[libvirt] with vhostuser I cannot use hugepages

Adnan Mundres amundres at yahoo.com
Wed Jan 24 21:04:37 UTC 2018

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='' 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" <sean.k.mooney at intel.com> wrote:

 #yiv3224014168 #yiv3224014168 -- _filtered #yiv3224014168 {panose-1:2 4 5 3 5 4 6 3 2 4;} _filtered #yiv3224014168 {font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;} _filtered #yiv3224014168 {}#yiv3224014168 #yiv3224014168 p.yiv3224014168MsoNormal, #yiv3224014168 li.yiv3224014168MsoNormal, #yiv3224014168 div.yiv3224014168MsoNormal {margin:0cm;margin-bottom:.0001pt;font-size:12.0pt;}#yiv3224014168 a:link, #yiv3224014168 span.yiv3224014168MsoHyperlink {color:#0563C1;text-decoration:underline;}#yiv3224014168 a:visited, #yiv3224014168 span.yiv3224014168MsoHyperlinkFollowed {color:#954F72;text-decoration:underline;}#yiv3224014168 span.yiv3224014168EmailStyle17 {color:#1F497D;}#yiv3224014168 span.yiv3224014168EmailStyle18 {color:#1F497D;}#yiv3224014168 .yiv3224014168MsoChpDefault {font-size:10.0pt;} _filtered #yiv3224014168 {margin:72.0pt 72.0pt 72.0pt 72.0pt;}#yiv3224014168 div.yiv3224014168WordSection1 {}#yiv3224014168       From: Mooney, Sean K
Sent: Wednesday, January 24, 2018 8:52 PM
To: Adnan Mundres <amundres at yahoo.com>; libvir-list at redhat.com
Cc: Mooney, Sean K <sean.k.mooney at intel.com>
Subject: RE: [libvirt] with vhostuser I cannot use hugepages          From:libvir-list-bounces at redhat.com [mailto:libvir-list-bounces at redhat.com]On Behalf Of Adnan Mundres
Sent: Wednesday, January 24, 2018 6:54 PM
To: libvir-list at redhat.com
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 herehttps://libvirt.org/formatdomain.html#elementsMemoryBacking   I have enabled hugepages during boot time    ot at 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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