On Fri, Jul 14, 2017 at 8:41 AM, Narayana Prasad Athreya < pathr...@caviumnetworks.com> wrote:
> Hi Bill > The reasons below dont jive with what ODP does today. If the routines > odp_pktio_mtu() and odp_pktio_mac_addr() exist today. They assume that MTU > can be configured and returned to the datapath. As an application > developer, it does make sense for me to use 2 different paths to talk to > the same underlying device for the same setting - one path for configuring > and one for reading the configuration. > An application needs to know the MAC address that has been associated with an interface. Being able to read the MTU was included for completeness. I have no objection to including the corresponding set functions (along with the odp_pktio_capability() extensions to indicate whether these are available--which they most likely will not be in NFV environments) but do question the need for MTU setting, which should be 9K by default for 10Gb and higher interfaces. > > So from this standpoint the ODP should either support both get and set > routines or not support either of them. > > On the control-plane vs data-plane debate, again as an application > developer, my integrated application will need access to the underlying > device for both control and data. If i am forced to right separate code and > potentially drivers for 2 paths, where is my incentive to use ODP API, > because anyway i'm losing portability. > > Thanks > Prasad > > > On Friday 14 July 2017 06:33 PM, Bill Fischofer wrote: > > > > On Fri, Jul 14, 2017 at 6:05 AM, Peltonen, Janne (Nokia - FI/Espoo) < > janne.pelto...@nokia.com> wrote: > >> Hi, >> >> ODP API should somewhere define what exactly MTU means in the context of >> ODP. >> >> One can guess that transmission and reception of L2 frames larger than the >> configured MTU is not guaranteed to succeed, but which bytes are taken >> into >> account? For instance, is Ethernet FCS counted towards the MTU? >> >> > We've had this discussion before. The whole concept of MTU is a bit of an > anachronism from the early days of Ethernet. At speeds ODP is designed for > (10Gb and above) all equipment should be running with jumbo frames (MTU = > 9K). All equipment capable of running at these speeds is capable of this > size, and 9K is the recommended default MTU for this equipment. So there's > really nothing one should need to control or change here. > > It would be interesting to understand the use case that is driving the > desire to be able to set MTU. > > The other consideration is that setting MTU (or MAC address) is a control > plane function, not a data plane function. Just as the control plane tells > the data plane which interfaces to use, the control plane is responsible > for this type of configuration, as well as managing and responding to > configuration changes. So again, it would be good to understand the use > case behind wanting to change these values in the data plane. > > > Janne >> >> >> > -----Original Message----- >> > From: lng-odp [mailto:lng-odp-boun...@lists.linaro.org] On Behalf Of >> Vamsi Attunuru >> > Sent: Friday, July 14, 2017 1:05 PM >> > To: lng-odp@lists.linaro.org >> > Cc: mcha...@cavium.com; pathr...@cavium.com; vattun...@cavium.com; >> sve...@cavium.com >> > Subject: [lng-odp] [API-NEXT PATCH v1 1/1] pktio APIs to set the MAC >> address and MTU size. >> > >> > Adds new pktio APIs to set MTU and MAC address on pktio interface. >> > >> > Signed-off-by: Vamsi Attunuru <vattun...@cavium.com> >> > Signed-off-by: Mahipal Challa <mcha...@cavium.com> >> > Signed-off-by: Shally Verma <sve...@cavium.com> >> > >> > --- >> > include/odp/api/spec/packet_io.h | 45 ++++++++++++++++++++++++++++++ >> ++++++++++ >> > 1 file changed, 45 insertions(+) >> > >> > diff --git a/include/odp/api/spec/packet_io.h >> b/include/odp/api/spec/packet_io.h >> > index 8802089..1269f44 100644 >> > --- a/include/odp/api/spec/packet_io.h >> > +++ b/include/odp/api/spec/packet_io.h >> > @@ -451,6 +451,10 @@ typedef union odp_pktio_set_op_t { >> > struct { >> > /** Promiscuous mode */ >> > uint32_t promisc_mode : 1; >> > + /** MAC address */ >> > + uint32_t mac : 1; >> > + /** MTU size */ >> > + uint32_t mtu : 1; >> > } op; >> > /** All bits of the bit field structure. >> > * This field can be used to set/clear all flags, or bitwise >> > @@ -482,6 +486,12 @@ typedef struct odp_pktio_capability_t { >> > * A boolean to denote whether loop back mode is supported on this >> > * specific interface. */ >> > odp_bool_t loop_supported; >> > + >> > + /** Maximum MTU size supported */ >> > + uint32_t max_mtu_size; >> > + >> > + /** Length of MAC address supported on this specific interface */ >> > + uint32_t mac_addr_len; >> > } odp_pktio_capability_t; >> > >> > /** >> > @@ -912,6 +922,21 @@ int odp_pktout_send(odp_pktout_queue_t queue, >> const odp_packet_t >> > packets[], >> > uint32_t odp_pktio_mtu(odp_pktio_t pktio); >> > >> > /** >> > + * Set MTU value of a packet IO interface. >> > + * >> > + * Application should pass value upto max_mtu_size as indicated by >> > + * odp_pktio_capability_t:max_mtu_size. Any value beyond max_mtu_size >> > + * limit will result in failure. >> > + * >> > + * @param pktio Packet IO handle. >> > + * @param mtu MTU value to be set. >> > + * >> > + * @return 0 on success >> > + * @retval <0 on failure >> > + */ >> > +int odp_pktio_mtu_set(odp_pktio_t pktio, uint32_t mtu); >> > + >> > +/** >> > * Enable/Disable promiscuous mode on a packet IO interface. >> > * >> > * @param[in] pktio Packet IO handle. >> > @@ -946,6 +971,26 @@ int odp_pktio_promisc_mode(odp_pktio_t pktio); >> > int odp_pktio_mac_addr(odp_pktio_t pktio, void *mac_addr, int size); >> > >> > /** >> > + * Set the MAC address of a packet IO interface. >> > + * >> > + * Application should pass mac_addr buffer with size >= >> > + * odp_pktio_capablity_t:mac_addr_len, size value less than >> > + * implementation supported will result in API failure. >> > + * >> > + * On success, Implementation would read mac_addr buffer bytes >> > + * upto mac_addr_len value indicated in capability information. >> > + * >> > + * @param pktio Packet IO handle >> > + * @param mac_addr Pointer to MAC address to be set >> > + * @param size Size of MAC address buffer >> > + * >> > + * @return 0 on success >> > + * @retval <0 on failure >> > + */ >> > +int odp_pktio_mac_addr_set(odp_pktio_t pktio, const uint8_t *mac_addr, >> > + int size); >> > + >> > +/** >> > * Setup per-port default class-of-service. >> > * >> > * @param[in] pktio Ingress port pktio handle. >> > -- >> > 1.9.3 >> >> > >
