[libvirt] [PATCH v2] network: Add network bandwidth support for ethernet interfaces

Mon Oct 6 18:16:59 UTC 2014

On 10/06/2014 02:07 AM, Martin Kletzander wrote:
> On Fri, Sep 26, 2014 at 10:52:57AM -0700, Anirban Chakraborty wrote:
>> V2:
>> Addressed comments raised in review of V1.
>> Consolidate calls to virNetDevBandwidthSet.
>> Clear bandwidth settings when the interface is detached or domain
>> destroyed.
>>
>> V1:
>> Ethernet interfaces in libvirt currently do not support bandwidth
>> setting.
>> For example, following xml file for an interface will not apply these
>> settings to corresponding qdiscs.
>>
>>    <interface type="ethernet">
>>      <mac address="02:36:1d:18:2a:e4"/>
>>      <model type="virtio"/>
>>      <script path=""/>
>>      <target dev="tap361d182a-e4"/>
>>      <bandwidth>
>>        <inbound average="984" peak="1024" burst="64"/>
>>        <outbound average="2000" peak="2048" burst="128"/>
>>      </bandwidth>
>>    </interface>
>>
>> Signed-off-by: Anirban Chakraborty <abchak at juniper.net>
>>
>> ---
>> src/lxc/lxc_process.c          | 26 +++++++++++++-------------
>> src/network/bridge_driver.c    |  7 ++++---
>> src/qemu/qemu_command.c        |  9 ++++-----
>> src/qemu/qemu_driver.c         | 22 +++++++++++++++++++++-
>> src/qemu/qemu_hotplug.c        | 14 +++++++++++++-
>> src/util/virnetdevbandwidth.c  | 23 ++++++++++++++++++++---
>> src/util/virnetdevbandwidth.h  |  7 ++++---
>> src/util/virnetdevmacvlan.c    | 10 ----------
>> src/util/virnetdevmacvlan.h    |  1 -
>> tests/virnetdevbandwidthtest.c |  3 ++-
>> 10 files changed, 81 insertions(+), 41 deletions(-)
>>
>> diff --git a/src/lxc/lxc_process.c b/src/lxc/lxc_process.c
>> index ed30c37..7f7e4ad 100644
>> --- a/src/lxc/lxc_process.c
>> +++ b/src/lxc/lxc_process.c
>> @@ -300,6 +295,7 @@ char
>> *virLXCProcessSetupInterfaceDirect(virConnectPtr conn,
>>     virNetDevBandwidthPtr bw;
>>     virNetDevVPortProfilePtr prof;
>>     virLXCDriverConfigPtr cfg = virLXCDriverGetConfig(driver);
>> +    const char *linkdev = virDomainNetGetActualDirectDev(net);
>>
>>     /* XXX how todo bandwidth controls ?
>>      * Since the 'net-ifname' is about to be moved to a different
>> @@ -329,16 +325,15 @@ char
>> *virLXCProcessSetupInterfaceDirect(virConnectPtr conn,
>>
>>     if (virNetDevMacVLanCreateWithVPortProfile(
>>             net->ifname, &net->mac,
>> -            virDomainNetGetActualDirectDev(net),
>> +            linkdev,
>>             virDomainNetGetActualDirectMode(net),
>>             false, def->uuid,
>> -            virDomainNetGetActualVirtPortProfile(net),
>> +            prof,
>>             &res_ifname,
>>             VIR_NETDEV_VPORT_PROFILE_OP_CREATE,
>>             cfg->stateDir,
>> -            virDomainNetGetActualBandwidth(net), 0) < 0)
>> +            0) < 0)
>>         goto cleanup;
>> -
>>     ret = res_ifname;
>>
>>  cleanup:
>> @@ -368,6 +363,7 @@ static int
>> virLXCProcessSetupInterfaces(virConnectPtr conn,
>>     int ret = -1;
>>     size_t i;
>>     size_t niface = 0;
>> +    int actualType;
>>
>>     for (i = 0; i < def->nnets; i++) {
>>         char *veth = NULL;
>> @@ -381,7 +377,8 @@ static int
>> virLXCProcessSetupInterfaces(virConnectPtr conn,
>>         if (VIR_EXPAND_N(*veths, *nveths, 1) < 0)
>>             goto cleanup;
>>
>> -        switch (virDomainNetGetActualType(def->nets[i])) {
>> +        actualType = virDomainNetGetActualType(def->nets[i]);
>> +        switch (actualType) {
>>         case VIR_DOMAIN_NET_TYPE_NETWORK: {
>>             virNetworkPtr network;
>>             char *brname = NULL;
>> @@ -444,11 +441,14 @@ static int
>> virLXCProcessSetupInterfaces(virConnectPtr conn,
>>         case VIR_DOMAIN_NET_TYPE_LAST:
>>             virReportError(VIR_ERR_INTERNAL_ERROR,
>>                            _("Unsupported network type %s"),
>> -                           virDomainNetTypeToString(
>> -                               virDomainNetGetActualType(def->nets[i])
>> -                               ));
>> +                           virDomainNetTypeToString(actualType));
>>             goto cleanup;
>>         }
>
> Hunks like these (that do not have any functional impact) could be
> separated to ease the review.

I second that - sometimes I spend time trying to figure out why a change
was needed, and when I don't find a reason I assume that I must be
confused about something...

>
>
>> diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
>> index 979fb13..2e1f821 100644
>> --- a/src/network/bridge_driver.c
>> +++ b/src/network/bridge_driver.c
>> @@ -2090,7 +2091,7 @@
>> networkStartNetworkVirtual(virNetworkDriverStatePtr driver,
>>     return 0;
>>
>>  err5:
>> -    virNetDevBandwidthClear(network->def->bridge);
>> +    virNetDevBandwidthClear(network->def->bridge,
>> VIR_DOMAIN_NET_TYPE_BRIDGE);
>
> You could change the virNetDevBandwidthClear() function to take the
> device definition as an argument and you wouldn't have to supply
> additional information for that device.

Actually you can't do that, because functions in the util directory
cannot #include anything from the conf directory.

For that matter, even what you've done here (using
VIR_DOMAIN_NET_TYPE_*) is illegal, for the same reason. It looks like
you're only using the type to decide if you want to return early. Going
quickly through the places where virNetDevBandwidth(Set|Clear) are
called, I think in most cases you wouldn't even get there if you didn't
have the right kind of interface, so you can likely just add in the
check in the couple of places where it is ambiguous.

BTW, I notice that you're allowing setting of bandwidth for macvtap
interfaces (VIR_DOMAIN_NET_TYPE_DIRECT). This was not originally
supported by the macvtap code in the kernels, although it has recently
been added (e.g. it is in Fedora 20, but not in RHEL7.0 or CentOS7.0).
Was this intentional, or accidental?

> Unfortunately, it cannot be
> done with Set(), I guess, but feel free to correct me if I'm wrong.
>
>> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
>> index 117138a..02eb680 100644
>> --- a/src/qemu/qemu_driver.c
>> +++ b/src/qemu/qemu_driver.c
>> @@ -186,6 +186,9 @@ qemuVMFilterRebuild(virDomainObjListIterator
>> iter, void *data)
>>     return virDomainObjListForEach(qemu_driver->domains, iter, data);
>> }
>>
>> +static void
>> +qemuDomainClearNetBandwidth(virDomainObjPtr vm);
>> +
>
> Whey don't you define the function up here in the file somewhere so
> that you don't have to do static prototypes?
>
>> diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
>> index d631887..4002afb 100644
>> --- a/src/qemu/qemu_hotplug.c
>> +++ b/src/qemu/qemu_hotplug.c
>> @@ -3517,6 +3522,13 @@ qemuDomainDetachNetDevice(virConnectPtr conn,
>>         }
>>     }
>>
>> +    actualType = virDomainNetGetActualType(detach);
>> +    if (virNetDevBandwidthClear(detach->ifname, actualType) < 0) {
>> +        virReportError(VIR_ERR_OPERATION_FAILED,
>> +                       _("cannot clear bandwidth setting for device
>> : %s"),
>> +                       detach->ifname);
>> +        goto cleanup;
>> +    }
>
> This is the only place you are checking for an error and this one
> actually doesn't make much sense.  Warning would be better, I guess.
>
>> diff --git a/src/util/virnetdevbandwidth.c
>> b/src/util/virnetdevbandwidth.c
>> index 5fa231a..34a224e 100644
>> --- a/src/util/virnetdevbandwidth.c
>> +++ b/src/util/virnetdevbandwidth.c
>> @@ -245,6 +255,7 @@ virNetDevBandwidthSet(const char *ifname,
>> /**
>>  * virNetDevBandwidthClear:
>>  * @ifname: on which interface
>> + * @type: interface tyoe
>
> s/tyoe/type/
>
> The rest looks fine, although having second opinion from anyone else
> more familiar with libvirt's networking would be good.  And as I
> mentioned, splitting the patch into 2 or 3 logical ones would be nice.
>
> Martin