From e7dc5d7becc558ca2410529045cc95977376f3de Mon Sep 17 00:00:00 2001 From: Matan Azrad Date: Thu, 18 Jan 2018 13:51:43 +0000 Subject: [PATCH] net/vdev_netvsc: implement core functionality As described in more details in the attached documentation (see patch contents), this virtual device driver manages NetVSC interfaces in virtual machines hosted by Hyper-V/Azure platforms. This driver does not manage traffic nor Ethernet devices directly; it acts as a thin configuration layer that automatically instantiates and controls fail-safe PMD instances combining tap and PCI sub-devices, so that each NetVSC interface is exposed as a single consolidated port to DPDK applications. PCI sub-devices being hot-pluggable (e.g. during VM migration), applications automatically benefit from increased throughput when present and automatic fallback on NetVSC otherwise without interruption thanks to fail-safe's hot-plug handling. Once initialized, the sole job of the vdev_netvsc driver is to regularly scan for PCI devices to associate with NetVSC interfaces and feed their addresses to corresponding fail-safe instances. Signed-off-by: Adrien Mazarguil Signed-off-by: Matan Azrad --- doc/guides/nics/vdev_netvsc.rst | 70 ++++ drivers/net/vdev_netvsc/Makefile | 4 + drivers/net/vdev_netvsc/vdev_netvsc.c | 550 +++++++++++++++++++++++++- 3 files changed, 623 insertions(+), 1 deletion(-) diff --git a/doc/guides/nics/vdev_netvsc.rst b/doc/guides/nics/vdev_netvsc.rst index a952908a28..fde1fb8f26 100644 --- a/doc/guides/nics/vdev_netvsc.rst +++ b/doc/guides/nics/vdev_netvsc.rst @@ -12,9 +12,79 @@ platforms. .. _Hyper-V: https://docs.microsoft.com/en-us/windows-hardware/drivers/network/overview-of-hyper-v +Implementation details +---------------------- + +Each instance of this driver effectively needs to drive two devices: the +NetVSC interface proper and its SR-IOV VF (referred to as "physical" from +this point on) counterpart sharing the same MAC address. + +Physical devices are part of the host system and cannot be maintained during +VM migration. From a VM standpoint they appear as hot-plug devices that come +and go without prior notice. + +When the physical device is present, egress and most of the ingress traffic +flows through it; only multicasts and other hypervisor control still flow +through NetVSC. Otherwise, NetVSC acts as a fallback for all traffic. + +To avoid unnecessary code duplication and ensure maximum performance, +handling of physical devices is left to their original PMDs; this virtual +device driver (also known as *vdev*) manages other PMDs as summarized by the +following block diagram:: + + .------------------. + | DPDK application | + `--------+---------' + | + .------+------. + | DPDK ethdev | + `------+------' Control + | | + .------------+------------. v .--------------------. + | failsafe PMD +---------+ vdev_netvsc driver | + `--+-------------------+--' `--------------------' + | | + | .........|......... + | : | : + .----+----. : .----+----. : + | tap PMD | : | any PMD | : + `----+----' : `----+----' : <-- Hot-pluggable + | : | : + .------+-------. : .-----+-----. : + | NetVSC-based | : | SR-IOV VF | : + | netdevice | : | device | : + `--------------' : `-----------' : + :.................: + + +This driver implementation may be temporary and should be improved or removed +either when hot-plug will be fully supported in EAL and bus drivers or when +a new NetVSC driver will be integrated. + Build options ------------- - ``CONFIG_RTE_LIBRTE_VDEV_NETVSC_PMD`` (default ``y``) Toggle compilation of this driver. + +Run-time parameters +------------------- + +To invoke this driver, applications have to explicitly provide the +``--vdev=net_vdev_netvsc`` EAL option. + +The following device parameters are supported: + +- ``iface`` [string] + + Provide a specific NetVSC interface (netdevice) name to attach this driver + to. Can be provided multiple times for additional instances. + +- ``mac`` [string] + + Same as ``iface`` except a suitable NetVSC interface is located using its + MAC address. + +Not specifying either ``iface`` or ``mac`` makes this driver attach itself to +all NetVSC interfaces found on the system. diff --git a/drivers/net/vdev_netvsc/Makefile b/drivers/net/vdev_netvsc/Makefile index 2fb059d9b2..f2b2ac5ec5 100644 --- a/drivers/net/vdev_netvsc/Makefile +++ b/drivers/net/vdev_netvsc/Makefile @@ -13,6 +13,9 @@ EXPORT_MAP := rte_pmd_vdev_netvsc_version.map CFLAGS += -O3 CFLAGS += -g CFLAGS += -std=c11 -pedantic -Wall -Wextra +CFLAGS += -D_XOPEN_SOURCE=600 +CFLAGS += -D_BSD_SOURCE +CFLAGS += -D_DEFAULT_SOURCE CFLAGS += $(WERROR_FLAGS) # Dependencies. @@ -20,6 +23,7 @@ LDLIBS += -lrte_bus_vdev LDLIBS += -lrte_eal LDLIBS += -lrte_ethdev LDLIBS += -lrte_kvargs +LDLIBS += -lrte_net # Source files. SRCS-$(CONFIG_RTE_LIBRTE_VDEV_NETVSC_PMD) += vdev_netvsc.c diff --git a/drivers/net/vdev_netvsc/vdev_netvsc.c b/drivers/net/vdev_netvsc/vdev_netvsc.c index e895b322f3..21c3265edf 100644 --- a/drivers/net/vdev_netvsc/vdev_netvsc.c +++ b/drivers/net/vdev_netvsc/vdev_netvsc.c @@ -3,17 +3,42 @@ * Copyright 2017 Mellanox Technologies, Ltd. */ +#include +#include +#include +#include +#include +#include +#include +#include #include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include #include #include #include +#include +#include +#include +#include #include #include #define VDEV_NETVSC_DRIVER net_vdev_netvsc #define VDEV_NETVSC_ARG_IFACE "iface" #define VDEV_NETVSC_ARG_MAC "mac" +#define VDEV_NETVSC_PROBE_MS 1000 + +#define NETVSC_CLASS_ID "{f8615163-df3e-46c5-913f-f2d2f965ed0e}" #define DRV_LOG(level, ...) \ rte_log(RTE_LOG_ ## level, \ @@ -25,12 +50,495 @@ /** Driver-specific log messages type. */ static int vdev_netvsc_logtype; +/** Context structure for a vdev_netvsc instance. */ +struct vdev_netvsc_ctx { + LIST_ENTRY(vdev_netvsc_ctx) entry; /**< Next entry in list. */ + unsigned int id; /**< Unique ID. */ + char name[64]; /**< Unique name. */ + char devname[64]; /**< Fail-safe instance name. */ + char devargs[256]; /**< Fail-safe device arguments. */ + char if_name[IF_NAMESIZE]; /**< NetVSC netdevice name. */ + unsigned int if_index; /**< NetVSC netdevice index. */ + struct ether_addr if_addr; /**< NetVSC MAC address. */ + int pipe[2]; /**< Fail-safe communication pipe. */ + char yield[256]; /**< PCI sub-device arguments. */ +}; + +/** Context list is common to all driver instances. */ +static LIST_HEAD(, vdev_netvsc_ctx) vdev_netvsc_ctx_list = + LIST_HEAD_INITIALIZER(vdev_netvsc_ctx_list); + +/** Number of entries in context list. */ +static unsigned int vdev_netvsc_ctx_count; + /** Number of driver instances relying on context list. */ static unsigned int vdev_netvsc_ctx_inst; +/** + * Destroy a vdev_netvsc context instance. + * + * @param ctx + * Context to destroy. + */ +static void +vdev_netvsc_ctx_destroy(struct vdev_netvsc_ctx *ctx) +{ + if (ctx->pipe[0] != -1) + close(ctx->pipe[0]); + if (ctx->pipe[1] != -1) + close(ctx->pipe[1]); + free(ctx); +} + +/** + * Iterate over system network interfaces. + * + * This function runs a given callback function for each netdevice found on + * the system. + * + * @param func + * Callback function pointer. List traversal is aborted when this function + * returns a nonzero value. + * @param ... + * Variable parameter list passed as @p va_list to @p func. + * + * @return + * 0 when the entire list is traversed successfully, a negative error code + * in case or failure, or the nonzero value returned by @p func when list + * traversal is aborted. + */ +static int +vdev_netvsc_foreach_iface(int (*func)(const struct if_nameindex *iface, + const struct ether_addr *eth_addr, + va_list ap), ...) +{ + struct if_nameindex *iface = if_nameindex(); + int s = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP); + unsigned int i; + int ret = 0; + + if (!iface) { + ret = -ENOBUFS; + DRV_LOG(ERR, "cannot retrieve system network interfaces"); + goto error; + } + if (s == -1) { + ret = -errno; + DRV_LOG(ERR, "cannot open socket: %s", rte_strerror(errno)); + goto error; + } + for (i = 0; iface[i].if_name; ++i) { + struct ifreq req; + struct ether_addr eth_addr; + va_list ap; + + strncpy(req.ifr_name, iface[i].if_name, sizeof(req.ifr_name)); + if (ioctl(s, SIOCGIFHWADDR, &req) == -1) { + DRV_LOG(WARNING, "cannot retrieve information about" + " interface \"%s\": %s", + req.ifr_name, rte_strerror(errno)); + continue; + } + if (req.ifr_hwaddr.sa_family != ARPHRD_ETHER) { + DRV_LOG(DEBUG, "interface %s is non-ethernet device", + req.ifr_name); + continue; + } + memcpy(eth_addr.addr_bytes, req.ifr_hwaddr.sa_data, + RTE_DIM(eth_addr.addr_bytes)); + va_start(ap, func); + ret = func(&iface[i], ð_addr, ap); + va_end(ap); + if (ret) + break; + } +error: + if (s != -1) + close(s); + if (iface) + if_freenameindex(iface); + return ret; +} + +/** + * Determine if a network interface is NetVSC. + * + * @param[in] iface + * Pointer to netdevice description structure (name and index). + * + * @return + * A nonzero value when interface is detected as NetVSC. In case of error, + * rte_errno is updated and 0 returned. + */ +static int +vdev_netvsc_iface_is_netvsc(const struct if_nameindex *iface) +{ + static const char temp[] = "/sys/class/net/%s/device/class_id"; + char path[sizeof(temp) + IF_NAMESIZE]; + FILE *f; + int ret; + int len = 0; + + ret = snprintf(path, sizeof(path), temp, iface->if_name); + if (ret == -1 || (size_t)ret >= sizeof(path)) { + rte_errno = ENOBUFS; + return 0; + } + f = fopen(path, "r"); + if (!f) { + rte_errno = errno; + return 0; + } + ret = fscanf(f, NETVSC_CLASS_ID "%n", &len); + if (ret == EOF) + rte_errno = errno; + ret = len == (int)strlen(NETVSC_CLASS_ID); + fclose(f); + return ret; +} + +/** + * Retrieve network interface data from sysfs symbolic link. + * + * @param[out] buf + * Output data buffer. + * @param size + * Output buffer size. + * @param[in] if_name + * Netdevice name. + * @param[in] relpath + * Symbolic link path relative to netdevice sysfs entry. + * + * @return + * 0 on success, a negative error code otherwise. + */ +static int +vdev_netvsc_sysfs_readlink(char *buf, size_t size, const char *if_name, + const char *relpath) +{ + int ret; + + ret = snprintf(buf, size, "/sys/class/net/%s/%s", if_name, relpath); + if (ret == -1 || (size_t)ret >= size) + return -ENOBUFS; + ret = readlink(buf, buf, size); + if (ret == -1) + return -errno; + if ((size_t)ret >= size - 1) + return -ENOBUFS; + buf[ret] = '\0'; + return 0; +} + +/** + * Probe a network interface to associate with vdev_netvsc context. + * + * This function determines if the network device matches the properties of + * the NetVSC interface associated with the vdev_netvsc context and + * communicates its bus address to the fail-safe PMD instance if so. + * + * It is normally used with vdev_netvsc_foreach_iface(). + * + * @param[in] iface + * Pointer to netdevice description structure (name and index). + * @param[in] eth_addr + * MAC address associated with @p iface. + * @param ap + * Variable arguments list comprising: + * + * - struct vdev_netvsc_ctx *ctx: + * Context to associate network interface with. + * + * @return + * A nonzero value when interface matches, 0 otherwise or in case of + * error. + */ +static int +vdev_netvsc_device_probe(const struct if_nameindex *iface, + const struct ether_addr *eth_addr, + va_list ap) +{ + struct vdev_netvsc_ctx *ctx = va_arg(ap, struct vdev_netvsc_ctx *); + char buf[RTE_MAX(sizeof(ctx->yield), 256u)]; + const char *addr; + size_t len; + int ret; + + /* Skip non-matching or unwanted NetVSC interfaces. */ + if (ctx->if_index == iface->if_index) { + if (!strcmp(ctx->if_name, iface->if_name)) + return 0; + DRV_LOG(DEBUG, + "NetVSC interface \"%s\" (index %u) renamed \"%s\"", + ctx->if_name, ctx->if_index, iface->if_name); + strncpy(ctx->if_name, iface->if_name, sizeof(ctx->if_name)); + return 0; + } + if (vdev_netvsc_iface_is_netvsc(iface)) + return 0; + if (!is_same_ether_addr(eth_addr, &ctx->if_addr)) + return 0; + /* Look for associated PCI device. */ + ret = vdev_netvsc_sysfs_readlink(buf, sizeof(buf), iface->if_name, + "device/subsystem"); + if (ret) + return 0; + addr = strrchr(buf, '/'); + addr = addr ? addr + 1 : buf; + if (strcmp(addr, "pci")) + return 0; + ret = vdev_netvsc_sysfs_readlink(buf, sizeof(buf), iface->if_name, + "device"); + if (ret) + return 0; + addr = strrchr(buf, '/'); + addr = addr ? addr + 1 : buf; + len = strlen(addr); + if (!len) + return 0; + /* Send PCI device argument to fail-safe PMD instance. */ + if (strcmp(addr, ctx->yield)) + DRV_LOG(DEBUG, "associating PCI device \"%s\" with NetVSC" + " interface \"%s\" (index %u)", addr, ctx->if_name, + ctx->if_index); + memmove(buf, addr, len + 1); + addr = buf; + buf[len] = '\n'; + ret = write(ctx->pipe[1], addr, len + 1); + buf[len] = '\0'; + if (ret == -1) { + if (errno == EINTR || errno == EAGAIN) + return 1; + DRV_LOG(WARNING, "cannot associate PCI device name \"%s\" with" + " interface \"%s\": %s", addr, ctx->if_name, + rte_strerror(errno)); + return 1; + } + if ((size_t)ret != len + 1) { + /* + * Attempt to override previous partial write, no need to + * recover if that fails. + */ + ret = write(ctx->pipe[1], "\n", 1); + (void)ret; + return 1; + } + fsync(ctx->pipe[1]); + memcpy(ctx->yield, addr, len + 1); + return 1; +} + +/** + * Alarm callback that regularly probes system network interfaces. + * + * This callback runs at a frequency determined by VDEV_NETVSC_PROBE_MS as + * long as an vdev_netvsc context instance exists. + * + * @param arg + * Ignored. + */ +static void +vdev_netvsc_alarm(__rte_unused void *arg) +{ + struct vdev_netvsc_ctx *ctx; + int ret; + + LIST_FOREACH(ctx, &vdev_netvsc_ctx_list, entry) { + ret = vdev_netvsc_foreach_iface(vdev_netvsc_device_probe, ctx); + if (ret) + break; + } + if (!vdev_netvsc_ctx_count) + return; + ret = rte_eal_alarm_set(VDEV_NETVSC_PROBE_MS * 1000, + vdev_netvsc_alarm, NULL); + if (ret < 0) { + DRV_LOG(ERR, "unable to reschedule alarm callback: %s", + rte_strerror(-ret)); + } +} + +/** + * Probe a NetVSC interface to generate a vdev_netvsc context from. + * + * This function instantiates vdev_netvsc contexts either for all NetVSC + * devices found on the system or only a subset provided as device + * arguments. + * + * It is normally used with vdev_netvsc_foreach_iface(). + * + * @param[in] iface + * Pointer to netdevice description structure (name and index). + * @param[in] eth_addr + * MAC address associated with @p iface. + * @param ap + * Variable arguments list comprising: + * + * - const char *name: + * Name associated with current driver instance. + * + * - struct rte_kvargs *kvargs: + * Device arguments provided to current driver instance. + * + * - unsigned int specified: + * Number of specific netdevices provided as device arguments. + * + * - unsigned int *matched: + * The number of specified netdevices matched by this function. + * + * @return + * A nonzero value when interface matches, 0 otherwise or in case of + * error. + */ +static int +vdev_netvsc_netvsc_probe(const struct if_nameindex *iface, + const struct ether_addr *eth_addr, + va_list ap) +{ + const char *name = va_arg(ap, const char *); + struct rte_kvargs *kvargs = va_arg(ap, struct rte_kvargs *); + unsigned int specified = va_arg(ap, unsigned int); + unsigned int *matched = va_arg(ap, unsigned int *); + unsigned int i; + struct vdev_netvsc_ctx *ctx; + int ret; + + /* Probe all interfaces when none are specified. */ + if (specified) { + for (i = 0; i != kvargs->count; ++i) { + const struct rte_kvargs_pair *pair = &kvargs->pairs[i]; + + if (!strcmp(pair->key, VDEV_NETVSC_ARG_IFACE)) { + if (!strcmp(pair->value, iface->if_name)) + break; + } else if (!strcmp(pair->key, VDEV_NETVSC_ARG_MAC)) { + struct ether_addr tmp; + + if (sscanf(pair->value, + "%" SCNx8 ":%" SCNx8 ":%" SCNx8 ":" + "%" SCNx8 ":%" SCNx8 ":%" SCNx8, + &tmp.addr_bytes[0], + &tmp.addr_bytes[1], + &tmp.addr_bytes[2], + &tmp.addr_bytes[3], + &tmp.addr_bytes[4], + &tmp.addr_bytes[5]) != 6) { + DRV_LOG(ERR, + "invalid MAC address format" + " \"%s\"", + pair->value); + return -EINVAL; + } + if (is_same_ether_addr(eth_addr, &tmp)) + break; + } + } + if (i == kvargs->count) + return 0; + ++(*matched); + } + /* Weed out interfaces already handled. */ + LIST_FOREACH(ctx, &vdev_netvsc_ctx_list, entry) + if (ctx->if_index == iface->if_index) + break; + if (ctx) { + if (!specified) + return 0; + DRV_LOG(WARNING, + "interface \"%s\" (index %u) is already handled," + " skipping", + iface->if_name, iface->if_index); + return 0; + } + if (!vdev_netvsc_iface_is_netvsc(iface)) { + if (!specified) + return 0; + DRV_LOG(WARNING, + "interface \"%s\" (index %u) is not NetVSC," + " skipping", + iface->if_name, iface->if_index); + return 0; + } + /* Create interface context. */ + ctx = calloc(1, sizeof(*ctx)); + if (!ctx) { + ret = -errno; + DRV_LOG(ERR, "cannot allocate context for interface \"%s\": %s", + iface->if_name, rte_strerror(errno)); + goto error; + } + ctx->id = vdev_netvsc_ctx_count; + strncpy(ctx->if_name, iface->if_name, sizeof(ctx->if_name)); + ctx->if_index = iface->if_index; + ctx->if_addr = *eth_addr; + ctx->pipe[0] = -1; + ctx->pipe[1] = -1; + ctx->yield[0] = '\0'; + if (pipe(ctx->pipe) == -1) { + ret = -errno; + DRV_LOG(ERR, + "cannot allocate control pipe for interface \"%s\": %s", + ctx->if_name, rte_strerror(errno)); + goto error; + } + for (i = 0; i != RTE_DIM(ctx->pipe); ++i) { + int flf = fcntl(ctx->pipe[i], F_GETFL); + + if (flf != -1 && + fcntl(ctx->pipe[i], F_SETFL, flf | O_NONBLOCK) != -1) + continue; + ret = -errno; + DRV_LOG(ERR, "cannot toggle non-blocking flag on control file" + " descriptor #%u (%d): %s", i, ctx->pipe[i], + rte_strerror(errno)); + goto error; + } + /* Generate virtual device name and arguments. */ + i = 0; + ret = snprintf(ctx->name, sizeof(ctx->name), "%s_id%u", + name, ctx->id); + if (ret == -1 || (size_t)ret >= sizeof(ctx->name)) + ++i; + ret = snprintf(ctx->devname, sizeof(ctx->devname), "net_failsafe_%s", + ctx->name); + if (ret == -1 || (size_t)ret >= sizeof(ctx->devname)) + ++i; + ret = snprintf(ctx->devargs, sizeof(ctx->devargs), + "fd(%d),dev(net_tap_%s,remote=%s)", + ctx->pipe[0], ctx->name, ctx->if_name); + if (ret == -1 || (size_t)ret >= sizeof(ctx->devargs)) + ++i; + if (i) { + ret = -ENOBUFS; + DRV_LOG(ERR, "generated virtual device name or argument list" + " too long for interface \"%s\"", ctx->if_name); + goto error; + } + /* Request virtual device generation. */ + DRV_LOG(DEBUG, "generating virtual device \"%s\" with arguments \"%s\"", + ctx->devname, ctx->devargs); + vdev_netvsc_foreach_iface(vdev_netvsc_device_probe, ctx); + ret = rte_eal_hotplug_add("vdev", ctx->devname, ctx->devargs); + if (ret) + goto error; + LIST_INSERT_HEAD(&vdev_netvsc_ctx_list, ctx, entry); + ++vdev_netvsc_ctx_count; + DRV_LOG(DEBUG, "added NetVSC interface \"%s\" to context list", + ctx->if_name); + return 0; +error: + if (ctx) + vdev_netvsc_ctx_destroy(ctx); + return ret; +} + /** * Probe NetVSC interfaces. * + * This function probes system netdevices according to the specified device + * arguments and starts a periodic alarm callback to notify the resulting + * fail-safe PMD instances of their sub-devices whereabouts. + * * @param dev * Virtual device context for driver instance. * @@ -49,12 +557,40 @@ vdev_netvsc_vdev_probe(struct rte_vdev_device *dev) const char *args = rte_vdev_device_args(dev); struct rte_kvargs *kvargs = rte_kvargs_parse(args ? args : "", vdev_netvsc_arg); + unsigned int specified = 0; + unsigned int matched = 0; + unsigned int i; + int ret; DRV_LOG(DEBUG, "invoked as \"%s\", using arguments \"%s\"", name, args); if (!kvargs) { DRV_LOG(ERR, "cannot parse arguments list"); goto error; } + for (i = 0; i != kvargs->count; ++i) { + const struct rte_kvargs_pair *pair = &kvargs->pairs[i]; + + if (!strcmp(pair->key, VDEV_NETVSC_ARG_IFACE) || + !strcmp(pair->key, VDEV_NETVSC_ARG_MAC)) + ++specified; + } + rte_eal_alarm_cancel(vdev_netvsc_alarm, NULL); + /* Gather interfaces. */ + ret = vdev_netvsc_foreach_iface(vdev_netvsc_netvsc_probe, name, kvargs, + specified, &matched); + if (ret < 0) + goto error; + if (matched < specified) + DRV_LOG(WARNING, + "some of the specified parameters did not match" + " recognized network interfaces"); + ret = rte_eal_alarm_set(VDEV_NETVSC_PROBE_MS * 1000, + vdev_netvsc_alarm, NULL); + if (ret < 0) { + DRV_LOG(ERR, "unable to schedule alarm callback: %s", + rte_strerror(-ret)); + goto error; + } error: if (kvargs) rte_kvargs_free(kvargs); @@ -65,6 +601,9 @@ error: /** * Remove driver instance. * + * The alarm callback and underlying vdev_netvsc context instances are only + * destroyed after the last PMD instance is removed. + * * @param dev * Virtual device context for driver instance. * @@ -74,7 +613,16 @@ error: static int vdev_netvsc_vdev_remove(__rte_unused struct rte_vdev_device *dev) { - --vdev_netvsc_ctx_inst; + if (--vdev_netvsc_ctx_inst) + return 0; + rte_eal_alarm_cancel(vdev_netvsc_alarm, NULL); + while (!LIST_EMPTY(&vdev_netvsc_ctx_list)) { + struct vdev_netvsc_ctx *ctx = LIST_FIRST(&vdev_netvsc_ctx_list); + + LIST_REMOVE(ctx, entry); + --vdev_netvsc_ctx_count; + vdev_netvsc_ctx_destroy(ctx); + } return 0; } -- 2.20.1