From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 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(). ... --- Documentation/networking/net_failover.rst | 184 ++++++++++++++++++++++++++++++ 1 file changed, 184 insertions(+) create mode 100644 Documentation/networking/net_failover.rst (limited to 'Documentation/networking/net_failover.rst') 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: +:: + + + + + + + + + + + + + + +
+ + + + +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: 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: 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: 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 + + + +
+ + + + + # 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 -- cgit v1.2.3