On Thu, May 25, 2023 at 6:25 PM Maxime Coquelin <maxime.coque...@redhat.com> wrote: > > Note: v2 is identical to v3, it is just a resend because > of an issue when posting v2 breaking the series in patchwork. > > This series introduces a new type of backend, VDUSE, > to the Vhost library. > > VDUSE stands for vDPA device in Userspace, it enables > implementing a Virtio device in userspace and have it > attached to the Kernel vDPA bus. > > Once attached to the vDPA bus, it can be used either by > Kernel Virtio drivers, like virtio-net in our case, via > the virtio-vdpa driver. Doing that, the device is visible > to the Kernel networking stack and is exposed to userspace > as a regular netdev. > > It can also be exposed to userspace thanks to the > vhost-vdpa driver, via a vhost-vdpa chardev that can be > passed to QEMU or Virtio-user PMD. > > While VDUSE support is already available in upstream > Kernel, a couple of patches are required to support > network device type: > > https://gitlab.com/mcoquelin/linux/-/tree/vduse_networking_rfc > > In order to attach the created VDUSE device to the vDPA > bus, a recent iproute2 version containing the vdpa tool is > required. > > Benchmark results: > ================== > > On this v2, PVP reference benchmark has been run & compared with > Vhost-user. > > When doing macswap forwarding in the worload, no difference is seen. > When doing io forwarding in the workload, we see 4% performance > degradation with VDUSE, comapred to Vhost-user/Virtio-user. It is > explained by the use of the IOTLB layer in the Vhost-library when using > VDUSE, whereas Vhost-user/Virtio-user does not make use of it. > > Usage: > ====== > > 1. Probe required Kernel modules > # modprobe vdpa > # modprobe vduse > # modprobe virtio-vdpa > > 2. Build (require vduse kernel headers to be available) > # meson build > # ninja -C build > > 3. Create a VDUSE device (vduse0) using Vhost PMD with > testpmd (with 4 queue pairs in this example) > # ./build/app/dpdk-testpmd --no-pci > --vdev=net_vhost0,iface=/dev/vduse/vduse0,queues=4 --log-level=*:9 -- -i > --txq=4 --rxq=4 > > 4. Attach the VDUSE device to the vDPA bus > # vdpa dev add name vduse0 mgmtdev vduse > => The virtio-net netdev shows up (eth0 here) > # ip l show eth0 > 21: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode > DEFAULT group default qlen 1000 > link/ether c2:73:ea:a7:68:6d brd ff:ff:ff:ff:ff:ff > > 5. Start/stop traffic in testpmd > testpmd> start > testpmd> show port stats 0 > ######################## NIC statistics for port 0 ######################## > RX-packets: 11 RX-missed: 0 RX-bytes: 1482 > RX-errors: 0 > RX-nombuf: 0 > TX-packets: 1 TX-errors: 0 TX-bytes: 62 > > Throughput (since last show) > Rx-pps: 0 Rx-bps: 0 > Tx-pps: 0 Tx-bps: 0 > ############################################################################ > testpmd> stop > > 6. Detach the VDUSE device from the vDPA bus > # vdpa dev del vduse0 > > 7. Quit testpmd > testpmd> quit > > Known issues & remaining work: > ============================== > - Fix issue in FD manager (still polling while FD has been removed) > - Add Netlink support in Vhost library > - Support device reconnection > -> a temporary patch to support reconnection via a tmpfs file is available, > upstream solution would be in-kernel and is being developed. > -> > https://gitlab.com/mcoquelin/dpdk-next-virtio/-/commit/5ad06ce14159a9ce36ee168dd13ef389cec91137 > - Support packed ring > - Provide more performance benchmark results > > Changes in v2/v3: > ================= > - Fixed mem_set_dump() parameter (patch 4) > - Fixed accidental comment change (patch 7, Chenbo) > - Change from __builtin_ctz to __builtin_ctzll (patch 9, Chenbo) > - move change from patch 12 to 13 (Chenbo) > - Enable locks annotation for control queue (Patch 17) > - Send control queue notification when used descriptors enqueued (Patch 17) > - Lock control queue IOTLB lock (Patch 17) > - Fix error path in virtio_net_ctrl_pop() (Patch 17, Chenbo) > - Set VDUSE dev FD as NONBLOCK (Patch 18) > - Enable more Virtio features (Patch 18) > - Remove calls to pthread_setcancelstate() (Patch 22) > - Add calls to fdset_pipe_notify() when adding and deleting FDs from a set > (Patch 22) > - Use RTE_DIM() to get requests string array size (Patch 22) > - Set reply result for IOTLB update message (Patch 25, Chenbo) > - Fix queues enablement with multiqueue (Patch 26) > - Move kickfd creation for better logging (Patch 26) > - Improve logging (Patch 26) > - Uninstall cvq kickfd in case of handler installation failure (Patch 27) > - Enable CVQ notifications once handler is installed (Patch 27) > - Don't advertise multiqueue and control queue if app only request single > queue pair (Patch 27) > - Add release notes > > Maxime Coquelin (28): > vhost: fix missing guest notif stat increment > vhost: fix invalid call FD handling > vhost: fix IOTLB entries overlap check with previous entry > vhost: add helper of IOTLB entries coredump > vhost: add helper for IOTLB entries shared page check > vhost: don't dump unneeded pages with IOTLB > vhost: change to single IOTLB cache per device > vhost: add offset field to IOTLB entries > vhost: add page size info to IOTLB entry > vhost: retry translating IOVA after IOTLB miss > vhost: introduce backend ops > vhost: add IOTLB cache entry removal callback > vhost: add helper for IOTLB misses > vhost: add helper for interrupt injection > vhost: add API to set max queue pairs > net/vhost: use API to set max queue pairs > vhost: add control virtqueue support > vhost: add VDUSE device creation and destruction > vhost: add VDUSE callback for IOTLB miss > vhost: add VDUSE callback for IOTLB entry removal > vhost: add VDUSE callback for IRQ injection > vhost: add VDUSE events handler > vhost: add support for virtqueue state get event > vhost: add support for VDUSE status set event > vhost: add support for VDUSE IOTLB update event > vhost: add VDUSE device startup > vhost: add multiqueue support to VDUSE > vhost: add VDUSE device stop > > doc/guides/prog_guide/vhost_lib.rst | 4 + > doc/guides/rel_notes/release_23_07.rst | 11 + > drivers/net/vhost/rte_eth_vhost.c | 3 + > lib/vhost/iotlb.c | 333 +++++++------ > lib/vhost/iotlb.h | 45 +- > lib/vhost/meson.build | 5 + > lib/vhost/rte_vhost.h | 17 + > lib/vhost/socket.c | 72 ++- > lib/vhost/vduse.c | 646 +++++++++++++++++++++++++ > lib/vhost/vduse.h | 33 ++ > lib/vhost/version.map | 3 + > lib/vhost/vhost.c | 51 +- > lib/vhost/vhost.h | 90 ++-- > lib/vhost/vhost_user.c | 51 +- > lib/vhost/vhost_user.h | 2 +- > lib/vhost/virtio_net_ctrl.c | 286 +++++++++++ > lib/vhost/virtio_net_ctrl.h | 10 + > 17 files changed, 1424 insertions(+), 238 deletions(-) > create mode 100644 lib/vhost/vduse.c > create mode 100644 lib/vhost/vduse.h > create mode 100644 lib/vhost/virtio_net_ctrl.c > create mode 100644 lib/vhost/virtio_net_ctrl.h
I did not do a in-depth review, but overall, the series lgtm (and per patch compilation looks fine). A few comments though: - patch 2 is the same as https://patchwork.dpdk.org/project/dpdk/patch/168431454344.558450.2397970324914136724.stgit@ebuild.local/ It would be cool to report the review tags in the first series that gets applied. - there may be a bug in patch 5, see comment on patch, - patch 4, 5 and 6 go together, with patch 6 being the fix itself. I understand it was easier to review as splitted patches, but maybe it would be simpler to squash them to make the backport trivial. - patch 7 (and some other patches in the series) will increase the virtio_net structure but we are not gaining anything on the vhost_virtqueue size, so a device + vqs memory footprint will slightly increase. This is not a problem afaics? - patch 15 breaks the doc, format is incorrect but the CI reported it so you will notice it before merging :-), -- David Marchand
