush=off -blockdev node-name=drive_image1,driver=qcow2,read-only=off,cache.direct=on,cache.no-flush=off,file=file_image1 -device scsi-hd,id=image1,drive=drive_image1,write-cache=on -blockdev node-name=nbd_nbddata,driver=nbd,auto-read-only=on,discard=unmap,server.type=inet,server.host=dell-per440-09.lab.eng.pek2.redhat.com,server.port=10810,reconnect-delay=30,cache.direct=on,cache.no-flush=off -blockdev node-name=drive_nbddata,driver=raw,read-only=off,cache.direct=on,cache.no-flush=off,file=nbd_nbddata -device scsi-hd,id=nbddata,drive=drive_nbddata,write-cache=on -device pcie-root-port,id=pcie-root-port-3,port=0x3,addr=0x1.0x3,bus=pcie.0,chassis=4 -device virtio-net-pci,mac=9a:ed:fc:56:77:68,id=idY9yr3Q,netdev=id1qEUjK,bus=pcie-root-port-3,addr=0x0 -netdev tap,id=id1qEUjK,vhost=on,vhostfd=22,fd=19 -vnc :0 -rtc base=utc,clock=host,driftfix=slew -boot menu=off,order=cdn,once=c,strict=off -enable-kvm -device pcie-root-port,id=pcie_extra_root_port_0,multifunction=on,bus=pcie.0,addr=0x3,chassis=5 Executable: /usr/libexec/qemu-kvm Control Group: /user.slice/user-0.slice/session-1.scope Unit: session-1.scope Slice: user-0.slice Session: 1 Owner UID: 0 (root) Boot ID: 0107346256b84e8ebd9076ae0ca431c0 Machine ID: 1437cd218cca45cbb2059307f6958ac6 Hostname: dell-per440-09.lab.eng.pek2.redhat.com Storage: /var/lib/systemd/coredump/core.qemu-kvm.0.0107346256b84e8ebd9076ae0ca431c0.236656.1639746002000000.zst (present) Disk Size: 123.9M Message: Process 236656 (qemu-kvm) of user 0 dumped core. Found module linux-vdso.so.1 with build-id: 0417c877078abdfaf5ca0d3d449ce6699e5a520c Found module libpcre2-8.so.0 with build-id: a5dafbac0243bdc2e3b5ab9a07d61d4b32f86927 Found module liblzma.so.5 with build-id: 66b7fca8b63a61d19c5ded440ee6a8bf05dcafa5 Found module libzstd.so.1 with build-id: 415c738420cd82e182b99fc4c6e6821098e80ce4 Found module libselinux.so.1 with build-id: c1d23d40bcf1fae271256fcbe90a46ff6dbcce20 Found module libkmod.so.2 with build-id: 722d3027106c561018756766be8bed5215ed0f31 Found module libuuid.so.1 with build-id: da656ae81596c151559892375d730bd35f76048c Found module libudev.so.1 with build-id: 7c275efc762b4b5a63016164ffd5a53962effbb1 Found module libcrypto.so.3 with build-id: e3a618644eec4fb65c7cd059c42592a686191f72 Found module libkeyutils.so.1 with build-id: 83c6539bd0d3140678ba836b8baa1b215efa2632 Found module libkrb5support.so.0 with build-id: 22e9f06a5b088d401df9153948492077b4e198af Found module libffi.so.8 with build-id: 48e3675db4765a2e42729140922e11a10016f7ab Found module libpcre.so.1 with build-id: cffb947bcc416dca3cd249cdb0a1c6f614549c30 Found module libnl-route-3.so.200 with build-id: 2f297144194e194e379c1c31dcd245220764a488 Found module libnl-3.so.200 with build-id: 5690fe17968270ad4ee00fdafe15cf0a4db9c7ed Found module libdaxctl.so.1 with build-id: c46dc4ef727b75a311e76e41940451a90b9f1080 Found module libndctl.so.6 with build-id: 8c52e205e3982b331bb9683f1a35d53bb1c11c50 Found module libresolv.so.2 with build-id: eaebc6c6a15dcc8af04ea904eb33aeb5557fcafd Found module libcom_err.so.2 with build-id: deb039f83bae82e65be49dd97ac3d900a053e265 Found module libk5crypto.so.3 with build-id: eca094d4bc539db337447b773462de7b592e785b Found module libkrb5.so.3 with build-id: a3fec09569ad99121e79e2d73b0d446169965d26 Found module libgssapi_krb5.so.2 with build-id: a2daa1c10270547f24b82fcb0034e84853d35344 Found module libcrypt.so.2 with build-id: 6ce4e5eb200e61d07398af52f8bcb316cf8466e0 Found module libgmp.so.10 with build-id: 754b87178e725c166a68353f043ba7638e0723e1 Found module libhogweed.so.6 with build-id: 21c32760f1f50b9d69b43e966b93fb3de8baa076 Found module libnettle.so.8 with build-id: 3eda844d5a5df2443a281158b0d7ca6e81483b59 Found module libtasn1.so.6 with build-id: 3d3a2f6f0d4a70919496afe25e329abd189b7882 Found module libunistring.so.2 with build-id: 15e34cdfafa3547f9c700489b842ceb86f6fb73e Found module libidn2.so.0 with build-id: 958c50fc94ecb196b24f3619762e7ec3f28a5b40 Found module libp11-kit.so.0 with build-id: b03163bf5b98313c7347e7270627a6b2dcd35060 Found module libstdc++.so.6 with build-id: 66b742a0a51ccd8a67fdf59a31663b0cd28dfcf2 Found module ld-linux-x86-64.so.2 with build-id: 2b7f1f415256e40ab15e5808c73eb7acf3c73ea3 Found module libc.so.6 with build-id: 723a5d3072f3b79f3716880303439e11f7661fc5 Found module libgcc_s.so.1 with build-id: a1a28a65f942690a11041922ba11c16f716565e2 Found module libm.so.6 with build-id: c58412f6a7fffa4068614708cdb5b15f2ba49c0a Found module libaio.so.1 with build-id: 9b75d21282f8e17ddfa06aff78dae4f8dcce4106 Found module libgmodule-2.0.so.0 with build-id: 952459b04fb217bc3e4a17b902759cf66c89a95d Found module libglib-2.0.so.0 with build-id: 0006a4eed3e835c7d7812e36e5d720c1a6eb8689 Found module libslirp.so.0 with build-id: fa9d492d6d050c6f5cb906a3f087a8a63e4201e2 Found module libibverbs.so.1 with build-id: 3e19d7349fe9ea4c79debeb8716df7000ab13159 Found module librdmacm.so.1 with build-id: 4f6798f3f4164a4aa4d75d8a890c760e2835c495 Found module libnuma.so.1 with build-id: a0c23354fdb39f51ec9e31aeae27a9f8ee034500 Found module libfdt.so.1 with build-id: 31a56e0009a8824c7a09267c8205034c91cb4095 Found module libseccomp.so.2 with build-id: 5a5b4ee3bb99ee0378bd937fdef7a7b7255d0428 Found module libpmem.so.1 with build-id: 084e72da2642981fe75b446293655ae4a68c0663 Found module libsasl2.so.3 with build-id: 2864d8e1600f3b46016fd62c44269e92c5ec0ca1 Found module libgnutls.so.30 with build-id: b08009ada925278615f5592e982e0776c06e065e Found module libpng16.so.16 with build-id: 698f67f36c58fa443c6ba891e4a0f106553a0452 Found module libz.so.1 with build-id: 62196acf9f75625acb09840435bb396c62829e12 Found module liblzo2.so.2 with build-id: c42a1f1fd2f73000efcbe3d2fb6ad196170fd1cf Found module libsnappy.so.1 with build-id: 83553ef5fb4b9e530a3f05b68d92f320a6d53772 Found module libpixman-1.so.0 with build-id: 4420cf633fcf726fc8cef2dd84d817083afe13e5 Found module qemu-kvm with build-id: debf9ea821f74b76b75f78c5558eba8ca491b1b5 Stack trace of thread 236656: #0 0x00007fef0ee7b7fc __pthread_kill_implementation (libc.so.6 + 0x8f7fc) #1 0x00007fef0ee2e676 raise (libc.so.6 + 0x42676) #2 0x00007fef0ee187d3 abort (libc.so.6 + 0x2c7d3) #3 0x00007fef0ee186fb __assert_fail_base.cold (libc.so.6 + 0x2c6fb) #4 0x00007fef0ee27396 __assert_fail (libc.so.6 + 0x3b396) #5 0x0000556d867a4791 qio_channel_restart_read (qemu-kvm + 0x760791) #6 0x0000556d869a147f aio_dispatch_handler (qemu-kvm + 0x95d47f) #7 0x0000556d869a132c aio_dispatch (qemu-kvm + 0x95d32c) #8 0x0000556d869bb522 aio_ctx_dispatch (qemu-kvm + 0x977522) #9 0x00007fef0f14df6f g_main_context_dispatch (libglib-2.0.so.0 + 0x54f6f) #10 0x0000556d869c81e3 main_loop_wait (qemu-kvm + 0x9841e3) #11 0x0000556d86647d37 qemu_main_loop (qemu-kvm + 0x603d37) #12 0x0000556d863a06f2 main (qemu-kvm + 0x35c6f2) #13 0x00007fef0ee19560 __libc_start_call_main (libc.so.6 + 0x2d560) #14 0x00007fef0ee1960c __libc_start_main@@GLIBC_2.34 (libc.so.6 + 0x2d60c) #15 0x0000556d8639fdb5 _start (qemu-kvm + 0x35bdb5) Stack trace of thread 236664: #0 0x00007fef0ee76870 __GI___lll_lock_wait (libc.so.6 + 0x8a870) #1 0x00007fef0ee7cea2 __pthread_mutex_lock.5 (libc.so.6 + 0x90ea2) #2 0x0000556d869a521f qemu_mutex_lock_impl (qemu-kvm + 0x96121f) #3 0x0000556d8663c78a flatview_read_continue (qemu-kvm + 0x5f878a) #4 0x0000556d8663c62e flatview_read (qemu-kvm + 0x5f862e) #5 0x0000556d8663f621 address_space_read_full (qemu-kvm + 0x5fb621) #6 0x0000556d8674c695 kvm_cpu_exec (qemu-kvm + 0x708695) #7 0x0000556d8674e5fa kvm_vcpu_thread_fn (qemu-kvm + 0x70a5fa) #8 0x0000556d869a609a qemu_thread_start (qemu-kvm + 0x96209a) #9 0x00007fef0ee79aaf start_thread (libc.so.6 + 0x8daaf) #10 0x00007fef0eefe740 __clone3 (libc.so.6 + 0x112740) Stack trace of thread 236668: #0 0x00007fef0eef33fb ioctl (libc.so.6 + 0x1073fb) #1 0x0000556d8674cd77 kvm_vcpu_ioctl (qemu-kvm + 0x708d77) #2 0x0000556d8674c601 kvm_cpu_exec (qemu-kvm + 0x708601) #3 0x0000556d8674e5fa kvm_vcpu_thread_fn (qemu-kvm + 0x70a5fa) #4 0x0000556d869a609a qemu_thread_start (qemu-kvm + 0x96209a) #5 0x00007fef0ee79aaf start_thread (libc.so.6 + 0x8daaf) #6 0x00007fef0eefe740 __clone3 (libc.so.6 + 0x112740) Stack trace of thread 236665: #0 0x00007fef0eef33fb ioctl (libc.so.6 + 0x1073fb) #1 0x0000556d8674cd77 kvm_vcpu_ioctl (qemu-kvm + 0x708d77) #2 0x0000556d8674c601 kvm_cpu_exec (qemu-kvm + 0x708601) #3 0x0000556d8674e5fa kvm_vcpu_thread_fn (qemu-kvm + 0x70a5fa) #4 0x0000556d869a609a qemu_thread_start (qemu-kvm + 0x96209a) #5 0x00007fef0ee79aaf start_thread (libc.so.6 + 0x8daaf) #6 0x00007fef0eefe740 __clone3 (libc.so.6 + 0x112740) Stack trace of thread 236670: #0 0x00007fef0eef33fb ioctl (libc.so.6 + 0x1073fb) #1 0x0000556d8674cd77 kvm_vcpu_ioctl (qemu-kvm + 0x708d77) #2 0x0000556d8674c601 kvm_cpu_exec (qemu-kvm + 0x708601) #3 0x0000556d8674e5fa kvm_vcpu_thread_fn (qemu-kvm + 0x70a5fa) #4 0x0000556d869a609a qemu_thread_start (qemu-kvm + 0x96209a) #5 0x00007fef0ee79aaf start_thread (libc.so.6 + 0x8daaf) #6 0x00007fef0eefe740 __clone3 (libc.so.6 + 0x112740) Stack trace of thread 236657: #0 0x00007fef0eef6fbd syscall (libc.so.6 + 0x10afbd) #1 0x0000556d869a5def qemu_event_wait (qemu-kvm + 0x961def) #2 0x0000556d869b1eb1 call_rcu_thread (qemu-kvm + 0x96deb1) #3 0x0000556d869a609a qemu_thread_start (qemu-kvm + 0x96209a) #4 0x00007fef0ee79aaf start_thread (libc.so.6 + 0x8daaf) #5 0x00007fef0eefe740 __clone3 (libc.so.6 + 0x112740) Stack trace of thread 236667: #0 0x00007fef0eef33fb ioctl (libc.so.6 + 0x1073fb) #1 0x0000556d8674cd77 kvm_vcpu_ioctl (qemu-kvm + 0x708d77) #2 0x0000556d8674c601 kvm_cpu_exec (qemu-kvm + 0x708601) #3 0x0000556d8674e5fa kvm_vcpu_thread_fn (qemu-kvm + 0x70a5fa) #4 0x0000556d869a609a qemu_thread_start (qemu-kvm + 0x96209a) #5 0x00007fef0ee79aaf start_thread (libc.so.6 + 0x8daaf) #6 0x00007fef0eefe740 __clone3 (libc.so.6 + 0x112740) Stack trace of thread 236663: #0 0x00007fef0eef187f __poll (libc.so.6 + 0x10587f) #1 0x00007fef0f1a256c g_main_context_iterate.constprop.0 (libglib-2.0.so.0 + 0xa956c) #2 0x00007fef0f14d533 g_main_loop_run (libglib-2.0.so.0 + 0x54533) #3 0x0000556d867cc924 iothread_run (qemu-kvm + 0x788924) #4 0x0000556d869a609a qemu_thread_start (qemu-kvm + 0x96209a) #5 0x00007fef0ee79aaf start_thread (libc.so.6 + 0x8daaf) #6 0x00007fef0eefe740 __clone3 (libc.so.6 + 0x112740) Stack trace of thread 236658: #0 0x00007fef0eef197e ppoll (libc.so.6 + 0x10597e) #1 0x0000556d869a2852 fdmon_poll_wait (qemu-kvm + 0x95e852) #2 0x0000556d869a1fe4 aio_poll (qemu-kvm + 0x95dfe4) #3 0x0000556d867cc906 iothread_run (qemu-kvm + 0x788906) #4 0x0000556d869a609a qemu_thread_start (qemu-kvm + 0x96209a) #5 0x00007fef0ee79aaf start_thread (libc.so.6 + 0x8daaf) #6 0x00007fef0eefe740 __clone3 (libc.so.6 + 0x112740) Stack trace of thread 236671: #0 0x00007fef0eef33fb ioctl (libc.so.6 + 0x1073fb) #1 0x0000556d8674cd77 kvm_vcpu_ioctl (qemu-kvm + 0x708d77) #2 0x0000556d8674c601 kvm_cpu_exec (qemu-kvm + 0x708601) #3 0x0000556d8674e5fa kvm_vcpu_thread_fn (qemu-kvm + 0x70a5fa) #4 0x0000556d869a609a qemu_thread_start (qemu-kvm + 0x96209a) #5 0x00007fef0ee79aaf start_thread (libc.so.6 + 0x8daaf) #6 0x00007fef0eefe740 __clone3 (libc.so.6 + 0x112740) Stack trace of thread 236731: #0 0x00007fef0ee7670a __futex_abstimed_wait_common (libc.so.6 + 0x8a70a) #1 0x00007fef0ee81813 __new_sem_wait_slow64.constprop.0 (libc.so.6 + 0x95813) #2 0x0000556d869a5b0b qemu_sem_timedwait (qemu-kvm + 0x961b0b) #3 0x0000556d869cc6b6 worker_thread (qemu-kvm + 0x9886b6) #4 0x0000556d869a609a qemu_thread_start (qemu-kvm + 0x96209a) #5 0x00007fef0ee79aaf start_thread (libc.so.6 + 0x8daaf) #6 0x00007fef0eefe740 __clone3 (libc.so.6 + 0x112740) Stack trace of thread 236730: #0 0x00007fef0ee7670a __futex_abstimed_wait_common (libc.so.6 + 0x8a70a) #1 0x00007fef0ee81813 __new_sem_wait_slow64.constprop.0 (libc.so.6 + 0x95813) #2 0x0000556d869a5b0b qemu_sem_timedwait (qemu-kvm + 0x961b0b) #3 0x0000556d869cc6b6 worker_thread (qemu-kvm + 0x9886b6) #4 0x0000556d869a609a qemu_thread_start (qemu-kvm + 0x96209a) #5 0x00007fef0ee79aaf start_thread (libc.so.6 + 0x8daaf) #6 0x00007fef0eefe740 __clone3 (libc.so.6 + 0x112740) Stack trace of thread 236675: #0 0x00007fef0ee7670a __futex_abstimed_wait_common (libc.so.6 + 0x8a70a) #1 0x00007fef0ee78e80 pthread_cond_wait@@GLIBC_2.3.2 (libc.so.6 + 0x8ce80) #2 0x0000556d869a56ff qemu_cond_wait_impl (qemu-kvm + 0x9616ff) #3 0x0000556d863dd657 vnc_worker_thread (qemu-kvm + 0x399657) #4 0x0000556d869a609a qemu_thread_start (qemu-kvm + 0x96209a) #5 0x00007fef0ee79aaf start_thread (libc.so.6 + 0x8daaf) #6 0x00007fef0eefe740 __clone3 (libc.so.6 + 0x112740) Stack trace of thread 236666: #0 0x00007fef0eef33fb ioctl (libc.so.6 + 0x1073fb) #1 0x0000556d8674cd77 kvm_vcpu_ioctl (qemu-kvm + 0x708d77) #2 0x0000556d8674c601 kvm_cpu_exec (qemu-kvm + 0x708601) #3 0x0000556d8674e5fa kvm_vcpu_thread_fn (qemu-kvm + 0x70a5fa) #4 0x0000556d869a609a qemu_thread_start (qemu-kvm + 0x96209a) #5 0x00007fef0ee79aaf start_thread (libc.so.6 + 0x8daaf) #6 0x00007fef0eefe740 __clone3 (libc.so.6 + 0x112740) Stack trace of thread 236672: #0 0x00007fef0eef33fb ioctl (libc.so.6 + 0x1073fb) #1 0x0000556d8674cd77 kvm_vcpu_ioctl (qemu-kvm + 0x708d77) #2 0x0000556d8674c601 kvm_cpu_exec (qemu-kvm + 0x708601) #3 0x0000556d8674e5fa kvm_vcpu_thread_fn (qemu-kvm + 0x70a5fa) #4 0x0000556d869a609a qemu_thread_start (qemu-kvm + 0x96209a) #5 0x00007fef0ee79aaf start_thread (libc.so.6 + 0x8daaf) #6 0x00007fef0eefe740 __clone3 (libc.so.6 + 0x112740) Stack trace of thread 236669: #0 0x00007fef0eef33fb ioctl (libc.so.6 + 0x1073fb) #1 0x0000556d8674cd77 kvm_vcpu_ioctl (qemu-kvm + 0x708d77) #2 0x0000556d8674c601 kvm_cpu_exec (qemu-kvm + 0x708601) #3 0x0000556d8674e5fa kvm_vcpu_thread_fn (qemu-kvm + 0x70a5fa) #4 0x0000556d869a609a qemu_thread_start (qemu-kvm + 0x96209a) #5 0x00007fef0ee79aaf start_thread (libc.so.6 + 0x8daaf) #6 0x00007fef0eefe740 __clone3 (libc.so.6 + 0x112740) Stack trace of thread 236673: #0 0x00007fef0eef33fb ioctl (libc.so.6 + 0x1073fb) #1 0x0000556d8674cd77 kvm_vcpu_ioctl (qemu-kvm + 0x708d77) #2 0x0000556d8674c601 kvm_cpu_exec (qemu-kvm + 0x708601) #3 0x0000556d8674e5fa kvm_vcpu_thread_fn (qemu-kvm + 0x70a5fa) #4 0x0000556d869a609a qemu_thread_start (qemu-kvm + 0x96209a) #5 0x00007fef0ee79aaf start_thread (libc.so.6 + 0x8daaf) #6 0x00007fef0eefe740 __clone3 (libc.so.6 + 0x112740) Expected results: VM can start successfully with exposed nbd data image. Additional info: Will attach core dump file later.