Hi, I try to use VT-d, but meet with a strange problem . I create a VM through "virsh create ***.xml",as follows: root@shahe26:~# virsh create vt_d_debian.xml Domain vt_d_debian created from vt_d_debian.xml root@shahe26:~# virsh list Id Name State ---------------------------------- 4 vt_d_debian running root@shahe26:~# virsh list Id Name State ---------------------------------- 4 vt_d_debian running root@shahe26:~# virsh list Id Name State ---------------------------------- 4 vt_d_debian running root@shahe26:~# virsh list Id Name State ---------------------------------- 4 vt_d_debian no state root@shahe26:~# virsh list Id Name State ---------------------------------- root@shahe26:~# vim vt_d_debian.xml The VM has already killed itself. user.log: May 4 06:53:30 shahe26 libvirtd: 06:53:30.649: warning : qemudParsePCIDeviceStrs:1422 : Unexpected exit status '1', qemu probably failed May 4 06:53:30 shahe26 libvirtd: 06:53:30.805: warning : qemudParsePCIDeviceStrs:1422 : Unexpected exit status '1', qemu probably failed May 4 06:53:38 shahe26 libvirtd: 06:53:38.393: error : qemuMonitorCommandWithHandler:255 : cannot send monitor command 'info balloon': Connection reset by peer May 4 06:53:38 shahe26 libvirtd: 06:53:38.393: error : qemuMonitorTextGetBalloonInfo:555 : operation failed: could not query memory balloon allocation kern.log: May 4 06:53:30 shahe26 kernel: [ 2249.587662] ixgbe: eth2: ixgbe_remove: complete May 4 06:53:30 shahe26 kernel: [ 2249.587680] ixgbe 0000:02:00.1: PCI INT B disabled May 4 06:53:30 shahe26 kernel: [ 2249.587718] pci-stub 0000:02:00.1: claimed by stub May 4 06:53:30 shahe26 kernel: [ 2249.697347] pci-stub 0000:02:00.1: PCI INT B -> GSI 34 (level, low) -> IRQ 34 May 4 06:53:30 shahe26 kernel: [ 2249.797730] pci-stub 0000:02:00.1: restoring config space at offset 0xf (was 0x200, writing 0x205) May 4 06:53:30 shahe26 kernel: [ 2249.797737] pci-stub 0000:02:00.1: restoring config space at offset 0xc (was 0x0, writing 0xfbd20000) May 4 06:53:30 shahe26 kernel: [ 2249.797745] pci-stub 0000:02:00.1: restoring config space at offset 0x8 (was 0x4, writing 0xfbd1c004) May 4 06:53:30 shahe26 kernel: [ 2249.797751] pci-stub 0000:02:00.1: restoring config space at offset 0x6 (was 0x1, writing 0xd881) May 4 06:53:30 shahe26 kernel: [ 2249.797756] pci-stub 0000:02:00.1: restoring config space at offset 0x4 (was 0x4, writing 0xfbd40004) May 4 06:53:30 shahe26 kernel: [ 2249.797761] pci-stub 0000:02:00.1: restoring config space at offset 0x3 (was 0x800010, writing 0x800040) May 4 06:53:30 shahe26 kernel: [ 2249.797767] pci-stub 0000:02:00.1: restoring config space at offset 0x1 (was 0x100000, writing 0x100143) May 4 06:53:31 shahe26 kernel: [ 2250.050962] assign device: host bdf = 2:0:1 May 4 06:53:37 shahe26 kernel: [ 2256.759165] pci-stub 0000:02:00.1: restoring config space at offset 0xf (was 0x200, writing 0x205) May 4 06:53:37 shahe26 kernel: [ 2256.759173] pci-stub 0000:02:00.1: restoring config space at offset 0xc (was 0x0, writing 0xfbd20000) May 4 06:53:37 shahe26 kernel: [ 2256.759183] pci-stub 0000:02:00.1: restoring config space at offset 0x8 (was 0x4, writing 0xfbd1c004) May 4 06:53:37 shahe26 kernel: [ 2256.759188] pci-stub 0000:02:00.1: restoring config space at offset 0x6 (was 0x1, writing 0xd881) May 4 06:53:37 shahe26 kernel: [ 2256.759192] pci-stub 0000:02:00.1: restoring config space at offset 0x4 (was 0x4, writing 0xfbd40004) May 4 06:53:37 shahe26 kernel: [ 2256.759195] pci-stub 0000:02:00.1: restoring config space at offset 0x3 (was 0x800010, writing 0x800040) May 4 06:53:37 shahe26 kernel: [ 2256.759200] pci-stub 0000:02:00.1: restoring config space at offset 0x1 (was 0x100000, writing 0x100147) May 4 06:53:37 shahe26 kernel: [ 2256.759230] pci-stub 0000:02:00.1: PCI INT B disabled May 4 06:53:38 shahe26 kernel: [ 2257.259706] ixgbe 0000:02:00.1: PCI INT B -> GSI 34 (level, low) -> IRQ 34 May 4 06:53:38 shahe26 kernel: [ 2257.259722] ixgbe 0000:02:00.1: setting latency timer to 64 May 4 06:53:38 shahe26 kernel: [ 2257.382635] ixgbe 0000:02:00.1: irq 105 for MSI/MSI-X May 4 06:53:38 shahe26 kernel: [ 2257.382638] ixgbe 0000:02:00.1: irq 106 for MSI/MSI-X May 4 06:53:38 shahe26 kernel: [ 2257.382689] ixgbe 0000:02:00.1: irq 128 for MSI/MSI-X May 4 06:53:38 shahe26 kernel: [ 2257.382691] ixgbe 0000:02:00.1: irq 129 for MSI/MSI-X May 4 06:53:38 shahe26 kernel: [ 2257.382694] ixgbe 0000:02:00.1: irq 130 for MSI/MSI-X May 4 06:53:38 shahe26 kernel: [ 2257.382696] ixgbe 0000:02:00.1: irq 131 for MSI/MSI-X May 4 06:53:38 shahe26 kernel: [ 2257.382698] ixgbe 0000:02:00.1: irq 132 for MSI/MSI-X May 4 06:53:38 shahe26 kernel: [ 2257.382700] ixgbe 0000:02:00.1: irq 133 for MSI/MSI-X May 4 06:53:38 shahe26 kernel: [ 2257.382703] ixgbe 0000:02:00.1: irq 134 for MSI/MSI-X May 4 06:53:38 shahe26 kernel: [ 2257.382705] ixgbe 0000:02:00.1: irq 135 for MSI/MSI-X May 4 06:53:38 shahe26 kernel: [ 2257.382707] ixgbe 0000:02:00.1: irq 136 for MSI/MSI-X May 4 06:53:38 shahe26 kernel: [ 2257.382709] ixgbe 0000:02:00.1: irq 137 for MSI/MSI-X May 4 06:53:38 shahe26 kernel: [ 2257.382744] ixgbe: 0000:02:00.1: ixgbe_init_interrupt_scheme: Multiqueue Enabled: Rx Queue count = 16, Tx Queue count = 16 May 4 06:53:38 shahe26 kernel: [ 2257.382749] ixgbe 0000:02:00.1: (PCI Express:5.0Gb/s:Width x8) 00:a0:d1:ec:dc:49 May 4 06:53:38 shahe26 kernel: [ 2257.382834] ixgbe 0000:02:00.1: MAC: 2, PHY: 7, SFP+: 3, PBA No: ffffff-0ff May 4 06:53:38 shahe26 kernel: [ 2257.383724] ixgbe 0000:02:00.1: Intel(R) 10 Gigabit Network Connection libvirt/qemu/vt_d_debian.log LC_ALL=C PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin HOME=/ QEMU_AUDIO_DRV=none /usr/bin/kvm -S -M pc-0.12 -enable-kvm -m 512 -smp 1,sockets=1,cores=1,threads=1 -name vt_d_debian -uuid 5ed196df-319b-7be2-28f4-a070e0ca9d77 -nodefaults -chardev socket,id=monitor,path=/var/lib/libvirt/qemu/vt_d_debian.monitor,server,nowait -mon chardev=monitor,mode=readline -rtc base=utc -boot c -drive file=/root/debian_dev.img,if=none,id=drive-virtio-disk0,boot=on,format=raw -device virtio-blk-pci,bus=pci.0,addr=0x3,drive=drive-virtio-disk0,id=virtio-disk0 -usb -device usb-mouse,id=input0 -vnc <a href="http://127.0.0.1:0">127.0.0.1:0</a> -vga cirrus -device pci-assign,host=02:00.1,id=hostdev0,bus=pci.0,addr=0x4 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x5 Failed to assign irq for "hostdev0": Operation not permitted Perhaps you are assigning a device that shares an IRQ with another device? Failed to assign irq for "hostdev0": Operation not permitted Perhaps you are assigning a device that shares an IRQ with another device? Failed to assign irq for "hostdev0": Operation not permitted Perhaps you are assigning a device that shares an IRQ with another device? Failed to assign irq for "hostdev0": Operation not permitted Perhaps you are assigning a device that shares an IRQ with another device? Failed to assign irq for "hostdev0": Operation not permitted Perhaps you are assigning a device that shares an IRQ with another device? Failed to assign irq for "hostdev0": Operation not permitted Perhaps you are assigning a device that shares an IRQ with another device? Failed to assign irq for "hostdev0": Operation not permitted Perhaps you are assigning a device that shares an IRQ with another device? Failed to assign irq for "hostdev0": Operation not permitted Perhaps you are assigning a device that shares an IRQ with another device? Failed to assign irq for "hostdev0": Operation not permitted Perhaps you are assigning a device that shares an IRQ with another device? Failed to assign irq for "hostdev0": Operation not permitted Perhaps you are assigning a device that shares an IRQ with another device? Failed to assign irq for "hostdev0": Operation not permitted Perhaps you are assigning a device that shares an IRQ with another device? assigned_dev_pci_read_config: pread failed, ret = 0 errno = 1 I don't know how to solve this problem ,can anyone help me ? best regards, qinguan dmesg information is in the attached file dmesg. <domain type='kvm'> <name>vt_d_debian</name> <description>just test using sriov!</description> <os> <type>hvm</type> <boot dev='hd'/> </os> <memory>524288</memory> <currentMemory>524288</currentMemory> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>restart</on_crash> <features><pae/><acpi/><apic/></features> <clock offset='utc'/> <devices> <input type='mouse' bus='usb'/> <disk type='file' device='disk'> <source file='/root/debian_dev.img'/>  <target dev='hda' bus='virtio'/> </disk> <emulator>/usr/bin/kvm</emulator> <graphics type='vnc' port='-1'/>  <hostdev mode='subsystem' type='pci' managed='yes'> <source> <address bus='0x2' slot='0x0' function='0x1'/> </source> </hostdev>  </devices> </domain>