[ovs-dev] [PATCH RFC 2/3] netdev-linux: add new netdev type afxdp.

William Tu u9012063 at gmail.com
Sat Aug 18 00:29:35 UTC 2018


The patch creates a new netdev type "afxdp" and copies some of the
afxdp api implementation from xdpsock_user.c at linux sample code.
The afxdp ebpf programs/maps are loaded when dpif-netdev is created,
and when users add a netdev with type="afxdp", ovs attaches the
ebpf program/map to the netdev, and initializes the af_xdp socket.

Signed-off-by: William Tu <u9012063 at gmail.com>
---
 lib/automake.mk       |   3 +-
 lib/dpif-netdev.c     |  74 ++++-
 lib/if_xdp.h          |  79 ++++++
 lib/netdev-dummy.c    |   1 +
 lib/netdev-linux.c    | 741 +++++++++++++++++++++++++++++++++++++++++++++++++-
 lib/netdev-provider.h |   2 +
 lib/netdev-vport.c    |   4 +
 lib/netdev.c          |  11 +
 lib/netdev.h          |   1 +
 9 files changed, 907 insertions(+), 9 deletions(-)
 create mode 100644 lib/if_xdp.h

diff --git a/lib/automake.mk b/lib/automake.mk
index 61fef23152d3..e0528f74989f 100644
--- a/lib/automake.mk
+++ b/lib/automake.mk
@@ -302,7 +302,8 @@ lib_libopenvswitch_la_SOURCES = \
 	lib/lldp/lldpd.c \
 	lib/lldp/lldpd.h \
 	lib/lldp/lldpd-structs.c \
-	lib/lldp/lldpd-structs.h
+	lib/lldp/lldpd-structs.h \
+	lib/if_xdp.h
 
 if WIN32
 lib_libopenvswitch_la_SOURCES += \
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index baff020fe3d0..9f0300ac4e91 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -76,6 +76,11 @@
 #include "unixctl.h"
 #include "util.h"
 
+#include "bpf.h"
+#include "netdev.h"
+#include "openvswitch/thread.h"
+#include <bpf/bpf.h>
+
 VLOG_DEFINE_THIS_MODULE(dpif_netdev);
 
 #define FLOW_DUMP_MAX_BATCH 50
@@ -507,6 +512,12 @@ struct tx_port {
     struct dp_netdev_rxq *output_pkts_rxqs[NETDEV_MAX_BURST];
 };
 
+static struct dp_bpf {
+    struct bpf_state bpf;
+    struct netdev *outport; /* Used for downcall. */
+} bpf_datapath;
+
+
 /* A set of properties for the current processing loop that is not directly
  * associated with the pmd thread itself, but with the packets being
  * processed or the short-term system configuration (for example, time).
@@ -1121,6 +1132,8 @@ dpif_netdev_pmd_info(struct unixctl_conn *conn, int argc, const char *argv[],
 static int
 dpif_netdev_init(void)
 {
+	int error;
+	static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
     static enum pmd_info_type show_aux = PMD_INFO_SHOW_STATS,
                               clear_aux = PMD_INFO_CLEAR_STATS,
                               poll_aux = PMD_INFO_SHOW_RXQ;
@@ -1137,6 +1150,17 @@ dpif_netdev_init(void)
     unixctl_command_register("dpif-netdev/pmd-rxq-rebalance", "[dp]",
                              0, 1, dpif_netdev_pmd_rebalance,
                              NULL);
+
+	// load the bpf program
+	if (ovsthread_once_start(&once)) {
+		// we don't need downcall device here
+		error = bpf_get(&bpf_datapath.bpf, true);
+		if (error) {
+			VLOG_ERR("%s: Load BPF datapath failed", __func__);
+		}
+	}
+	ovsthread_once_done(&once);
+
     return 0;
 }
 
@@ -1504,7 +1528,26 @@ dp_netdev_reload_pmd__(struct dp_netdev_pmd_thread *pmd)
     ovs_mutex_cond_wait(&pmd->cond, &pmd->cond_mutex);
     ovs_mutex_unlock(&pmd->cond_mutex);
 }
-
+/*
+static bool output_to_local_stack(struct netdev *netdev)
+{
+    return !strcmp(netdev_get_type(netdev), "tap");
+}
+*/
+static bool netdev_support_xdp(const char *devname)
+{
+    /*
+    struct netdev_linux *netdev_linux = netdev_linux_cast(netdev_linux);
+    if (netdev_linux->ifindex == 0)
+        return false;
+*/
+    if (!strstr(devname, "afxdp")) {
+        return false;
+    } else {
+        return true;
+    }
+}
+static int afxdp_idx;
 static int
 port_create(const char *devname, const char *type,
             odp_port_t port_no, struct dp_netdev_port **portp)
@@ -1519,7 +1562,7 @@ port_create(const char *devname, const char *type,
 
     /* Open and validate network device. */
     error = netdev_open(devname, type, &netdev);
-    VLOG_INFO("%s %s error %d", __func__, devname, error);
+    VLOG_INFO("%s %s type = %s error %d", __func__, devname, type, error);
     if (error) {
         return error;
     }
@@ -1538,6 +1581,23 @@ port_create(const char *devname, const char *type,
         goto out;
     }
 
+    if (!strcmp(type, "afxdp")) {
+        // or a separate set_af_xdp?
+        // FIXME:
+        VLOG_INFO("using afxdp port idx %d", afxdp_idx);
+        error = netdev_set_xdp(netdev, &bpf_datapath.bpf.afxdp[afxdp_idx]);
+        if (error) {
+            VLOG_WARN("%s XDP set failed", __func__);
+            goto out;
+        }
+        error = netdev_set_xskmap(netdev, bpf_datapath.bpf.xsks_map[afxdp_idx].fd);
+        if (error) {
+            VLOG_ERR("%s XSK map set error\n", __func__);
+            goto out;
+        }
+        afxdp_idx++;
+    }
+
     port = xzalloc(sizeof *port);
     port->port_no = port_no;
     port->netdev = netdev;
@@ -5008,8 +5068,11 @@ emc_processing(struct dp_netdev_pmd_thread *pmd,
         struct dp_netdev_flow *flow;
 
         if (OVS_UNLIKELY(dp_packet_size(packet) < ETH_HEADER_LEN)) {
+            static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
+
             dp_packet_delete(packet);
             n_dropped++;
+            VLOG_ERR_RL(&rl, "%s dropped packet size %d\n", __func__, dp_packet_size(packet));
             continue;
         }
 
@@ -5254,6 +5317,13 @@ dp_netdev_input__(struct dp_netdev_pmd_thread *pmd,
     n_batches = 0;
     emc_processing(pmd, packets, keys, batches, &n_batches,
                             md_is_valid, port_no);
+/*
+    if (dp_packet_batch_is_empty(packets)) {
+        VLOG_WARN("%s: batch is empty ", __func__);
+    } else {
+        VLOG_WARN("%s: batch is %lu ", __func__, packets->count);
+    }
+*/
     if (!dp_packet_batch_is_empty(packets)) {
         /* Get ingress port from first packet's metadata. */
         in_port = packets->packets[0]->md.in_port.odp_port;
diff --git a/lib/if_xdp.h b/lib/if_xdp.h
new file mode 100644
index 000000000000..2a8c5780166f
--- /dev/null
+++ b/lib/if_xdp.h
@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * if_xdp: XDP socket user-space interface
+ * Copyright(c) 2018 Intel Corporation.
+ *
+ * Author(s): Björn Töpel <bjorn.topel at intel.com>
+ *	      Magnus Karlsson <magnus.karlsson at intel.com>
+ */
+
+#ifndef _LINUX_IF_XDP_H
+#define _LINUX_IF_XDP_H
+
+#include <linux/types.h>
+#include <stdbool.h>
+
+/* Options for the sxdp_flags field */
+#define XDP_SHARED_UMEM	(1 << 0)
+#define XDP_COPY	(1 << 1) /* Force copy-mode */
+#define XDP_ZEROCOPY	(1 << 2) /* Force zero-copy mode */
+
+struct sockaddr_xdp {
+	__u16 sxdp_family;
+	__u16 sxdp_flags;
+	__u32 sxdp_ifindex;
+	__u32 sxdp_queue_id;
+	__u32 sxdp_shared_umem_fd;
+};
+
+struct xdp_ring_offset {
+	__u64 producer;
+	__u64 consumer;
+	__u64 desc;
+};
+
+struct xdp_mmap_offsets {
+	struct xdp_ring_offset rx;
+	struct xdp_ring_offset tx;
+	struct xdp_ring_offset fr; /* Fill */
+	struct xdp_ring_offset cr; /* Completion */
+};
+
+/* XDP socket options */
+#define XDP_MMAP_OFFSETS		1
+#define XDP_RX_RING			2
+#define XDP_TX_RING			3
+#define XDP_UMEM_REG			4
+#define XDP_UMEM_FILL_RING		5
+#define XDP_UMEM_COMPLETION_RING	6
+#define XDP_STATISTICS			7
+
+struct xdp_umem_reg {
+	__u64 addr; /* Start of packet data area */
+	__u64 len; /* Length of packet data area */
+	__u32 chunk_size;
+	__u32 headroom;
+};
+
+struct xdp_statistics {
+	__u64 rx_dropped; /* Dropped for reasons other than invalid desc */
+	__u64 rx_invalid_descs; /* Dropped due to invalid descriptor */
+	__u64 tx_invalid_descs; /* Dropped due to invalid descriptor */
+};
+
+/* Pgoff for mmaping the rings */
+#define XDP_PGOFF_RX_RING			  0
+#define XDP_PGOFF_TX_RING		 0x80000000
+#define XDP_UMEM_PGOFF_FILL_RING	0x100000000ULL
+#define XDP_UMEM_PGOFF_COMPLETION_RING	0x180000000ULL
+
+/* Rx/Tx descriptor */
+struct xdp_desc {
+	__u64 addr;
+	__u32 len;
+	__u32 options;
+};
+
+/* UMEM descriptor is __u64 */
+
+#endif /* _LINUX_IF_XDP_H */
diff --git a/lib/netdev-dummy.c b/lib/netdev-dummy.c
index 44c9458a9a22..c7a065ed7ba8 100644
--- a/lib/netdev-dummy.c
+++ b/lib/netdev-dummy.c
@@ -1429,6 +1429,7 @@ netdev_dummy_update_flags(struct netdev *netdev_,
     NULL,                       /* set_policing */              \
     NULL,                       /* set_filter */                \
     NULL,                       /* set_xdp */                   \
+    NULL,                       /* set_xskmap */                   \
     NULL,                       /* get_qos_types */             \
     NULL,                       /* get_qos_capabilities */      \
     NULL,                       /* get_qos */                   \
diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c
index 121dd3bc738e..6546ff88aee6 100644
--- a/lib/netdev-linux.c
+++ b/lib/netdev-linux.c
@@ -88,6 +88,519 @@ COVERAGE_DEFINE(netdev_set_hwaddr);
 COVERAGE_DEFINE(netdev_get_ethtool);
 COVERAGE_DEFINE(netdev_set_ethtool);
 
+#ifdef AFXDP_NETDEV
+// =========================================================
+#ifndef SOL_XDP
+#define SOL_XDP 283
+#endif
+
+#ifndef AF_XDP
+#define AF_XDP 44
+#endif
+
+#ifndef PF_XDP
+#define PF_XDP AF_XDP
+#endif
+
+#define NUM_FRAMES 128
+#define FRAME_HEADROOM 0
+#define FRAME_SIZE 2048
+#define NUM_DESCS 32
+
+#define FQ_NUM_DESCS 32
+#define CQ_NUM_DESCS 32
+
+#define DEBUG_HEXDUMP 0
+
+typedef __u32 u32;
+typedef uint64_t u64;
+
+#include "lib/xdpsock.h"
+static u32 opt_xdp_flags; // now alwyas set to SKB_MODE at bpf_set_link_xdp_fd
+static u32 opt_xdp_bind_flags;
+
+struct xdp_uqueue {
+    u32 cached_prod;
+    u32 cached_cons;
+    u32 mask;
+    u32 size;
+    u32 *producer;
+    u32 *consumer;
+    struct xdp_desc *ring;
+    void *map;
+};
+
+struct xdpsock {
+    struct xdp_uqueue rx;
+    struct xdp_uqueue tx;
+    int sfd;
+    struct xdp_umem *umem;
+    u32 outstanding_tx;
+    unsigned long rx_npkts;
+    unsigned long tx_npkts;
+    unsigned long prev_rx_npkts;
+    unsigned long prev_tx_npkts;
+};
+
+#define MAX_SOCKS 4
+
+#define barrier() __asm__ __volatile__("": : :"memory")
+#define u_smp_rmb() barrier()
+#define u_smp_wmb() barrier()
+#define likely(x) __builtin_expect(!!(x), 1)
+#define unlikely(x) __builtin_expect(!!(x), 0)
+
+static const char pkt_data[] =
+    "\x3c\xfd\xfe\x9e\x7f\x71\xec\xb1\xd7\x98\x3a\xc0\x08\x00\x45\x00"
+    "\x00\x2e\x00\x00\x00\x00\x40\x11\x88\x97\x05\x08\x07\x08\xc8\x14"
+    "\x1e\x04\x10\x92\x10\x92\x00\x1a\x6d\xa3\x34\x33\x1f\x69\x40\x6b"
+    "\x54\x59\xb6\x14\x2d\x11\x44\xbf\xaf\xd9\xbe\xaa";
+
+static inline u32 xq_nb_avail(struct xdp_uqueue *q, u32 ndescs)
+{
+    u32 entries = q->cached_prod - q->cached_cons;
+
+    if (entries == 0) {
+        q->cached_prod = *q->producer;
+        entries = q->cached_prod - q->cached_cons;
+    }
+
+    return (entries > ndescs) ? ndescs : entries;
+}
+
+static inline u32 umem_nb_free(struct xdp_umem_uqueue *q, u32 nb)
+{
+    u32 free_entries = q->cached_cons - q->cached_prod;
+    VLOG_INFO("0: %s cons %d prod %d\n", __func__, q->cached_cons, q->cached_prod);
+
+    if (free_entries >= nb)
+        return free_entries;
+
+    /* Refresh the local tail pointer */
+    q->cached_cons = (*q->consumer + q->size) & q->mask;
+
+    VLOG_INFO("%s cons %d prod %d\n", __func__, q->cached_cons, q->cached_prod);
+    VLOG_INFO("consumer %d, size %d\n", *q->consumer, q->size);
+
+    return q->cached_cons - q->cached_prod;
+}
+
+static inline int umem_fill_to_kernel_ex(struct xdp_umem_uqueue *fq,
+                                         struct xdp_desc *d,
+                                         size_t nb)
+{
+        u32 i;
+
+        VLOG_INFO("%s nb = %d", __func__, nb);
+        if (umem_nb_free(fq, nb) < nb)  {
+            VLOG_ERR("%s error\n", __func__);
+            return -ENOSPC;
+        }
+
+        for (i = 0; i < nb; i++) {
+                u32 idx = fq->cached_prod++ & fq->mask;
+
+                fq->ring[idx] = d[i].addr;
+        }
+
+        u_smp_wmb();
+
+        *fq->producer = fq->cached_prod;
+
+        VLOG_INFO("%s producer at %d\n", __func__, *fq->producer);
+        return 0;
+}
+
+static inline int umem_fill_to_kernel(struct xdp_umem_uqueue *fq, uint64_t *d,
+                      size_t nb)
+{
+    u32 i;
+
+    if (umem_nb_free(fq, nb) < nb) {
+        VLOG_ERR("%s error\n", __func__);
+        return -ENOSPC;
+    }
+
+    for (i = 0; i < nb; i++) {
+        u32 idx = fq->cached_prod++ & fq->mask;
+
+        fq->ring[idx] = d[i];
+    }
+
+    u_smp_wmb();
+
+    *fq->producer = fq->cached_prod;
+
+    VLOG_INFO("%s producer at %d\n", __func__, *fq->producer);
+    return 0;
+}
+
+static inline u32 umem_nb_avail(struct xdp_umem_uqueue *q, u32 nb)
+{
+    u32 entries = q->cached_prod - q->cached_cons;
+
+    if (entries == 0) {
+        q->cached_prod = *q->producer;
+        entries = q->cached_prod - q->cached_cons;
+    }
+
+    return (entries > nb) ? nb : entries;
+}
+
+static inline size_t umem_complete_from_kernel(struct xdp_umem_uqueue *cq,
+                           uint64_t *d, size_t nb)
+{
+    u32 idx, i, entries = umem_nb_avail(cq, nb);
+
+    u_smp_rmb();
+
+    for (i = 0; i < entries; i++) {
+        idx = cq->cached_cons++ & cq->mask;
+        d[i] = cq->ring[idx];
+    }
+
+    if (entries > 0) {
+        u_smp_wmb();
+
+        *cq->consumer = cq->cached_cons;
+    }
+
+    return entries;
+}
+
+static struct xdp_umem *xdp_umem_configure(int sfd)
+{
+    int fq_size = FQ_NUM_DESCS, cq_size = CQ_NUM_DESCS;
+    struct xdp_mmap_offsets off;
+    struct xdp_umem_reg mr;
+    struct xdp_umem *umem;
+    socklen_t optlen;
+    void *bufs;
+
+    umem = calloc(1, sizeof(*umem));
+    ovs_assert(umem);
+
+    VLOG_DBG("enter: %s \n", __func__);
+    ovs_assert(posix_memalign(&bufs, getpagesize(), /* PAGE_SIZE aligned */
+                   NUM_FRAMES * FRAME_SIZE) == 0);
+
+    VLOG_INFO("%s shared umem from %p to %p", __func__,
+              bufs, (char*)bufs + NUM_FRAMES * FRAME_SIZE);
+
+    mr.addr = (__u64)bufs;
+    mr.len = NUM_FRAMES * FRAME_SIZE;
+    mr.chunk_size = FRAME_SIZE;
+    mr.headroom = FRAME_HEADROOM;
+
+    ovs_assert(setsockopt(sfd, SOL_XDP, XDP_UMEM_REG, &mr, sizeof(mr)) == 0);
+    ovs_assert(setsockopt(sfd, SOL_XDP, XDP_UMEM_FILL_RING, &fq_size,
+               sizeof(int)) == 0);
+    ovs_assert(setsockopt(sfd, SOL_XDP, XDP_UMEM_COMPLETION_RING, &cq_size,
+               sizeof(int)) == 0);
+
+    optlen = sizeof(off);
+    ovs_assert(getsockopt(sfd, SOL_XDP, XDP_MMAP_OFFSETS, &off,
+               &optlen) == 0);
+
+    umem->fq.map = mmap(0, off.fr.desc +
+                FQ_NUM_DESCS * sizeof(u64),
+                PROT_READ | PROT_WRITE,
+                MAP_SHARED | MAP_POPULATE, sfd,
+                XDP_UMEM_PGOFF_FILL_RING);
+    ovs_assert(umem->fq.map != MAP_FAILED);
+
+    umem->fq.mask = FQ_NUM_DESCS - 1;
+    umem->fq.size = FQ_NUM_DESCS;
+    umem->fq.producer = (void *)((char *)umem->fq.map + off.fr.producer);
+    umem->fq.consumer = (void *)((char *)umem->fq.map + off.fr.consumer);
+    umem->fq.ring = (void *)((char *)umem->fq.map + off.fr.desc);
+    umem->fq.cached_cons = FQ_NUM_DESCS;
+
+    umem->cq.map = mmap(0, off.cr.desc +
+                 CQ_NUM_DESCS * sizeof(u64),
+                 PROT_READ | PROT_WRITE,
+                 MAP_SHARED | MAP_POPULATE, sfd,
+                 XDP_UMEM_PGOFF_COMPLETION_RING);
+    ovs_assert(umem->cq.map != MAP_FAILED);
+
+    umem->cq.mask = CQ_NUM_DESCS - 1;
+    umem->cq.size = CQ_NUM_DESCS;
+    umem->cq.producer = umem->cq.map + off.cr.producer;
+    umem->cq.consumer = umem->cq.map + off.cr.consumer;
+    umem->cq.ring = umem->cq.map + off.cr.desc;
+
+    umem->frames = bufs;
+    umem->fd = sfd;
+
+#if 0
+    if (opt_bench == BENCH_TXONLY) {
+        int i;
+
+        for (i = 0; i < NUM_FRAMES; i++)
+            (void)gen_eth_frame(&umem->frames[i][0]);
+    }
+#endif
+    return umem;
+}
+
+static struct xdpsock *xsk_configure(struct xdp_umem *umem,
+                                     int ifindex, int queue)
+{
+    struct sockaddr_xdp sxdp = {};
+    struct xdp_mmap_offsets off;
+    int sfd, ndescs = NUM_DESCS;
+    struct xdpsock *xsk;
+    bool shared = false;
+    socklen_t optlen;
+    u64 i;
+
+    opt_xdp_flags |= XDP_FLAGS_SKB_MODE;
+    opt_xdp_bind_flags |= XDP_COPY;
+
+    sfd = socket(PF_XDP, SOCK_RAW, 0);
+    ovs_assert(sfd >= 0);
+
+    xsk = calloc(1, sizeof(*xsk));
+    ovs_assert(xsk);
+
+    xsk->sfd = sfd;
+    xsk->outstanding_tx = 0;
+
+    VLOG_DBG("enter: %s xsk fd %d", __func__, sfd);
+    if (!umem) {
+        shared = false;
+        xsk->umem = xdp_umem_configure(sfd);
+    } else {
+        xsk->umem = umem;
+        ovs_assert(0);
+    }
+
+    ovs_assert(setsockopt(sfd, SOL_XDP, XDP_RX_RING,
+               &ndescs, sizeof(int)) == 0);
+    ovs_assert(setsockopt(sfd, SOL_XDP, XDP_TX_RING,
+               &ndescs, sizeof(int)) == 0);
+    optlen = sizeof(off);
+    ovs_assert(getsockopt(sfd, SOL_XDP, XDP_MMAP_OFFSETS, &off,
+               &optlen) == 0);
+
+    /* Rx */
+    xsk->rx.map = mmap(NULL,
+               off.rx.desc +
+               NUM_DESCS * sizeof(struct xdp_desc),
+               PROT_READ | PROT_WRITE,
+               MAP_SHARED | MAP_POPULATE, sfd,
+               XDP_PGOFF_RX_RING);
+    ovs_assert(xsk->rx.map != MAP_FAILED);
+
+    if (!shared) {
+        for (i = 0; i < NUM_DESCS * FRAME_SIZE; i += FRAME_SIZE)
+            ovs_assert(umem_fill_to_kernel(&xsk->umem->fq, &i, 1)
+                == 0);
+    }
+
+    // FIXME: we also configure tx here
+    /* Tx */
+    xsk->tx.map = mmap(NULL,
+               off.tx.desc +
+               NUM_DESCS * sizeof(struct xdp_desc),
+               PROT_READ | PROT_WRITE,
+               MAP_SHARED | MAP_POPULATE, sfd,
+               XDP_PGOFF_TX_RING);
+    ovs_assert(xsk->tx.map != MAP_FAILED);
+
+    xsk->rx.mask = NUM_DESCS - 1;
+    xsk->rx.size = NUM_DESCS;
+    xsk->rx.producer = xsk->rx.map + off.rx.producer;
+    xsk->rx.consumer = xsk->rx.map + off.rx.consumer;
+    xsk->rx.ring = xsk->rx.map + off.rx.desc;
+
+    xsk->tx.mask = NUM_DESCS - 1;
+    xsk->tx.size = NUM_DESCS;
+    xsk->tx.producer = xsk->tx.map + off.tx.producer;
+    xsk->tx.consumer = xsk->tx.map + off.tx.consumer;
+    xsk->tx.ring = xsk->tx.map + off.tx.desc;
+    xsk->tx.cached_cons = NUM_DESCS;
+
+    /* XSK socket */
+    sxdp.sxdp_family = PF_XDP;
+    sxdp.sxdp_ifindex = ifindex;
+    sxdp.sxdp_queue_id = queue;
+
+    if (shared) {
+        sxdp.sxdp_flags = XDP_SHARED_UMEM;
+        sxdp.sxdp_shared_umem_fd = umem->fd;
+    } else {
+        sxdp.sxdp_flags = opt_xdp_bind_flags;
+    }
+
+    ovs_assert(bind(sfd, (struct sockaddr *)&sxdp, sizeof(sxdp)) == 0);
+
+    return xsk;
+}
+
+static inline int xq_deq(struct xdp_uqueue *uq,
+             struct xdp_desc *descs,
+             int ndescs)
+{
+    struct xdp_desc *r = uq->ring;
+    unsigned int idx;
+    int i, entries;
+
+    entries = xq_nb_avail(uq, ndescs);
+
+    u_smp_rmb();
+
+    for (i = 0; i < entries; i++) {
+        idx = uq->cached_cons++ & uq->mask;
+        descs[i] = r[idx];
+    }
+
+    if (entries > 0) {
+        u_smp_wmb();
+
+        *uq->consumer = uq->cached_cons;
+        VLOG_INFO("%s entries %d consumer %d\n", __func__, entries, *uq->consumer);
+    }
+    return entries;
+}
+
+static inline void *xq_get_data(struct xdpsock *xsk, u64 addr)
+{
+    return &xsk->umem->frames[addr];
+}
+
+static void vlog_hex_dump(const void *buf, size_t count)
+{
+    struct ds ds = DS_EMPTY_INITIALIZER;
+    ds_put_hex_dump(&ds, buf, count, 0, false);
+    VLOG_INFO("\n%s", ds_cstr(&ds));
+    ds_destroy(&ds);
+}
+
+static void kick_tx(int fd)
+{
+    int ret;
+
+    VLOG_DBG("%s: send to fd %d", __func__, fd);
+    ret = sendto(fd, NULL, 0, MSG_DONTWAIT, NULL, 0);
+    if (ret >= 0 || errno == ENOBUFS || errno == EAGAIN)
+        return;
+    ovs_assert(0);
+}
+
+static inline void complete_tx_l2fwd(struct xdpsock *xsk)
+{
+    u64 descs[BATCH_SIZE];
+    unsigned int rcvd;
+    size_t ndescs;
+
+    if (!xsk->outstanding_tx)
+        return;
+
+    kick_tx(xsk->sfd);
+    ndescs = (xsk->outstanding_tx > BATCH_SIZE) ? BATCH_SIZE :
+         xsk->outstanding_tx;
+
+    /* re-add completed Tx buffers */
+    rcvd = umem_complete_from_kernel(&xsk->umem->cq, descs, ndescs);
+
+    if (rcvd > 0) {
+        umem_fill_to_kernel(&xsk->umem->fq, descs, rcvd);
+        xsk->outstanding_tx -= rcvd;
+        xsk->tx_npkts += rcvd;
+    }
+}
+
+static inline void complete_tx_only(struct xdpsock *xsk)
+{
+	u64 descs[BATCH_SIZE];
+	unsigned int rcvd;
+
+	if (!xsk->outstanding_tx) {
+        VLOG_DBG("no outstanding_tx");
+		return;
+    }
+
+	kick_tx(xsk->sfd);
+
+	rcvd = umem_complete_from_kernel(&xsk->umem->cq, descs, BATCH_SIZE);
+	if (rcvd > 0) {
+			xsk->outstanding_tx -= rcvd;
+			xsk->tx_npkts += rcvd;
+	}
+}
+
+static inline u32 xq_nb_free(struct xdp_uqueue *q, u32 ndescs)
+{
+    u32 free_entries = q->cached_cons - q->cached_prod;
+
+    if (free_entries >= ndescs)
+        return free_entries;
+
+    /* Refresh the local tail pointer */
+    q->cached_cons = *q->consumer + q->size;
+    return q->cached_cons - q->cached_prod;
+}
+
+static inline int xq_enq(struct xdp_uqueue *uq,
+             const struct xdp_desc *descs,
+             unsigned int ndescs)
+{
+    struct xdp_desc *r = uq->ring;
+    unsigned int i;
+
+    if (xq_nb_free(uq, ndescs) < ndescs)
+        return -ENOSPC;
+
+    for (i = 0; i < ndescs; i++) {
+        u32 idx = uq->cached_prod++ & uq->mask;
+
+        r[idx].addr = descs[i].addr;
+        r[idx].len = descs[i].len;
+    }
+
+    u_smp_wmb();
+
+    *uq->producer = uq->cached_prod;
+    return 0;
+}
+
+static inline int xq_enq_tx_only(struct xdp_uqueue *uq,
+                 unsigned int id, unsigned int ndescs)
+{
+    struct xdp_desc *r = uq->ring;
+    unsigned int i;
+
+    if (xq_nb_free(uq, ndescs) < ndescs)
+        return -ENOSPC;
+
+    for (i = 0; i < ndescs; i++) {
+        u32 idx = uq->cached_prod++ & uq->mask;
+
+        r[idx].addr = (id + i) << FRAME_SHIFT;
+        r[idx].len  = sizeof(pkt_data) - 1;
+    }
+
+    u_smp_wmb();
+
+    *uq->producer = uq->cached_prod;
+    return 0;
+}
+
+static inline void print_xsk_stat(struct xdpsock *xsk) {
+    struct xdp_statistics stat;
+    socklen_t optlen;
+
+    optlen = sizeof(stat);
+    ovs_assert(getsockopt(xsk->sfd, SOL_XDP, XDP_STATISTICS,
+                &stat, &optlen) == 0);
+
+    VLOG_INFO("rx dropped %llu, rx_invalid %llu, tx_invalid %llu",
+             stat.rx_dropped, stat.rx_invalid_descs, stat.tx_invalid_descs);
+
+}
+// =========================================================
+#endif
 
 /* These were introduced in Linux 2.6.14, so they might be missing if we have
  * old headers. */
@@ -522,6 +1035,8 @@ struct netdev_linux {
     int tap_fd;
     bool present;               /* If the device is present in the namespace */
     uint64_t tx_dropped;        /* tap device can drop if the iface is down */
+    struct xdpsock *xsk[16];    /* af_xdp socket: each queue has one xdp sock */
+    int xskmap_fd;              /* map netdev's queue id to xsk fd */
 };
 
 struct netdev_rxq_linux {
@@ -571,6 +1086,12 @@ is_netdev_linux_class(const struct netdev_class *netdev_class)
 }
 
 static bool
+is_afxdp_netdev(const struct netdev *netdev)
+{
+    return netdev_get_class(netdev) == &netdev_afxdp_class;
+}
+
+static bool
 is_tap_netdev(const struct netdev *netdev)
 {
     return netdev_get_class(netdev) == &netdev_tap_class;
@@ -921,6 +1442,13 @@ netdev_linux_destruct(struct netdev *netdev_)
         atomic_count_dec(&miimon_cnt);
     }
 
+    if (is_afxdp_netdev(netdev_)) {
+        int ifindex;
+
+        get_ifindex(netdev_, &ifindex);
+        bpf_set_link_xdp_fd(ifindex, -1, XDP_FLAGS_SKB_MODE);
+    }
+
     ovs_mutex_destroy(&netdev->mutex);
 }
 
@@ -950,6 +1478,44 @@ netdev_linux_rxq_construct(struct netdev_rxq *rxq_)
     rx->is_tap = is_tap_netdev(netdev_);
     if (rx->is_tap) {
         rx->fd = netdev->tap_fd;
+    } else if (is_afxdp_netdev(netdev_)) {
+        // setup AF_XDP socket here, see xsk_configure
+        struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+        int ifindex, num_socks = 0;
+        struct xdpsock *xsk;
+        int queue_id = 0; // FIXME
+        int key = 0;
+        int xsk_fd;
+
+        if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+            VLOG_ERR("ERROR: setrlimit(RLIMIT_MEMLOCK) \"%s\"\n",
+                      ovs_strerror(errno));
+            ovs_assert(0);
+        }
+
+        VLOG_INFO("%s: %s: queue=%d configuring xdp sock",
+                  __func__, netdev_->name, queue_id);
+
+        /* Get ethernet device index. */
+        error = get_ifindex(&netdev->up, &ifindex);
+        if (error) {
+            goto error;
+        }
+
+        xsk = xsk_configure(NULL, ifindex, queue_id);
+
+        netdev->xsk[num_socks++] = xsk;
+        rx->fd = xsk->sfd; //for upper layer to poll
+        xsk_fd = xsk->sfd;
+
+        if (xsk_fd) {
+            error = bpf_map_update_elem(netdev->xskmap_fd, &key, &xsk_fd, 0);
+            if (error) {
+                VLOG_ERR("failed to set xsks_map: %s", ovs_strerror(error));
+                return error;
+            }
+        }
+
     } else {
         struct sockaddr_ll sll;
         int ifindex, val;
@@ -1149,6 +1715,58 @@ netdev_linux_rxq_recv_tap(int fd, struct dp_packet *buffer)
     return 0;
 }
 
+/* Receive packet from AF_XDP socket */
+static int
+netdev_linux_rxq_xsk(struct xdpsock *xsk,
+                     struct dp_packet_batch *batch)
+{
+    struct xdp_desc descs[NETDEV_MAX_BURST];
+    unsigned int rcvd, i = 0;
+    int ret = 0;
+
+    rcvd = xq_deq(&xsk->rx, descs, NETDEV_MAX_BURST);
+    if (rcvd == 0) {
+        return 0;
+    }
+
+    VLOG_INFO("%s receive %d packets xsk fd %d",
+              __func__, rcvd, xsk->sfd);
+
+    for (i = 0; i < rcvd; i++) {
+        struct dp_packet *packet;
+        void *base, *new_packet;
+
+        packet = xmalloc(sizeof *packet);
+
+        VLOG_INFO("%s packet len %d", __func__, descs[i].len);
+        base = xq_get_data(xsk, descs[i].addr);
+
+        //vlog_hex_dump(base, 14);
+        new_packet = malloc(2048);
+        memcpy(new_packet, base, descs[i].len);
+
+        //dp_packet_use(packet, base, descs[i].len);
+        dp_packet_use(packet, new_packet, descs[i].len);
+
+        packet->source = DPBUF_MALLOC;
+        //dp_packet_set_data(packet, base); // no offset now?
+        dp_packet_set_data(packet, new_packet); // no offset now?
+        dp_packet_set_size(packet, descs[i].len);
+
+        /* add packet into batch, batch->count inc */
+        dp_packet_batch_add(batch, packet);
+    }
+
+    xsk->rx_npkts += rcvd;
+    umem_fill_to_kernel_ex(&xsk->umem->fq, descs, rcvd);
+
+    //batch->count = rcvd; // batch_add inc the counter
+    //don't put it back to FILL queue yet.
+
+    print_xsk_stat(xsk);
+    return ret;
+}
+
 static int
 netdev_linux_rxq_recv(struct netdev_rxq *rxq_, struct dp_packet_batch *batch)
 {
@@ -1157,6 +1775,8 @@ netdev_linux_rxq_recv(struct netdev_rxq *rxq_, struct dp_packet_batch *batch)
     struct dp_packet *buffer;
     ssize_t retval;
     int mtu;
+    struct netdev_linux *netdev_ = netdev_linux_cast(netdev);
+
 
     if (netdev_linux_get_mtu__(netdev_linux_cast(netdev), &mtu)) {
         mtu = ETH_PAYLOAD_MAX;
@@ -1166,15 +1786,20 @@ netdev_linux_rxq_recv(struct netdev_rxq *rxq_, struct dp_packet_batch *batch)
     buffer = dp_packet_new_with_headroom(VLAN_ETH_HEADER_LEN + mtu,
                                            DP_NETDEV_HEADROOM);
     retval = (rx->is_tap
-              ? netdev_linux_rxq_recv_tap(rx->fd, buffer)
-              : netdev_linux_rxq_recv_sock(rx->fd, buffer));
-
+              ? netdev_linux_rxq_recv_tap(rx->fd, buffer) :
+              (is_afxdp_netdev(netdev) ?      netdev_linux_rxq_xsk(netdev_->xsk[0], batch) :
+                                        netdev_linux_rxq_recv_sock(rx->fd, buffer)));
     if (retval) {
         if (retval != EAGAIN && retval != EMSGSIZE) {
             VLOG_WARN_RL(&rl, "error receiving Ethernet packet on %s: %s",
                          netdev_rxq_get_name(rxq_), ovs_strerror(errno));
         }
         dp_packet_delete(buffer);
+    } else if (is_afxdp_netdev(netdev)) {
+        dp_packet_batch_init_packet_fields(batch);
+
+        if (batch->count != 0)
+            VLOG_INFO("%s AFXDP recv %lu packets", __func__, batch->count);
     } else {
         dp_packet_batch_init_packet(batch, buffer);
     }
@@ -1208,6 +1833,66 @@ netdev_linux_rxq_drain(struct netdev_rxq *rxq_)
 }
 
 static int
+netdev_linux_afxdp_batch_send(struct xdpsock *xsk, /* send to xdp socket! */
+                              struct dp_packet_batch *batch)
+{
+    struct dp_packet *packet;
+    struct xdp_uqueue *uq;
+    struct xdp_desc *r;
+    int ndescs = batch->count;
+    u32 id = NUM_FRAMES / 2;
+
+    VLOG_INFO("%s send %lu packet to fd %d", __func__, batch->count, xsk->sfd);
+    VLOG_INFO("%s outstanding tx %d", __func__, xsk->outstanding_tx);
+
+    /* cleanup and refill */
+    uq = &xsk->tx;
+    r = uq->ring;
+
+    // see tx_only and xq_enq_tx_only
+    if (xq_nb_free(uq, ndescs) < ndescs) {
+        VLOG_ERR("no free desc");
+        return -ENOSPC;
+    }
+
+    DP_PACKET_BATCH_FOR_EACH (packet, batch) {
+            void *umem_buf;
+
+            u32 idx = uq->cached_prod++ & uq->mask;
+            // FIXME: find available id
+            umem_buf = xsk->umem->frames + (id << FRAME_SHIFT);
+
+            memcpy(umem_buf, dp_packet_data(packet), dp_packet_size(packet));
+            //vlog_hex_dump(dp_packet_data(packet), 14);
+            r[idx].addr = (id << FRAME_SHIFT);
+            r[idx].len = dp_packet_size(packet);
+            id++;
+#if 0 /* avoid copy */
+        } else {
+            u32 idx = uq->cached_prod++ & uq->mask;
+
+            VLOG_WARN("packet from umem %p", dp_packet_base(packet));
+            vlog_hex_dump(dp_packet_base(packet), 14);
+
+            r[idx].addr = (u64)(u64 *)dp_packet_base(packet);
+            r[idx].len = dp_packet_size(packet);
+        }
+#endif
+    }
+    u_smp_wmb();
+
+    *uq->producer = uq->cached_prod;
+
+    xsk->outstanding_tx += batch->count;
+
+    complete_tx_only(xsk);
+    print_xsk_stat(xsk);
+
+    return 0;
+}
+
+
+static int
 netdev_linux_sock_batch_send(int sock, int ifindex,
                              struct dp_packet_batch *batch)
 {
@@ -1312,21 +1997,32 @@ netdev_linux_send(struct netdev *netdev_, int qid OVS_UNUSED,
     int error = 0;
     int sock = 0;
 
-    if (!is_tap_netdev(netdev_)) {
+    if (!is_tap_netdev(netdev_) &&
+        !is_afxdp_netdev(netdev_)) {
         sock = af_packet_sock();
         if (sock < 0) {
             error = -sock;
+            VLOG_WARN("%s af sock < 0", __func__);
             goto free_batch;
         }
 
         int ifindex = netdev_get_ifindex(netdev_);
         if (ifindex < 0) {
+            VLOG_WARN("%s ifindex < 0", __func__);
             error = -ifindex;
             goto free_batch;
         }
 
         error = netdev_linux_sock_batch_send(sock, ifindex, batch);
+    } else if (is_afxdp_netdev(netdev_)) {
+        struct xdpsock *xsk;
+        struct netdev_linux *netdev = netdev_linux_cast(netdev_);
+
+        xsk = netdev->xsk[0]; // FIXME: always use queue 0
+        VLOG_INFO_RL(&rl, "XXX %s sent to AFXDP dev xsk %d", __func__, xsk->sfd);
+        error = netdev_linux_afxdp_batch_send(xsk, batch);
     } else {
+        VLOG_INFO_RL(&rl, "%s sent to tap dev", __func__);
         error = netdev_linux_tap_batch_send(netdev_, batch);
     }
     if (error) {
@@ -2426,12 +3122,22 @@ netdev_linux_set_xdp__(struct netdev *netdev_, const struct bpf_prog *prog,
 {
     struct netdev_linux *netdev = netdev_linux_cast(netdev_);
     const char *netdev_name = netdev_get_name(netdev_);
-    int ifindex = netdev->ifindex;
+    int ifindex;
     int error;
 
-    VLOG_DBG("Setting %s XDP filter %d on %s (ifindex %d)", prog->name,
+    error = get_ifindex(netdev_, &ifindex);
+    if (error) {
+        return ENODEV;
+    }
+
+
+    VLOG_INFO("Setting %s XDP filter %d on %s (ifindex %d)", prog->name,
              prog->fd, netdev_name, ifindex);
 
+    if (ifindex == 0) {
+        VLOG_WARN("skip device %s", netdev_name);
+        return 0;
+    }
     if (netdev->cache_valid & valid_bit) {
         error = *filter_error;
         if (error || (prog && prog->fd == *netdev_filter)) {
@@ -2456,6 +3162,19 @@ out:
 }
 
 static int
+netdev_linux_set_xskmap(struct netdev *netdev_, int xskmap_fd)
+{
+    struct netdev_linux *netdev = netdev_linux_cast(netdev_);
+
+    ovs_assert(xskmap_fd != 0);
+
+    VLOG_INFO("%s xsks_map fd %d", __func__, xskmap_fd);
+    netdev->xskmap_fd = xskmap_fd;
+
+    return 0;
+}
+
+static int
 netdev_linux_set_xdp(struct netdev *netdev_, const struct bpf_prog *prog)
 {
     struct netdev_linux *netdev = netdev_linux_cast(netdev_);
@@ -3167,6 +3886,7 @@ netdev_linux_update_flags(struct netdev *netdev_, enum netdev_flags off,
     netdev_linux_set_policing,                                  \
     netdev_linux_set_filter,                                    \
     netdev_linux_set_xdp,                                       \
+    netdev_linux_set_xskmap,                                    \
     netdev_linux_get_qos_types,                                 \
     netdev_linux_get_qos_capabilities,                          \
     netdev_linux_get_qos,                                       \
@@ -3201,6 +3921,15 @@ netdev_linux_update_flags(struct netdev *netdev_, enum netdev_flags off,
     FLOW_OFFLOAD_API                                            \
 }
 
+const struct netdev_class netdev_afxdp_class =
+    NETDEV_LINUX_CLASS(
+        "afxdp",
+        netdev_linux_construct,
+        netdev_linux_get_stats,
+        netdev_linux_get_features,
+        netdev_linux_get_status,
+        LINUX_FLOW_OFFLOAD_API);
+
 const struct netdev_class netdev_linux_class =
     NETDEV_LINUX_CLASS(
         "system",
diff --git a/lib/netdev-provider.h b/lib/netdev-provider.h
index 3e53a5b76272..df92275d5aff 100644
--- a/lib/netdev-provider.h
+++ b/lib/netdev-provider.h
@@ -515,6 +515,7 @@ struct netdev_class {
      *
      * This function may be set to null if filters are not supported. */
     int (*set_xdp)(struct netdev *netdev, const struct bpf_prog *);
+    int (*set_xskmap)(struct netdev *netdev, int xsks_map_fd);
 
     /* Adds to 'types' all of the forms of QoS supported by 'netdev', or leaves
      * it empty if 'netdev' does not support QoS.  Any names added to 'types'
@@ -884,6 +885,7 @@ extern const struct netdev_class netdev_bsd_class;
 extern const struct netdev_class netdev_windows_class;
 #else
 extern const struct netdev_class netdev_linux_class;
+extern const struct netdev_class netdev_afxdp_class;
 #endif
 extern const struct netdev_class netdev_internal_class;
 extern const struct netdev_class netdev_tap_class;
diff --git a/lib/netdev-vport.c b/lib/netdev-vport.c
index 4341c89894a3..a61ff4b6808c 100644
--- a/lib/netdev-vport.c
+++ b/lib/netdev-vport.c
@@ -1000,6 +1000,9 @@ netdev_vport_set_xdp(struct netdev *netdev_, const struct bpf_prog *prog)
     ifindex = netdev_vport_get_ifindex(netdev_);
     error = bpf_set_link_xdp_fd(ifindex, prog->fd,
                                    XDP_FLAGS_SKB_MODE);
+    // FIXME / TODO
+    // update xsks_map_fd
+
     ovs_mutex_unlock(&netdev->mutex);
 
     VLOG_INFO("%s %d", __func__, error);
@@ -1057,6 +1060,7 @@ netdev_vport_set_xdp(struct netdev *netdev_, const struct bpf_prog *prog)
     NULL,                       /* set_policing */          \
     netdev_vport_set_filter,    /* set_filter */            \
     netdev_vport_set_xdp,       /* set_xdp */               \
+    NULL,                      /* set_xskmap */            \
     NULL,                       /* get_qos_types */         \
     NULL,                       /* get_qos_capabilities */  \
     NULL,                       /* get_qos */               \
diff --git a/lib/netdev.c b/lib/netdev.c
index c44a1a683b92..826555dd92f6 100644
--- a/lib/netdev.c
+++ b/lib/netdev.c
@@ -142,6 +142,7 @@ netdev_initialize(void)
 
 #ifdef __linux__
         netdev_register_provider(&netdev_linux_class);
+        netdev_register_provider(&netdev_afxdp_class);
         netdev_register_provider(&netdev_internal_class);
         netdev_register_provider(&netdev_tap_class);
         netdev_vport_tunnel_register();
@@ -1474,6 +1475,16 @@ netdev_set_xdp(struct netdev *netdev, struct bpf_prog *prog)
             : EOPNOTSUPP);
 }
 
+/* set xsk map */
+int
+netdev_set_xskmap(struct netdev *netdev, int xskmap)
+{
+    return (netdev->netdev_class->set_xskmap
+            ? netdev->netdev_class->set_xskmap(netdev, xskmap)
+            : EOPNOTSUPP);
+}
+
+
 /* Adds to 'types' all of the forms of QoS supported by 'netdev', or leaves it
  * empty if 'netdev' does not support QoS.  Any names added to 'types' should
  * be documented as valid for the "type" column in the "QoS" table in
diff --git a/lib/netdev.h b/lib/netdev.h
index 3388504d85c9..3a8d7118378e 100644
--- a/lib/netdev.h
+++ b/lib/netdev.h
@@ -320,6 +320,7 @@ int netdev_set_policing(struct netdev *, uint32_t kbits_rate,
                         uint32_t kbits_burst);
 int netdev_set_filter(struct netdev *netdev, struct bpf_prog *prog);
 int netdev_set_xdp(struct netdev *netdev, struct bpf_prog *prog);
+int netdev_set_xskmap(struct netdev *netdev, int xsks_map_fd);
 
 int netdev_get_qos_types(const struct netdev *, struct sset *types);
 int netdev_get_qos_capabilities(const struct netdev *,
-- 
2.7.4



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