Red Hat Bugzilla – Bug 1340971
qemu: accel=tcg does not implement SSE 4 properly
Last modified: 2016-11-03 16:14:04 EDT
Can we get this fixed in RHEL too please? Managing to reliably hit it just by calling: strstr("pacemaker-1.0.rng", ".rng") +++ This bug was initially created as a clone of Bug #1270703 +++ Description of problem: An old SSE4 strstr from glibc returns incorrect results if running with qemu in accel=tcg mode. Version-Release number of selected component (if applicable): qemu-kvm-2.3.1-3.fc22.x86_64 How reproducible: Always. Steps to Reproduce: 1. Compile the attached self-contained reproducer. 2. Run it with ./tst-strstr Actual results: Output looks like this: error: needle not found at offset 3 (0x4007a3) error: needle not found at offset 4 (0x4007a4) error: needle not found at offset 5 (0x4007a5) … Expected results: No output. Additional info: Test case was extracted from glibc 2.17. Current Fedora no longer has this strstr implementation, but you can test with CentOS 7 in a guest as well. qemu-kvm command line: /usr/bin/qemu-system-x86_64 -machine accel=kvm -name rhel7.0 -S -machine pc-i440fx-2.3,accel=tcg,usb=off -cpu SandyBridge -m 2048 -realtime mlock=off -smp 2,sockets=2,cores=1,threads=1 -uuid b885eb90-c211-4554-bb3e-9406008d8cb5 -no-user-config -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/rhel7.0.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc,driftfix=slew -global kvm-pit.lost_tick_policy=discard -no-hpet -no-shutdown -global PIIX4_PM.disable_s3=1 -global PIIX4_PM.disable_s4=1 -boot strict=on -device ich9-usb-ehci1,id=usb,bus=pci.0,addr=0x6.0x7 -device ich9-usb-uhci1,masterbus=usb.0,firstport=0,bus=pci.0,multifunction=on,addr=0x6 -device ich9-usb-uhci2,masterbus=usb.0,firstport=2,bus=pci.0,addr=0x6.0x1 -device ich9-usb-uhci3,masterbus=usb.0,firstport=4,bus=pci.0,addr=0x6.0x2 -device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x5 -drive file=/var/lib/libvirt/images/rhel7.0.qcow2,if=none,id=drive-virtio-disk0,format=qcow2 -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x7,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 -netdev tap,fd=23,id=hostnet0 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:05:91:43,bus=pci.0,addr=0x3 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -chardev socket,id=charchannel0,path=/var/lib/libvirt/qemu/channel/target/rhel7.0.org.qemu.guest_agent.0,server,nowait -device virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=org.qemu.guest_agent.0 -chardev spicevmc,id=charchannel1,name=vdagent -device virtserialport,bus=virtio-serial0.0,nr=2,chardev=charchannel1,id=channel1,name=com.redhat.spice.0 -device usb-tablet,id=input0 -spice port=5900,addr=127.0.0.1,disable-ticketing,image-compression=off,seamless-migration=on -device qxl-vga,id=video0,ram_size=67108864,vram_size=67108864,vgamem_mb=16,bus=pci.0,addr=0x2 -device intel-hda,id=sound0,bus=pci.0,addr=0x4 -device hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0 -chardev spicevmc,id=charredir0,name=usbredir -device usb-redir,chardev=charredir0,id=redir0 -chardev spicevmc,id=charredir1,name=usbredir -device usb-redir,chardev=charredir1,id=redir1 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x8 -msg timestamp=on --- Additional comment from Florian Weimer on 2015-10-12 04:16 EDT --- compiled x86_64 program --- Additional comment from Paolo Bonzini on 2015-10-12 05:11:16 EDT --- Can you attach a statically linked binary? --- Additional comment from Paolo Bonzini on 2015-10-12 05:24:51 EDT --- Nevermind, I can reproduce it with the attached binary. --- Additional comment from Florian Weimer on 2015-10-12 09:00:10 EDT --- Paolo posted a fix upstream: http://lists.nongnu.org/archive/html/qemu-devel/2015-10/msg02605.html --- Additional comment from Fedora Update System on 2015-12-07 16:30:10 EST --- qemu-2.3.1-8.fc22 has been submitted as an update to Fedora 22. https://bodhi.fedoraproject.org/updates/FEDORA-2015-686f289aa5 --- Additional comment from Fedora Update System on 2015-12-08 18:51:22 EST --- qemu-2.3.1-8.fc22 has been pushed to the Fedora 22 testing repository. If problems still persist, please make note of it in this bug report. If you want to test the update, you can install it with $ su -c 'dnf --enablerepo=updates-testing update qemu' You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2015-686f289aa5 --- Additional comment from Cole Robinson on 2015-12-30 15:40:07 EST --- Update is in stable now
Fix included in qemu-kvm-1.5.3-114.el7
Yes please :)
Fix included in qemu-kvm-1.5.3-105.el7_2.8
Created attachment 1200445 [details] seabios log ans screenshot Test against qemu-kvm-1.5.3-123.el7.x86_64, rhel7.3 guest cannot boot when using accel=tcg. qemu cli used: /usr/libexec/qemu-kvm -name rhel7.3 -m 2048 \ -machine accel=kvm \ -machine pc,accel=tcg \ -vga qxl\ -spice port=3003,disable-ticketing \ -device virtio-serial -chardev spicevmc,id=vdagent,debug=0,name=vdagent \ -serial unix:/tmp/m,server,nowait \ -device virtserialport,chardev=vdagent,name=com.redhat.spice.0 \ -drive file=/home/ss1rhel73.qcow2,if=none,id=drive-scsi-disk0,format=qcow2,cache=none,werror=stop,rerror=stop -device virtio-scsi-pci,id=scsi0 -device scsi-hd,drive=drive-scsi-disk0,bus=scsi0.0,scsi-id=0,lun=0,id=scsi-disk0,bootindex=1 \ -monitor stdio \ -usb -device usb-kbd,id=input0 \ -netdev tap,id=idinWyYp,vhost=on -device virtio-net-pci,mac=42:ce:a9:d2:4d:d7,id=idlbq7eA,netdev=idinWyYp \ -qmp tcp:localhost:4444,server,nowait \ -global isa-debugcon.iobase=0x402 -debugcon file:/home/seabios.log \ Rhel7.3 guest can boot if remove -machine pc,accel=tcg. Only seabios boot information present in spice, please see screenshot of the problem. Attach seabios log also
Hi Paolo, could u look at this? BR/ Guo, Zhiyi
Can you put the qcow2 image somewhere for me to download?
Hi Zhiyi, I couldn't find the root cause but you can work around the failure by disabling the NIC ("-net none" and no "-netdev" or "-device virtio-net-pci"). Also, please add "-cpu SandyBridge" to ensure that your guest uses SSE4. Here is the command line I used: /usr/libexec/qemu-kvm -name rhel7.3 -m 2048 -machine pc,accel=tcg \ -serial mon:stdio -global isa-debugcon.iobase=0x402 \ -debugcon file:/home/seabios.log -hda ../ss1rhel73.qcow2 \ -snapshot -serial mon:stdio -vnc :0 -net none -cpu SandyBridge The NIC failure certainly wouldn't be approved for 7.3, and the OpenStack team is more interested in 7.2.z so I'll open a separate bug. Thanks!
Thanks Paolo! Reproduce this issue against qemu-kvm-1.5.3-113.el7.x86_64 and rhel7.3 host with kernel 3.10.0-505.el7.x86_64 qemu cli used: /usr/libexec/qemu-kvm -name rhel7.3 -m 2048 -machine pc,accel=tcg \ -serial mon:stdio -global isa-debugcon.iobase=0x402 \ -debugcon file:/home/seabios.log -hda ../ss1rhel73.qcow2 \ -snapshot -serial mon:stdio -vnc :0 -net none -cpu SandyBridge Steps: 1. execute reproducer bin from https://bugzilla.redhat.com/attachment.cgi?id=1081905 inside host results: #./tst-strstr error: needle not found at offset 3 (0x400cc3) error: needle not found at offset 4 (0x400cc4) error: needle not found at offset 5 (0x400cc5) error: needle not found at offset 6 (0x400cc6) .... Verify this issue against qemu-kvm-1.5.3-123.el7.x86_64, nothing output after executing reproducer bin.
Move to verified per comment 15
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, 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://rhn.redhat.com/errata/RHSA-2016-2585.html