Re: [RFC PATCH 00/10] VirtioNet RSS support

Ping On Wed, Jul 28, 2021 at 11:17 AM Andrew Melnychenko <andrew(a)daynix.com&gt; wrote: > This series of patches add RSS property support for virtio-net-pci. > > Virtio RSS effectively works with TAP devices, it requires additional > vectors for VirtioNet, queues for TAP device, and vCPU cores. > Example of device configuration: > ``` > <interface type="network"> > <mac address="52:54:00:c4:90:25"/> > <source network="default"/> > <model type="virtio"/> > <driver name="qemu" queues="9" rss="on" rss_hash_report="off"/> > <address type="pci" domain="0x0000" bus="0x01" slot="0x00" > function="0x0"/> > </interface> > ``` > > Capability "rss" enables RSS, "rss_hash_report" - enables hashes in > vheader. > Qemu uses eBPF program as RSS driver. > For loading RSS eBPF program, the helper is used. > Path to the helper is provided by Qemu through "query-helper-paths" qmp > command. > The helper "qemu-ebpf-rss-helper" is built with Qemu and may differ from > build to build. > So it's required that the Qemu should provide a proper helper path. > Libvirt would call the helper and receive the program and map fd through > unix socket. > Fds would be passed to Qemu in "ebpf_rss_fds" property by passing to > child process or unix socket. > If libvirt would fail at helper call or Qemu didn't provide the path, > the Qemu would be launched without "ebpf_rss_fds" property. > Without "ebpf_rss_fds" property, Qemu would try to load eBPF program by > itself - usually, it would require additional system permissions. > Qemu may use "in-qemu" RSS as a fallback option, which will not require > system > permissions, but doesn't work with vhost TAP. > > Qemu patches: > https://lists.nongnu.org/archive/html/qemu-devel/2021-07/msg03535.html > > Andrew Melnychenko (10): > domain_conf: Added configs for RSS and Hash report. > qemu_capabilities: Added capabilites for qemu's "rss" and "hash". > qemu_command: Added "rss" and "hash" properties. > virsocket: Added receive for multiple fds. > qemu_capabilities: Added capability for qemu's "ebpf_rss_fds". > qemu_capabilities: Added capability for ebpf helper path. > qemu_interface: Added ebpf helper call. > qemu_command: Added ebpf RSS helper call for NIC creation. > qemu_hotplug: Added helper call for hotplug NIC. > docs: Added descriptions for "rss" and "rss_hash_report" > configurations. > > docs/formatdomain.rst | 16 +++++++ > src/conf/domain_conf.c | 31 +++++++++++++- > src/conf/domain_conf.h | 2 + > src/libvirt_private.syms | 1 + > src/qemu/qemu_capabilities.c | 48 +++++++++++++++++++++ > src/qemu/qemu_capabilities.h | 5 +++ > src/qemu/qemu_command.c | 46 +++++++++++++++++++- > src/qemu/qemu_command.h | 2 + > src/qemu/qemu_hotplug.c | 30 ++++++++++++- > src/qemu/qemu_interface.c | 54 +++++++++++++++++++++++ > src/qemu/qemu_interface.h | 2 + > src/qemu/qemu_monitor.c | 9 ++++ > src/qemu/qemu_monitor.h | 3 ++ > src/qemu/qemu_monitor_json.c | 50 ++++++++++++++++++++++ > src/qemu/qemu_monitor_json.h | 3 ++ > src/qemu/qemu_validate.c | 16 +++++++ > src/util/virsocket.c | 83 ++++++++++++++++++++++++++++++++++++ > src/util/virsocket.h | 2 + > 18 files changed, 399 insertions(+), 4 deletions(-) > > -- > 2.31.1 > >