"Kavanagh, Mark B" <mark.b.kavan...@intel.com> writes:
>>
>>"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.
I don't think it would be a show stopper as long as other devices wouldn't
be negatively impacted, but it's a place where a /*XXX: This is a
workaround for dpdk*/ comment should be included so that we can fix it
when/if it is updated in the library. What do you think?
>>>><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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>>>>_______________________________________________
>>>>dev mailing list
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>>>>http://openvswitch.org/mailman/listinfo/dev
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