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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/networking/net_failover.rst | |
download | linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip |
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski:
"Core:
- Add dedicated kmem_cache for typical/small skb->head, avoid having
to access struct page at kfree time, and improve memory use.
- Introduce sysctl to set default RPS configuration for new netdevs.
- Define Netlink protocol specification format which can be used to
describe messages used by each family and auto-generate parsers.
Add tools for generating kernel data structures and uAPI headers.
- Expose all net/core sysctls inside netns.
- Remove 4s sleep in netpoll if carrier is instantly detected on
boot.
- Add configurable limit of MDB entries per port, and port-vlan.
- Continue populating drop reasons throughout the stack.
- Retire a handful of legacy Qdiscs and classifiers.
Protocols:
- Support IPv4 big TCP (TSO frames larger than 64kB).
- Add IP_LOCAL_PORT_RANGE socket option, to control local port range
on socket by socket basis.
- Track and report in procfs number of MPTCP sockets used.
- Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
manager.
- IPv6: don't check net.ipv6.route.max_size and rely on garbage
collection to free memory (similarly to IPv4).
- Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).
- ICMP: add per-rate limit counters.
- Add support for user scanning requests in ieee802154.
- Remove static WEP support.
- Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
reporting.
- WiFi 7 EHT channel puncturing support (client & AP).
BPF:
- Add a rbtree data structure following the "next-gen data structure"
precedent set by recently added linked list, that is, by using
kfunc + kptr instead of adding a new BPF map type.
- Expose XDP hints via kfuncs with initial support for RX hash and
timestamp metadata.
- Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
better support decap on GRE tunnel devices not operating in collect
metadata.
- Improve x86 JIT's codegen for PROBE_MEM runtime error checks.
- Remove the need for trace_printk_lock for bpf_trace_printk and
bpf_trace_vprintk helpers.
- Extend libbpf's bpf_tracing.h support for tracing arguments of
kprobes/uprobes and syscall as a special case.
- Significantly reduce the search time for module symbols by
livepatch and BPF.
- Enable cpumasks to be used as kptrs, which is useful for tracing
programs tracking which tasks end up running on which CPUs in
different time intervals.
- Add support for BPF trampoline on s390x and riscv64.
- Add capability to export the XDP features supported by the NIC.
- Add __bpf_kfunc tag for marking kernel functions as kfuncs.
- Add cgroup.memory=nobpf kernel parameter option to disable BPF
memory accounting for container environments.
Netfilter:
- Remove the CLUSTERIP target. It has been marked as obsolete for
years, and we still have WARN splats wrt races of the out-of-band
/proc interface installed by this target.
- Add 'destroy' commands to nf_tables. They are identical to the
existing 'delete' commands, but do not return an error if the
referenced object (set, chain, rule...) did not exist.
Driver API:
- Improve cpumask_local_spread() locality to help NICs set the right
IRQ affinity on AMD platforms.
- Separate C22 and C45 MDIO bus transactions more clearly.
- Introduce new DCB table to control DSCP rewrite on egress.
- Support configuration of Physical Layer Collision Avoidance (PLCA)
Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
shared medium Ethernet.
- Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
preemption of low priority frames by high priority frames.
- Add support for controlling MACSec offload using netlink SET.
- Rework devlink instance refcounts to allow registration and
de-registration under the instance lock. Split the code into
multiple files, drop some of the unnecessarily granular locks and
factor out common parts of netlink operation handling.
- Add TX frame aggregation parameters (for USB drivers).
- Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
messages with notifications for debug.
- Allow offloading of UDP NEW connections via act_ct.
- Add support for per action HW stats in TC.
- Support hardware miss to TC action (continue processing in SW from
a specific point in the action chain).
- Warn if old Wireless Extension user space interface is used with
modern cfg80211/mac80211 drivers. Do not support Wireless
Extensions for Wi-Fi 7 devices at all. Everyone should switch to
using nl80211 interface instead.
- Improve the CAN bit timing configuration. Use extack to return
error messages directly to user space, update the SJW handling,
including the definition of a new default value that will benefit
CAN-FD controllers, by increasing their oscillator tolerance.
New hardware / drivers:
- Ethernet:
- nVidia BlueField-3 support (control traffic driver)
- Ethernet support for imx93 SoCs
- Motorcomm yt8531 gigabit Ethernet PHY
- onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
- Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
- Amlogic gxl MDIO mux
- WiFi:
- RealTek RTL8188EU (rtl8xxxu)
- Qualcomm Wi-Fi 7 devices (ath12k)
- CAN:
- Renesas R-Car V4H
Drivers:
- Bluetooth:
- Set Per Platform Antenna Gain (PPAG) for Intel controllers.
- Ethernet NICs:
- Intel (1G, igc):
- support TSN / Qbv / packet scheduling features of i226 model
- Intel (100G, ice):
- use GNSS subsystem instead of TTY
- multi-buffer XDP support
- extend support for GPIO pins to E823 devices
- nVidia/Mellanox:
- update the shared buffer configuration on PFC commands
- implement PTP adjphase function for HW offset control
- TC support for Geneve and GRE with VF tunnel offload
- more efficient crypto key management method
- multi-port eswitch support
- Netronome/Corigine:
- add DCB IEEE support
- support IPsec offloading for NFP3800
- Freescale/NXP (enetc):
- support XDP_REDIRECT for XDP non-linear buffers
- improve reconfig, avoid link flap and waiting for idle
- support MAC Merge layer
- Other NICs:
- sfc/ef100: add basic devlink support for ef100
- ionic: rx_push mode operation (writing descriptors via MMIO)
- bnxt: use the auxiliary bus abstraction for RDMA
- r8169: disable ASPM and reset bus in case of tx timeout
- cpsw: support QSGMII mode for J721e CPSW9G
- cpts: support pulse-per-second output
- ngbe: add an mdio bus driver
- usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
- r8152: handle devices with FW with NCM support
- amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
- virtio-net: support multi buffer XDP
- virtio/vsock: replace virtio_vsock_pkt with sk_buff
- tsnep: XDP support
- Ethernet high-speed switches:
- nVidia/Mellanox (mlxsw):
- add support for latency TLV (in FW control messages)
- Microchip (sparx5):
- separate explicit and implicit traffic forwarding rules, make
the implicit rules always active
- add support for egress DSCP rewrite
- IS0 VCAP support (Ingress Classification)
- IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
etc.)
- ES2 VCAP support (Egress Access Control)
- support for Per-Stream Filtering and Policing (802.1Q,
8.6.5.1)
- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- add MAB (port auth) offload support
- enable PTP receive for mv88e6390
- NXP (ocelot):
- support MAC Merge layer
- support for the the vsc7512 internal copper phys
- Microchip:
- lan9303: convert to PHYLINK
- lan966x: support TC flower filter statistics
- lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
- lan937x: support Credit Based Shaper configuration
- ksz9477: support Energy Efficient Ethernet
- other:
- qca8k: convert to regmap read/write API, use bulk operations
- rswitch: Improve TX timestamp accuracy
- Intel WiFi (iwlwifi):
- EHT (Wi-Fi 7) rate reporting
- STEP equalizer support: transfer some STEP (connection to radio
on platforms with integrated wifi) related parameters from the
BIOS to the firmware.
- Qualcomm 802.11ax WiFi (ath11k):
- IPQ5018 support
- Fine Timing Measurement (FTM) responder role support
- channel 177 support
- MediaTek WiFi (mt76):
- per-PHY LED support
- mt7996: EHT (Wi-Fi 7) support
- Wireless Ethernet Dispatch (WED) reset support
- switch to using page pool allocator
- RealTek WiFi (rtw89):
- support new version of Bluetooth co-existance
- Mobile:
- rmnet: support TX aggregation"
* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
page_pool: add a comment explaining the fragment counter usage
net: ethtool: fix __ethtool_dev_mm_supported() implementation
ethtool: pse-pd: Fix double word in comments
xsk: add linux/vmalloc.h to xsk.c
sefltests: netdevsim: wait for devlink instance after netns removal
selftest: fib_tests: Always cleanup before exit
net/mlx5e: Align IPsec ASO result memory to be as required by hardware
net/mlx5e: TC, Set CT miss to the specific ct action instance
net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
net/mlx5: Refactor tc miss handling to a single function
net/mlx5: Kconfig: Make tc offload depend on tc skb extension
net/sched: flower: Support hardware miss to tc action
net/sched: flower: Move filter handle initialization earlier
net/sched: cls_api: Support hardware miss to tc action
net/sched: Rename user cookie and act cookie
sfc: fix builds without CONFIG_RTC_LIB
sfc: clean up some inconsistent indentings
net/mlx4_en: Introduce flexible array to silence overflow warning
net: lan966x: Fix possible deadlock inside PTP
net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
...
Diffstat (limited to 'Documentation/networking/net_failover.rst')
-rw-r--r-- | Documentation/networking/net_failover.rst | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/Documentation/networking/net_failover.rst b/Documentation/networking/net_failover.rst new file mode 100644 index 000000000..f4e1b4e07 --- /dev/null +++ b/Documentation/networking/net_failover.rst @@ -0,0 +1,184 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============ +NET_FAILOVER +============ + +Overview +======== + +The net_failover driver provides an automated failover mechanism via APIs +to create and destroy a failover master netdev and manages a primary and +standby slave netdevs that get registered via the generic failover +infrastructure. + +The failover netdev acts a master device and controls 2 slave devices. The +original paravirtual interface is registered as 'standby' slave netdev and +a passthru/vf device with the same MAC gets registered as 'primary' slave +netdev. Both 'standby' and 'failover' netdevs are associated with the same +'pci' device. The user accesses the network interface via 'failover' netdev. +The 'failover' netdev chooses 'primary' netdev as default for transmits when +it is available with link up and running. + +This can be used by paravirtual drivers to enable an alternate low latency +datapath. It also enables hypervisor controlled live migration of a VM with +direct attached VF by failing over to the paravirtual datapath when the VF +is unplugged. + +virtio-net accelerated datapath: STANDBY mode +============================================= + +net_failover enables hypervisor controlled accelerated datapath to virtio-net +enabled VMs in a transparent manner with no/minimal guest userspace changes. + +To support this, the hypervisor needs to enable VIRTIO_NET_F_STANDBY +feature on the virtio-net interface and assign the same MAC address to both +virtio-net and VF interfaces. + +Here is an example libvirt XML snippet that shows such configuration: +:: + + <interface type='network'> + <mac address='52:54:00:00:12:53'/> + <source network='enp66s0f0_br'/> + <target dev='tap01'/> + <model type='virtio'/> + <driver name='vhost' queues='4'/> + <link state='down'/> + <teaming type='persistent'/> + <alias name='ua-backup0'/> + </interface> + <interface type='hostdev' managed='yes'> + <mac address='52:54:00:00:12:53'/> + <source> + <address type='pci' domain='0x0000' bus='0x42' slot='0x02' function='0x5'/> + </source> + <teaming type='transient' persistent='ua-backup0'/> + </interface> + +In this configuration, the first device definition is for the virtio-net +interface and this acts as the 'persistent' device indicating that this +interface will always be plugged in. This is specified by the 'teaming' tag with +required attribute type having value 'persistent'. The link state for the +virtio-net device is set to 'down' to ensure that the 'failover' netdev prefers +the VF passthrough device for normal communication. The virtio-net device will +be brought UP during live migration to allow uninterrupted communication. + +The second device definition is for the VF passthrough interface. Here the +'teaming' tag is provided with type 'transient' indicating that this device may +periodically be unplugged. A second attribute - 'persistent' is provided and +points to the alias name declared for the virtio-net device. + +Booting a VM with the above configuration will result in the following 3 +interfaces created in the VM: +:: + + 4: ens10: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 + link/ether 52:54:00:00:12:53 brd ff:ff:ff:ff:ff:ff + inet 192.168.12.53/24 brd 192.168.12.255 scope global dynamic ens10 + valid_lft 42482sec preferred_lft 42482sec + inet6 fe80::97d8:db2:8c10:b6d6/64 scope link + valid_lft forever preferred_lft forever + 5: ens10nsby: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel master ens10 state DOWN group default qlen 1000 + link/ether 52:54:00:00:12:53 brd ff:ff:ff:ff:ff:ff + 7: ens11: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master ens10 state UP group default qlen 1000 + link/ether 52:54:00:00:12:53 brd ff:ff:ff:ff:ff:ff + +Here, ens10 is the 'failover' master interface, ens10nsby is the slave 'standby' +virtio-net interface, and ens11 is the slave 'primary' VF passthrough interface. + +One point to note here is that some user space network configuration daemons +like systemd-networkd, ifupdown, etc, do not understand the 'net_failover' +device; and on the first boot, the VM might end up with both 'failover' device +and VF acquiring IP addresses (either same or different) from the DHCP server. +This will result in lack of connectivity to the VM. So some tweaks might be +needed to these network configuration daemons to make sure that an IP is +received only on the 'failover' device. + +Below is the patch snippet used with 'cloud-ifupdown-helper' script found on +Debian cloud images: + +:: + @@ -27,6 +27,8 @@ do_setup() { + local working="$cfgdir/.$INTERFACE" + local final="$cfgdir/$INTERFACE" + + + if [ -d "/sys/class/net/${INTERFACE}/master" ]; then exit 0; fi + + + if ifup --no-act "$INTERFACE" > /dev/null 2>&1; then + # interface is already known to ifupdown, no need to generate cfg + log "Skipping configuration generation for $INTERFACE" + + +Live Migration of a VM with SR-IOV VF & virtio-net in STANDBY mode +================================================================== + +net_failover also enables hypervisor controlled live migration to be supported +with VMs that have direct attached SR-IOV VF devices by automatic failover to +the paravirtual datapath when the VF is unplugged. + +Here is a sample script that shows the steps to initiate live migration from +the source hypervisor. Note: It is assumed that the VM is connected to a +software bridge 'br0' which has a single VF attached to it along with the vnet +device to the VM. This is not the VF that was passthrough'd to the VM (seen in +the vf.xml file). +:: + + # cat vf.xml + <interface type='hostdev' managed='yes'> + <mac address='52:54:00:00:12:53'/> + <source> + <address type='pci' domain='0x0000' bus='0x42' slot='0x02' function='0x5'/> + </source> + <teaming type='transient' persistent='ua-backup0'/> + </interface> + + # Source Hypervisor migrate.sh + #!/bin/bash + + DOMAIN=vm-01 + PF=ens6np0 + VF=ens6v1 # VF attached to the bridge. + VF_NUM=1 + TAP_IF=vmtap01 # virtio-net interface in the VM. + VF_XML=vf.xml + + MAC=52:54:00:00:12:53 + ZERO_MAC=00:00:00:00:00:00 + + # Set the virtio-net interface up. + virsh domif-setlink $DOMAIN $TAP_IF up + + # Remove the VF that was passthrough'd to the VM. + virsh detach-device --live --config $DOMAIN $VF_XML + + ip link set $PF vf $VF_NUM mac $ZERO_MAC + + # Add FDB entry for traffic to continue going to the VM via + # the VF -> br0 -> vnet interface path. + bridge fdb add $MAC dev $VF + bridge fdb add $MAC dev $TAP_IF master + + # Migrate the VM + virsh migrate --live --persistent $DOMAIN qemu+ssh://$REMOTE_HOST/system + + # Clean up FDB entries after migration completes. + bridge fdb del $MAC dev $VF + bridge fdb del $MAC dev $TAP_IF master + +On the destination hypervisor, a shared bridge 'br0' is created before migration +starts, and a VF from the destination PF is added to the bridge. Similarly an +appropriate FDB entry is added. + +The following script is executed on the destination hypervisor once migration +completes, and it reattaches the VF to the VM and brings down the virtio-net +interface. + +:: + # reattach-vf.sh + #!/bin/bash + + bridge fdb del 52:54:00:00:12:53 dev ens36v0 + bridge fdb del 52:54:00:00:12:53 dev vmtap01 master + virsh attach-device --config --live vm01 vf.xml + virsh domif-setlink vm01 vmtap01 down |