[PATCH v5 00/26] Add VDUSE support to Vhost library
Maxime Coquelin
maxime.coquelin at redhat.com
Thu Jun 8 16:29:49 CEST 2023
On 6/6/23 10:18, Maxime Coquelin wrote:
> 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 v5:
> ==============
> - Delay starting/stopping the device to after having replied to the VDUSE
> event in order to avoid a deadlock encountered when testing with OVS.
> - Mention reconnection support lack in the release note.
>
> Changes in v4:
> ==============
> - Applied patch 1 and patch 2 from v3
> - Rebased on top of Eelco series
> - Fix coredump clear in IOTLB cache removal (David)
> - Remove uneeded ret variable in vhost_vring_inject_irq (David)
> - Fixed release note (David, Chenbo)
>
> 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 (26):
> 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 | 12 +
> 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 | 1 +
> lib/vhost/vhost.c | 70 ++-
> lib/vhost/vhost.h | 57 ++-
> 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, 1409 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
>
Applied to dpdk-next-virtio/main.
Thanks,
Maxime
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