Hi Laine, As for the hot-unplug behavior, I have one more question about it, could you please help to confirm?
unplugging a PCI device properly requires cooperation from the guest OS. > If the guest OS isn't running yet, the unplug won't complete, so qemu > (and libvirt) still show the device as plugged into the guest. > > virsh reports success on the unplug because unplugging a device is done > asynchronously - the "success" means "libvirt successfully told qemu to > unplug the device, qemu has told the virtual machine to unplug the > device, and is waiting for acknowledgment from the virtual machine that > the guest has completed removal". At some later time the guest OS may > complete its part of the unplug; when that happens, qemu will get a > notification and will send an event to libvirt - at that time the device > will be removed from libvirt's list of devices. > > tl;dr - this is all expected. > The question is that, when I unplug it during boot, the virsh cmd will succeed but the interface still exists, which is expected. After the vm boot successfully, the guest OS will *not* complete this removal. When I tried to detach it again, it reported that the device was in the process of unplugging. Is this acceptable? # virsh detach-interface rhel_new network 52:54:00:36:a8:d4 Interface detached successfully # virsh domiflist rhel_new Interface Type Source Model MAC ------------------------------------------------------------- vnet4 network default virtio 52:54:00:36:a8:d4 # virsh detach-interface rhel_new network 52:54:00:36:a8:d4 error: Failed to detach interface error: internal error: unable to execute QEMU command 'device_del': Device net0 is already in the process of unplug Thank you! Yalan On Thu, Sep 14, 2017 at 12:48 AM Laine Stump <la...@laine.org> wrote: > On 09/04/2017 03:37 AM, Yalan Zhang wrote: > > Hi guys, > > > > when I detach an interface from vm during boot (vm boot not finished), it > > always fail. I'm not sure if there is an existing bug. I have > > confirmed with someone that for disk, there is similar behavior, if > > this is also acceptable? > > unplugging a PCI device properly requires cooperation from the guest OS. > If the guest OS isn't running yet, the unplug won't complete, so qemu > (and libvirt) still show the device as plugged into the guest. > > virsh reports success on the unplug because unplugging a device is done > asynchronously - the "success" means "libvirt successfully told qemu to > unplug the device, qemu has told the virtual machine to unplug the > device, and is waiting for acknowledgment from the virtual machine that > the guest has completed removal". At some later time the guest OS may > complete its part of the unplug; when that happens, qemu will get a > notification and will send an event to libvirt - at that time the device > will be removed from libvirt's list of devices. > > tl;dr - this is all expected. > > > > > > # virsh destroy rhel7.2; virsh start rhel7.2 ;sleep 2; virsh > > detach-interface rhel7.2 network 52:54:00:98:c4:a0; sleep 2; virsh > > dumpxml rhel7.2 |grep /interface -B9 > > Domain rhel7.2 destroyed > > > > Domain rhel7.2 started > > > > Interface detached successfully > > > > <address type='pci' domain='0x0000' bus='0x00' slot='0x06' > > function='0x0'/> > > </controller> > > <interface type='network'> > > <mac address='52:54:00:98:c4:a0'/> > > <source network='default' bridge='virbr0'/> > > <target dev='vnet0'/> > > <model type='rtl8139'/> > > <alias name='net0'/> > > <address type='pci' domain='0x0000' bus='0x00' slot='0x03' > > function='0x0'/> > > </interface> > > > > When I detach after the vm boot, expand the sleep time to 10, it will > succeed. > > > > # virsh destroy rhel7.2; virsh start rhel7.2 ;sleep 10; virsh > > detach-interface rhel7.2 network 52:54:00:98:c4:a0; sleep 2; virsh > > dumpxml rhel7.2 |grep /interface -B9 > > Domain rhel7.2 destroyed > > > > Domain rhel7.2 started > > > > Interface detached successfully > > > > > > ------- > > Best Regards, > > Yalan Zhang > > IRC: yalzhang > > Internal phone: 8389413 > > > > _______________________________________________ > > libvirt-users mailing list > > libvirt-users@redhat.com > > https://www.redhat.com/mailman/listinfo/libvirt-users > > > >
