Re: [libvirt-users] Sluggish performance with virtio and Win10

John Obaterspok
Thu, 18 Feb 2016 11:59:52 -0000

2016-02-18 11:25 GMT+01:00 Martin Kletzander <mkletzan@redhat.com>:

> On Thu, Feb 18, 2016 at 10:41:42AM +0100, John Obaterspok wrote:
>
>> 2016-02-18 10:13 GMT+01:00 Martin Kletzander
<mkletzan@redhat.com>:
>>
>> On Thu, Feb 18, 2016 at 08:49:38AM +0100, John Obaterspok wrote:
>>>
>>> Hello,
>>>>
>>>> I'm using virt-manager on my F23 box to run a Windows 10
image but the
>>>> performance is so bad it's killing me.
>>>>
>>>> I have "vmx" flag in /proc/cpuinfo
>>>>
>>>> # lsmod |grep kvm
>>>> kvm_intel             167936  6
>>>> kvm                   503808  1 kvm_intel
>>>>
>>>> virtio-win-0.1.112-1.noarch
>>>>
>>>> But no virtio modules loaded. Should they be loaded nowadays?
>>>>
>>>>
>>> Not on the host AFAIK.
>>>
>>> The disk format used is vmdk with no caching and native mode.
>>>
>>>> The io is 100% in windows task manager performing less than
1MB/s
>>>>
>>>> Any clues?
>>>>
>>>>
>>>> What are the figures from the host?  What is qemu doing and
what are the
>>> other processes and devices doing?
>>>
>>>
>>> What is the best way to find this out?
>>
>>
> {,a,h}top should do for the initial runs, just to see if the block layer
> is busy or the CPU is busy or something else is blocking it
>
>
atop seems to indicate that sdd is busy?

DSK |          sdd |  busy     96% |              |  read    1455 | write
1319 |  KiB/r      5 | KiB/w      9 |               | MBr/s   0.74 | MBw/s
  1.26  | avq     1.01 |               | avio 3.43 ms |

# mount | grep sdd
/dev/sdd2 on /vm type ext4 (rw,relatime,seclabel,data=ordered)


guest configuration is below:

<domain type='kvm'>
  <name>win10-box</name>
  <uuid>d4a67adb-5d30-42f8-b8c6-d3c4598700f2</uuid>
  <memory unit='KiB'>4194304</memory>
  <currentMemory unit='KiB'>4194304</currentMemory>
  <vcpu placement='static'>4</vcpu>
  <os>
    <type arch='x86_64'
machine='pc-i440fx-2.4'>hvm</type>
  </os>
  <features>
    <acpi/>
    <apic/>
    <pae/>
    <hyperv>
      <relaxed state='on'/>
      <vapic state='on'/>
      <spinlocks state='on' retries='8191'/>
    </hyperv>
    <kvm>
      <hidden state='on'/>
    </kvm>
    <vmport state='off'/>
  </features>
  <cpu mode='host-model'>
    <model fallback='allow'/>
  </cpu>
  <clock offset='localtime'>
    <timer name='rtc' tickpolicy='catchup'/>
    <timer name='pit' tickpolicy='delay'/>
    <timer name='hpet' present='no'/>
    <timer name='hypervclock' present='yes'/>
  </clock>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <pm>
    <suspend-to-mem enabled='no'/>
    <suspend-to-disk enabled='no'/>
  </pm>
  <devices>
    <emulator>/usr/bin/qemu-kvm</emulator>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>

      <target dev='hda' bus='ide'/>
      <readonly/>
      <address type='drive' controller='0' bus='0'
target='0' unit='0'/>
    </disk>
    <disk type='file' device='disk'>
      <driver name='qemu' type='vmdk' cache='none'
io='native'/>

      <target dev='vda' bus='virtio'/>
      <boot order='1'/>
      <address type='pci' domain='0x0000' bus='0x00'
slot='0x0a'
function='0x0'/>
    </disk>
    <controller type='usb' index='0'
model='ich9-ehci1'>
      <address type='pci' domain='0x0000' bus='0x00'
slot='0x06'
function='0x7'/>
    </controller>
    <controller type='usb' index='0'
model='ich9-uhci1'>
      <master startport='0'/>
      <address type='pci' domain='0x0000' bus='0x00'
slot='0x06'
function='0x0' multifunction='on'/>
    </controller>
    <controller type='usb' index='0'
model='ich9-uhci2'>
      <master startport='2'/>
      <address type='pci' domain='0x0000' bus='0x00'
slot='0x06'
function='0x1'/>
    </controller>
    <controller type='usb' index='0'
model='ich9-uhci3'>
      <master startport='4'/>
      <address type='pci' domain='0x0000' bus='0x00'
slot='0x06'
function='0x2'/>
    </controller>
    <controller type='pci' index='0'
model='pci-root'/>
    <controller type='ide' index='0'>
      <address type='pci' domain='0x0000' bus='0x00'
slot='0x01'
function='0x1'/>
    </controller>
    <controller type='virtio-serial' index='0'>
      <address type='pci' domain='0x0000' bus='0x00'
slot='0x05'
function='0x0'/>
    </controller>
    <controller type='sata' index='0'>
      <address type='pci' domain='0x0000' bus='0x00'
slot='0x08'
function='0x0'/>
    </controller>
    <interface type='direct'>
      <mac address='52:54:00:cc:f0:31'/>

      <model type='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00'
slot='0x03'
function='0x0'/>
    </interface>
    <serial type='pty'>
      <target port='0'/>
    </serial>
    <console type='pty'>
      <target type='serial' port='0'/>
    </console>



    <graphics type='spice' autoport='yes'/>
    <sound model='ich6'>
      <address type='pci' domain='0x0000' bus='0x00'
slot='0x04'
function='0x0'/>
    </sound>

      <model type='vga' vram='16384' heads='1'/>
      <address type='pci' domain='0x0000' bus='0x00'
slot='0x02'
function='0x0'/>

    <memballoon model='virtio'>
      <address type='pci' domain='0x0000' bus='0x00'
slot='0x07'
function='0x0'/>