I am having the same problem. I am new to unRAID and built an AMD system and enabled all the AMD virtualization settings I could find in the BIOS. As soon as I start the VM, my unRAID server becomes unstable and unresponsive. I can't even do a clean shut down from the powerdown plugin via SSH. I am unable to shut down the VM - even commands from CLI hang. The only thing I could do was do a hard reset.
I tried a Windows 10 and Ubuntu 14.04 VM. I thought maybe I had bad settings on the VMs - I tried Host Passthrough and Emulated CPU Modes, I tried different Machine type settings - nothing has worked so far.
If anyone has any suggestions, I'd really appreciate it!
tail -100 /var/log/libvirt/libvirtd.log
2016-05-09 20:02:45.771+0000: 5969: info : libvirt version: 1.3.1
2016-05-09 20:02:45.771+0000: 5969: info : hostname: beast
2016-05-09 20:02:45.771+0000: 5969: warning : virHookCheck:135 : Non-executable hook script /etc/libvirt/hooks/qemu
2016-05-09 20:06:27.703+0000: 5969: error : virNetDevSendEthtoolIoctl:3191 : ethtool ioctl error: No such device
2016-05-09 20:06:27.715+0000: 5969: error : virNetDevSendEthtoolIoctl:3191 : ethtool ioctl error: No such device
2016-05-09 20:06:27.727+0000: 5969: error : virNetDevSendEthtoolIoctl:3191 : ethtool ioctl error: No such device
2016-05-09 20:06:27.741+0000: 5969: error : virNetDevSendEthtoolIoctl:3191 : ethtool ioctl error: No such device
2016-05-09 20:06:29.040+0000: 5969: error : virNetDevSendEthtoolIoctl:3191 : ethtool ioctl error: No such device
2016-05-09 20:06:29.052+0000: 5969: error : virNetDevSendEthtoolIoctl:3191 : ethtool ioctl error: No such device
2016-05-09 20:06:29.054+0000: 5969: error : virNetDevSendEthtoolIoctl:3191 : ethtool ioctl error: No such device
2016-05-09 20:06:29.068+0000: 5969: error : virNetDevSendEthtoolIoctl:3191 : ethtool ioctl error: No such device
2016-05-09 22:06:54.911+0000: 5970: warning : qemuDomainObjTaint:2223 : Domain id=1 name='Ubuntu' uuid=b8345267-8517-5b86-3396-234afc63ab9b is tainted: high-privileges
2016-05-09 22:06:54.911+0000: 5970: warning : qemuDomainObjTaint:2223 : Domain id=1 name='Ubuntu' uuid=b8345267-8517-5b86-3396-234afc63ab9b is tainted: host-cpu
2016-05-09 22:10:47.006+0000: 5973: error : qemuAgentSend:898 : Guest agent is not responding: Guest agent not available for now
2016-05-09 22:11:03.323+0000: 5973: error : virProcessKillPainfully:398 : Failed to terminate process 13788 with SIGKILL: Device or resource busy
2016-05-09 22:36:13.695+0000: 5969: error : virNetSocketReadWire:1613 : End of file while reading data: Input/output error
2016-05-09 22:36:20.810+0000: 5971: error : virProcessKillPainfully:398 : Failed to terminate process 13788 with SIGKILL: Device or resource busy
2016-05-09 22:37:49.811+0000: 5970: error : virProcessKillPainfully:398 : Failed to terminate process 13788 with SIGKILL: Device or resource busy
2016-05-09 22:40:55.829+0000: 5972: warning : qemuDomainObjBeginJobInternal:1668 : Cannot start job (modify, none) for domain Ubuntu; current job is (query, none) owned by (5973 remoteDispatchDomainGetBlockInfo, 0 <null>) for (1789s, 0s)
2016-05-09 22:40:55.829+0000: 5972: error : qemuDomainObjBeginJobInternal:1680 : Timed out during operation: cannot acquire state change lock (held by remoteDispatchDomainGetBlockInfo)
2016-05-09 22:44:03.661+0000: 5972: error : virProcessKillPainfully:398 : Failed to terminate process 13788 with SIGKILL: Device or resource busy
tail -100 /var/log/libvirt/qemu/Ubuntu.log
2016-05-09 22:06:54.911+0000: starting up libvirt version: 1.3.1, qemu version: 2.5.1, hostname: beast
LC_ALL=C PATH=/bin:/sbin:/usr/bin:/usr/sbin HOME=/ QEMU_AUDIO_DRV=none /usr/local/sbin/qemu -name Ubuntu -S -machine pc-q35-2.5,accel=kvm,usb=off,mem-merge=off -cpu host -drive file=/usr/share/qemu/ovmf-x64/OVMF_CODE-pure-efi.fd,if=pflash,format=raw,unit=0,readonly=on -drive file=/etc/libvirt/qemu/nvram/b8345267-8517-5b86-3396-234afc63ab9b_VARS-pure-efi.fd,if=pflash,format=raw,unit=1 -m 2048 -realtime mlock=off -smp 1,sockets=1,cores=1,threads=1 -uuid b8345267-8517-5b86-3396-234afc63ab9b -no-user-config -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/domain-Ubuntu/monitor.sock,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 -boot strict=on -device i82801b11-bridge,id=pci.1,bus=pcie.0,addr=0x1e -device pci-bridge,chassis_nr=2,id=pci.2,bus=pci.1,addr=0x1 -device ich9-usb-ehci1,id=usb,bus=pcie.0,addr=0x7.0x7 -device ich9-usb-uhci1,masterbus=usb.0,firstport=0,bus=pcie.0,multifunction=on,addr=0x7 -device ich9-usb-uhci2,masterbus=usb.0,firstport=2,bus=pcie.0,addr=0x7.0x1 -device ich9-usb-uhci3,masterbus=usb.0,firstport=4,bus=pcie.0,addr=0x7.0x2 -device virtio-serial-pci,id=virtio-serial0,bus=pci.2,addr=0x3 -drive file=/mnt/user/vm/Ubuntu/vdisk1.img,format=raw,if=none,id=drive-virtio-disk2,cache=writeback -device virtio-blk-pci,scsi=off,bus=pci.2,addr=0x4,drive=drive-virtio-disk2,id=virtio-disk2,bootindex=1 -drive file=/mnt/user/isos/ubuntu-14.04.2-desktop-amd64.iso,format=raw,if=none,media=cdrom,id=drive-sata0-0-0,readonly=on -device ide-cd,bus=ide.0,drive=drive-sata0-0-0,id=sata0-0-0,bootindex=2 -fsdev local,security_model=passthrough,id=fsdev-fs0,path=/mnt/user/ -device virtio-9p-pci,id=fs0,fsdev=fsdev-fs0,mount_tag=shared,bus=pci.2,addr=0x1 -netdev tap,fd=23,id=hostnet0,vhost=on,vhostfd=24 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:41:3b:7b,bus=pci.2,addr=0x2 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -chardev socket,id=charchannel0,path=/var/lib/libvirt/qemu/channel/target/domain-Ubuntu/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 -device usb-tablet,id=input0 -vnc 0.0.0.0:0,websocket=5700 -k en-us -device qxl-vga,id=video0,ram_size=67108864,vram_size=67108864,vgamem_mb=16,bus=pcie.0,addr=0x1 -device virtio-balloon-pci,id=balloon0,bus=pci.2,addr=0x5 -msg timestamp=on
Domain id=1 is tainted: high-privileges
Domain id=1 is tainted: host-cpu
char device redirected to /dev/pts/0 (label charserial0)
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 0]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 1]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 2]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 3]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 4]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 5]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 6]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 7]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 8]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 9]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 12]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 13]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 14]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 15]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 16]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 17]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 23]
warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 24]
2016-05-09T22:10:48.314243Z qemu-system-x86_64: terminating on signal 15 from pid 5969