Re: [libvirt] Using Libvirt to change the bridge a virtual network card of a running vm is connected to

I wrote a patch to change the mapping between a virtual bridge interface and the host bridge while the host is up. It's based on commit 6fba577e505611e6c25c68e322942eab7754de7e. The host and the interface definition I used for testing are also attached. I would be glad if the patch could be added to the repo.

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c index 4b60839..f791795 100644 --- a/src/qemu/qemu_hotplug.c +++ b/src/qemu/qemu_hotplug.c @@ -40,6 +40,7 @@ #include "qemu_cgroup.h" #include "locking/domain_lock.h" #include "network/bridge_driver.h" +#include "util/virnetdevbridge.h" #define VIR_FROM_THIS VIR_FROM_QEMU @@ -1163,6 +1164,28 @@ static virDomainNetDefPtr qemuDomainFindNet(virDomainObjPtr vm, return NULL; } +int qemuDomainChangeNetBridge(virDomainNetDefPtr olddev, + virDomainNetDefPtr newdev) +{ + const char *oldbridge=olddev->data.bridge.brname; + const char *newbridge=newdev->data.bridge.brname; + VIR_DEBUG("Change bridge for interface %s: %s -> %s", olddev->ifname, oldbridge, newbridge);

+ if(virNetDevBridgeRemovePort(oldbridge, olddev->ifname)<0) { + qemuReportError(VIR_ERR_OPERATION_FAILED, + _("unable to remove port from bridge"));

+ return -1; + } + if(virNetDevBridgeAddPort(newbridge, newdev->ifname)<0) { + qemuReportError(VIR_ERR_OPERATION_FAILED, + _("unable to add port to bridge")); + return -1; + }

+ VIR_FREE(olddev->data.bridge.brname); + olddev->data.bridge.brname=strdup(newbridge);

+ return 0; +}

+ int qemuDomainChangeNetLinkState(struct qemud_driver *driver, virDomainObjPtr vm, virDomainNetDefPtr dev, @@ -1293,6 +1316,12 @@ int qemuDomainChangeNet(struct qemud_driver *driver, return -1; } + if(olddev->type==VIR_DOMAIN_NET_TYPE_BRIDGE + && dev->type==VIR_DOMAIN_NET_TYPE_BRIDGE + && STRNEQ(olddev->data.bridge.brname, dev->data.bridge.brname)) { + qemuDomainChangeNetBridge(olddev, dev); + }

+ if (olddev->linkstate != dev->linkstate) { if ((ret = qemuDomainChangeNetLinkState(driver, vm, olddev, dev->linkstate)) < 0) return ret; diff --git a/src/qemu/qemu_hotplug.h b/src/qemu/qemu_hotplug.h index 0310361..1e1f75c 100644 --- a/src/qemu/qemu_hotplug.h +++ b/src/qemu/qemu_hotplug.h @@ -80,6 +80,8 @@ int qemuDomainChangeNetLinkState(struct qemud_driver *driver, virDomainObjPtr vm, virDomainNetDefPtr dev, int linkstate); +int qemuDomainChangeNetBridge(virDomainNetDefPtr olddev, + virDomainNetDefPtr newdev); int qemuDomainDetachPciDiskDevice(struct qemud_driver *driver, virDomainObjPtr vm, virDomainDeviceDefPtr dev); Host definition: <domain type='kvm'> <name>test</name> <memory>32768</memory> <currentMemory>32768</currentMemory> <vcpu>1</vcpu> <os> <type arch='x86_64' machine='pc-0.12'>hvm</type> <boot dev='cdrom'/> <bootmenu enable='no'/> </os> <features> <acpi/> <apic/> <pae/> </features> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>restart</on_crash> <devices> <emulator>/usr/bin/kvm</emulator> <controller type='ide' index='0'> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/> </controller> <interface type='bridge'> <mac address='52:54:00:ab:cd:02'/> <source bridge='br0'/> <target dev='testif'/> <link state='up'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> <serial type='pty'> <target port='0'/> </serial> <console type='pty'> <target type='serial' port='0'/> </console> <input type='tablet' bus='usb'/> <input type='mouse' bus='ps2'/> <graphics type='vnc' port='-1' autoport='yes'/> <video> <model type='cirrus' vram='9216' heads='1'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </video> <memballoon model='virtio'> <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </memballoon> </devices> </domain> Interface definition: <interface type="bridge"> <mac address="52:54:00:ab:cd:02"/> <source bridge="br1"/> <target dev="testif"/> <link state="up"/> <alias name="net0"/> <address type="pci" domain="0x0000" bus="0x00" slot="0x03" function="0x0"/> </interface> Best regards Hendrik Schwartke -- libvir-list mailing list libvir-list(a)redhat.com https://www.redhat.com/mailman/listinfo/libvir-list