"Gonglei (Arei)" <arei.gong...@huawei.com> writes: > Hi, > >> > > Il 26/04/2014 10:56, Gonglei (Arei) ha scritto: >> > > > Public bug reported: >> > > > >> > > > I want to repeated hot-plug/unplug the virtio-net in the latest qemu >> > > upstream >> > > > (commit 839a5547574e57cce62f49bfc50fe1f04b00589a), but I am failed >> at >> > > the >> > > > second time hot plug the virtio-net to guest. >> > > > >> > > > Then I tried to use Qemu-2.0.0 release version, but I got the error >> > > > too. >> > > > >> > > > Cmdline for vm: >> > > > >> > > > /mnt/sdb/gonglei/qemu/x86_64-softmmu/qemu-system-x86_64 >> -enable-kvm >> > > -m 4096 -smp 4 -name sles-et -boot c -drive file=/mnt/sdb/gonglei/image/ >> > > sles-3.img -vnc 0.0.0.0:10 -monitor stdio >> > > > QEMU 1.7.50 monitor - type 'help' for more information >> > > >> > > For commit 839a5547574e57cce62f49bfc50fe1f04b00589a you should have >> > > gotten 1.7.90 as the version number. >> > > >> > Maybe just because Peter Maydell merge remote-tracking branch. But it >> doesn't matter. >> > >> > > > (qemu) device_add virtio-net-pci,id=net1 >> > > > (qemu) device_del net1 >> > > > (qemu) device_add virtio-net-pci,id=net1 >> > > > Duplicate ID 'net1' for device >> > > > (qemu) >> > > >> > > I cannot reproduce this on Fedora running the 2.0.0 package from the >> > > virt-preview repository (qemu-system-x86-2.0.0-2.fc20.x86_64). >> > > >> > > For what it's worth, I get this for --version: >> > > >> > > $ qemu-system-x86_64 --version >> > > QEMU emulator version 2.0.0, Copyright (c) 2003-2008 Fabrice Bellard >> > > >> > > and likewise, when starting QEMU with "-monitor stdio": >> > > >> > > QEMU 2.0.0 monitor - type 'help' for more information >> > > >> > I got the QEMU 2.0.0 version from http://wiki.qemu.org/Download >> > >> > The issue was reproduced perforce: >> > UVP:/mnt/sdb/gonglei/code/qemu-2.0.0/x86_64-softmmu >> #./qemu-system-x86_64 -enable-kvm -m 4096 -smp 4 -name sles \ >> > -boot c -drive file=/mnt/sdb/gonglei/image/sles-3.img -vnc 0.0.0.0:10 >> -monitor stdio >> > QEMU 2.0.0 monitor - type 'help' for more information >> > (qemu) device_add virtio-net-pci,id=net1 >> > (qemu) device_del net1 >> > (qemu) device_add virtio-net-pci,id=net1 >> > Duplicate ID 'net1' for device >> > (qemu) >> > >> > Anything wrong? Thanks! >> >> Issue confirmed with both -monitor and qmp-shell with different other device >> models like e1000. > > Thanks. This issue confused me two weeks now, any helps will be appreciated. > > Cc'ing Peter and Michael for additional insights.
I suspect your second device_add fails because the unplug initiated by device_del hasn't completed, yet. More detailed explanation of the ACPI unplug dance: https://lists.nongnu.org/archive/html/qemu-devel/2013-03/msg01362.html Please verify the device is gone with "info pci", "info qtree" or similar before you try device_del. In QMP, you get a DEVICE_DELETED event when the unplug completes. See qmp/qmp-events.txt.
