Thanks for the reply. I didn't realize it either that some bridge may 
be managed 
outside. In this situation, bandwidth setting in xml can cause chaos, so users 
have to 
be aware of it. On the contrary, if it does not work when setting qos on ovs 
network 
in xml managed by libvirt, it is also confusing. I will push another patch if 
we are to 
open this pandora's box.

-------
Best Regards,
Jinsheng Zhang

-----邮件原件-----
发件人: Laine Stump [mailto:[email protected]] 
发送时间: 2021年11月8日 23:13
收件人: Michal Prívozník; jx8zjs; [email protected]
抄送: Norman Shen(申嘉童); Jinsheng Zhang (张金生)-云服务集团
主题: Re: [PATCH 1/1] bridge_driver: use ovs-vsctl to setup and clean Qos when

On 11/8/21 5:18 AM, Michal Prívozník wrote:
> On 11/3/21 4:11 AM, jx8zjs wrote:
>> From: zhangjl02 <[email protected]>
>>
>> Fix bug 1826168: bridge type network with ovs bridge can start with 
>> Qos setting which do not take any effect
>>
>> Resolves:https://bugzilla.redhat.com/show_bug.cgi?id=1826168
>> Signed-off-by: zhangjl02 <[email protected]>
>> ---
>>   src/network/bridge_driver.c | 65 +++++++++++++++++++++++++++++++------
>>   1 file changed, 55 insertions(+), 10 deletions(-)
>>
>> diff --git a/src/network/bridge_driver.c 
>> b/src/network/bridge_driver.c index 498c45d0a7..d0627848cd 100644
>> --- a/src/network/bridge_driver.c
>> +++ b/src/network/bridge_driver.c
>> @@ -2305,6 +2305,15 @@ networkAddRouteToBridge(virNetworkObj *obj,
>>   }
>>   
>>   
>> +static int
>> +networkDefIsOvsBridge(virNetworkDef *def)
> 
> This @def should have been const too. And function returns a bool, 
> effectively.
> 
>> +{
>> +    const virNetDevVPortProfile *vport = def->virtPortProfile;
>> +    return vport &&
>> +        vport->virtPortType == VIR_NETDEV_VPORT_PROFILE_OPENVSWITCH;
>> +}
>> +
>> +
>>   static int
>>   networkStartNetworkVirtual(virNetworkDriverState *driver,
>>                              virNetworkObj *obj) @@ -2320,6 +2329,7 
>> @@ networkStartNetworkVirtual(virNetworkDriverState *driver,
>>       bool dnsmasqStarted = false;
>>       bool devOnline = false;
>>       bool firewalRulesAdded = false;
>> +    bool ovsType = networkDefIsOvsBridge(def);
>>   
>>       /* Check to see if any network IP collides with an existing route */
>>       if (networkCheckRouteCollision(def) < 0) @@ -2439,15 +2449,29 
>> @@ networkStartNetworkVirtual(virNetworkDriverState *driver,
>>       if (v6present && networkStartRadvd(driver, obj) < 0)
>>           goto error;
>>   
>> -    if (virNetDevBandwidthSet(def->bridge, def->bandwidth, true, true) < 0)
>> -        goto error;
>> +    if (ovsType) {
>> +        if (virNetDevOpenvswitchInterfaceSetQos(def->bridge, def->bandwidth,
>> +                                                def->uuid,
>> +                                                true) < 0)
>> +            goto error;
>> +    } else {
>> +        if (virNetDevBandwidthSet(def->bridge, def->bandwidth, true, true) 
>> < 0)
>> +            goto error;
>> +    }
> 
> I don't think this should be here. At this point, the bridge was 
> created using netlink (definitely NOT ovs-vsctl add-br). Therefore,
> virNetDevOpenvswitchInterfaceSetQos() must fail because it won't be 
> able to find any ports/queues/...

Beyond that, networks of the type that would end up calling 
networkStartNetworkVirtual (forward modes 'route' and "nat') don't support 
using OVS bridges anyway, so this code in networkStartNetworkVirtual and 
networkShutdownNetworkVirtual will never be executed anyway.

> 
>>   
>>       return 0;
>>   
>>    error:
>>       virErrorPreserveLast(&save_err);
>> -    if (def->bandwidth)
>> -       virNetDevBandwidthClear(def->bridge);
>> +    if (ovsType) {
>> +        if (virNetDevOpenvswitchInterfaceClearQos(def->bridge, def->uuid) < 
>> 0)
>> +            VIR_WARN("cannot clear bandwidth setting for ovs bridge : %s",
>> +                     def->bridge);
>> +    } else {
>> +        if (def->bandwidth) {
>> +            virNetDevBandwidthClear(def->bridge);
>> +        }
>> +    }
>>   
> 
> Similarly, this shouldn't be here either.
> 
>>       if (dnsmasqStarted) {
>>           pid_t dnsmasqPid = virNetworkObjGetDnsmasqPid(obj); @@ 
>> -2536,13 +2560,21 @@ static int
>>   networkStartNetworkBridge(virNetworkObj *obj)
>>   {
>>       virNetworkDef *def = virNetworkObjGetDef(obj);
>> +    bool ovsType = networkDefIsOvsBridge(def);
>>   
>>       /* put anything here that needs to be done each time a network of
>>        * type BRIDGE, is started. On failure, undo anything you've done,
>>        * and return -1. On success return 0.
>>        */
>> -    if (virNetDevBandwidthSet(def->bridge, def->bandwidth, true, true) < 0)
>> -        goto error;
>> +    if (ovsType) {
>> +        if (virNetDevOpenvswitchInterfaceSetQos(def->bridge, def->bandwidth,
>> +                                                def->uuid,
>> +                                                true) < 0)
>> +            goto error;
>> +    } else {
>> +        if (virNetDevBandwidthSet(def->bridge, def->bandwidth, true, true) 
>> < 0)
>> +            goto error;
>> +    }
>>   
>>       if (networkStartHandleMACTableManagerMode(obj) < 0)
>>           goto error;
>> @@ -2550,8 +2582,15 @@ networkStartNetworkBridge(virNetworkObj *obj)
>>       return 0;
>>   
>>    error:
>> -    if (def->bandwidth)
>> -       virNetDevBandwidthClear(def->bridge);
>> +    if (ovsType) {
>> +        if (virNetDevOpenvswitchInterfaceClearQos(def->bridge, def->uuid) < 
>> 0)
>> +            VIR_WARN("cannot clear bandwidth setting for ovs bridge : %s",
>> +                     def->bridge);
>> +    } else {
>> +        if (def->bandwidth) {
>> +            virNetDevBandwidthClear(def->bridge);
>> +        }
>> +    }
>>       return -1;
>>   }
>>   
>> @@ -2565,9 +2604,15 @@ networkShutdownNetworkBridge(virNetworkObj *obj 
>> G_GNUC_UNUSED)
>>        * type BRIDGE is shutdown. On failure, undo anything you've done,
>>        * and return -1. On success return 0.
>>        */
>> -    if (def->bandwidth)
>> -       virNetDevBandwidthClear(def->bridge);
>>   
>> +    if (networkDefIsOvsBridge(def)) {
>> +        if (virNetDevOpenvswitchInterfaceClearQos(def->bridge, def->uuid) < 
>> 0)
>> +            VIR_WARN("cannot clear bandwidth setting for ovs bridge : %s",
>> +                     def->bridge);
>> +    } else {
>> +        if (def->bandwidth)
>> +            virNetDevBandwidthClear(def->bridge);
>> +    }
>>       return 0;
>>   }
>>   
>>
> 
> Alright, these last three hunks are important because they set QoS on 
> the correct type of network. But I wonder if they belong in libvirt at 
> all. I mean, the sole purpose of having openvswitch type of network is 
> that libvirt just plugs TAPs into an OVS controlled bridge without 
> touching it in any other way. IOW, the OVS bridge is created and 
> controlled outside of libvirt. That may include configuring QoS. 
> Merging this patch would open a pandora's box: what should happen if 
> <bandwidth/> is configured in network XML and there's some QoS already 
> set on the bridge?

That was my thought too. Although I looked back in the git history and saw that 
support for setting the bandwidth of forward mode='bridge' (aka "unamanaged 
bridge network") was added incidentally as a part of decoupling the network 
driver from the hypervisor drivers:

https://gitlab.com/libvirt/libvirt/-/commit/0a85aad582322034b758f8aa0199641b42be173e

which was a bugfix on top of

https://gitlab.com/libvirt/libvirt/-/commit/42a92ee93d5432ebd9ebfd409903b5287fc7d7ff

So setting the QoS for an unmanaged bridge goes against the original philosophy 
of that type of network, but we already do it in the case of Linux host 
bridges. I suppose if someone goes to the effort of adding the extra config to 
set bandwidth, then they must know that this is going to trash any existing 
bandwidth setting for the bridge, and are willing to accept that (most likely 
because they *haven't* set anything directly via OVS).


Reply via email to