Why does this need to be a PMD? Maybe we need some platform infrastructure? My definition of PMD is it can send and receive
On Dec 22, 2017 10:01, "Adrien Mazarguil" <adrien.mazarg...@6wind.com> wrote: > Virtual machines hosted by Hyper-V/Azure platforms are fitted with > simplified virtual network devices named NetVSC that are used for fast > communication between VM to VM, VM to hypervisor, and the outside. > > They appear as standard system netdevices to user-land applications, the > main difference being they are implemented on top of VMBUS [1] instead of > emulated PCI devices. > > While this reads like a case for a standard DPDK PMD, there is more to it. > > To accelerate outside communication, NetVSC devices as they appear in a VM > can be paired with physical SR-IOV virtual function (VF) devices owned by > that same VM [2]. Both netdevices share the same MAC address in that case. > > When paired, egress and most of the ingress traffic flow through the VF > device, while part of it (e.g. multicasts, hypervisor control data) still > flows through NetVSC. Moreover VF devices are not retained and disappear > during VM migration; from a VM standpoint, they can be hot-plugged anytime > with NetVSC acting as a fallback. > > Running DPDK applications in such a context involves driving VF devices > using their dedicated PMDs in a vendor-independent fashion (to benefit from > maximum performance without writing dedicated code) while simultaneously > listening to NetVSC and handling the related hot-plug events. > > This new virtual PMD (referred to as "vdev_netvsc" from this point on) > automatically coordinates the Hyper-V/Azure-specific management part > described above by relying on vendor-specific, failsafe and tap PMDs to > expose a single consolidated Ethernet device usable directly by existing > applications. > > .------------------. > | DPDK application | > `--------+---------' > | > .------+------. > | DPDK ethdev | > `------+------' Control > | | > .------------+------------. v .-----------------. > | failsafe PMD +---------+ vdev_netvsc PMD | > `--+-------------------+--' `-----------------' > | | > | .........|......... > | : | : > .----+----. : .----+----. : > | tap PMD | : | any PMD | : > `----+----' : `----+----' : <-- Hot-pluggable > | : | : > .------+-------. : .-----+-----. : > | NetVSC-based | : | SR-IOV VF | : > | netdevice | : | device | : > `--------------' : `-----------' : > :.................: > > Note this diagram differs from that of the original RFC [3], with > vdev_netvsc no longer acting as a data plane layer. > > This initial version of the driver only works in whitelist mode. Users have > to provide the --vdev net_vdev_netvsc EAL option at least once to trigger > it. > > Subsequent work will add support for blacklist mode based on automatic > detection of the host environment. > > [1] http://dpdk.org/ml/archives/dev/2017-January/054165.html > [2] https://docs.microsoft.com/en-us/windows-hardware/drivers/ > network/overview-of-hyper-v > [3] http://dpdk.org/ml/archives/dev/2017-November/082339.html > > v2 changes: > > - Renamed driver from "hyperv" to "vdev_netvsc". This change covers > documentation and symbols prefix. > - Driver is now tagged EXPERIMENTAL. > - Replaced ether_addr_from_str() with a basic sscanf() call. > - Removed debugging code (memset() poisoning). > - Fixed hyperv_iface_is_netvsc()'s buffer allocation according to comments. > - Removed hyperv_basename(). > - Discarded unused variables through __rte_unused. > - Added separate but necessary free() bugfix for failsafe PMD. > - Added file descriptor input support to failsafe PMD. > - Replaced temporary bash execution; failsafe now reads device definitions > directly through a pipe without an intermediate bash one-liner. > - Expanded DEBUG/INFO/WARN/ERROR() macros as PMD_DRV_LOG(). > - Added dynamic log type (pmd.vdev_netvsc). > - Modified initialization code to probe devices immediately during startup. > - Fixed several snprintf() return value checks ("ret >= sizeof(foo)" is > more > appropriate than "ret >= sizeof(foo) - 1"). > > Adrien Mazarguil (5): > net/failsafe: fix invalid free > net/failsafe: add "fd" parameter > net/vdev_netvsc: introduce Hyper-V platform driver > net/vdev_netvsc: implement core functionality > net/vdev_netvsc: add "force" parameter > > MAINTAINERS | 6 + > config/common_base | 5 + > config/common_linuxapp | 1 + > doc/guides/nics/fail_safe.rst | 9 + > doc/guides/nics/features/vdev_netvsc.ini | 12 + > doc/guides/nics/index.rst | 1 + > doc/guides/nics/vdev_netvsc.rst | 116 +++ > drivers/net/Makefile | 1 + > drivers/net/failsafe/failsafe_args.c | 88 ++- > drivers/net/failsafe/failsafe_private.h | 3 + > drivers/net/vdev_netvsc/Makefile | 58 ++ > .../vdev_netvsc/rte_pmd_vdev_netvsc_version.map | 4 + > drivers/net/vdev_netvsc/vdev_netvsc.c | 722 +++++++++++++++++++ > mk/rte.app.mk | 1 + > 14 files changed, 1025 insertions(+), 2 deletions(-) > create mode 100644 doc/guides/nics/features/vdev_netvsc.ini > create mode 100644 doc/guides/nics/vdev_netvsc.rst > create mode 100644 drivers/net/vdev_netvsc/Makefile > create mode 100644 drivers/net/vdev_netvsc/rte_ > pmd_vdev_netvsc_version.map > create mode 100644 drivers/net/vdev_netvsc/vdev_netvsc.c > > -- > 2.11.0 >