>
>"Kavanagh, Mark B" <mark.b.kavan...@intel.com> writes:
>> Further clarifications below Aaron - please let me know if you have
>> any additional comments.
>>
>> Thanks,
>> Mark
>
>Thanks again for this work, Mark!
>
>>>
>>>One addendum below, Aaron.
>>>
>>>>
>>>>>Hi Mark,
>>>>>
>>>>>Thanks for the patch! I've not done a very thorough review of this, but
>>>>>my first-blush comments are inline.
>>>>
>>>>Thanks for the review Aaron!
>>>>
>>>>Any additional comments are welcome - my initial responses are inline,
>>>>below.
>>>>
>>>>Thanks,
>>>>Mark
>>>>
>>>>>
>>>>>Mark Kavanagh <mark.b.kavan...@intel.com> writes:
>>>>>> Add support for Jumbo Frames to DPDK-enabled port types,
>>>>>> using single-segment-mbufs.
>>>>>>
>>>>>> Using this approach, the amount of memory allocated for each mbuf
>>>>>> to store frame data is increased to a value greater than 1518B
>>>>>> (typical Ethernet maximum frame length). The increased space
>>>>>> available in the mbuf means that an entire Jumbo Frame can be carried
>>>>>> in a single mbuf, as opposed to partitioning it across multiple mbuf
>>>>>> segments.
>>>>>>
>>>>>> The amount of space allocated to each mbuf to hold frame data is
>>>>>> defined dynamically by the user when adding a DPDK port to a bridge.
>>>>>> If an MTU value is not supplied, or the user-supplied value is invalid,
>>>>>> the MTU for the port defaults to standard Ethernet MTU (i.e. 1500B).
>>>>>>
>>>>>> Signed-off-by: Mark Kavanagh <mark.b.kavan...@intel.com>
>>>>>> ---
>>>>>
>>>>>This is a new feature which has user-visible impact, so should be
>>>>>announced in NEWS (plus, it's great news).
>>>>
>>>>No problem - I'll add an entry.
>>>>
>>>>>
>>>>>> INSTALL.DPDK.md | 59 ++++++++-
>>>>>> lib/netdev-dpdk.c | 356
>> +++++++++++++++++++++++++++++++++++++++++-------------
>>>>>> 2 files changed, 328 insertions(+), 87 deletions(-)
>>>>>>
>>>>>> diff --git a/INSTALL.DPDK.md b/INSTALL.DPDK.md
>>>>>> index 96b686c..2f23e27 100644
>>>>>> --- a/INSTALL.DPDK.md
>>>>>> +++ b/INSTALL.DPDK.md
>>>>>> @@ -859,10 +859,61 @@ by adding the following string:
>>>>>> to <interface> sections of all network devices used by DPDK. Parameter
>>>>>> 'N'
>>>>>> determines how many queues can be used by the guest.
>>>>>>
>>>>>> +
>>>>>> +Jumbo Frames
>>>>>> +------------
>>>>>> +
>>>>>> +Support for Jumbo Frames may be enabled at run-time for DPDK-type ports.
>>>>>> +
>>>>>> +To avail of Jumbo Frame support, add the '--dpdk-mtu' option to
>> the ovs-vsctl
>>>>>> +'add-port' command-line, along with the required MTU for the port.
>>>>>> +e.g.
>>>>>
>>>>>This text and the example do not match. I think '--dpdk-mtu' is not valid.
>>>>
>>>>Good catch, thanks.
>>>>
>>>>>
>>>>>> +
>>>>>> + ```
>>>>>> + ovs-vsctl add-port br0 dpdk0 -- set Interface dpdk0 type=dpdk
>> options:dpdk-mtu=9000
>>>>>> + ```
>>>>>> +
>>>>>> +When Jumbo Frames are enabled, the size of a DPDK port's mbuf segments
>>>>>> are
>>>>>> +increased, such that a full Jumbo Frame may be accommodated
>> inside a single
>>>>>> +mbuf segment. Once set, the MTU for a DPDK port is immutable.
>>>>>
>>>>>Why no support? DPDK supports changing the mtu.
>>>>
>>>>I guess my rationale here is that an MTU change can't be triggered
>> via OVS command-line, nor
>>>>can it be triggered programmatically via DPDK (apart from an explicit call
>>>>to
>>>>rte_eth_dev_set_mtu).
>>>>So, while technically it's possibly, from a user's point of view,
>> there's no way to
>>>configure
>>>>it, outside of modifying the code directly. If I've missed something
>> here, please let me
>>>>know.
>>>>
>>>>>
>>>>>> +Jumbo frame support has been validated against 13312B frames, using the
>>>>>> +DPDK `igb_uio` driver, but larger frames and other DPDK NIC drivers may
>>>>>> +theoretically be supported. Supported port types excludes
>> vHost-Cuse ports, as
>>>>>> +this feature is pending deprecation.
>>>>>> +
>>>>>> +
>>>>>> +vHost Ports and Jumbo Frames
>>>>>> +----------------------------
>>>>>> +Jumbo frame support is available for DPDK vHost-User ports
>> only. Some additional
>>>>>> +configuration is needed to take advantage of this feature:
>>>>>> +
>>>>>> + 1. `mergeable buffers` must be enabled for vHost ports, as
>> demonstrated in
>>>>>> + the QEMU command line snippet below:
>>>>>> +
>>>>>> + ```
>>>>>> + '-netdev type=vhost-user,id=mynet1,chardev=char0,vhostforce \'
>>>>>> + '-device
>> virtio-net-pci,mac=00:00:00:00:00:01,netdev=mynet1,mrg_rxbuf=on'
>>>>>> + ```
>>>>>> +
>>>>>> + 2. Where virtio devices are bound to the Linux kernel driver in a
>>>>>> guest
>>>>>> + environment (i.e. interfaces are not bound to an in-guest DPDK
>> driver), the
>>>>>> + MTU of those logical network interfaces must also be increased.
>>>>>> This
>>>>>> + avoids segmentation of Jumbo Frames in the guest. Note that
>> 'MTU' refers
>>>>>> + to the length of the IP packet only, and not that of the entire
>> frame.
>>>>>> +
>>>>>> + e.g. To calculate the exact MTU of a standard IPv4 frame,
>> subtract the L2
>>>>>> + header and CRC lengths (i.e. 18B) from the max supported frame
>>>>>> size.
>>>>>> + So, to set the MTU for a 13312B Jumbo Frame:
>>>>>> +
>>>>>> + ```
>>>>>> + ifconfig eth1 mtu 13294
>>>>>> + ```
>>>>>> +
>>>>>> +
>>>>>> Restrictions:
>>>>>> -------------
>>>>>>
>>>>>> - - Work with 1500 MTU, needs few changes in DPDK lib to fix this issue.
>>>>>> - Currently DPDK port does not make use any offload functionality.
>>>>>> - DPDK-vHost support works with 1G huge pages.
>>>>>>
>>>>>> @@ -903,6 +954,12 @@ Restrictions:
>>>>>> the next release of DPDK (which includes the above patch) is
>> available and
>>>>>> integrated into OVS.
>>>>>>
>>>>>> + Jumbo Frames:
>>>>>> + - `virtio-pmd`: DPDK apps in the guest do not exit
>> gracefully. The source of
>>>>>> + this issue is currently being investigated.
>>>>>> + - vHost-Cuse: Jumbo Frame support is not available for vHost Cuse
>>>>>> ports.
>>>>>> +
>>>>>> +
>>>>>> Bug Reporting:
>>>>>> --------------
>>>>>>
>>>>>> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
>>>>>> index de7e488..5f23e28 100644
>>>>>> --- a/lib/netdev-dpdk.c
>>>>>> +++ b/lib/netdev-dpdk.c
>>>>>> @@ -62,20 +62,25 @@ static struct vlog_rate_limit rl =
>> VLOG_RATE_LIMIT_INIT(5, 20);
>>>>>> #define OVS_CACHE_LINE_SIZE CACHE_LINE_SIZE
>>>>>> #define OVS_VPORT_DPDK "ovs_dpdk"
>>>>>>
>>>>>> +#define NETDEV_DPDK_JUMBO_FRAME_ENABLED 1
>>>>>> +#define NETDEV_DPDK_DEFAULT_RX_BUFSIZE 1024
>>>>>> +
>>>>>> /*
>>>>>> * need to reserve tons of extra space in the mbufs so we can align the
>>>>>> * DMA addresses to 4KB.
>>>>>> * The minimum mbuf size is limited to avoid scatter behaviour and drop
>>>>>> in
>>>>>> * performance for standard Ethernet MTU.
>>>>>> */
>>>>>> -#define MTU_TO_MAX_LEN(mtu) ((mtu) + ETHER_HDR_LEN + ETHER_CRC_LEN)
>>>>>> -#define MBUF_SIZE_MTU(mtu) (MTU_TO_MAX_LEN(mtu) \
>>>>>> - + sizeof(struct dp_packet) \
>>>>>> - + RTE_PKTMBUF_HEADROOM)
>>>>>> -#define MBUF_SIZE_DRIVER (2048 \
>>>>>> - + sizeof (struct rte_mbuf) \
>>>>>> - + RTE_PKTMBUF_HEADROOM)
>>>>>> -#define MBUF_SIZE(mtu) MAX(MBUF_SIZE_MTU(mtu), MBUF_SIZE_DRIVER)
>>>>>> +#define MTU_TO_FRAME_LEN(mtu) ((mtu) + ETHER_HDR_LEN +
>> ETHER_CRC_LEN)
>>>>>> +#define FRAME_LEN_TO_MTU(frame_len) ((frame_len)- ETHER_HDR_LEN
>> - ETHER_CRC_LEN)
>>>>>> +#define MBUF_SEGMENT_SIZE(mtu) ( MTU_TO_FRAME_LEN(mtu) \
>>>>>> + + sizeof(struct dp_packet) \
>>>>>> + + RTE_PKTMBUF_HEADROOM)
>>>>>> +
>>>>>> +/* This value should be specified as a multiple of the DPDK NIC driver's
>>>>>> + * 'min_rx_bufsize' attribute (currently 1024B for 'igb_uio').
>>>>>> + */
>>>>>> +#define NETDEV_DPDK_MAX_FRAME_LEN 13312
>>>>>>
>>>>>> /* Max and min number of packets in the mempool. OVS tries to allocate
>>>>>> a
>>>>>> * mempool with MAX_NB_MBUF: if this fails (because the system
>> doesn't have
>>>>>> @@ -86,6 +91,8 @@ static struct vlog_rate_limit rl =
>> VLOG_RATE_LIMIT_INIT(5, 20);
>>>>>> #define MIN_NB_MBUF (4096 * 4)
>>>>>> #define MP_CACHE_SZ RTE_MEMPOOL_CACHE_MAX_SIZE
>>>>>>
>>>>>> +#define DPDK_VLAN_TAG_LEN 4
>>>>>> +
>>>>>> /* MAX_NB_MBUF can be divided by 2 many times, until MIN_NB_MBUF */
>>>>>> BUILD_ASSERT_DECL(MAX_NB_MBUF %
>> ROUND_DOWN_POW2(MAX_NB_MBUF/MIN_NB_MBUF) == 0);
>>>>>>
>>>>>> @@ -114,7 +121,6 @@ static const struct rte_eth_conf port_conf = {
>>>>>> .header_split = 0, /* Header Split disabled */
>>>>>> .hw_ip_checksum = 0, /* IP checksum offload disabled */
>>>>>> .hw_vlan_filter = 0, /* VLAN filtering disabled */
>>>>>> - .jumbo_frame = 0, /* Jumbo Frame Support disabled */
>>>>>> .hw_strip_crc = 0,
>>>>>> },
>>>>>> .rx_adv_conf = {
>>>>>> @@ -254,6 +260,39 @@ is_dpdk_class(const struct netdev_class *class)
>>>>>> return class->construct == netdev_dpdk_construct;
>>>>>> }
>>>>>>
>>>>>> +/* DPDK NIC drivers allocate RX buffers at a particular granularity
>>>>>> + * (specified by rte_eth_dev_info.min_rx_bufsize - currently 1K
>> for igb_uio).
>>>>>> + * If 'frame_len' is not a multiple of this value, insufficient
>> buffers are
>>>>>> + * allocated to accomodate the packet in its
>> entirety. Furthermore, the igb_uio
>>>>>> + * driver needs to ensure that there is also sufficient space in
>> the Rx buffer
>>>>>> + * to accommodate two VLAN tags (for QinQ frames). If the RX buffer is
>>>>>> too
>>>>>> + * small, then the driver enables scatter RX behaviour, which reduces
>>>>>> + * performance. To prevent this, use a buffer size that is closest to
>>>>>> + * 'frame_len', but which satisfies the aforementioned criteria.
>>>>>> + */
>>>>>> +static uint32_t
>>>>>> +dpdk_buf_size(struct netdev_dpdk *netdev, int frame_len)
>>>>>> +{
>>>>>> + struct rte_eth_dev_info info;
>>>>>> + uint32_t buf_size;
>>>>>> + uint32_t len = frame_len + (2 * DPDK_VLAN_TAG_LEN);
>>>>>> +
>>>>>> + if(netdev->type == DPDK_DEV_ETH) {
>>>>>> + rte_eth_dev_info_get(netdev->port_id, &info);
>>>>>> + buf_size = (info.min_rx_bufsize == 0) ?
>>>>>> + NETDEV_DPDK_DEFAULT_RX_BUFSIZE :
>>>>>> + info.min_rx_bufsize;
>>>>>
>>>>>Why not use the rte_eth_dev_get_mtu call to get the port configured mtu?
>>>>
>>>>I'm not sure if I follow - the MTU isn't the issue here, but rather
>> the buffer size used
>>>>when creating the rte_mempool, which must be a multiple of the
>> driver's min_rx_bufsize.
>>>>
>>>>>
>>>>>> + } else {
>>>>>> + buf_size = NETDEV_DPDK_DEFAULT_RX_BUFSIZE;
>>>>>> + }
>>>>>> +
>>>>>> + if(len % buf_size) {
>>>>>> + len = buf_size * ((len/buf_size) + 1);
>>>>>> + }
>>>>>> +
>>>>>> + return len;
>>>>>> +}
>>>>>> +
>>>>>> /* XXX: use dpdk malloc for entire OVS. in fact huge page should be used
>>>>>> * for all other segments data, bss and text. */
>>>>>>
>>>>>> @@ -280,31 +319,70 @@ free_dpdk_buf(struct dp_packet *p)
>>>>>> }
>>>>>>
>>>>>> static void
>>>>>> -__rte_pktmbuf_init(struct rte_mempool *mp,
>>>>>> - void *opaque_arg OVS_UNUSED,
>>>>>> - void *_m,
>>>>>> - unsigned i OVS_UNUSED)
>>>>>> +ovs_rte_pktmbuf_pool_init(struct rte_mempool *mp, void *opaque_arg)
>>>>>> {
>>>>>> - struct rte_mbuf *m = _m;
>>>>>> - uint32_t buf_len = mp->elt_size - sizeof(struct dp_packet);
>>>>>> + struct rte_pktmbuf_pool_private *user_mbp_priv, *mbp_priv;
>>>>>> + struct rte_pktmbuf_pool_private default_mbp_priv;
>>>>>> + uint16_t roomsz;
>>>>>>
>>>>>> RTE_MBUF_ASSERT(mp->elt_size >= sizeof(struct dp_packet));
>>>>>>
>>>>>> - memset(m, 0, mp->elt_size);
>>>>>> + /* if no structure is provided, assume no mbuf private area */
>>>>>> +
>>>>>> + user_mbp_priv = opaque_arg;
>>>>>> + if (user_mbp_priv == NULL) {
>>>>>> + default_mbp_priv.mbuf_priv_size = 0;
>>>>>> + if (mp->elt_size > sizeof(struct dp_packet)) {
>>>>>> + roomsz = mp->elt_size - sizeof(struct dp_packet);
>>>>>> + } else {
>>>>>> + roomsz = 0;
>>>>>> + }
>>>>>> + default_mbp_priv.mbuf_data_room_size = roomsz;
>>>>>> + user_mbp_priv = &default_mbp_priv;
>>>>>> + }
>>>>>> +
>>>>>> + RTE_MBUF_ASSERT(mp->elt_size >= sizeof(struct dp_packet) +
>>>>>> + user_mbp_priv->mbuf_data_room_size +
>>>>>> + user_mbp_priv->mbuf_priv_size);
>>>>>> +
>>>>>> + mbp_priv = rte_mempool_get_priv(mp);
>>>>>> + memcpy(mbp_priv, user_mbp_priv, sizeof(*mbp_priv));
>>>>>> +}
>>>>>> +
>>>>>> +/* Initialise some fields in the mbuf structure that are not
>> modified by the
>>>>>> + * user once created (origin pool, buffer start address, etc.*/
>>>>>> +static void
>>>>>> +__ovs_rte_pktmbuf_init(struct rte_mempool *mp,
>>>>>> + void *opaque_arg OVS_UNUSED,
>>>>>> + void *_m,
>>>>>> + unsigned i OVS_UNUSED)
>>>>>> +{
>>>>>> + struct rte_mbuf *m = _m;
>>>>>> + uint32_t buf_size, buf_len, priv_size;
>>>>>> +
>>>>>> + priv_size = rte_pktmbuf_priv_size(mp);
>>>>>> + buf_size = sizeof(struct dp_packet) + priv_size;
>>>>>> + buf_len = rte_pktmbuf_data_room_size(mp);
>>>>>>
>>>>>> - /* start of buffer is just after mbuf structure */
>>>>>> - m->buf_addr = (char *)m + sizeof(struct dp_packet);
>>>>>> - m->buf_physaddr = rte_mempool_virt2phy(mp, m) +
>>>>>> - sizeof(struct dp_packet);
>>>>>> - m->buf_len = (uint16_t)buf_len;
>>>>>> + RTE_MBUF_ASSERT(RTE_ALIGN(priv_size, RTE_MBUF_PRIV_ALIGN) ==
>>>>>> priv_size);
>>>>>> + RTE_MBUF_ASSERT(mp->elt_size >= buf_size);
>>>>>> + RTE_MBUF_ASSERT(buf_len <= UINT16_MAX);
>>>>>>
>>>>>> - /* keep some headroom between start of buffer and data */
>>>>>> - m->data_off = RTE_MIN(RTE_PKTMBUF_HEADROOM, m->buf_len);
>>>>>> + memset(m, 0, mp->elt_size);
>>>>>>
>>>>>> - /* init some constant fields */
>>>>>> - m->pool = mp;
>>>>>> - m->nb_segs = 1;
>>>>>> - m->port = 0xff;
>>>>>> + /* start of buffer is after dp_packet structure and priv data */
>>>>>> + m->priv_size = priv_size;
>>>>>> + m->buf_addr = (char *)m + buf_size;
>>>>>> + m->buf_physaddr = rte_mempool_virt2phy(mp, m) + buf_size;
>>>>>> + m->buf_len = (uint16_t)buf_len;
>>>>>> +
>>>>>> + /* keep some headroom between start of buffer and data */
>>>>>> + m->data_off = RTE_MIN(RTE_PKTMBUF_HEADROOM,
>>>>>> (uint16_t)m->buf_len);
>>>>>> +
>>>>>> + /* init some constant fields */
>>>>>> + m->pool = mp;
>>>>>> + m->nb_segs = 1;
>>>>>> + m->port = 0xff;
>>>>>
>>>>>Please don't mix tabs and spaces in the file.
>>>>
>>>>Apologies - this was a copy/paste from a DPDK file, which uses tabs.
>>>>
>>>>>
>>>>>> }
>>>>>>
>>>>>> static void
>>>>>> @@ -315,7 +393,7 @@ ovs_rte_pktmbuf_init(struct rte_mempool *mp,
>>>>>> {
>>>>>> struct rte_mbuf *m = _m;
>>>>>>
>>>>>> - __rte_pktmbuf_init(mp, opaque_arg, _m, i);
>>>>>> + __ovs_rte_pktmbuf_init(mp, opaque_arg, m, i);
>>>>>>
>>>>>> dp_packet_init_dpdk((struct dp_packet *) m, m->buf_len);
>>>>>> }
>>>>>> @@ -326,6 +404,7 @@ dpdk_mp_get(int socket_id, int mtu)
>> OVS_REQUIRES(dpdk_mutex)
>>>>>> struct dpdk_mp *dmp = NULL;
>>>>>> char mp_name[RTE_MEMPOOL_NAMESIZE];
>>>>>> unsigned mp_size;
>>>>>> + struct rte_pktmbuf_pool_private mbp_priv;
>>>>>>
>>>>>> LIST_FOR_EACH (dmp, list_node, &dpdk_mp_list) {
>>>>>> if (dmp->socket_id == socket_id && dmp->mtu == mtu) {
>>>>>> @@ -338,6 +417,8 @@ dpdk_mp_get(int socket_id, int mtu)
>> OVS_REQUIRES(dpdk_mutex)
>>>>>> dmp->socket_id = socket_id;
>>>>>> dmp->mtu = mtu;
>>>>>> dmp->refcount = 1;
>>>>>> + mbp_priv.mbuf_data_room_size = MTU_TO_FRAME_LEN(mtu) +
>> RTE_PKTMBUF_HEADROOM;
>>>>>> + mbp_priv.mbuf_priv_size = 0;
>>>>>>
>>>>>> mp_size = MAX_NB_MBUF;
>>>>>> do {
>>>>>> @@ -346,10 +427,10 @@ dpdk_mp_get(int socket_id, int mtu)
>> OVS_REQUIRES(dpdk_mutex)
>>>>>> return NULL;
>>>>>> }
>>>>>>
>>>>>> - dmp->mp = rte_mempool_create(mp_name, mp_size, MBUF_SIZE(mtu),
>>>>>> + dmp->mp = rte_mempool_create(mp_name, mp_size,
>> MBUF_SEGMENT_SIZE(mtu),
>>>>>> MP_CACHE_SZ,
>>>>>> sizeof(struct rte_pktmbuf_pool_private),
>>>>>> - rte_pktmbuf_pool_init, NULL,
>>>>>> + ovs_rte_pktmbuf_pool_init,
>>>>>> &mbp_priv,
>>>>>> ovs_rte_pktmbuf_init, NULL,
>>>>>> socket_id, 0);
>>>>>> } while (!dmp->mp && rte_errno == ENOMEM && (mp_size /= 2) >=
>> MIN_NB_MBUF);
>>>>>> @@ -433,6 +514,7 @@ dpdk_eth_dev_queue_setup(struct netdev_dpdk
>> *dev, int n_rxq, int
>>>>n_txq)
>>>>>> {
>>>>>> int diag = 0;
>>>>>> int i;
>>>>>> + struct rte_eth_conf conf = port_conf;
>>>>>>
>>>>>> /* A device may report more queues than it makes available (this has
>>>>>> * been observed for Intel xl710, which reserves some of them for
>>>>>> @@ -444,7 +526,12 @@ dpdk_eth_dev_queue_setup(struct netdev_dpdk
>> *dev, int n_rxq, int
>>>>>n_txq)
>>>>>> VLOG_INFO("Retrying setup with (rxq:%d txq:%d)", n_rxq, n_txq);
>>>>>> }
>>>>>>
>>>>>> - diag = rte_eth_dev_configure(dev->port_id, n_rxq, n_txq,
>> &port_conf);
>>>>>> + if(OVS_UNLIKELY(dev->mtu > ETHER_MTU)) {
>>>>>> + conf.rxmode.jumbo_frame = NETDEV_DPDK_JUMBO_FRAME_ENABLED;
>>>>>> + conf.rxmode.max_rx_pkt_len = MTU_TO_FRAME_LEN(dev->mtu);
>>>>>> + }
>>>>>> +
>>>>>> + diag = rte_eth_dev_configure(dev->port_id, n_rxq, n_txq, &conf);
>>>>>> if (diag) {
>>>>>> break;
>>>>>> }
>>>>>> @@ -586,6 +673,7 @@ netdev_dpdk_init(struct netdev *netdev_,
>> unsigned int port_no,
>>>>>> struct netdev_dpdk *netdev = netdev_dpdk_cast(netdev_);
>>>>>> int sid;
>>>>>> int err = 0;
>>>>>> + uint32_t buf_size;
>>>>>>
>>>>>> ovs_mutex_init(&netdev->mutex);
>>>>>> ovs_mutex_lock(&netdev->mutex);
>>>>>> @@ -605,10 +693,16 @@ netdev_dpdk_init(struct netdev *netdev_,
>> unsigned int port_no,
>>>>>> netdev->port_id = port_no;
>>>>>> netdev->type = type;
>>>>>> netdev->flags = 0;
>>>>>> +
>>>>>> + /* Initialize port's MTU and frame len to the default Ethernet
>>>>>> values.
>>>>>> + * Larger, user-specified (jumbo) frame buffers are accommodated in
>>>>>> + * netdev_dpdk_set_config.
>>>>>> + */
>>>>>> + netdev->max_packet_len = ETHER_MAX_LEN;
>>>>>> netdev->mtu = ETHER_MTU;
>>>>>> - netdev->max_packet_len = MTU_TO_MAX_LEN(netdev->mtu);
>>>>>>
>>>>>> - netdev->dpdk_mp = dpdk_mp_get(netdev->socket_id, netdev->mtu);
>>>>>> + buf_size = dpdk_buf_size(netdev, ETHER_MAX_LEN);
>>>>>> + netdev->dpdk_mp = dpdk_mp_get(netdev->socket_id,
>> FRAME_LEN_TO_MTU(buf_size));
>>>>>> if (!netdev->dpdk_mp) {
>>>>>> err = ENOMEM;
>>>>>> goto unlock;
>>>>>> @@ -651,6 +745,24 @@ dpdk_dev_parse_name(const char dev_name[],
>> const char prefix[],
>>>>>> return 0;
>>>>>> }
>>>>>>
>>>>>> +static void
>>>>>> +dpdk_dev_parse_mtu(const struct smap *args, int *mtu)
>>>>>> +{
>>>>>> + const char *mtu_str = smap_get(args, "dpdk-mtu");
>>>>>> + int local_mtu;
>>>>>> +
>>>>>> + if(mtu_str) {
>>>>>> + local_mtu = atoi(mtu_str);
>>>>>
>>>>>Please use strtol or strtoul here, and detect errors in the string by
>>>>>checking endptr. That way, we can be sure that random garbage on the
>>>>>stack won't accidentally become the mtu.
>>>>
>>>>Will do, thanks.
>>>>
>>>>>
>>>>>> + }
>>>>>> + if(!mtu_str || local_mtu < ETHER_MTU ||
>>>>>> + local_mtu > FRAME_LEN_TO_MTU(NETDEV_DPDK_MAX_FRAME_LEN)) {
>>>>>> + local_mtu = ETHER_MTU;
>>>>>> + VLOG_WARN("Invalid or missing dpdk-mtu parameter - defaulting
>> to %d.\n",
>>>>>> + local_mtu);
>>>>>> + }
>>>>>> + *mtu = local_mtu;
>>>>>> +}
>>>>>> +
>>>>>> static int
>>>>>> vhost_construct_helper(struct netdev *netdev_) OVS_REQUIRES(dpdk_mutex)
>>>>>> {
>>>>>> @@ -777,11 +889,77 @@ netdev_dpdk_get_config(const struct netdev
>> *netdev_, struct smap
>>>>>*args)
>>>>>> smap_add_format(args, "configured_rx_queues", "%d", netdev_->n_rxq);
>>>>>> smap_add_format(args, "requested_tx_queues", "%d", netdev_->n_txq);
>>>>>> smap_add_format(args, "configured_tx_queues", "%d",
>>>>>> dev->real_n_txq);
>>>>>> + smap_add_format(args, "mtu", "%d", dev->mtu);
>>>>>> ovs_mutex_unlock(&dev->mutex);
>>>>>>
>>>>>> return 0;
>>>>>> }
>>>>>>
>>>>>> +/* Set the mtu of DPDK_DEV_ETH ports */
>>>>>> +static int
>>>>>> +netdev_dpdk_set_mtu(const struct netdev *netdev, int mtu)
>>>>>> +{
>>>>>> + struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
>>>>>> + int old_mtu, err;
>>>>>> + uint32_t buf_size;
>>>>>> + int dpdk_mtu;
>>>>>> + struct dpdk_mp *old_mp;
>>>>>> + struct dpdk_mp *mp;
>>>>>> +
>>>>>> + ovs_mutex_lock(&dpdk_mutex);
>>>>>> + ovs_mutex_lock(&dev->mutex);
>>>>>> + if (dev->mtu == mtu) {
>>>>>> + err = 0;
>>>>>> + goto out;
>>>>>> + }
>>>>>> +
>>>>>> + buf_size = dpdk_buf_size(dev, MTU_TO_FRAME_LEN(mtu));
>>>>>> + dpdk_mtu = FRAME_LEN_TO_MTU(buf_size);
>>>>>> +
>>>>>> + mp = dpdk_mp_get(dev->socket_id, dpdk_mtu);
>>>>>> + if (!mp) {
>>>>>> + err = ENOMEM;
>>>>>> + goto out;
>>>>>> + }
>>>>>> +
>>>>>> + rte_eth_dev_stop(dev->port_id);
>>>>>> +
>>>>>> + old_mtu = dev->mtu;
>>>>>> + old_mp = dev->dpdk_mp;
>>>>>> + dev->dpdk_mp = mp;
>>>>>> + dev->mtu = mtu;
>>>>>> + dev->max_packet_len = MTU_TO_FRAME_LEN(dev->mtu);
>>>>>> +
>>>>>> + err = dpdk_eth_dev_init(dev);
>>>>>
>>>>>Why call the dpdk_eth_dev_init here? Since you are directly calling
>>>>>rte_eth_dev_X functions here - wouldn't it make sense to use the
>>>>>rte_eth_dev_start() instead?
>>
>> The rx queues for the device need to be assigned the mempool that was
>> allocated for the jumbo frames; since dpdk_eth_dev_init handles the
>> queue setup, rte_eth_dev configuration, etc. it makes sense to call it
>> here.
>>
>>>>
>>>>This is legacy code, but I can refactor if needs be.
>>>>
>>>>>
>>>>>> + if (err) {
>>>>>> + VLOG_WARN("Unable to set MTU '%d' for '%s'; reverting to last
>> known "
>>>>>> + "good value '%d'\n", mtu, dev->up.name, old_mtu);
>>>>>> + dpdk_mp_put(mp);
>>>>>> + dev->mtu = old_mtu;
>>>>>> + dev->dpdk_mp = old_mp;
>>>>>> + dev->max_packet_len = MTU_TO_FRAME_LEN(dev->mtu);
>>>>>> + err = dpdk_eth_dev_init(dev);
>>>>>
>>>>>What happens if this returns a failure? By using dpdk_eth_dev_init, you
>>>>>will cause a queue reconfiguration action, which is not needed, and can
>>>>>error.
>>
>> This call is needed, in case the eth_dev's queue configuration was
>> changed by the previous call.
>> The error handling for this call is arguably outside the scope of this
>> patch, and could be submitted as a separate patch - what do you think?
>
>That's probably a good idea.
>
>>>>>
>>>>
>>>>As above.
>>>>
>>>>>If you are intending to set MTU, I would have expected calls to
>>>>>rte_eth_dev_set_mtu. However, I don't see any. Is there a reason? I
>>>>>recognize that much of this is legacy, but since you are touching it :)
>>>>
>>>>I actually had a number of issues with rte_eth_dev_set_mtu early on
>> in the patch; I can take
>>>>a second look now that the code is more stable though.
>>>
>>>I remembered why I didn't use this.
>>>
>>>If you look at the IXGBE driver's mtu_set function, it refuses frame
>> lengths which are larger
>>>than the eth_dev's min_rx_buf_size (- RTE_PKTMBUF_HEADROOM).
>>>This might be avoided by configuring the device for scatter RX
>> behavior, but this incurs a
>>>performance impact.
>
>It seems strange to me that we need to ignore the library API for this
>one case, right? What if the user is only doing vhostuser PMDs mixed
>with a bnx2x card?
>
I can't say that I've familiar enough with this setup to form an answer on that
one Aaron.
>It would be better to get it fixed in the library, I think. After all,
>they gave a generic setting to change MTU - why don't they make it
>behave well?
>
Let me follow up on that with some local DPDK folks here.
Would you consider this a showstopper for upstreaming of this feature? If we
need to wait for a change to DPDK, Jumbo Frames will miss the 2.5 window.
>>><snippet>
>>>ixgbe_dev_mtu_set(...) {
>>>
>>>...
>>>
>>> /* refuse mtu that requires the support of scattered packets when this
>>> * feature has not been enabled before. */
>>> if (!dev->data->scattered_rx &&
>>> (frame_size + 2 * IXGBE_VLAN_TAG_SIZE >
>>> dev->data->min_rx_buf_size - RTE_PKTMBUF_HEADROOM))
>>> return -EINVAL;
>>>
>>>...
>>>}
>>></snippet>
>>>
>>>
>>>>
>>>>>
>>>>>> + goto out;
>>>>>> + }
>>>>>> +
>>>>>> + dpdk_mp_put(old_mp);
>>>>>> + netdev_change_seq_changed(netdev);
>>>>>> +out:
>>>>>> + ovs_mutex_unlock(&dev->mutex);
>>>>>> + ovs_mutex_unlock(&dpdk_mutex);
>>>>>> + return err;
>>>>>> +}
>>>>>> +
>>>>>> +static int
>>>>>> +netdev_dpdk_set_config(struct netdev *netdev_, const struct smap *args)
>>>>>> +{
>>>>>> + int mtu;
>>>>>> +
>>>>>> + dpdk_dev_parse_mtu(args, &mtu);
>>>>>> +
>>>>>> + return netdev_dpdk_set_mtu(netdev_, mtu);
>>>>>> +}
>>>>>> +
>>>>>> static int
>>>>>> netdev_dpdk_get_numa_id(const struct netdev *netdev_)
>>>>>> {
>>>>>> @@ -1358,54 +1536,6 @@ netdev_dpdk_get_mtu(const struct netdev
>> *netdev, int *mtup)
>>>>>>
>>>>>> return 0;
>>>>>> }
>>>>>> -
>>>>>> -static int
>>>>>> -netdev_dpdk_set_mtu(const struct netdev *netdev, int mtu)
>>>>>> -{
>>>>>> - struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
>>>>>> - int old_mtu, err;
>>>>>> - struct dpdk_mp *old_mp;
>>>>>> - struct dpdk_mp *mp;
>>>>>> -
>>>>>> - ovs_mutex_lock(&dpdk_mutex);
>>>>>> - ovs_mutex_lock(&dev->mutex);
>>>>>> - if (dev->mtu == mtu) {
>>>>>> - err = 0;
>>>>>> - goto out;
>>>>>> - }
>>>>>> -
>>>>>> - mp = dpdk_mp_get(dev->socket_id, dev->mtu);
>>>>>> - if (!mp) {
>>>>>> - err = ENOMEM;
>>>>>> - goto out;
>>>>>> - }
>>>>>> -
>>>>>> - rte_eth_dev_stop(dev->port_id);
>>>>>> -
>>>>>> - old_mtu = dev->mtu;
>>>>>> - old_mp = dev->dpdk_mp;
>>>>>> - dev->dpdk_mp = mp;
>>>>>> - dev->mtu = mtu;
>>>>>> - dev->max_packet_len = MTU_TO_MAX_LEN(dev->mtu);
>>>>>> -
>>>>>> - err = dpdk_eth_dev_init(dev);
>>>>>> - if (err) {
>>>>>> - dpdk_mp_put(mp);
>>>>>> - dev->mtu = old_mtu;
>>>>>> - dev->dpdk_mp = old_mp;
>>>>>> - dev->max_packet_len = MTU_TO_MAX_LEN(dev->mtu);
>>>>>> - dpdk_eth_dev_init(dev);
>>>>>> - goto out;
>>>>>> - }
>>>>>> -
>>>>>> - dpdk_mp_put(old_mp);
>>>>>> - netdev_change_seq_changed(netdev);
>>>>>> -out:
>>>>>> - ovs_mutex_unlock(&dev->mutex);
>>>>>> - ovs_mutex_unlock(&dpdk_mutex);
>>>>>> - return err;
>>>>>> -}
>>>>>> -
>>>>>> static int
>>>>>> netdev_dpdk_get_carrier(const struct netdev *netdev_, bool *carrier);
>>>>>>
>>>>>> @@ -1682,7 +1812,7 @@ netdev_dpdk_get_status(const struct netdev
>> *netdev_, struct smap
>>>>>*args)
>>>>>> smap_add_format(args, "numa_id", "%d",
>> rte_eth_dev_socket_id(dev->port_id));
>>>>>> smap_add_format(args, "driver_name", "%s", dev_info.driver_name);
>>>>>> smap_add_format(args, "min_rx_bufsize", "%u",
>> dev_info.min_rx_bufsize);
>>>>>> - smap_add_format(args, "max_rx_pktlen", "%u",
>>>>>> dev_info.max_rx_pktlen);
>>>>>> + smap_add_format(args, "max_rx_pktlen", "%u", dev->max_packet_len);
>>>>>> smap_add_format(args, "max_rx_queues", "%u",
>>>>>> dev_info.max_rx_queues);
>>>>>> smap_add_format(args, "max_tx_queues", "%u",
>>>>>> dev_info.max_tx_queues);
>>>>>> smap_add_format(args, "max_mac_addrs", "%u",
>>>>>> dev_info.max_mac_addrs);
>>>>>> @@ -1904,6 +2034,51 @@ dpdk_vhost_user_class_init(void)
>>>>>> return 0;
>>>>>> }
>>>>>>
>>>>>> +/* Set the mtu of DPDK_DEV_VHOST ports */
>>>>>> +static int
>>>>>> +netdev_dpdk_vhost_set_mtu(const struct netdev *netdev, int mtu)
>>>>>> +{
>>>>>> + struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
>>>>>> + int err = 0;
>>>>>> + struct dpdk_mp *old_mp;
>>>>>> + struct dpdk_mp *mp;
>>>>>> +
>>>>>> + ovs_mutex_lock(&dpdk_mutex);
>>>>>> + ovs_mutex_lock(&dev->mutex);
>>>>>> + if (dev->mtu == mtu) {
>>>>>> + err = 0;
>>>>>> + goto out;
>>>>>> + }
>>>>>> +
>>>>>> + mp = dpdk_mp_get(dev->socket_id, mtu);
>>>>>> + if (!mp) {
>>>>>> + err = ENOMEM;
>>>>>> + goto out;
>>>>>> + }
>>>>>> +
>>>>>> + old_mp = dev->dpdk_mp;
>>>>>> + dev->dpdk_mp = mp;
>>>>>> + dev->mtu = mtu;
>>>>>> + dev->max_packet_len = MTU_TO_FRAME_LEN(dev->mtu);
>>>>>> +
>>>>>> + dpdk_mp_put(old_mp);
>>>>>> + netdev_change_seq_changed(netdev);
>>>>>> +out:
>>>>>> + ovs_mutex_unlock(&dev->mutex);
>>>>>> + ovs_mutex_unlock(&dpdk_mutex);
>>>>>> + return err;
>>>>>> +}
>>>>>> +
>>>>>> +static int
>>>>>> +netdev_dpdk_vhost_set_config(struct netdev *netdev_, const
>> struct smap *args)
>>>>>> +{
>>>>>> + int mtu;
>>>>>> +
>>>>>> + dpdk_dev_parse_mtu(args, &mtu);
>>>>>> +
>>>>>> + return netdev_dpdk_vhost_set_mtu(netdev_, mtu);
>>>>>> +}
>>>>>> +
>>>>>> static void
>>>>>> dpdk_common_init(void)
>>>>>> {
>>>>>> @@ -2040,8 +2215,9 @@ unlock_dpdk:
>>>>>> return err;
>>>>>> }
>>>>>>
>>>>>> -#define NETDEV_DPDK_CLASS(NAME, INIT, CONSTRUCT, DESTRUCT, MULTIQ,
>>>>>> SEND, \
>>>>>> - GET_CARRIER, GET_STATS, GET_FEATURES, GET_STATUS, RXQ_RECV)
>>>>>> \
>>>>>> +#define NETDEV_DPDK_CLASS(NAME, INIT, CONSTRUCT, DESTRUCT, SET_CONFIG, \
>>>>>> + MULTIQ, SEND, SET_MTU, GET_CARRIER, GET_STATS, GET_FEATURES, \
>>>>>> + GET_STATUS, RXQ_RECV) \
>>>>>> { \
>>>>>> NAME, \
>>>>>> INIT, /* init */ \
>>>>>> @@ -2053,7 +2229,7 @@ unlock_dpdk:
>>>>>> DESTRUCT, \
>>>>>> netdev_dpdk_dealloc, \
>>>>>> netdev_dpdk_get_config, \
>>>>>> - NULL, /* netdev_dpdk_set_config */ \
>>>>>> + SET_CONFIG, \
>>>>>> NULL, /* get_tunnel_config */ \
>>>>>> NULL, /* build header */ \
>>>>>> NULL, /* push header */ \
>>>>>> @@ -2067,7 +2243,7 @@ unlock_dpdk:
>>>>>> netdev_dpdk_set_etheraddr, \
>>>>>> netdev_dpdk_get_etheraddr, \
>>>>>> netdev_dpdk_get_mtu, \
>>>>>> - netdev_dpdk_set_mtu, \
>>>>>> + SET_MTU, \
>>>>>> netdev_dpdk_get_ifindex, \
>>>>>> GET_CARRIER, \
>>>>>> netdev_dpdk_get_carrier_resets, \
>>>>>> @@ -2213,8 +2389,10 @@ static const struct netdev_class dpdk_class =
>>>>>> NULL,
>>>>>> netdev_dpdk_construct,
>>>>>> netdev_dpdk_destruct,
>>>>>> + netdev_dpdk_set_config,
>>>>>> netdev_dpdk_set_multiq,
>>>>>> netdev_dpdk_eth_send,
>>>>>> + netdev_dpdk_set_mtu,
>>>>>> netdev_dpdk_get_carrier,
>>>>>> netdev_dpdk_get_stats,
>>>>>> netdev_dpdk_get_features,
>>>>>> @@ -2227,8 +2405,10 @@ static const struct netdev_class dpdk_ring_class =
>>>>>> NULL,
>>>>>> netdev_dpdk_ring_construct,
>>>>>> netdev_dpdk_destruct,
>>>>>> + netdev_dpdk_set_config,
>>>>>> netdev_dpdk_set_multiq,
>>>>>> netdev_dpdk_ring_send,
>>>>>> + netdev_dpdk_set_mtu,
>>>>>> netdev_dpdk_get_carrier,
>>>>>> netdev_dpdk_get_stats,
>>>>>> netdev_dpdk_get_features,
>>>>>> @@ -2241,8 +2421,10 @@ static const struct netdev_class
>> OVS_UNUSED dpdk_vhost_cuse_class
>>>=
>>>>>> dpdk_vhost_cuse_class_init,
>>>>>> netdev_dpdk_vhost_cuse_construct,
>>>>>> netdev_dpdk_vhost_destruct,
>>>>>> + NULL,
>>>>>> netdev_dpdk_vhost_set_multiq,
>>>>>> netdev_dpdk_vhost_send,
>>>>>> + NULL,
>>>>>> netdev_dpdk_vhost_get_carrier,
>>>>>> netdev_dpdk_vhost_get_stats,
>>>>>> NULL,
>>>>>> @@ -2255,8 +2437,10 @@ static const struct netdev_class
>> OVS_UNUSED dpdk_vhost_user_class
>>>=
>>>>>> dpdk_vhost_user_class_init,
>>>>>> netdev_dpdk_vhost_user_construct,
>>>>>> netdev_dpdk_vhost_destruct,
>>>>>> + netdev_dpdk_vhost_set_config,
>>>>>> netdev_dpdk_vhost_set_multiq,
>>>>>> netdev_dpdk_vhost_send,
>>>>>> + netdev_dpdk_vhost_set_mtu,
>>>>>> netdev_dpdk_vhost_get_carrier,
>>>>>> netdev_dpdk_vhost_get_stats,
>>>>>> NULL,
>>>>_______________________________________________
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>>>>http://openvswitch.org/mailman/listinfo/dev
>>>_______________________________________________
>>>dev mailing list
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>>>http://openvswitch.org/mailman/listinfo/dev
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