The bug occurred when upgrading from 12.04.1 (3.2 kernel) to 14.04 (3.13 kernel). Booting with the old 3.2 kernel resolves the problem.
Guest command line - qemu-system-x86_64 -enable-kvm -name test -S-machine pc-i440fx-1.4,accel=kvm,usb=off -cpu qemu64,hv_relaxed -m 4096 -realtimemlock=off -smp 2,sockets=2,cores=1,threads=1 -uuid e00d6bde-ca3e-8e6c-2c92-d5b5ec632b9a -no-user-config -nodefaults -chardevsocket,id=charmonitor,path=/var/lib/libvirt/qemu/test.monitor,server,nowait -monchardev=charmonitor,id=monitor,mode=contro l-rtcbase=localtime,driftfix=slew -no-hpet -no-shutdown -bootstrict=on -devicepiix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -drive file=rbd:ssd/test:auth_supported=none,if=none,id=drive-virtio-disk0-devicevirtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=2 -drive if=none,id=drive-ide0-1-0,readonly=on,format=raw-deviceide-cd,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0,bootindex=1 -netdevtap,fd=24,id=hostnet0,vhost=on,vhostfd=25 -devicevirtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:48:81:8a,bus=pci.0,addr=0x3-chardevpty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0-vnc127.0.0.1:0 -devicecirrus-vga,id=video0,bus=pci.0,addr=0x2 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4
Attached is a perf record of the qemu process whilst the fault was occuring.
The bug occurred when upgrading from 12.04.1 (3.2 kernel) to 14.04 (3.13 kernel). Booting with the old 3.2 kernel resolves the problem.
Guest command line - 1.4,accel= kvm,usb= off -cpu qemu64,hv_relaxed -m 4096 -realtimemlock=off -smp 2,sockets= 2,cores= 1,threads= 1 -uuid e00d6bde- ca3e-8e6c- 2c92-d5b5ec632b 9a -no-user-config -nodefaults -chardevsocket, id=charmonitor, path=/var/ lib/libvirt/ qemu/test. monitor, server, nowait -monchardev= charmonitor, id=monitor, mode=contro l-rtcbase= localtime, driftfix= slew -no-hpet -no-shutdown -bootstrict=on -devicepiix3- usb-uhci, id=usb, bus=pci. 0,addr= 0x1.0x2 -drive file=rbd: ssd/test: auth_supported= none,if= none,id= drive-virtio- disk0-devicevir tio-blk- pci,scsi= off,bus= pci.0,addr= 0x5,drive= drive-virtio- disk0,id= virtio- disk0,bootindex =2 -drive if=none, id=drive- ide0-1- 0,readonly= on,format= raw-deviceide- cd,bus= ide.1,unit= 0,drive= drive-ide0- 1-0,id= ide0-1- 0,bootindex= 1 -netdevtap, fd=24,id= hostnet0, vhost=on, vhostfd= 25 -devicevirtio- net-pci, netdev= hostnet0, id=net0, mac=52: 54:00:48: 81:8a,bus= pci.0,addr= 0x3-chardevpty, id=charserial0 -device isa-serial, chardev= charserial0, id=serial0- vnc127. 0.0.1:0 -devicecirrus- vga,id= video0, bus=pci. 0,addr= 0x2 -device virtio- balloon- pci,id= balloon0, bus=pci. 0,addr= 0x4
qemu-system-x86_64 -enable-kvm -name test -S-machine pc-i440fx-
Attached is a perf record of the qemu process whilst the fault was occuring.