On 16.05.2019 2:27, William Tu wrote:
> Hi Ilya,
>
> Thanks for your feedback.
>
> On Mon, May 13, 2019 at 10:48 AM Ilya Maximets <[email protected]> wrote:
>>
>> On 10.05.2019 2:54, William Tu wrote:
>>> The patch introduces experimental AF_XDP support for OVS netdev.
>>> AF_XDP, Address Family of the eXpress Data Path, is a new Linux socket type
>>> built upon the eBPF and XDP technology. It is aims to have comparable
>>> performance to DPDK but cooperate better with existing kernel's networking
>>> stack. An AF_XDP socket receives and sends packets from an eBPF/XDP program
>>> attached to the netdev, by-passing a couple of Linux kernel's subsystems
>>> As a result, AF_XDP socket shows much better performance than AF_PACKET
>>> For more details about AF_XDP, please see linux kernel's
>>> Documentation/networking/af_xdp.rst. Note that by default, this is not
>>> compiled in.
>>>
>>> Signed-off-by: William Tu <[email protected]>
>>>
>>> ---
>
> snip
>
>>> +netdev_afxdp_set_config(struct netdev *netdev, const struct smap *args,
>>> + char **errp OVS_UNUSED)
>>> +{
>>> + struct netdev_linux *dev = netdev_linux_cast(netdev);
>>> + const char *xdpmode;
>>> + int new_n_rxq;
>>> +
>>> + ovs_mutex_lock(&dev->mutex);
>>> +
>>> + new_n_rxq = MAX(smap_get_int(args, "n_rxq", NR_QUEUE), 1);
>>> + if (new_n_rxq > MAX_XSKQ) {
>>> + ovs_mutex_unlock(&dev->mutex);
>>> + return EINVAL;
>>> + }
>>> +
>>> + if (new_n_rxq != netdev->n_rxq) {
>>> + dev->requested_n_rxq = new_n_rxq;
>>> + netdev_request_reconfigure(netdev);
>>> + }
>>> +
>>> + xdpmode = smap_get(args, "xdpmode");
>>> + if (xdpmode && strncmp(xdpmode, "drv", 3) == 0) {
>>> + dev->requested_xdpmode = XDP_ZEROCOPY;
>>> + if (dev->xdpmode != dev->requested_xdpmode) {
>>> + netdev_request_reconfigure(netdev);
>>> + }
>>> + } else {
>>> + dev->requested_xdpmode = XDP_COPY;
>>> + if (dev->xdpmode != dev->requested_xdpmode) {
>>> + netdev_request_reconfigure(netdev);
>>> + }
>>> + }
>>
>> Above code will request reconfiguration infinitely until it reconfiguration
>> finished. This could cause multiple reconfigurations in a row for the same
>> configuration change. Better version could look like this:
>>
>> new_n_rxq = MAX(smap_get_int(args, "n_rxq", NR_QUEUE), 1);
>> if (new_n_rxq > MAX_XSKQ) {
>> ovs_mutex_unlock(&dev->mutex);
>> VLOG_ERR("%s: Too big 'n_rxq' (%d > %d).",
>> netdev_get_name(netdev), new_n_rxq, MAX_XSKQ);
>> return EINVAL;
>> }
>>
>> str_xdpmode = smap_get_def(args, "xdpmode", "skb");
>> if (!strcasecmp(str_xdpmode, "drv")) {
>> xdpmode = XDP_ZEROCOPY;
>> } else if (!strcasecmp(str_xdpmode, "skb")) {
>> xdpmode = XDP_COPY;
>> } else {
>> VLOG_ERR("%s: Incorrect xdpmode (%s).",
>> netdev_get_name(netdev), str_xdpmode);
>> ovs_mutex_unlock(&dev->mutex);
>> return EINVAL;
>> }
>>
>> if (dev->requested_n_rxq != new_n_rxq
>> || dev->requested_xdpmode != xdpmode) {
>> dev->requested_n_rxq = new_n_rxq;
>> dev->requested_xdpmode = xdpmode
>> netdev_request_reconfigure(netdev);
>> }
>>
>> The main difference is checking "new" with "requested", not the "new" with
>> "current". This allows us to request reconfiguration only once for each
>> change. I also made few cosmetic changes which you may find useful, however
>> it's up to you.
>
> Thanks, will fix it in next version.
>
>>
>>> + for (i = 0; i < rcvd; i++) {
>>> + uint64_t addr = xsk_ring_cons__rx_desc(&xsk->rx, idx_rx)->addr;
>>> + uint32_t len = xsk_ring_cons__rx_desc(&xsk->rx, idx_rx)->len;
>>> + char *pkt = xsk_umem__get_data(xsk->umem->buffer, addr);
>>> + uint64_t index;
>>> +
>>> + struct dp_packet_afxdp *xpacket;
>>> + struct dp_packet *packet;
>>> +
>>> + index = addr >> FRAME_SHIFT;
>>> + xpacket = UMEM2XPKT(xsk->umem->xpool.array, index);
>>> +
>>> + packet = &xpacket->packet;
>>> + xpacket->mpool = &xsk->umem->mpool;
>>> +
>>> + /* Initialize the struct dp_packet */
>>> + dp_packet_use_afxdp(packet, pkt, FRAME_SIZE - FRAME_HEADROOM);
>>> + dp_packet_set_size(packet, len);
>>> +
>>> + /* Add packet into batch, increase batch->count */
>>> + dp_packet_batch_add(batch, packet);
>>> +
>>> + idx_rx++;
>>> + }
>>> +
>>> + /* We've consume rcvd packets in RX, now re-fill the
>>> + * same number back to FILL queue.
>>> + */
>>> + ret = umem_elem_pop_n(&xsk->umem->mpool, rcvd, (void **)elems);
>>> + if (OVS_UNLIKELY(ret)) {> + return -ENOMEM;
>>> + }
>>
>> Can this be done before actually receiving packets? i.e. don't receive
>> anything if cant refill.
>
> I'm not sure I understand your point.
> Do you suggest moving this umem_elem_pop_n in the beginning?
Yes. I meant this.
It's just an optimization. We don't need to iterate over 'xsk->rx'
if 'umem_elem_pop_n' failed because you're returning error and the
batch will not be used.
Actually, I looked at the code again and I see that in case of
'umem_elem_pop_n' failure you're not releasing the packets, i.e.
xsk_ring_cons__peek() reserved some packets, but xsk_ring_cons__release()
never called. This will break the rx ring on the next call.
I think that code should look like this:
rcvd = xsk_ring_cons__peek(&xsk->rx ...)
if (!rcvd) {
return 0;
}
ret = umem_elem_pop_n(rcvd)
if (OVS_UNLIKELY(ret)) {
xsk_ring_cons__release(&xsk->rx, rcvd);
/* TODO: Account packets as dropped. */
return -ENOMEM;
}
for (i = 0; i < rcvd; i++) {
...
dp_packet_use_afxdp(packet, pkt, FRAME_SIZE - FRAME_HEADROOM);
...
dp_packet_batch_add(batch, packet);
}
/* Release the RX queue */
xsk_ring_cons__release(&xsk->rx, rcvd);
for (i = 0; i < rcvd; i++) {
...
*xsk_ring_prod__fill_addr(&xsk->umem->fq, idx_fq) = index;
}
xsk_ring_prod__submit(&xsk->umem->fq, rcvd);
> I think at this point the rcvd is > 0, otherwise it will return.
> So we already know there are packets at rx ring.
>
>>
>>> +
>>> + for (i = 0; i < rcvd; i++) {
>>> + uint64_t index;
>>> + struct umem_elem *elem;
>>> +
>>> + ret = xsk_ring_prod__reserve(&xsk->umem->fq, 1, &idx_fq);
>>> + while (OVS_UNLIKELY(ret == 0)) {
>>> + /* The FILL queue is full, so retry. (or skip)? */
>>> + ret = xsk_ring_prod__reserve(&xsk->umem->fq, 1, &idx_fq);
>>> + }
>
> And if we can't refill, we will keep trying.
One additional point here is that you don't need to call prod__reserve
for each packet. you could use:
while (!xsk_ring_prod__reserve(&xsk->umem->fq, rcvd, &idx_fq)) {
/* The FILL queue is full, so retry. */
}
xsk_ring_prod__reserve() doesn't support partial allocations, i.e. it will
reserve rcvd or 0 elements.
>
>>> +
>>> + /* Get one free umem, program it into FILL queue */
>>> + elem = elems[i];
>>> + index = (uint64_t)((char *)elem - (char *)xsk->umem->buffer);
>>> + ovs_assert((index & FRAME_SHIFT_MASK) == 0);
>>> + *xsk_ring_prod__fill_addr(&xsk->umem->fq, idx_fq) = index;
>>> +
>>> + idx_fq++;
>>> + }
>>> + xsk_ring_prod__submit(&xsk->umem->fq, rcvd);
>>> +
>>> + /* Release the RX queue */
>>> + xsk_ring_cons__release(&xsk->rx, rcvd);
>>> + xsk->rx_npkts += rcvd;
>>> +
>>> +#ifdef AFXDP_DEBUG
>>> + print_xsk_stat(xsk);
>>> +#endif
>>> + return 0;
>>> +}
>>> +
>>> +static inline int kick_tx(struct xsk_socket_info *xsk)
>>> +{
>>> + int ret;
>>> +
>>> + /* This causes system call into kernel's xsk_sendmsg, and
>>> + * xsk_generic_xmit (skb mode) or xsk_async_xmit (driver mode).
>>> + */
>>> + ret = sendto(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, 0);
>>> + if (OVS_UNLIKELY(ret < 0)) {
>>> + if (errno == ENXIO || errno == ENOBUFS || errno == EOPNOTSUPP) {
>>> + return errno;
>>> + }
>>> + }
>>> + /* no error, or EBUSY or EAGAIN */
>>> + return 0;
>>> +}
>>> +
>>> +int
>>> +netdev_linux_afxdp_batch_send(struct xsk_socket_info *xsk,
>>> + struct dp_packet_batch *batch)
>>> +{
>>> + struct umem_elem *elems_pop[BATCH_SIZE];
>>> + struct umem_elem *elems_push[BATCH_SIZE];
>>> + uint32_t tx_done, idx_cq = 0;
>>> + struct dp_packet *packet;
>>> + uint32_t idx = 0;
>>> + int j, ret, retry_count = 0;
>>> + const int max_retry = 4;
>>> +
>>> + ret = umem_elem_pop_n(&xsk->umem->mpool, batch->count, (void
>>> **)elems_pop);
>>> + if (OVS_UNLIKELY(ret)) {
>>> + return EAGAIN;
>>> + }
>>> +
>>> + /* Make sure we have enough TX descs */
>>> + ret = xsk_ring_prod__reserve(&xsk->tx, batch->count, &idx);
>>> + if (OVS_UNLIKELY(ret == 0)) {
>>> + umem_elem_push_n(&xsk->umem->mpool, batch->count, (void
>>> **)elems_pop);
>>> + return EAGAIN;
>>> + }
>>> +
>>> + DP_PACKET_BATCH_FOR_EACH (i, packet, batch) {
>>> + struct umem_elem *elem;
>>> + uint64_t index;
>>> +
>>> + elem = elems_pop[i];
>>> + /* Copy the packet to the umem we just pop from umem pool.
>>> + * We can avoid this copy if the packet and the pop umem
>>> + * are located in the same umem.
>>> + */
>>> + memcpy(elem, dp_packet_data(packet), dp_packet_size(packet));
>>> +
>>> + index = (uint64_t)((char *)elem - (char *)xsk->umem->buffer);
>>> + xsk_ring_prod__tx_desc(&xsk->tx, idx + i)->addr = index;
>>> + xsk_ring_prod__tx_desc(&xsk->tx, idx + i)->len
>>> + = dp_packet_size(packet);
>>> + }
>>> + xsk_ring_prod__submit(&xsk->tx, batch->count);
>>> + xsk->outstanding_tx += batch->count;
>>> +
>>> + ret = kick_tx(xsk);
>>> + if (OVS_UNLIKELY(ret)) {
>>> + umem_elem_push_n(&xsk->umem->mpool, batch->count, (void
>>> **)elems_pop);
>>> + VLOG_WARN_RL(&rl, "error sending AF_XDP packet: %s",
>>> + ovs_strerror(ret));
>>> + return ret;
>>> + }
>>> +
>>> +retry:
>>> + /* Process CQ */
>>> + tx_done = xsk_ring_cons__peek(&xsk->umem->cq, batch->count, &idx_cq);
>>> + if (tx_done > 0) {
>>> + xsk->outstanding_tx -= tx_done;
>>> + xsk->tx_npkts += tx_done;
>>> + }
>>> +
>>> + /* Recycle back to umem pool */
>>> + for (j = 0; j < tx_done; j++) {
>>> + struct umem_elem *elem;
>>> + uint64_t addr;
>>> +
>>> + addr = *xsk_ring_cons__comp_addr(&xsk->umem->cq, idx_cq++);
>>> +
>>> + elem = ALIGNED_CAST(struct umem_elem *,
>>> + (char *)xsk->umem->buffer + addr);
>>> + elems_push[j] = elem;
>>> + }
>>> +
>>> + ret = umem_elem_push_n(&xsk->umem->mpool, tx_done, (void
>>> **)elems_push);
>>> + ovs_assert(ret == 0);
>>> +
>>> + xsk_ring_cons__release(&xsk->umem->cq, tx_done);
>>> +
>>> + if (xsk->outstanding_tx > PROD_NUM_DESCS - (PROD_NUM_DESCS >> 2)) {
>>> + /* If there are still a lot not transmitted, try harder. */
>>> + if (retry_count++ > max_retry) {
>>> + return 0;
>>> + }
>>> + goto retry;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> diff --git a/lib/netdev-afxdp.h b/lib/netdev-afxdp.h
>>> new file mode 100644
>>> index 000000000000..6518d8fca0b5
>>> --- /dev/null
>>> +++ b/lib/netdev-afxdp.h
>>> @@ -0,0 +1,53 @@
>>> +/*
>>> + * Copyright (c) 2018 Nicira, Inc.
>>> + *
>>> + * Licensed under the Apache License, Version 2.0 (the "License");
>>> + * you may not use this file except in compliance with the License.
>>> + * You may obtain a copy of the License at:
>>> + *
>>> + * http://www.apache.org/licenses/LICENSE-2.0
>>> + *
>>> + * Unless required by applicable law or agreed to in writing, software
>>> + * distributed under the License is distributed on an "AS IS" BASIS,
>>> + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
>>> + * See the License for the specific language governing permissions and
>>> + * limitations under the License.
>>> + */
>>> +
>>> +#ifndef NETDEV_AFXDP_H
>>> +#define NETDEV_AFXDP_H 1
>>> +
>>> +#include <stdint.h>
>>> +#include <stdbool.h>
>>> +
>>> +/* These functions are Linux AF_XDP specific, so they should be used
>>> directly
>>> + * only by Linux-specific code. */
>>> +#define MAX_XSKQ 16
>>> +struct netdev;
>>> +struct xsk_socket_info;
>>> +struct xdp_umem;
>>> +struct dp_packet_batch;
>>> +struct smap;
>>> +struct dp_packet;
>>> +
>>> +struct dp_packet_afxdp * dp_packet_cast_afxdp(const struct dp_packet *d);
>>> +
>>> +int xsk_configure_all(struct netdev *netdev);
>>> +
>>> +void xsk_destroy_all(struct netdev *netdev);
>>> +
>>> +int netdev_linux_rxq_xsk(struct xsk_socket_info *xsk,
>>> + struct dp_packet_batch *batch);
>>> +
>>> +int netdev_linux_afxdp_batch_send(struct xsk_socket_info *xsk,
>>> + struct dp_packet_batch *batch);
>>> +
>>> +int netdev_afxdp_set_config(struct netdev *netdev, const struct smap *args,
>>> + char **errp);
>>> +int netdev_afxdp_get_config(const struct netdev *netdev, struct smap
>>> *args);
>>> +int netdev_afxdp_get_numa_id(const struct netdev *netdev);
>>> +
>>> +void free_afxdp_buf(struct dp_packet *p);
>>> +void free_afxdp_buf_batch(struct dp_packet_batch *batch);
>>> +int netdev_afxdp_reconfigure(struct netdev *netdev);
>>> +#endif /* netdev-afxdp.h */
>>> diff --git a/lib/netdev-linux-private.h b/lib/netdev-linux-private.h
>>> new file mode 100644
>>> index 000000000000..3dd3d902b3c4
>>> --- /dev/null
>>> +++ b/lib/netdev-linux-private.h
>>> @@ -0,0 +1,124 @@
>>> +/*
>>> + * Copyright (c) 2019 Nicira, Inc.
>>> + *
>>> + * Licensed under the Apache License, Version 2.0 (the "License");
>>> + * you may not use this file except in compliance with the License.
>>> + * You may obtain a copy of the License at:
>>> + *
>>> + * http://www.apache.org/licenses/LICENSE-2.0
>>> + *
>>> + * Unless required by applicable law or agreed to in writing, software
>>> + * distributed under the License is distributed on an "AS IS" BASIS,
>>> + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
>>> + * See the License for the specific language governing permissions and
>>> + * limitations under the License.
>>> + */
>>> +
>>> +#ifndef NETDEV_LINUX_PRIVATE_H
>>> +#define NETDEV_LINUX_PRIVATE_H 1
>>> +
>>> +#include <config.h>
>>> +
>>> +#include <linux/filter.h>
>>> +#include <linux/gen_stats.h>
>>> +#include <linux/if_ether.h>
>>> +#include <linux/if_tun.h>
>>> +#include <linux/types.h>
>>> +#include <linux/ethtool.h>
>>> +#include <linux/mii.h>
>>> +#include <stdint.h>
>>> +#include <stdbool.h>
>>> +
>>> +#include "netdev-provider.h"
>>> +#include "netdev-tc-offloads.h"
>>> +#include "netdev-vport.h"
>>> +#include "openvswitch/thread.h"
>>> +#include "ovs-atomic.h"
>>> +#include "timer.h"
>>> +
>>> +#if HAVE_AF_XDP
>>> +#include "netdev-afxdp.h"
>>> +#endif
>>> +
>>> +/* These functions are Linux specific, so they should be used directly
>>> only by
>>> + * Linux-specific code. */
>>> +
>>> +struct netdev;
>>> +
>>> +int netdev_linux_ethtool_set_flag(struct netdev *netdev, uint32_t flag,
>>> + const char *flag_name, bool enable);
>>> +int linux_get_ifindex(const char *netdev_name);
>>> +
>>> +#define LINUX_FLOW_OFFLOAD_API \
>>> + .flow_flush = netdev_tc_flow_flush, \
>>> + .flow_dump_create = netdev_tc_flow_dump_create, \
>>> + .flow_dump_destroy = netdev_tc_flow_dump_destroy, \
>>> + .flow_dump_next = netdev_tc_flow_dump_next, \
>>> + .flow_put = netdev_tc_flow_put, \
>>> + .flow_get = netdev_tc_flow_get, \
>>> + .flow_del = netdev_tc_flow_del, \
>>> + .init_flow_api = netdev_tc_init_flow_api
>>> +
>>> +struct netdev_linux {
>>> + struct netdev up;
>>> +
>>> + /* Protects all members below. */
>>> + struct ovs_mutex mutex;
>>> +
>>> + unsigned int cache_valid;
>>> +
>>> + bool miimon; /* Link status of last poll. */
>>> + long long int miimon_interval; /* Miimon Poll rate. Disabled if <= 0.
>>> */
>>> + struct timer miimon_timer;
>>> +
>>> + int netnsid; /* Network namespace ID. */
>>> + /* The following are figured out "on demand" only. They are only valid
>>> + * when the corresponding VALID_* bit in 'cache_valid' is set. */
>>> + int ifindex;
>>> + struct eth_addr etheraddr;
>>> + int mtu;
>>> + unsigned int ifi_flags;
>>> + long long int carrier_resets;
>>> + uint32_t kbits_rate; /* Policing data. */
>>> + uint32_t kbits_burst;
>>> + int vport_stats_error; /* Cached error code from
>>> vport_get_stats().
>>> + 0 or an errno value. */
>>> + int netdev_mtu_error; /* Cached error code from SIOCGIFMTU
>>> + * or SIOCSIFMTU.
>>> + */
>>> + int ether_addr_error; /* Cached error code from set/get
>>> etheraddr. */
>>> + int netdev_policing_error; /* Cached error code from set policing. */
>>> + int get_features_error; /* Cached error code from ETHTOOL_GSET. */
>>> + int get_ifindex_error; /* Cached error code from SIOCGIFINDEX. */
>>> +
>>> + enum netdev_features current; /* Cached from ETHTOOL_GSET. */
>>> + enum netdev_features advertised; /* Cached from ETHTOOL_GSET. */
>>> + enum netdev_features supported; /* Cached from ETHTOOL_GSET. */
>>> +
>>> + struct ethtool_drvinfo drvinfo; /* Cached from ETHTOOL_GDRVINFO. */
>>> + struct tc *tc;
>>> +
>>> + /* For devices of class netdev_tap_class only. */
>>> + 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 */
>>> +
>>> + /* LAG information. */
>>> + bool is_lag_master; /* True if the netdev is a LAG master. */
>>> +
>>> + /* AF_XDP information */
>>> +#ifdef HAVE_AF_XDP
>>> + struct xsk_socket_info *xsk[MAX_XSKQ];
>>> + int requested_n_rxq;
>>> + int xdpmode, requested_xdpmode; /* detect mode changed */
>>> + int xdp_flags, xdp_bind_flags;
>>> +#endif
>>> +};
>>> +
>>> +static struct netdev_linux *
>>> +netdev_linux_cast(const struct netdev *netdev)
>>> +{
>>> + return CONTAINER_OF(netdev, struct netdev_linux, up);
>>> +}
>>> +
>>> +#endif /* netdev-linux-private.h */
>>> diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c
>>> index f75d73fd39f8..1f190406d145 100644
>>> --- a/lib/netdev-linux.c
>>> +++ b/lib/netdev-linux.c
>>> @@ -17,6 +17,7 @@
>>> #include <config.h>
>>>
>>> #include "netdev-linux.h"
>>> +#include "netdev-linux-private.h"
>>>
>>> #include <errno.h>
>>> #include <fcntl.h>
>>> @@ -54,6 +55,7 @@
>>> #include "fatal-signal.h"
>>> #include "hash.h"
>>> #include "openvswitch/hmap.h"
>>> +#include "netdev-afxdp.h"
>>> #include "netdev-provider.h"
>>> #include "netdev-tc-offloads.h"
>>> #include "netdev-vport.h"
>>> @@ -487,51 +489,6 @@ static int tc_calc_cell_log(unsigned int mtu);
>>> static void tc_fill_rate(struct tc_ratespec *rate, uint64_t bps, int mtu);
>>> static int tc_calc_buffer(unsigned int Bps, int mtu, uint64_t burst_bytes);
>>>
>>> -struct netdev_linux {
>>> - struct netdev up;
>>> -
>>> - /* Protects all members below. */
>>> - struct ovs_mutex mutex;
>>> -
>>> - unsigned int cache_valid;
>>> -
>>> - bool miimon; /* Link status of last poll. */
>>> - long long int miimon_interval; /* Miimon Poll rate. Disabled if <= 0.
>>> */
>>> - struct timer miimon_timer;
>>> -
>>> - int netnsid; /* Network namespace ID. */
>>> - /* The following are figured out "on demand" only. They are only valid
>>> - * when the corresponding VALID_* bit in 'cache_valid' is set. */
>>> - int ifindex;
>>> - struct eth_addr etheraddr;
>>> - int mtu;
>>> - unsigned int ifi_flags;
>>> - long long int carrier_resets;
>>> - uint32_t kbits_rate; /* Policing data. */
>>> - uint32_t kbits_burst;
>>> - int vport_stats_error; /* Cached error code from
>>> vport_get_stats().
>>> - 0 or an errno value. */
>>> - int netdev_mtu_error; /* Cached error code from SIOCGIFMTU or
>>> SIOCSIFMTU. */
>>> - int ether_addr_error; /* Cached error code from set/get
>>> etheraddr. */
>>> - int netdev_policing_error; /* Cached error code from set policing. */
>>> - int get_features_error; /* Cached error code from ETHTOOL_GSET. */
>>> - int get_ifindex_error; /* Cached error code from SIOCGIFINDEX. */
>>> -
>>> - enum netdev_features current; /* Cached from ETHTOOL_GSET. */
>>> - enum netdev_features advertised; /* Cached from ETHTOOL_GSET. */
>>> - enum netdev_features supported; /* Cached from ETHTOOL_GSET. */
>>> -
>>> - struct ethtool_drvinfo drvinfo; /* Cached from ETHTOOL_GDRVINFO. */
>>> - struct tc *tc;
>>> -
>>> - /* For devices of class netdev_tap_class only. */
>>> - 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 */
>>> -
>>> - /* LAG information. */
>>> - bool is_lag_master; /* True if the netdev is a LAG master. */
>>> -};
>>>
>>> struct netdev_rxq_linux {
>>> struct netdev_rxq up;
>>> @@ -579,18 +536,23 @@ is_netdev_linux_class(const struct netdev_class
>>> *netdev_class)
>>> return netdev_class->run == netdev_linux_run;
>>> }
>>>
>>> +#if HAVE_AF_XDP
>>> static bool
>>> -is_tap_netdev(const struct netdev *netdev)
>>> +is_afxdp_netdev(const struct netdev *netdev)
>>> {
>>> - return netdev_get_class(netdev) == &netdev_tap_class;
>>> + return netdev_get_class(netdev) == &netdev_afxdp_class;
>>> }
>>> -
>>> -static struct netdev_linux *
>>> -netdev_linux_cast(const struct netdev *netdev)
>>> +#else
>>> +static bool
>>> +is_afxdp_netdev(const struct netdev *netdev OVS_UNUSED)
>>> {
>>> - ovs_assert(is_netdev_linux_class(netdev_get_class(netdev)));
>>> -
>>> - return CONTAINER_OF(netdev, struct netdev_linux, up);
>>> + return false;
>>> +}
>>> +#endif
>>> +static bool
>>> +is_tap_netdev(const struct netdev *netdev)
>>> +{
>>> + return netdev_get_class(netdev) == &netdev_tap_class;
>>> }
>>>
>>> static struct netdev_rxq_linux *
>>> @@ -1084,6 +1046,11 @@ netdev_linux_destruct(struct netdev *netdev_)
>>> atomic_count_dec(&miimon_cnt);
>>> }
>>>
>>> +#if HAVE_AF_XDP
>>> + if (is_afxdp_netdev(netdev_)) {
>>> + xsk_destroy_all(netdev_);
>>> + }
>>> +#endif
>>> ovs_mutex_destroy(&netdev->mutex);
>>> }
>>>
>>> @@ -1113,7 +1080,7 @@ 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 {
>>> + } else if (!is_afxdp_netdev(netdev_)) {
>>> struct sockaddr_ll sll;
>>> int ifindex, val;
>>> /* Result of tcpdump -dd inbound */
>>> @@ -1318,10 +1285,18 @@ netdev_linux_rxq_recv(struct netdev_rxq *rxq_,
>>> struct dp_packet_batch *batch,
>>> {
>>> struct netdev_rxq_linux *rx = netdev_rxq_linux_cast(rxq_);
>>> struct netdev *netdev = rx->up.netdev;
>>> - struct dp_packet *buffer;
>>> + struct dp_packet *buffer = NULL;
>>> ssize_t retval;
>>> int mtu;
>>>
>>> +#if HAVE_AF_XDP
>>> + if (is_afxdp_netdev(netdev)) {
>>> + struct netdev_linux *dev = netdev_linux_cast(netdev);
>>> + int qid = rxq_->queue_id;
>>> +
>>> + return netdev_linux_rxq_xsk(dev->xsk[qid], batch);
>>> + }
>>
>> Maybe it's better to just implement '.rxq_recv' inside netdev-afxdp.c ?
>> Also, you missed clearing the '*qfill'.
>>
>>> +#endif
>>> if (netdev_linux_get_mtu__(netdev_linux_cast(netdev), &mtu)) {
>>> mtu = ETH_PAYLOAD_MAX;
>>> }
>>> @@ -1329,6 +1304,7 @@ netdev_linux_rxq_recv(struct netdev_rxq *rxq_, struct
>>> dp_packet_batch *batch,
>>> /* Assume Ethernet port. No need to set packet_type. */
>>> 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));
>>> @@ -1480,7 +1456,8 @@ 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_)) {
>>> if (netdev_linux_netnsid_is_remote(netdev_linux_cast(netdev_))) {
>>> error = EOPNOTSUPP;
>>> goto free_batch;
>>> @@ -1499,6 +1476,36 @@ netdev_linux_send(struct netdev *netdev_, int qid
>>> OVS_UNUSED,
>>> }
>>>
>>> error = netdev_linux_sock_batch_send(sock, ifindex, batch);
>>> +#if HAVE_AF_XDP
>>> + } else if (is_afxdp_netdev(netdev_)) {
>>> + struct netdev_linux *dev = netdev_linux_cast(netdev_);
>>> + struct dp_packet_afxdp *xpacket;
>>> + struct umem_pool *first_mpool;
>>> + struct dp_packet *packet;
>>> +
>>> + error = netdev_linux_afxdp_batch_send(dev->xsk[qid], batch);
>>> +
>>> + /* all packets must come frome the same umem pool
>>> + * and has DPBUF_AFXDP type, otherwise free on-by-one
>>> + */
>>> + DP_PACKET_BATCH_FOR_EACH (i, packet, batch) {
>>> + if (packet->source != DPBUF_AFXDP) {
>>> + goto free_batch;
>>> + }
>>> +
>>> + xpacket = dp_packet_cast_afxdp(packet);
>>> + if (i == 0) {
>>> + first_mpool = xpacket->mpool;
>>> + continue;
>>> + }
>>> + if (xpacket->mpool != first_mpool) {
>>> + goto free_batch;
>>> + }
>>> + }
>>> + /* free in batch */
>>> + free_afxdp_buf_batch(batch);
>>> + return error;
>>
>>
>> There are a lot of afxdp specific code here and 'netdev_linux_send' doesn't
>> provide any magic, i.e. has no real code suitable for all netdev types.
>> Maybe it's better to just implement own '.send' function inside
>> netdev-afxdp.c ?
>
> Yes, I will do that.
>
>>
>>> +#endif
>>> } else {
>>> error = netdev_linux_tap_batch_send(netdev_, batch);
>>> }
>>> @@ -3323,6 +3330,7 @@ const struct netdev_class netdev_linux_class = {
>>> NETDEV_LINUX_CLASS_COMMON,
>>> LINUX_FLOW_OFFLOAD_API,
>>> .type = "system",
>>> + .is_pmd = false,
>>> .construct = netdev_linux_construct,
>>> .get_stats = netdev_linux_get_stats,
>>> .get_features = netdev_linux_get_features,
>>> @@ -3333,6 +3341,7 @@ const struct netdev_class netdev_linux_class = {
>>> const struct netdev_class netdev_tap_class = {
>>> NETDEV_LINUX_CLASS_COMMON,
>>> .type = "tap",
>>> + .is_pmd = false,
>>> .construct = netdev_linux_construct_tap,
>>> .get_stats = netdev_tap_get_stats,
>>> .get_features = netdev_linux_get_features,
>>> @@ -3343,10 +3352,26 @@ const struct netdev_class netdev_internal_class = {
>>> NETDEV_LINUX_CLASS_COMMON,
>>> LINUX_FLOW_OFFLOAD_API,
>>> .type = "internal",
>>> + .is_pmd = false,
>>> .construct = netdev_linux_construct,
>>> .get_stats = netdev_internal_get_stats,
>>> .get_status = netdev_internal_get_status,
>>> };
>>> +
>>> +#ifdef HAVE_AF_XDP
>>> +const struct netdev_class netdev_afxdp_class = {
>>> + NETDEV_LINUX_CLASS_COMMON,
>>> + .type = "afxdp",
>>> + .is_pmd = true,
>>> + .construct = netdev_linux_construct,
>>> + .get_stats = netdev_linux_get_stats,
>>> + .get_status = netdev_linux_get_status,
>>> + .set_config = netdev_afxdp_set_config,
>>> + .get_config = netdev_afxdp_get_config,
>>> + .reconfigure = netdev_afxdp_reconfigure,
>>> + .get_numa_id = netdev_afxdp_get_numa_id,
>>> +};
>>> +#endif
>>>
>>>
>>> #define CODEL_N_QUEUES 0x0000
>>> diff --git a/lib/netdev-linux.h b/lib/netdev-linux.h
>>> index 17ca9120168a..b812e64cb078 100644
>>> --- a/lib/netdev-linux.h
>>> +++ b/lib/netdev-linux.h
>>> @@ -19,6 +19,20 @@
>>>
>>> #include <stdint.h>
>>> #include <stdbool.h>
>>> +#include <linux/filter.h>
>>> +#include <linux/gen_stats.h>
>>> +#include <linux/if_ether.h>
>>> +#include <linux/if_tun.h>
>>> +#include <linux/types.h>
>>> +#include <linux/ethtool.h>
>>> +#include <linux/mii.h>
>>> +
>>> +#include "netdev-provider.h"
>>> +#include "netdev-tc-offloads.h"
>>> +#include "netdev-vport.h"
>>> +#include "openvswitch/thread.h"
>>> +#include "ovs-atomic.h"
>>> +#include "timer.h"
>>>
>>> /* These functions are Linux specific, so they should be used directly
>>> only by
>>> * Linux-specific code. */
>>> diff --git a/lib/netdev-provider.h b/lib/netdev-provider.h
>>> index fb0c27e6e8e8..d433818f7064 100644
>>> --- a/lib/netdev-provider.h
>>> +++ b/lib/netdev-provider.h
>>> @@ -902,7 +902,9 @@ extern const struct netdev_class netdev_linux_class;
>>> #endif
>>> extern const struct netdev_class netdev_internal_class;
>>> extern const struct netdev_class netdev_tap_class;
>>> -
>>> +#if HAVE_AF_XDP
>>> +extern const struct netdev_class netdev_afxdp_class;
>>> +#endif
>>> #ifdef __cplusplus
>>> }
>>> #endif
>>> diff --git a/lib/netdev.c b/lib/netdev.c
>>> index 7d7ecf6f0946..e2fae37d5a5e 100644
>>> --- a/lib/netdev.c
>>> +++ b/lib/netdev.c
>>> @@ -146,6 +146,9 @@ netdev_initialize(void)
>>> netdev_register_provider(&netdev_internal_class);
>>> netdev_register_provider(&netdev_tap_class);
>>> netdev_vport_tunnel_register();
>>> +#ifdef HAVE_AF_XDP
>>> + netdev_register_provider(&netdev_afxdp_class);
>>> +#endif
>>> #endif
>>> #if defined(__FreeBSD__) || defined(__NetBSD__)
>>> netdev_register_provider(&netdev_tap_class);
>>> diff --git a/lib/xdpsock.c b/lib/xdpsock.c
>>> new file mode 100644
>>> index 000000000000..2d80e74d69e4
>>> --- /dev/null
>>> +++ b/lib/xdpsock.c
>>> @@ -0,0 +1,239 @@
>>> +/*
>>> + * Copyright (c) 2018, 2019 Nicira, Inc.
>>> + *
>>> + * Licensed under the Apache License, Version 2.0 (the "License");
>>> + * you may not use this file except in compliance with the License.
>>> + * You may obtain a copy of the License at:
>>> + *
>>> + * http://www.apache.org/licenses/LICENSE-2.0
>>> + *
>>> + * Unless required by applicable law or agreed to in writing, software
>>> + * distributed under the License is distributed on an "AS IS" BASIS,
>>> + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
>>> + * See the License for the specific language governing permissions and
>>> + * limitations under the License.
>>> + */
>>> +#include <config.h>
>>> +
>>> +#include "xdpsock.h"
>>> +
>>> +#include <ctype.h>
>>> +#include <errno.h>
>>> +#include <fcntl.h>
>>> +#include <stdarg.h>
>>> +#include <stdlib.h>
>>> +#include <string.h>
>>> +#include <sys/stat.h>
>>> +#include <sys/types.h>
>>> +#include <syslog.h>
>>> +#include <time.h>
>>> +#include <unistd.h>
>>> +
>>> +#include "async-append.h"
>>> +#include "coverage.h"
>>> +#include "dirs.h"
>>> +#include "dp-packet.h"
>>> +#include "openvswitch/compiler.h"
>>> +#include "openvswitch/vlog.h"
>>> +#include "ovs-atomic.h"
>>> +#include "ovs-thread.h"
>>> +#include "sat-math.h"
>>> +#include "socket-util.h"
>>> +#include "svec.h"
>>> +#include "syslog-direct.h"
>>> +#include "syslog-libc.h"
>>> +#include "syslog-provider.h"
>>> +#include "timeval.h"
>>> +#include "unixctl.h"
>>> +#include "util.h"
>>> +
>>> +static inline void
>>> +ovs_spinlock_init(ovs_spinlock_t *sl)
>>> +{
>>> + atomic_init(&sl->locked, 0);
>>> +}
>>> +
>>> +static inline void
>>> +ovs_spin_lock(ovs_spinlock_t *sl)
>>> +{
>>> + int exp = 0, locked = 0;
>>> +
>>> + while (!atomic_compare_exchange_strong_explicit(&sl->locked, &exp, 1,
>>> + memory_order_acquire,
>>> + memory_order_relaxed)) {
>>> + locked = 1;
>>> + while (locked) {
>>> + atomic_read_relaxed(&sl->locked, &locked);
>>> + }
>>> + exp = 0;
>>> + }
>>> +}
>>> +
>>> +static inline void
>>> +ovs_spin_unlock(ovs_spinlock_t *sl)
>>> +{
>>> + atomic_store_explicit(&sl->locked, 0, memory_order_release);
>>> +}
>>> +
>>> +static inline int OVS_UNUSED
>>> +ovs_spin_trylock(ovs_spinlock_t *sl)
>>> +{
>>> + int exp = 0;
>>> + return atomic_compare_exchange_strong_explicit(&sl->locked, &exp, 1,
>>> + memory_order_acquire,
>>> + memory_order_relaxed);
>>> +}
>>> +
>>> +inline int
>>> +__umem_elem_push_n(struct umem_pool *umemp, int n, void **addrs)
>>> +{
>>> + void *ptr;
>>> +
>>> + if (OVS_UNLIKELY(umemp->index + n > umemp->size)) {
>>> + return -ENOMEM;
>>> + }
>>> +
>>> + ptr = &umemp->array[umemp->index];
>>> + memcpy(ptr, addrs, n * sizeof(void *));
>>> + umemp->index += n;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +int umem_elem_push_n(struct umem_pool *umemp, int n, void **addrs)
>>> +{
>>> + int ret;
>>> +
>>> + ovs_spin_lock(&umemp->mutex);
>>> + ret = __umem_elem_push_n(umemp, n, addrs);
>>> + ovs_spin_unlock(&umemp->mutex);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +inline void
>>> +__umem_elem_push(struct umem_pool *umemp, void *addr)
>>> +{
>>> + umemp->array[umemp->index++] = addr;
>>> +}
>>> +
>>> +void
>>> +umem_elem_push(struct umem_pool *umemp, void *addr)
>>> +{
>>> +
>>> + if (OVS_UNLIKELY(umemp->index >= umemp->size)) {
>>> + /* stack is overflow, this should not happen */
>>> + OVS_NOT_REACHED();
>>> + }
>>> +
>>> + ovs_assert(((uint64_t)addr & FRAME_SHIFT_MASK) == 0);
>>> +
>>> + ovs_spin_lock(&umemp->mutex);
>>> + __umem_elem_push(umemp, addr);
>>> + ovs_spin_unlock(&umemp->mutex);
>>> +}
>>> +
>>> +inline int
>>> +__umem_elem_pop_n(struct umem_pool *umemp, int n, void **addrs)
>>> +{
>>> + void *ptr;
>>> +
>>> + if (OVS_UNLIKELY(umemp->index - n < 0)) {
>>> + return -ENOMEM;
>>> + }
>>> +
>>> + umemp->index -= n;
>>> + ptr = &umemp->array[umemp->index];
>>> + memcpy(addrs, ptr, n * sizeof(void *));
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +int
>>> +umem_elem_pop_n(struct umem_pool *umemp, int n, void **addrs)
>>> +{
>>> + int ret;
>>> +
>>> + ovs_spin_lock(&umemp->mutex);
>>> + ret = __umem_elem_pop_n(umemp, n, addrs);
>>> + ovs_spin_unlock(&umemp->mutex);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +inline void *
>>> +__umem_elem_pop(struct umem_pool *umemp)
>>> +{
>>> + return umemp->array[--umemp->index];
>>> +}
>>> +
>>> +void *
>>> +umem_elem_pop(struct umem_pool *umemp)
>>> +{
>>> + void *ptr;
>>> +
>>> + ovs_spin_lock(&umemp->mutex);
>>> + ptr = __umem_elem_pop(umemp);
>>> + ovs_spin_unlock(&umemp->mutex);
>>> +
>>> + return ptr;
>>> +}
>>> +
>>> +void **
>>> +__umem_pool_alloc(unsigned int size)
>>> +{
>>> + void *bufs;
>>> +
>>> + ovs_assert(posix_memalign(&bufs, getpagesize(),
>>> + size * sizeof(void *)) == 0);
>>> + memset(bufs, 0, size * sizeof(void *));
>>> + return (void **)bufs;
>>> +}
>>> +
>>> +unsigned int
>>> +umem_elem_count(struct umem_pool *mpool)
>>> +{
>>> + return mpool->index;
>>> +}
>>> +
>>> +int
>>> +umem_pool_init(struct umem_pool *umemp, unsigned int size)
>>> +{
>>> + umemp->array = __umem_pool_alloc(size);
>>> + if (!umemp->array) {
>>> + OVS_NOT_REACHED();
>>> + }
>>> +
>>> + umemp->size = size;
>>> + umemp->index = 0;
>>> + ovs_spinlock_init(&umemp->mutex);
>>> + return 0;
>>> +}
>>> +
>>> +void
>>> +umem_pool_cleanup(struct umem_pool *umemp)
>>> +{
>>> + free(umemp->array);
>>> +}
>>> +
>>> +/* AF_XDP metadata init/destroy */
>>> +int
>>> +xpacket_pool_init(struct xpacket_pool *xp, unsigned int size)
>>> +{
>>> + void *bufs;
>>> +
>>> + /* TODO: check HAVE_POSIX_MEMALIGN */
>>> + ovs_assert(posix_memalign(&bufs, getpagesize(),
>>> + size * sizeof(struct dp_packet_afxdp)) == 0);
>>> + memset(bufs, 0, size * sizeof(struct dp_packet_afxdp));
>>> +
>>> + xp->array = bufs;
>>> + xp->size = size;
>>> + return 0;
>>> +}
>>> +
>>> +void
>>> +xpacket_pool_cleanup(struct xpacket_pool *xp)
>>> +{
>>> + free(xp->array);
>>> +}
>>> diff --git a/lib/xdpsock.h b/lib/xdpsock.h
>>> new file mode 100644
>>> index 000000000000..aabaa8e5df24
>>> --- /dev/null
>>> +++ b/lib/xdpsock.h
>>> @@ -0,0 +1,123 @@
>>> +/*
>>> + * Copyright (c) 2018, 2019 Nicira, Inc.
>>> + *
>>> + * Licensed under the Apache License, Version 2.0 (the "License");
>>> + * you may not use this file except in compliance with the License.
>>> + * You may obtain a copy of the License at:
>>> + *
>>> + * http://www.apache.org/licenses/LICENSE-2.0
>>> + *
>>> + * Unless required by applicable law or agreed to in writing, software
>>> + * distributed under the License is distributed on an "AS IS" BASIS,
>>> + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
>>> + * See the License for the specific language governing permissions and
>>> + * limitations under the License.
>>> + */
>>> +
>>> +#ifndef XDPSOCK_H
>>> +#define XDPSOCK_H 1
>>> +
>>> +#include <bpf/libbpf.h>
>>> +#include <bpf/xsk.h>
>>> +#include <errno.h>
>>> +#include <getopt.h>
>>> +#include <libgen.h>
>>> +#include <linux/bpf.h>
>>> +#include <linux/if_link.h>
>>> +#include <linux/if_xdp.h>
>>> +#include <linux/if_ether.h>
>>> +#include <locale.h>
>>> +#include <net/if.h>
>>> +#include <poll.h>
>>> +#include <pthread.h>
>>> +#include <signal.h>
>>> +#include <stdbool.h>
>>> +#include <stdio.h>
>>> +#include <stdlib.h>
>>> +#include <string.h>
>>> +#include <sys/resource.h>
>>> +#include <sys/socket.h>
>>> +#include <sys/types.h>
>>> +#include <sys/mman.h>
>>> +#include <time.h>
>>> +#include <unistd.h>
>>> +
>>> +#include "openvswitch/thread.h"
>>> +#include "ovs-atomic.h"
>>> +
>>> +#define FRAME_HEADROOM XDP_PACKET_HEADROOM
>>> +#define FRAME_SIZE XSK_UMEM__DEFAULT_FRAME_SIZE
>>> +#define BATCH_SIZE NETDEV_MAX_BURST
>>> +#define FRAME_SHIFT XSK_UMEM__DEFAULT_FRAME_SHIFT
>>> +#define FRAME_SHIFT_MASK ((1 << FRAME_SHIFT) - 1)
>>> +
>>> +#define NUM_FRAMES 4096
>>> +#define PROD_NUM_DESCS 512
>>> +#define CONS_NUM_DESCS 512
>>> +
>>> +#ifdef USE_XSK_DEFAULT
>>> +#define PROD_NUM_DESCS XSK_RING_PROD__DEFAULT_NUM_DESCS
>>> +#define CONS_NUM_DESCS XSK_RING_CONS__DEFAULT_NUM_DESCS
>>> +#endif
>>
>> Should there be ifdef-else-endif ?
>
> good catch, thanks.
> William
>
>
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