[dpdk-dev] [PATCH 0/4 for 2.3] vhost-user live migration support

Pavel Fedin p.fedin at samsung.com
Wed Dec 16 13:43:06 CET 2015


 Hello!

> However, I'm more curious about the ping loss? Did you still see
> that? And to be more specific, have the wireshark captured the
> GRAP from the guest?

 Yes, everything is fine.

root at nfv_test_x86_64 /var/log/libvirt/qemu # tshark -i ovs-br0
Running as user "root" and group "root". This could be dangerous.
Capturing on 'ovs-br0'
  1   0.000000 RealtekU_3b:83:1a -> Broadcast    ARP 42 Gratuitous ARP for 192.168.6.2 (Request)
  2   0.000024 fe80::5054:ff:fe3b:831a -> ff02::1      ICMPv6 86 Neighbor Advertisement fe80::5054:ff:fe3b:831a (ovr) is at
52:54:00:3b:83:1a
  3   0.049490 RealtekU_3b:83:1a -> Broadcast    ARP 42 Gratuitous ARP for 192.168.6.2 (Request)
  4   0.049497 fe80::5054:ff:fe3b:831a -> ff02::1      ICMPv6 86 Neighbor Advertisement fe80::5054:ff:fe3b:831a (ovr) is at
52:54:00:3b:83:1a
  5   0.199485 RealtekU_3b:83:1a -> Broadcast    ARP 42 Gratuitous ARP for 192.168.6.2 (Request)
  6   0.199492 fe80::5054:ff:fe3b:831a -> ff02::1      ICMPv6 86 Neighbor Advertisement fe80::5054:ff:fe3b:831a (ovr) is at
52:54:00:3b:83:1a
  7   0.449500 RealtekU_3b:83:1a -> Broadcast    ARP 42 Gratuitous ARP for 192.168.6.2 (Request)
  8   0.449508 fe80::5054:ff:fe3b:831a -> ff02::1      ICMPv6 86 Neighbor Advertisement fe80::5054:ff:fe3b:831a (ovr) is at
52:54:00:3b:83:1a
  9   0.517229  192.168.6.2 -> 192.168.6.1  ICMP 98 Echo (ping) request  id=0x04af, seq=70/17920, ttl=64
 10   0.517277  192.168.6.1 -> 192.168.6.2  ICMP 98 Echo (ping) reply    id=0x04af, seq=70/17920, ttl=64 (request in 9)
 11   0.799521 RealtekU_3b:83:1a -> Broadcast    ARP 42 Gratuitous ARP for 192.168.6.2 (Request)
 12   0.799553 fe80::5054:ff:fe3b:831a -> ff02::1      ICMPv6 86 Neighbor Advertisement fe80::5054:ff:fe3b:831a (ovr) is at
52:54:00:3b:83:1a
 13   1.517210  192.168.6.2 -> 192.168.6.1  ICMP 98 Echo (ping) request  id=0x04af, seq=71/18176, ttl=64
 14   1.517238  192.168.6.1 -> 192.168.6.2  ICMP 98 Echo (ping) reply    id=0x04af, seq=71/18176, ttl=64 (request in 13)
 15   2.517219  192.168.6.2 -> 192.168.6.1  ICMP 98 Echo (ping) request  id=0x04af, seq=72/18432, ttl=64
 16   2.517256  192.168.6.1 -> 192.168.6.2  ICMP 98 Echo (ping) reply    id=0x04af, seq=72/18432, ttl=64 (request in 15)
 17   3.517497  192.168.6.2 -> 192.168.6.1  ICMP 98 Echo (ping) request  id=0x04af, seq=73/18688, ttl=64
 18   3.517518  192.168.6.1 -> 192.168.6.2  ICMP 98 Echo (ping) reply    id=0x04af, seq=73/18688, ttl=64 (request in 17)
 19   4.517219  192.168.6.2 -> 192.168.6.1  ICMP 98 Echo (ping) request  id=0x04af, seq=74/18944, ttl=64
 20   4.517237  192.168.6.1 -> 192.168.6.2  ICMP 98 Echo (ping) reply    id=0x04af, seq=74/18944, ttl=64 (request in 19)
 21   5.517222  192.168.6.2 -> 192.168.6.1  ICMP 98 Echo (ping) request  id=0x04af, seq=75/19200, ttl=64
 22   5.517242  192.168.6.1 -> 192.168.6.2  ICMP 98 Echo (ping) reply    id=0x04af, seq=75/19200, ttl=64 (request in 21)
 23   6.517235  192.168.6.2 -> 192.168.6.1  ICMP 98 Echo (ping) request  id=0x04af, seq=76/19456, ttl=64
 24   6.517256  192.168.6.1 -> 192.168.6.2  ICMP 98 Echo (ping) reply    id=0x04af, seq=76/19456, ttl=64 (request in 23)
 25   6.531466 be:e1:71:c1:47:4d -> RealtekU_3b:83:1a ARP 42 Who has 192.168.6.2?  Tell 192.168.6.1
 26   6.531619 RealtekU_3b:83:1a -> be:e1:71:c1:47:4d ARP 42 192.168.6.2 is at 52:54:00:3b:83:1a
 27   7.517212  192.168.6.2 -> 192.168.6.1  ICMP 98 Echo (ping) request  id=0x04af, seq=77/19712, ttl=64
 28   7.517229  192.168.6.1 -> 192.168.6.2  ICMP 98 Echo (ping) reply    id=0x04af, seq=77/19712, ttl=64 (request in 27)

 But there's one important detail here. Any replicated network interfaces (LOCAL port in my example) should be fully cloned on both
hosts, including MAC addresses. Otherwise after the migration the guest continues to send packets to old MAC, and, obvious, there's
still ping loss until it redoes the ARP for its ping target.

>  And what's the output of 'grep virtio /proc/interrupts' inside guest?

11:          0          0          0          0   IO-APIC  11-fasteoi   uhci_hcd:usb1, virtio3
 24:          0          0          0          0   PCI-MSI 114688-edge      virtio2-config
 25:       3544          0          0          0   PCI-MSI 114689-edge      virtio2-req.0
 26:         10          0          0          0   PCI-MSI 49152-edge      virtio0-config
 27:        852          0          0          0   PCI-MSI 49153-edge      virtio0-input.0
 28:          3          0          0          0   PCI-MSI 49154-edge      virtio0-output.0
 29:         10          0          0          0   PCI-MSI 65536-edge      virtio1-config
 30:        172          0          0          0   PCI-MSI 65537-edge      virtio1-input.0
 31:          1          0          0          0   PCI-MSI 65538-edge      virtio1-output.0

Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia




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