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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /tools/virtio/ringtest/ring.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
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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 'tools/virtio/ringtest/ring.c')
-rw-r--r--tools/virtio/ringtest/ring.c270
1 files changed, 270 insertions, 0 deletions
diff --git a/tools/virtio/ringtest/ring.c b/tools/virtio/ringtest/ring.c
new file mode 100644
index 000000000..58e7d33bd
--- /dev/null
+++ b/tools/virtio/ringtest/ring.c
@@ -0,0 +1,270 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2016 Red Hat, Inc.
+ * Author: Michael S. Tsirkin <mst@redhat.com>
+ *
+ * Simple descriptor-based ring. virtio 0.9 compatible event index is used for
+ * signalling, unconditionally.
+ */
+#define _GNU_SOURCE
+#include "main.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+/* Next - Where next entry will be written.
+ * Prev - "Next" value when event triggered previously.
+ * Event - Peer requested event after writing this entry.
+ */
+static inline bool need_event(unsigned short event,
+ unsigned short next,
+ unsigned short prev)
+{
+ return (unsigned short)(next - event - 1) < (unsigned short)(next - prev);
+}
+
+/* Design:
+ * Guest adds descriptors with unique index values and DESC_HW in flags.
+ * Host overwrites used descriptors with correct len, index, and DESC_HW clear.
+ * Flags are always set last.
+ */
+#define DESC_HW 0x1
+
+struct desc {
+ unsigned short flags;
+ unsigned short index;
+ unsigned len;
+ unsigned long long addr;
+};
+
+/* how much padding is needed to avoid false cache sharing */
+#define HOST_GUEST_PADDING 0x80
+
+/* Mostly read */
+struct event {
+ unsigned short kick_index;
+ unsigned char reserved0[HOST_GUEST_PADDING - 2];
+ unsigned short call_index;
+ unsigned char reserved1[HOST_GUEST_PADDING - 2];
+};
+
+struct data {
+ void *buf; /* descriptor is writeable, we can't get buf from there */
+ void *data;
+} *data;
+
+struct desc *ring;
+struct event *event;
+
+struct guest {
+ unsigned avail_idx;
+ unsigned last_used_idx;
+ unsigned num_free;
+ unsigned kicked_avail_idx;
+ unsigned char reserved[HOST_GUEST_PADDING - 12];
+} guest;
+
+struct host {
+ /* we do not need to track last avail index
+ * unless we have more than one in flight.
+ */
+ unsigned used_idx;
+ unsigned called_used_idx;
+ unsigned char reserved[HOST_GUEST_PADDING - 4];
+} host;
+
+/* implemented by ring */
+void alloc_ring(void)
+{
+ int ret;
+ int i;
+
+ ret = posix_memalign((void **)&ring, 0x1000, ring_size * sizeof *ring);
+ if (ret) {
+ perror("Unable to allocate ring buffer.\n");
+ exit(3);
+ }
+ event = calloc(1, sizeof(*event));
+ if (!event) {
+ perror("Unable to allocate event buffer.\n");
+ exit(3);
+ }
+ guest.avail_idx = 0;
+ guest.kicked_avail_idx = -1;
+ guest.last_used_idx = 0;
+ host.used_idx = 0;
+ host.called_used_idx = -1;
+ for (i = 0; i < ring_size; ++i) {
+ struct desc desc = {
+ .index = i,
+ };
+ ring[i] = desc;
+ }
+ guest.num_free = ring_size;
+ data = calloc(ring_size, sizeof(*data));
+ if (!data) {
+ perror("Unable to allocate data buffer.\n");
+ exit(3);
+ }
+}
+
+/* guest side */
+int add_inbuf(unsigned len, void *buf, void *datap)
+{
+ unsigned head, index;
+
+ if (!guest.num_free)
+ return -1;
+
+ guest.num_free--;
+ head = (ring_size - 1) & (guest.avail_idx++);
+
+ /* Start with a write. On MESI architectures this helps
+ * avoid a shared state with consumer that is polling this descriptor.
+ */
+ ring[head].addr = (unsigned long)(void*)buf;
+ ring[head].len = len;
+ /* read below might bypass write above. That is OK because it's just an
+ * optimization. If this happens, we will get the cache line in a
+ * shared state which is unfortunate, but probably not worth it to
+ * add an explicit full barrier to avoid this.
+ */
+ barrier();
+ index = ring[head].index;
+ data[index].buf = buf;
+ data[index].data = datap;
+ /* Barrier A (for pairing) */
+ smp_release();
+ ring[head].flags = DESC_HW;
+
+ return 0;
+}
+
+void *get_buf(unsigned *lenp, void **bufp)
+{
+ unsigned head = (ring_size - 1) & guest.last_used_idx;
+ unsigned index;
+ void *datap;
+
+ if (ring[head].flags & DESC_HW)
+ return NULL;
+ /* Barrier B (for pairing) */
+ smp_acquire();
+ *lenp = ring[head].len;
+ index = ring[head].index & (ring_size - 1);
+ datap = data[index].data;
+ *bufp = data[index].buf;
+ data[index].buf = NULL;
+ data[index].data = NULL;
+ guest.num_free++;
+ guest.last_used_idx++;
+ return datap;
+}
+
+bool used_empty()
+{
+ unsigned head = (ring_size - 1) & guest.last_used_idx;
+
+ return (ring[head].flags & DESC_HW);
+}
+
+void disable_call()
+{
+ /* Doing nothing to disable calls might cause
+ * extra interrupts, but reduces the number of cache misses.
+ */
+}
+
+bool enable_call()
+{
+ event->call_index = guest.last_used_idx;
+ /* Flush call index write */
+ /* Barrier D (for pairing) */
+ smp_mb();
+ return used_empty();
+}
+
+void kick_available(void)
+{
+ bool need;
+
+ /* Flush in previous flags write */
+ /* Barrier C (for pairing) */
+ smp_mb();
+ need = need_event(event->kick_index,
+ guest.avail_idx,
+ guest.kicked_avail_idx);
+
+ guest.kicked_avail_idx = guest.avail_idx;
+ if (need)
+ kick();
+}
+
+/* host side */
+void disable_kick()
+{
+ /* Doing nothing to disable kicks might cause
+ * extra interrupts, but reduces the number of cache misses.
+ */
+}
+
+bool enable_kick()
+{
+ event->kick_index = host.used_idx;
+ /* Barrier C (for pairing) */
+ smp_mb();
+ return avail_empty();
+}
+
+bool avail_empty()
+{
+ unsigned head = (ring_size - 1) & host.used_idx;
+
+ return !(ring[head].flags & DESC_HW);
+}
+
+bool use_buf(unsigned *lenp, void **bufp)
+{
+ unsigned head = (ring_size - 1) & host.used_idx;
+
+ if (!(ring[head].flags & DESC_HW))
+ return false;
+
+ /* make sure length read below is not speculated */
+ /* Barrier A (for pairing) */
+ smp_acquire();
+
+ /* simple in-order completion: we don't need
+ * to touch index at all. This also means we
+ * can just modify the descriptor in-place.
+ */
+ ring[head].len--;
+ /* Make sure len is valid before flags.
+ * Note: alternative is to write len and flags in one access -
+ * possible on 64 bit architectures but wmb is free on Intel anyway
+ * so I have no way to test whether it's a gain.
+ */
+ /* Barrier B (for pairing) */
+ smp_release();
+ ring[head].flags = 0;
+ host.used_idx++;
+ return true;
+}
+
+void call_used(void)
+{
+ bool need;
+
+ /* Flush in previous flags write */
+ /* Barrier D (for pairing) */
+ smp_mb();
+
+ need = need_event(event->call_index,
+ host.used_idx,
+ host.called_used_idx);
+
+ host.called_used_idx = host.used_idx;
+
+ if (need)
+ call();
+}