I've been looking at libvirt and qemu for other work, I'm doing, and I've criceld back to take another look at this.
Since I first looked at this, my testbed has updated to use the "oneiric-proposed" qemu-kvm package '0.14.1+noroms-0ubuntu6.1' while retaining the libvirt-bin package 0.9.2-4ubuntu15.1 I tried to duplicate the problem again, but this time my Linux virt had 'acpiphp.ko' (the PCI hotplug module) loaded, and I was *unable* to reproduce the 'Duplicate ID' error. Instead, continued attach/detach cycles resulted in success every time after .gt. 30 iterations. == **As a side-note and possibly to be addressed as a separate bug, the drive does not actually get attached as the specified device each time inside the virt. So even though the 'attach-disk --target' specifies, say, vdb, the virt kernel increments the devname inside itself, so that we get vdc, vdd, vde.... The attaches subsequent to the detatch of vdz results in vdaa,, vdab, vdac and so on. == Now here's the kicker. If you do an 'rmmod' on the PCI hotplug module within the virt and try the attach/detach/attach, the 'Duplicate ID' problem re-occurs. This implies to me that there is some sort of effective interaction between qemu-kvm and the virt that affects this. That is, when the virt actually gets and handles a device eject, then qemu-kvm behaves differently than when the virt does not get/handle it. -- Dec 14 09:54:16 base1 kernel: [ 2226.835417] acpiphp_glue: handle_hotplug_event_func: Device eject notify on \_SB_.PCI0.S27_ Dec 14 09:54:16 base1 kernel: [ 2226.877208] virtio-pci 0000:00:1b.0: PCI INT A disabled -- So, this gives us a better characterization of the bug, and I will look into it some more with this in mind. -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/897750 Title: libvirt/kvm problem with disk attach/detach/reattach on running virt Status in QEMU: New Status in “qemu-kvm” package in Ubuntu: Confirmed Bug description: Release: Ubuntu 11.10 (Oneiric) libvirt-bin: 0.9.2-4ubuntu15.1 qemu-kvm: 0.14.1+noroms-0ubuntu6 Summary: With a running KVM virt, performing an 'attach-disk', then a 'detach-disk', then another 'attach-disk' in an attempt to reattach the volume at the same point on the virt, fails, with the qemu reporting back to libvirt a 'Duplicate ID' error. Expected behavior: The 2nd invocation of 'attach-disk' should have succeeded Actual behavior: Duplicate ID error reported I believe this is most likely a qemu-kvm issue, as the DOM kvm spits back at libvirt after the 'detach-disk' does not show the just-detached disk. There is some kind of registry/lookup for devices in qemu-kvm and for whatever reason, the entry for the disk does not get removed when it is detached from the virt. Specifically, the error gets reported at the 2nd attach-disk attempt from: qemu-option.c:qemu_opts_create:697 684 QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id, int fail_if_exists) 685 { 686 QemuOpts *opts = NULL; 687 688 if (id) { 689 if (!id_wellformed(id)) { 690 qerror_report(QERR_INVALID_PARAMETER_VALUE, "id", "an identifier"); 691 error_printf_unless_qmp("Identifiers consist of letters, digits, '-', '.', '_', starting with a letter.\n"); 692 return NULL; 693 } 694 opts = qemu_opts_find(list, id); 695 if (opts != NULL) { 696 if (fail_if_exists) { 697 qerror_report(QERR_DUPLICATE_ID, id, list->name); <<<< ====== HERE =========== 698 return NULL; 699 } else { 700 return opts; 701 } 702 } 703 } 704 opts = qemu_mallocz(sizeof(*opts)); 705 if (id) { 706 opts->id = qemu_strdup(id); 707 } 708 opts->list = list; 709 loc_save(&opts->loc); 710 QTAILQ_INIT(&opts->head); 711 QTAILQ_INSERT_TAIL(&list->head, opts, next); 712 return opts; 713 } ======================================== Output of my attach/detach/attach ======================================== virsh # attach-disk base1 /var/lib/libvirt/images/extrastorage.img vdb Disk attached successfully virsh # dumpxml base1 <domain type='kvm' id='2'> <name>base1</name> <uuid>9ebebe7f-7dfa-4735-a80c-c19ebe4e1459</uuid> <memory>1048576</memory> <currentMemory>1048576</currentMemory> <vcpu>2</vcpu> <os> <type arch='x86_64' machine='pc-0.14'>hvm</type> <boot dev='hd'/> </os> <features> <acpi/> <apic/> <pae/> </features> <cpu match='exact'> <model>Opteron_G3</model> <vendor>AMD</vendor> <feature policy='require' name='skinit'/> <feature policy='require' name='vme'/> <feature policy='require' name='mmxext'/> <feature policy='require' name='fxsr_opt'/> <feature policy='require' name='cr8legacy'/> <feature policy='require' name='ht'/> <feature policy='require' name='3dnowprefetch'/> <feature policy='require' name='3dnowext'/> <feature policy='require' name='wdt'/> <feature policy='require' name='extapic'/> <feature policy='require' name='pdpe1gb'/> <feature policy='require' name='osvw'/> <feature policy='require' name='cmp_legacy'/> <feature policy='require' name='3dnow'/> </cpu> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>restart</on_crash> <devices> <emulator>/usr/bin/kvm</emulator> <disk type='file' device='disk'> <driver name='qemu' type='raw'/> <source file='/dev/rbd1'/> <target dev='vda' bus='virtio'/> <alias name='virtio-disk0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> </disk> <disk type='block' device='disk'> <driver name='qemu' type='raw'/> <source dev='/var/lib/libvirt/images/extrastorage.img'/> <target dev='vdb' bus='virtio'/> <alias name='virtio-disk1'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/> </disk> <controller type='ide' index='0'> <alias name='ide0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/> </controller> <interface type='bridge'> <mac address='52:54:00:a2:c1:2d'/> <source bridge='br0'/> <target dev='vnet0'/> <model type='virtio'/> <alias name='net0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> <serial type='pty'> <source path='/dev/pts/1'/> <target port='0'/> <alias name='serial0'/> </serial> <console type='pty' tty='/dev/pts/1'> <source path='/dev/pts/1'/> <target type='serial' port='0'/> <alias name='serial0'/> </console> <input type='mouse' bus='ps2'/> <graphics type='vnc' port='5900' autoport='yes'/> <sound model='ich6'> <alias name='sound0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> </sound> <video> <model type='cirrus' vram='9216' heads='1'/> <alias name='video0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </video> <memballoon model='virtio'> <alias name='balloon0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </memballoon> </devices> <seclabel type='dynamic' model='apparmor'> <label>libvirt-9ebebe7f-7dfa-4735-a80c-c19ebe4e1459</label> <imagelabel>libvirt-9ebebe7f-7dfa-4735-a80c-c19ebe4e1459</imagelabel> </seclabel> </domain> virsh # detach-disk base1 vdb Disk detached successfully virsh # dumpxml base1 <domain type='kvm' id='2'> <name>base1</name> <uuid>9ebebe7f-7dfa-4735-a80c-c19ebe4e1459</uuid> <memory>1048576</memory> <currentMemory>1048576</currentMemory> <vcpu>2</vcpu> <os> <type arch='x86_64' machine='pc-0.14'>hvm</type> <boot dev='hd'/> </os> <features> <acpi/> <apic/> <pae/> </features> <cpu match='exact'> <model>Opteron_G3</model> <vendor>AMD</vendor> <feature policy='require' name='skinit'/> <feature policy='require' name='vme'/> <feature policy='require' name='mmxext'/> <feature policy='require' name='fxsr_opt'/> <feature policy='require' name='cr8legacy'/> <feature policy='require' name='ht'/> <feature policy='require' name='3dnowprefetch'/> <feature policy='require' name='3dnowext'/> <feature policy='require' name='wdt'/> <feature policy='require' name='extapic'/> <feature policy='require' name='pdpe1gb'/> <feature policy='require' name='osvw'/> <feature policy='require' name='cmp_legacy'/> <feature policy='require' name='3dnow'/> </cpu> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>restart</on_crash> <devices> <emulator>/usr/bin/kvm</emulator> <disk type='file' device='disk'> <driver name='qemu' type='raw'/> <source file='/dev/rbd1'/> <target dev='vda' bus='virtio'/> <alias name='virtio-disk0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> </disk> <controller type='ide' index='0'> <alias name='ide0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/> </controller> <interface type='bridge'> <mac address='52:54:00:a2:c1:2d'/> <source bridge='br0'/> <target dev='vnet0'/> <model type='virtio'/> <alias name='net0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> <serial type='pty'> <source path='/dev/pts/1'/> <target port='0'/> <alias name='serial0'/> </serial> <console type='pty' tty='/dev/pts/1'> <source path='/dev/pts/1'/> <target type='serial' port='0'/> <alias name='serial0'/> </console> <input type='mouse' bus='ps2'/> <graphics type='vnc' port='5900' autoport='yes'/> <sound model='ich6'> <alias name='sound0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> </sound> <video> <model type='cirrus' vram='9216' heads='1'/> <alias name='video0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </video> <memballoon model='virtio'> <alias name='balloon0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </memballoon> </devices> <seclabel type='dynamic' model='apparmor'> <label>libvirt-9ebebe7f-7dfa-4735-a80c-c19ebe4e1459</label> <imagelabel>libvirt-9ebebe7f-7dfa-4735-a80c-c19ebe4e1459</imagelabel> </seclabel> </domain> virsh # attach-disk base1 /var/lib/libvirt/images/extrastorage.img vdb error: Failed to attach disk error: operation failed: adding virtio-blk-pci,bus=pci.0,addr=0x8,drive=drive-virtio-disk1,id=virtio-disk1 device failed: Duplicate ID 'virtio-disk1' for device ====================================================== To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/897750/+subscriptions
