Re: [libvirt] [PATCH v2 2/2] processNicRxFilterChangedEvent: Take appropriate actions for NET_TYPE_NETWORK too

Because packets going through the egress from a bridge (where our bandwidth limiting takes place) have no information about which interface they came from, the QoS rules that we create instead use the source MAC address of the packets to make their decisions about which QDisc the packet should be in. One flaw in this is that when a guest changed the MAC address it used, packets from the guest would no longer be put into the correct QDisc, but would instead be put in an "unprivileged" class, resulting in the bandwidth "floor" (minimum guaranteed) being no longer honored. Now that libvirt has infrastructure to capture and respond to RX_FILTER_CHANGE events from qemu (sent whenever a guest interface modifies its MAC address, among other things), we can notice when a guest MAC address changes, and update the QoS rules accordingly, so that bandwidth floor is honored even after a guest MAC address change. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/qemu/qemu_driver.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 6fc9696..6209754b 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -4377,6 +4377,18 @@ processNicRxFilterChangedEvent(virQEMUDriverPtr driver, syncNicRxFilterDeviceOptions(def->ifname, guestFilter, hostFilter); } + if (virDomainNetGetActualType(def) == VIR_DOMAIN_NET_TYPE_NETWORK) { + const char *brname = virDomainNetGetActualBridgeName(def); + + /* For libivrt network connections, set the following TUN/TAP network + * device attributes to match those of the guest network device: + * - QoS filters (which are based on MAC address) + */

+ if (virNetDevBandwidthUpdateFilter(brname, &guestFilter->mac, + def->data.network.actual->class_id) < 0)

+ goto endjob; + } + endjob: qemuDomainObjEndJob(driver, vm);