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Description of problem: boot guest with a multiple virtio nics, and every 8 virtio nics depend on a slot via multifunction=on option. after unhotplug one of 8 virtio nics, the dependent slot will be deleted too. Version-Release number of selected component (if applicable): # rpm -qa|grep qemu qemu-kvm-0.12.1.2-2.209.el6.x86_64 # uname -r 2.6.32-214.el6.x86_64 guest: win7-64 How reproducible: Steps to Reproduce: 1./usr/libexec/qemu-kvm -M rhel6.2.0 -monitor stdio -enable-kvm -m 4G -smp 2,sockets=2,cores=1,threads=1 -name rhel6 -uuid 745fe449-aac8-29f1-0c2d-5042a707263b -boot c -drive file=/home/win7_x64.qcow2,if=none,id=drive-ide0-0-0,format=qcow2,cache=none,aio=threads -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1 -spice disable-ticketing,port=5914 \ -netdev tap,id=hostnet0,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet0,mac=00:12:17:18:49:30,bus=pci.0,id=virtio-net-pci0,multifunction=on,addr=0x03.0 \ -netdev tap,id=hostnet1,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet1,mac=00:12:17:18:49:31,bus=pci.0,id=virtio-net-pci1,multifunction=on,addr=0x03.1 \ -netdev tap,id=hostnet2,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet2,mac=00:12:17:18:49:32,bus=pci.0,id=virtio-net-pci2,multifunction=on,addr=0x03.2 \ -netdev tap,id=hostnet3,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet3,mac=00:12:17:18:49:33,bus=pci.0,id=virtio-net-pci3,multifunction=on,addr=0x03.3 \ -netdev tap,id=hostnet4,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet4,mac=00:12:17:18:49:34,bus=pci.0,id=virtio-net-pci4,multifunction=on,addr=0x03.4 \ -netdev tap,id=hostnet5,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet5,mac=00:12:17:18:49:35,bus=pci.0,id=virtio-net-pci5,multifunction=on,addr=0x03.5 \ -netdev tap,id=hostnet6,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet6,mac=00:12:17:18:49:36,bus=pci.0,id=virtio-net-pci6,multifunction=on,addr=0x03.6 \ -netdev tap,id=hostnet7,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet7,mac=00:12:17:18:49:37,bus=pci.0,id=virtio-net-pci7,multifunction=on,addr=0x03.7 \ -netdev tap,id=hostnet8,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet8,mac=00:12:17:18:40:30,bus=pci.0,id=virtio-net-pci8,multifunction=on,addr=0x04.0 \ -netdev tap,id=hostnet9,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet9,mac=00:12:17:18:41:31,bus=pci.0,id=virtio-net-pci9,multifunction=on,addr=0x04.1 \ -netdev tap,id=hostnet10,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet10,mac=00:12:17:18:42:32,bus=pci.0,id=virtio-net-pci10,multifunction=on,addr=0x04.2 \ -netdev tap,id=hostnet11,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet11,mac=00:12:17:18:43:33,bus=pci.0,id=virtio-net-pci11,multifunction=on,addr=0x04.3 \ -netdev tap,id=hostnet12,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet12,mac=00:12:17:18:44:34,bus=pci.0,id=virtio-net-pci12,multifunction=on,addr=0x04.4 \ -netdev tap,id=hostnet13,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet13,mac=00:12:17:18:45:35,bus=pci.0,id=virtio-net-pci13,multifunction=on,addr=0x04.5 \ -netdev tap,id=hostnet14,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet14,mac=00:12:17:18:46:36,bus=pci.0,id=virtio-net-pci14,multifunction=on,addr=0x04.6 \ -netdev tap,id=hostnet15,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet15,mac=00:12:17:18:47:37,bus=pci.0,id=virtio-net-pci15,multifunction=on,addr=0x04.7 \ 2.(qemu)device_del virtio-net-pci14 3.info pci Actual results: delete virtio-net-pci8...virtio-net-pci15 Expected results: only delete virtio-net-pci14 Additional info: if hotplug virtio nic(multifunction=on), qemu work well
we are not very whether we support hot unplug pci device or not,for now,if we don't support that,please free to add FEAT
(In reply to comment #2) > we are not very whether we support hot unplug pci device or not,for now,if we > don't support that,please free to add FEAT Correction we are not very whether we support hot unplug pci device with enable multifunction or not,for now,if we don't support that,please free to add FEAT
PCI hotplug operates on a slot, not on a function. You can plug or unplug a physical PCI card (slot), but not logical parts of it (functions). qemu-kvm doesn't quite emulate that properly. Hotplug/unplug of multifunction devices doesn't work, only coldplug. As far as I can tell, libvirt doesn't let you unplug multifunction devices. RHEL-6 supports multifunction=on *only* with -device pci-assign, not with -virtio-net-pci, precisely because it doesn't play nice with unplug. See "Virtualization Administration Guide", chapter "qemu-kvm Whitelist", section "Device options".
Closing, since PCI does not support unplug a single virtual function. At best the operation should fail, but since libvirt is not using it, it is not worth the effort.