[libvirt] [PATCH-RFC] qemu: Add network bandwidth setting for ethernet interfaces

[Anirban Chakraborty]

On 9/5/14, 1:31 AM, "Martin Kletzander" <mkletzan at redhat.com> wrote:

>On Thu, Sep 04, 2014 at 03:02:54PM -0700, Anirban Chakraborty wrote:
>>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>
>>-----
>>
>>This patch fixes the behavior.
>
>Although this doesn't confuse git, it might confuse something else.
>Leaving it without '----' is ok.
>
>>Please review it and if it appears ok, please apply.
>>
>>thanks,
>>Anirban Chakraborty
>>
>
>No need to have this in the commit message, it's kept in the log then.
>
>>
>>Signed-off-by: Anirban Chakraborty <abchak at juniper.net>
>>---
>> src/qemu/qemu_command.c | 5 +++++
>> src/qemu/qemu_hotplug.c | 3 +++
>> 2 files changed, 9 insertions(+), 1 deletion(-)
>>
>>diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
>>index 2184caa..258c6a7 100644
>>--- a/src/qemu/qemu_command.c
>>+++ b/src/qemu/qemu_command.c
>>@@ -7251,6 +7251,11 @@ qemuBuildInterfaceCommandLine(virCommandPtr cmd,
>>         if (tapfd[0] < 0)
>>             goto cleanup;
>>     }
>>+	/* Configure network bandwidth for ethernet type network interfaces */
>>+	if (actualType == VIR_DOMAIN_NET_TYPE_ETHERNET)
>>+		if (virNetDevBandwidthSet(net->ifname,
>>+			virDomainNetGetActualBandwidth(net), false) < 0)
>>+			goto cleanup;
>>
>
>In libvirt, we indent by spaces.  This would be caught by running
>'make syntax-check'.  Anyway, running 'make syntax-check check' is a
>good practice to follow before formatting the patches.

Got it. Thanks for the pointer.

>
>>     if ((actualType == VIR_DOMAIN_NET_TYPE_NETWORK ||
>>          actualType == VIR_DOMAIN_NET_TYPE_BRIDGE ||
>>diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
>>index a364c52..aeb53c5 100644
>>--- a/src/qemu/qemu_hotplug.c
>>+++ b/src/qemu/qemu_hotplug.c
>>@@ -940,6 +940,9 @@ int qemuDomainAttachNetDevice(virConnectPtr conn,
>>         if (qemuOpenVhostNet(vm->def, net, priv->qemuCaps, vhostfd,
>>&vhostfdSize) < 0)
>>             goto cleanup;
>>     } else if (actualType == VIR_DOMAIN_NET_TYPE_ETHERNET) {
>>+		if (virNetDevBandwidthSet(net->ifname,
>>+				virDomainNetGetActualBandwidth(net), false) < 0)
>>+			goto cleanup;
>
>Same here.
>
>We need to clear the bandwidth settings when shutting down the domain
>or unplugging the device.

If I am not mistaken, currently, the bandwidth setting has been cleared
only for bridged devices (via
networkShutdownNetworkVirtual‹>virNetDevBandwidthClear ). Are you saying
that we should explicitly clear the bandwidth settings for unplugging and
shut down events? As far as my understanding, for both of these events,
the tap interface gets deleted, so there is no need to cleanup qdisc
settings of these devices.

>
>Looking forward to v2,

I am working on it right now and will send it out soon. Thanks for the
feedback.

Anirban