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
