Red Hat Bugzilla – Bug 802856
Missing support for persistent hotplug attach/detach of <hostdev> devices
Last modified: 2012-06-20 02:50:17 EDT
Fixed in this upstream commit: commit edb6fc3a7f0de4a4881862287b412b66b8153768 Author: Laine Stump <laine@laine.org> Date: Wed Mar 7 16:05:34 2012 -0500 qemu: support persistent hotplug of <hostdev> devices For some reason, although live hotplug of <hostdev> devices is supported, persistent hotplug is not. This patch adds the proper VIR_DOMAIN_DEVICE_HOSTDEV cases to the switches in qemuDomainAttachDeviceConfig and qemuDomainDetachDeviceConfig.
A backported fix has been posted to rhvirt-patches for inclusion in the RHEL build of libvirt: http://post-office.corp.redhat.com/archives/rhvirt-patches/2012-March/msg01461.html
Use libvirt-0.9.10-2.el6.x86_64 to reproduce the bug. #virsh attach-device rhel6 hostdev.xml --persistent error: Failed to attach device from hostdev.xml error: unsupported configuration:persistent attach of device is not supported. Verify steps 1.enable kernel iommu. edit grub.conf add intel_iommu=on at the end of kernel line. 2.For platform just support vt-d1(host kernel) and host kernel larger than 171 kernel, do the following steps. modprobe -r kvm_intel modprobe -r kvm modprobe kvm allow_unsafe_assigned_interrupts=1 modprobe kvm_intel 3.# rpm -q libvirt libvirt-0.9.10-6.el6.x86_64 4.Check device list, prepare hotplug network from host to guest. computer | +- pci_0000_00_19_0 | | | +- net_eth0_44_37_e6_67_11_a2 4.# virsh nodedev-dumpxml pci_0000_00_19_0 5. Prepare hostdev.xml that like as following <hostdev mode='subsystem' type='pci' managed='yes'> <source> <address domain='0x0000' bus='0x00' slot='0x19' function='0x0'/> </source> </hostdev> 5.# virsh attach-device rhel6 hostdev.xml --persistent Device attached successfully 6. In guest, using lspci, and ping to check the host network device is working fine. 7. # virsh destroy rhel6 8. # virsh start rhel6 9. The host network device still works fine in guest. 10. # virsh detach-device rhel6 hostdev.xml --persistent Device detached successfully The host network device automatically be re-attached to host. 11. # virsh destroy rhel6 12. # virsh start rhel6 Results The host network device don't exist in guest. So it is verified.
Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: In previous versions of RHEL, a <hostdev> device could be hotplugged to a guest, but making that device persistent across restarts of the guest required separately editing the guest configuration. The patch that closes this bug adds support for persistent hotplug of <hostdev> devices, both to the libvirt API and to the virsh commandline utility.
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. http://rhn.redhat.com/errata/RHSA-2012-0748.html