Re: [PATCH v6 00/13] vhost-user multiple queues enabling

[Flavio Leitner <fbl@sysclose.org>]

On Fri, Oct 09, 2015 at 01:45:59PM +0800, Yuanhan Liu wrote:
> This patch set enables vhost-user multiple queues.
> 
> Overview
> ========
> 
> It depends on some QEMU patches that has already been merged to upstream.
> Those qemu patches introduce some new vhost-user messages, for vhost-user
> mq enabling negotiation. Here is the main negotiation steps (Qemu
> as master, and DPDK vhost-user as slave):
> 
> - Master queries features by VHOST_USER_GET_FEATURES from slave
> 
> - Check if VHOST_USER_F_PROTOCOL_FEATURES exist. If not, mq is not
>   supported. (check patch 1 for why VHOST_USER_F_PROTOCOL_FEATURES
>   is introduced)
> 
> - Master then sends another command, VHOST_USER_GET_QUEUE_NUM, for
>   querying how many queues the slave supports.
> 
>   Master will compare the result with the requested queue number.
>   Qemu exits if the former is smaller.
> 
> - Master then tries to initiate all queue pairs by sending some vhost
>   user commands, including VHOST_USER_SET_VRING_CALL, which will
>   trigger the slave to do related vring setup, such as vring allocation.
> 
> 
> Till now, all necessary initiation and negotiation are done. And master
> could send another message, VHOST_USER_SET_VRING_ENABLE, to enable/disable
> a specific queue dynamically later.
> 
> 
> Patchset
> ========
> 
> Patch 1-6 are all prepare works for enabling mq; they are all atomic
> changes, with "do not breaking anything" beared in mind while making
> them.
> 
> Patch 7 acutally enables mq feature, by setting two key feature flags.
> 
> Patch 8 handles VHOST_USER_SET_VRING_ENABLE message, which is for enabling
> disabling a specific virt queue pair, and there is only one queue pair is
> enabled by default.
> 
> Patch 9-12 is for demostrating the mq feature.
> 
> Patch 13 udpates the doc release note.
> 
> 
> Testing
> =======
> 
> Host side
> ----------
> 
> - # Start vhost-switch
> 
>   sudo mount -t hugetlbfs nodev /mnt/huge
>   sudo modprobe uio
>   sudo insmod $RTE_SDK/$RTE_TARGET/kmod/igb_uio.ko
> 
>   sudo $RTE_SDK/tools/dpdk_nic_bind.py --bind igb_uio 0000:08:00.0
> 
>   sudo $RTE_SDK/examples/vhost/build/vhost-switch -c 0xf0 -n 4     \
>        --huge-dir /mnt/huge --socket-mem 2048,0 -- -p 1 --vm2vm 0  \
>        --dev-basename usvhost --rxq 2
> 
>   # Above common generates a usvhost socket file at PWD. You could also
>   # specify "--stats 1" option to enable stats dumping.
> 
> 
> 
> - # start qemu
> 
> 
>   sudo sudo mount -t hugetlbfs nodev $HOME/hugetlbfs
>   $QEMU_DIR/x86_64-softmmu/qemu-system-x86_64 -machine accel=kvm -m 4G \
>         -object memory-backend-file,id=mem,size=4G,mem-path=$HOME/hugetlbfs,share=on \
> 	-numa node,memdev=mem -chardev socket,id=chr0,path=/path/to/usvhost \
> 	-netdev vhost-user,id=net0,chardev=chr0,vhostforce,queues=2     \
> 	-device virtio-net-pci,netdev=net0,mq=on,vectors=6,mac=52:54:00:12:34:58,csum=off,gso=off,guest_tso4=off,guest_tso6=off,guest_ecn=off \
> 	-hda $HOME/iso/fc-22-x86_64.img -smp 10 -cpu core2duo,+sse3,+sse4.1,+sse4.2
> 
> 
> Guest side
> ----------
> 
>    modprobe uio
>    insmod $RTE_SDK/$RTE_TARGET/kmod/igb_uio.ko
>    echo 1024 > /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages
>    ./tools/dpdk_nic_bind.py --bind igb_uio 00:03.0
>     
>    $RTE_SDK/$RTE_TARGET/app/testpmd -c 1f -n 4 -- --rxq=2 --txq=2 \
>         --nb-cores=4 -i --disable-hw-vlan --txqflags 0xf00
> 
>    > set fwd mac
>    > start tx_first
>  
> 
> After those setups, you then could use packet generator for packet tx/rx testing.
> 
> 
> 
> Test with OVS
> =============
> 
> Marcel also created a simple yet quite clear test guide with OVS at:
> 
>    http://wiki.qemu.org/Features/vhost-user-ovs-dpdk
> 
> BTW, Marcel, would you please complete the page on mq testing?
> 
> 
> ---

I reviewed the patch and tested with success using Open vSwitch.
The Open vSwitch patch is posted here:
http://openvswitch.org/pipermail/dev/2015-October/061413.html

Acked-by: Flavio Leitner <fbl@sysclose.org>

Thanks,
fbl