Ah I see the error
You have
<memoryBacking>
<hugepages/>
<page size='1' unit='G' nodeset='0'/>
</memoryBacking>
Not
<memoryBacking>
<hugepages>
<page size='1' unit='G' nodeset='0'/>
</hugepages>
</memoryBacking>
From: Adnan Mundres [mailto:[email protected]]
Sent: Wednesday, January 24, 2018 9:05 PM
To: Mooney, Sean K <[email protected]>; [email protected]
Subject: Re: [libvirt] with vhostuser I cannot use hugepages
Hi Sean
,
Thanks for you reply. I do have hugepages configuration in my xml and still it
is not getting the memory from Hugepage. Following is my complete xml file
<domain type='kvm'>
<uuid>c1f7a3d0-ccb7-4a85-b0f0-dd4bab73ba54</uuid>
<description>Timos VM</description>
<memory>16777216</memory>
<currentMemory>16777216</currentMemory>
<cpu mode='host-model'>
<numa>
<cell id="0" cpus="0" memory="16777216" unit='KiB' memAccess="shared"/>
</numa>
</cpu>
<memoryBacking>
<hugepages/>
<page size='1' unit='G' nodeset='0'/>
</memoryBacking>
<numatune>
<memory mode='strict' nodeset='1'/>
</numatune>
<vcpu current='7'>7</vcpu>
<cputune>
<vcpupin vcpu='0' cpuset='2'/>
<vcpupin vcpu='1' cpuset='3'/>
<vcpupin vcpu='2' cpuset='4'/>
<vcpupin vcpu='3' cpuset='5'/>
<vcpupin vcpu='4' cpuset='6'/>
<vcpupin vcpu='5' cpuset='7'/>
<vcpupin vcpu='6' cpuset='8'/>
<emulatorpin cpuset="0,1"/>
</cputune>
<os>
<type arch='x86_64' machine='pc'>hvm</type>
<smbios mode='sysinfo'/>
</os>
<sysinfo type ='smbios'
<clock offset='utc'>
<timer name='pit' tickpolicy='delay'/>
<timer name='rtc' tickpolicy='delay'/>
</clock>
<devices>
<emulator>/usr/libexec/qemu-kvm</emulator>
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2' cache='none'/>
<source file='/mvmgptb11/images/flexibed/vm_5/sros-vm.qcow2'/>
<target dev='hda' bus='virtio'/>
</disk>
<interface type='bridge'>
<mac address='FA:AC:A5:00:7E:00'/>
<source bridge='breth0'/>
<model type='virtio'/>
</interface>
<interface type='bridge'>
<mac address='FA:AC:A5:00:7E:01'/>
<source bridge='breth1'/>
<model type='virtio'/>
</interface>
<interface type='vhostuser'>
<mac address='FA:AC:A5:00:7E:02'/>
<source type='unix' path='/var/run/openvswitch/vhost-user-1'
mode='client'/>
<model type='virtio'/>
</interface>
<interface type='vhostuser'>
<mac address='FA:AC:A5:00:7E:04'/>
<source type='unix' path='/var/run/openvswitch/vhost-user-3'
mode='client'/>
<model type='virtio'/>
</interface>
<interface type='vhostuser'>
<mac address='FA:AC:A5:00:7E:05'/>
<source type='unix' path='/var/run/openvswitch/vhost-user-2'
mode='client'/>
<model type='virtio'/>
</interface>
<console type='tcp'>
<source mode='bind' host='0.0.0.0' service='2501'/>
<protocol type='telnet'/>
<target type='virtio' port='0'/>
</console>
<watchdog model='i6300esb' action='reset'/>
</devices>
<seclabel type='none'/>
</domain>
On Wednesday, January 24, 2018 12:54 PM, "Mooney, Sean K"
<[email protected]<mailto:[email protected]>> wrote:
From: Mooney, Sean K
Sent: Wednesday, January 24, 2018 8:52 PM
To: Adnan Mundres <[email protected]<mailto:[email protected]>>;
[email protected]<mailto:[email protected]>
Cc: Mooney, Sean K <[email protected]<mailto:[email protected]>>
Subject: RE: [libvirt] with vhostuser I cannot use hugepages
From: [email protected]<mailto:[email protected]>
[mailto:[email protected]] On Behalf Of Adnan Mundres
Sent: Wednesday, January 24, 2018 6:54 PM
To: [email protected]<mailto:[email protected]>
Subject: [libvirt] with vhostuser I cannot use hugepages
In my setup I am using qemu-kvm without openstack. I am trying to use ovs with
dpdk. In my xml file I added following lines for the dpdkvhostuser
<cpu mode='host-passthrough'>
<numa>
<cell id="0" cpus="0-6" memory="16777216" unit='KiB' memAccess="shared"/>
</numa>
</cpu>
[Mooney, Sean K] this xml snippit is not requsting the use of huge page memory.
It is requesting memory to be allocated form a single numa node and for that
to be mmaped shared.
Dpdk does not actually need the guest to use hugepages it just improves the
performance. What it requires
Is that the gues uses file descriptor backed, pre allocated, locked, shared
memory.
e.g.
<memoryBacking>
<locked/>
<source type='file'/>
<access mode='shared'/>
<allocation mode='immediate'/>
</memoryBacking>
Hugepages will enable all of the above features implicitly.
to enable hugepages add
<memoryBacking>
<hugepages>
<page size="16" unit="G" nodeset="0"/>
</hugepages>
</memoryBacking>
[Mooney, Sean K] oh I forgot to say you can find the relevant documentation
here https://libvirt.org/formatdomain.html#elementsMemoryBacking
I have enabled hugepages during boot time
ot@mvmgptb11hyp01 hyp-1]# cat /proc/meminfo | grep -i huge
AnonHugePages: 126976 kB
HugePages_Total: 100
HugePages_Free: 80
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 1048576 kB
But When I start my vm (virsh start vm1.xml) I am seeing that this vm is not
using memory from hugepages, rather it is taking memory from total memory. When
I checked the log file I see that it is using
-object
memory-backend-file,id=ram-node0,prealloc=yes,mem-path=/var/lib/libvirt/qemu/ram,share=yes
It should use backend memory as following
-object
memory-backend-file,id=ram-node0,prealloc=yes,mem-path=/dev/hugepages/libvirt/qemu/vm1,share=yes
Any idea how can I use memory from hugepages
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