Re: [dpdk-dev] [PATCH v5 resend 03/12] vhost: vring queue setup for multiple queue support

[Marcel Apfelbaum <marcel@redhat.com>]

On 09/22/2015 12:21 PM, Yuanhan Liu wrote:
> On Tue, Sep 22, 2015 at 11:47:34AM +0300, Marcel Apfelbaum wrote:
>> On 09/22/2015 11:34 AM, Yuanhan Liu wrote:
>>> On Tue, Sep 22, 2015 at 11:10:13AM +0300, Marcel Apfelbaum wrote:
>>>> On 09/22/2015 10:31 AM, Yuanhan Liu wrote:
>>>>> On Mon, Sep 21, 2015 at 08:56:30PM +0300, Marcel Apfelbaum wrote:
>>>> [...]
>>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> I have made 4 cleanup patches few weeks before, including the patch
>>>>>>> to define kickfd and callfd as int type, and they have already got
>>>>>>> the ACK from Huawei Xie, and Chuangchun Ouyang. It's likely that
>>>>>>> they will be merged, hence I made this patchset based on them.
>>>>>>>
>>>>>>> This will also answer the question from your another email: can't
>>>>>>> apply.
>>>>>>
>>>>>> Hi,
>>>>>> Thank you for the response, it makes sense now.
>>>>>>
>>>>>> T have another issue, maybe you can help.
>>>>>> I have some problems making it work with OVS/DPDK backend and virtio-net driver in guest.
>>>>>>
>>>>>> I am using a simple setup:
>>>>>>      http://wiki.qemu.org/Features/vhost-user-ovs-dpdk
>>>>>> that connects 2 VMs using OVS's dpdkvhostuser ports (regular virtio-net driver in guest, not the PMD driver).
>>>>>>
>>>>>> The setup worked fine with the prev DPDK MQ implementation (V4), however on this one the traffic stops
>>>>>> once I set queues=n in guest.
>>>>>
>>>>> Hi,
>>>>>
>>>>> Could you be more specific about that? It also would be helpful if you
>>>>> could tell me the steps, besides those setup steps you mentioned in the
>>>>> qemu wiki and this email, you did for testing.
>>>>>
>>>>
>>>> Hi,
>>>> Thank you for your help.
>>>>
>>>> I am sorry the wiki is not enough, I'll be happy to add all the missing parts.
>>>> In the meantime maybe you can tell me where the problem is, I also suggest to
>>>> post here the output of journalctl command.
>>>>
>>>> We only need a regular machine and we want traffic between 2 VMs. I'll try to summarize the steps:
>>>>
>>>> 1. Be sure you have enough hugepages enabled (2M pages are enough) and mounted.
>>>> 2. Configure and start OVS following the wiki
>>>>     - we only want one bridge with 2 dpdkvhostuser ports.
>>>> 3. Start VMs using the wiki command line
>>>>     - check journalctl for possible errors. You can use
>>>>          journalctl  --since `date +%T --date="-10 minutes"`
>>>>       to see only last 10 minutes.
>>>> 4. Configure the guests IPs.
>>>>     - Disable the Network Manager as described bellow in the mail.
>>>> 5. At this point you should be able to ping between guests.
>>>>
>>>> Please let me know if you have any problem until this point.
>>>> I'll be happy to help. Please point any special steps you made that
>>>> are not in the WIKI. The journalctl logs would also help.
>>>>
>>>> Does the ping between VMS work now?
>>>
>>> Yes, it works, too. I can ping the other vm inside a vm.
>>>
>>>      [root@dpdk-kvm ~]# ethtool -l eth0
>>>      Channel parameters for eth0:
>>>      Pre-set maximums:
>>>      RX:             0
>>>      TX:             0
>>>      Other:          0
>>>      Combined:       2
>>>      Current hardware settings:
>>>      RX:             0
>>>      TX:             0
>>>      Other:          0
>>>      Combined:       2
>>>
>>>      [root@dpdk-kvm ~]# ifconfig eth0
>>>      eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
>>>              inet 192.168.100.11  netmask 255.255.255.0  broadcast 192.168.100.255
>>>              inet6 fe80::5054:ff:fe12:3459  prefixlen 64  scopeid 0x20<link>
>>>              ether 52:54:00:12:34:59  txqueuelen 1000  (Ethernet)
>>>              RX packets 56  bytes 5166 (5.0 KiB)
>>>              RX errors 0  dropped 0  overruns 0  frame 0
>>>              TX packets 84  bytes 8303 (8.1 KiB)
>>>              TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
>>>
>>>      [root@dpdk-kvm ~]# ping 192.168.100.10
>>>      PING 192.168.100.10 (192.168.100.10) 56(84) bytes of data.
>>>      64 bytes from 192.168.100.10: icmp_seq=1 ttl=64 time=0.213 ms
>>>      64 bytes from 192.168.100.10: icmp_seq=2 ttl=64 time=0.094 ms
>>>      64 bytes from 192.168.100.10: icmp_seq=3 ttl=64 time=0.246 ms
>>>      64 bytes from 192.168.100.10: icmp_seq=4 ttl=64 time=0.153 ms
>>>      64 bytes from 192.168.100.10: icmp_seq=5 ttl=64 time=0.104 ms
>>>      ^C
>>>>
>>>> If yes, please let me know and I'll go over MQ enabling.
>>>
>>> I'm just wondering why it doesn't work on your side.
>>
>> Hi,
>>
>> This is working also for me, but without enabling the MQ. (ethtool -L eth0 combined n (n>1) )
>> The problem starts when I am applying the patches and I enable MQ. (Need a slightly different QEMU commandline)
>>
>>>
>>>>
>>>>> I had a very rough testing based on your test guides, I indeed found
>>>>> an issue: the IP address assigned by "ifconfig" disappears soon in the
>>>>> first few times and after about 2 or 3 times reset, it never changes.
>>>>>
>>>>> (well, I saw that quite few times before while trying different QEMU
>>>>> net devices. So, it might be a system configuration issue, or something
>>>>> else?)
>>>>>
>>>>
>>>> You are right, this is a guest config issue, I think you should disable NetworkManager
>>>
>>> Yeah, I figured it out by my self, and it worked when I hardcoded it at
>>> /etc/sysconfig/network-scripts/ifcfg-eth0.
>>>
>>>> for static IP addresses. Please use only the virtio-net device.
>>>>
>>>> You cant try this:
>>>> sudo systemctl stop NetworkManager
>>>> sudo systemctl disable NetworkManager
>>>
>>> Thanks for the info and tip!
>>>
>>>>
>>>>> Besides that, it works, say, I can wget a big file from host.
>>>>>
>>>>
>>>> The target here is traffic between 2 VMs.
>>>> We want to be able to ping (for example) between VMS when MQ > 1 is enabled on both guests:
>>>> - ethtool -L eth0 combined <queues nr, the same as QEMU>
>>>
>>> As you can see from my command log, I did so and it worked :)
>>>
>>
>> Let me understand, it worked after applying MQ patches on all 3 projects (DPDK, QEMU and OVS)?
>> It worked with MQ enabled? MQ >1 ?
>
> Yes, however, I tried few more times this time, and found it sometimes
> worked, and sometimes not. Sounds like there is a bug somewhere.
>

Yes, I've been hunting it since you submitted the series :)

>>
>> You can be sure by using the following command in one of the VMs:
>>    cat /proc/interrupts | grep virtio
>> and see that you have interrupts for all virtio0-input.0/1/...
>
>       [root@dpdk-kvm ~]# cat /proc/interrupts | grep virtio
>       24:        0        0    PCI-MSI-edge       virtio0-config
>       25:      425        0    PCI-MSI-edge       virtio0-virtqueues
>

Here it shows that MQ is not enabled in the guest.
For queues=2 in qemu commandline and  'ethtool -L eth0 combined 2' in guest you should see:

  24:          0          0          0          0   PCI-MSI 65536-edge      virtio0-config
  25:         32          0         14          0   PCI-MSI 65537-edge      virtio0-input.0
  26:          1          0          0          0   PCI-MSI 65538-edge      virtio0-output.0
  27:         53          0          0          0   PCI-MSI 65539-edge      virtio0-input.1
  28:          1          0          0          0   PCI-MSI 65540-edge      virtio0-output.1


So, you are very close to reproduce the MQ bug:
Please ensure:
1. You have applied MQ patches to QEMU/DPDK
2. You applies the MQ patch to *OVS*:
    https://www.mail-archive.com/dev@openvswitch.org/msg49198.html
    - It does not apply correctly, just remove the chunk with the "if" statement that it fails to compile
3. Configure OVS for 2 queues:
   - ovs-vsctl set Open_vSwitch . other_config:n-dpdk-rxqs=2
   - ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=0xff00
4. Enable MQ on virtio-net device:
    -netdev type=vhost-user,id=mynet1,chardev=char0,vhostforce,queues=2 \
    -device virtio-net-pci,netdev=mynet1,mac=52:54:00:02:d9:$2,mq=on,vectors=8 \

At this stage you should still have ping working between VMS.

However, when running on both VMs:
    ethtool -L eth0 combined 2
traffic stops...

Thanks again for the help!

>
> BTW, I have seen some warnings from ovs:
>
>      2015-09-22T02:08:58Z|00003|ofproto_dpif_upcall(pmd45)|WARN|upcall_cb failure: ukey installation fails
>
>      2015-09-22T02:11:05Z|00003|ofproto_dpif_upcall(pmd44)|WARN|Dropped 29 log messages in last 127 seconds (most recently, 82 seconds ago) due to excessive rate
>      2015-09-22T02:11:05Z|00004|ofproto_dpif_upcall(pmd44)|WARN|upcall_cb failure: ukey installation fails
>      2015-09-22T02:12:17Z|00005|ofproto_dpif_upcall(pmd44)|WARN|Dropped 11 log messages in last 32 seconds (most recently, 14 seconds ago) due to excessive rate
>      2015-09-22T02:12:17Z|00006|ofproto_dpif_upcall(pmd44)|WARN|upcall_cb failure: ukey installation fails
>      2015-09-22T02:14:59Z|00007|ofproto_dpif_upcall(pmd44)|WARN|Dropped 2 log messages in last 161 seconds (most recently, 161 seconds ago) due to excessive rate
>      2015-09-22T02:14:59Z|00008|ofproto_dpif_upcall(pmd44)|WARN|upcall_cb failure: ukey installation fails
>
>
> Does that look abnormal to you?

Nope, but since you have ping between VMS it should not bother
>
> Anyway, I here check if there is anything I can fix.
Thanks!!!

Marcel
>
> 	--yliu
>