- Users - libvirt List Archives

[libvirt-users] Efficacy of jitterentropy RNG on qemu-kvm Guests
by procmem 17 Aug '18

17 Aug '18

Hello. I'm a distro maintainer and was wondering about the efficacy of entropy daemons like haveged and jitterentropyd in qemu-kvm. One of the authors of haveged [0] pointed out if the hardware cycles counter is emulated and deterministic, and thus predictible. He therefore does not recommend using HAVEGE on those systems. Is this the case with KVM's counters? PS. I will be setting VM CPU settings to host-passthrough. Bonus: Also if anyone knows the answer to this question about Xen please let me know because its the other main platform we support and they don't have the luxury of virtio-rng in PVH mode. Thanks. [0] https://github.com/BetterCrypto/Applied-Crypto-Hardening/commit/cf7cef7a870…

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[libvirt-users] qemu guest agent
by Cobin Bluth 15 Aug '18

15 Aug '18

Hello Libvirt-Users! I have a quick question about the qemu guest agent. Is it possible to use the guest agent from inside the guest in order to query the name of its own domain? For example, I use a base-image.qcow2 with a baked-in hostname. I would like to include a little tool in my guest image to change the hostname to the name of the domain. Is this sort of thing possible? -Cobin

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[libvirt-users] New Application to add to web site
by Matthew 11 Aug '18

11 Aug '18

Hello, Could you please add the OpenVM Dashboard to the list of applications that use libvirt. Below is the URL and description. Also, to all the developers who put libvirt-php together...THANK YOU! Thanks, Matthew Penning URL: https://openvm.tech <https://openvm.tech/> Description: The OpenVM Dashboard is an open source HTML5 and PHP based web interface for the KVM and QEMU hypervisor. It is designed to be a easy-to-use management platform allowing users to create and manage domains (virtual machines) using the libvirt-php module.

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Re: [libvirt-users] Windows Guest I/O performance issues (already using virtio) (Matt Schumacher)
by Allence 09 Aug '18

09 Aug '18

I think performance is not just about your xml, the host system will have a bigger impact. Maybe you can see this link: Https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/ht… >Date: Wed, 8 Aug 2018 17:35:11 +0000 >From: Matt Schumacher <matt.s(a)aptalaska.com> >To: "libvirt-users(a)redhat.com" <libvirt-users(a)redhat.com> >Subject: [libvirt-users] Windows Guest I/O performance issues (already > using virtio) >Message-ID: <30EE4896-CF82-4E23-82D5-0C56B38F5E09(a)aptalaska.com> >Content-Type: text/plain; charset="utf-8" > >List, > >I have a number of Windows 2016 servers I am deploying, but I?m having some I/O performance issues. I have done all of the obvious things like virtio drivers, but am finding there is more performance to be found with hyper-v extensions, how we virtualize the hardware clock, and iothreads. I?m using ZVOLs to back the VM, and I?m using 4k block sizes, which seems to offer the best 4k random read/write performance (mail and database workloads), but maybe I?m missing something at this layer too. > >Questions: > > > 1. Does my VM config look reasonable for the latest releases of windows? Are there features I should be using that will help performance? > 2. Why does the hypervclock timer make so much performance difference in windows VMs? > 3. Does my virtualized CPU model make sense? I defined Haswell-noTSX-IBRS and libvirt added the features. > 4. Which kernel branch offers the best stability and performance? > 5. Are there performance gains in using UEFI booting the windows guest and defining ?<blockio logical_block_size='4096' physical_block_size='4096'/>?? Perhaps better block size consistency through to the zvol? > > >Here is my setup: > >48 core Haswell CPU >192G Ram >Linux 4.14.61 or 4.9.114 (testing both) >ZFS file system on optane SSD drive or ZFS file system on dumb HBA with 8 spindles of 15k disks (testing both) >4k block size zvol for virtual machines >32G arc cache > >Here is my VM: > ><domain type='kvm' id='12'> > <name>testvm</name> > <memory unit='KiB'>33554432</memory> > <currentMemory unit='KiB'>33554432</currentMemory> > <vcpu placement='static'>12</vcpu> > <iothreads>1</iothreads> > <os> > <type arch='x86_64' machine='pc-i440fx-2.12'>hvm</type> > <boot dev='cdrom'/> > <boot dev='hd'/> > </os> > <features> > <acpi/> > <hyperv> > <relaxed state='on'/> > <vapic state='on'/> > <spinlocks state='on' retries='8191'/> > <vpindex state='on'/> > <runtime state='on'/> > <synic state='on'/> > <reset state='on'/> > <vendor_id state='on' value='KVM Hv'/> > </hyperv> > </features> > <cpu mode='custom' match='exact' check='full'> > <model fallback='forbid'>Haswell-noTSX-IBRS</model> > <topology sockets='1' cores='6' threads='2'/> > <feature policy='require' name='vme'/> > <feature policy='require' name='f16c'/> > <feature policy='require' name='rdrand'/> > <feature policy='require' name='hypervisor'/> > <feature policy='require' name='arat'/> > <feature policy='disable' name='spec-ctrl'/> > <feature policy='require' name='xsaveopt'/> > <feature policy='require' name='abm'/> > </cpu> > <clock offset='localtime'> > <timer name='rtc' tickpolicy='catchup'/> > <timer name='pit' tickpolicy='delay'/> > <timer name='hpet' present='yes'/> > <timer name='hypervclock' present='yes'/> > </clock> > <on_poweroff>destroy</on_poweroff> > <on_reboot>restart</on_reboot> > <on_crash>destroy</on_crash> > <devices> > <emulator>/usr/bin/qemu-system-x86_64</emulator> > <disk type='block' device='disk'> > <driver name='qemu' type='raw' cache='none' io='native' ioeventfd='on' iothread='1'/> > <source dev='/dev/zvol/datastore/vm/testvm-vda'/> > <backingStore/> > <target dev='vda' bus='virtio'/> > <alias name='virtio-disk0'/> > <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> > </disk> > <disk type='file' device='cdrom'> > <driver name='qemu'/> > <target dev='hdc' bus='ide'/> > <readonly/> > <alias name='ide0-1-0'/> > <address type='drive' controller='0' bus='1' target='0' unit='0'/> > </disk> > <controller type='ide' index='0'> > <alias name='ide'/> > <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/> > </controller> > <controller type='usb' index='0' model='piix3-uhci'> > <alias name='usb'/> > <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/> > </controller> > <controller type='pci' index='0' model='pci-root'> > <alias name='pci.0'/> > </controller> > <controller type='virtio-serial' index='0'> > <alias name='virtio-serial0'/> > <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> > </controller> > <interface type='bridge'> > <source bridge='lan'/> > <target dev='vnet0'/> > <model type='virtio'/> > <alias name='net0'/> > <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> > </interface> > <channel type='unix'> > <source mode='bind' path='/var/lib/libvirt/qemu/channel/target/domain-12-testvm/org.qemu.guest_agent.0'/> > <target type='virtio' name='org.qemu.guest_agent.0' state='connected'/> > <alias name='channel0'/> > <address type='virtio-serial' controller='0' bus='0' port='1'/> > </channel> > <input type='tablet' bus='usb'> > <alias name='input0'/> > <address type='usb' bus='0' port='1'/> > </input> > <input type='mouse' bus='ps2'> > <alias name='input1'/> > </input> > <input type='keyboard' bus='ps2'> > <alias name='input2'/> > </input> > <graphics type='vnc' port='5901' autoport='no' listen='0.0.0.0'> > <listen type='address' address='0.0.0.0'/> > </graphics> > <video> > <model type='cirrus' vram='16384' heads='1' primary='yes'/> > <alias name='video0'/> > <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> > </video> > <memballoon model='none'/> > </devices> > <seclabel type='dynamic' model='dac' relabel='yes'> > <label>+0:+100</label> > <imagelabel>+0:+100</imagelabel> > </seclabel> ></domain>

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[libvirt-users] Mount URL as cdrom/iso KVM/QEMU
by Inception Hosting 09 Aug '18

09 Aug '18

Hi Folks, According to the examples in http://libvirt.org/formatdomain.html#elementsDisks it should be possible to mount an iso /url as a cdrom, the example given is: </disk> <disk type='network' device='cdrom'> <driver name='qemu' type='raw'/> <source protocol="http" name="url_path"> <host name="hostname" port="80"/> </source> <target dev='hde' bus='ide' tray='open'/> <readonly/> </disk> I am unable to get this to work at all and wondered if I am just missing something obvious: Boot failed: Could not read from CDROM (code 0003) Actual XML in use snippet: <disk type='network' device='cdrom'> <driver name='qemu' type='raw'/> <source protocol="http" name="/debian-cd/current/amd64/iso-cd/debian-9.5.0-amd64-netinst.iso"> <host name="mirror.bytemark.co.uk" port="80"/> </source> <target dev='hdb' bus='ide' tray='open'/> <readonly/> </disk> libvirtd (libvirt) 3.9.0 QEMU emulator version 2.10.0 Is anyone able to offer any assistance or tips? I have tried putting the complete path including fqdn in the url_path as well, with and without http:// Many Thanks. Anthony.

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[libvirt-users] Windows Guest I/O performance issues (already using virtio)
by Matt Schumacher 08 Aug '18

08 Aug '18

List, I have a number of Windows 2016 servers I am deploying, but I’m having some I/O performance issues. I have done all of the obvious things like virtio drivers, but am finding there is more performance to be found with hyper-v extensions, how we virtualize the hardware clock, and iothreads. I’m using ZVOLs to back the VM, and I’m using 4k block sizes, which seems to offer the best 4k random read/write performance (mail and database workloads), but maybe I’m missing something at this layer too. Questions: 1. Does my VM config look reasonable for the latest releases of windows? Are there features I should be using that will help performance? 2. Why does the hypervclock timer make so much performance difference in windows VMs? 3. Does my virtualized CPU model make sense? I defined Haswell-noTSX-IBRS and libvirt added the features. 4. Which kernel branch offers the best stability and performance? 5. Are there performance gains in using UEFI booting the windows guest and defining “<blockio logical_block_size='4096' physical_block_size='4096'/>”? Perhaps better block size consistency through to the zvol? Here is my setup: 48 core Haswell CPU 192G Ram Linux 4.14.61 or 4.9.114 (testing both) ZFS file system on optane SSD drive or ZFS file system on dumb HBA with 8 spindles of 15k disks (testing both) 4k block size zvol for virtual machines 32G arc cache Here is my VM: <domain type='kvm' id='12'> <name>testvm</name> <memory unit='KiB'>33554432</memory> <currentMemory unit='KiB'>33554432</currentMemory> <vcpu placement='static'>12</vcpu> <iothreads>1</iothreads> <os> <type arch='x86_64' machine='pc-i440fx-2.12'>hvm</type> <boot dev='cdrom'/> <boot dev='hd'/> </os> <features> <acpi/> <hyperv> <relaxed state='on'/> <vapic state='on'/> <spinlocks state='on' retries='8191'/> <vpindex state='on'/> <runtime state='on'/> <synic state='on'/> <reset state='on'/> <vendor_id state='on' value='KVM Hv'/> </hyperv> </features> <cpu mode='custom' match='exact' check='full'> <model fallback='forbid'>Haswell-noTSX-IBRS</model> <topology sockets='1' cores='6' threads='2'/> <feature policy='require' name='vme'/> <feature policy='require' name='f16c'/> <feature policy='require' name='rdrand'/> <feature policy='require' name='hypervisor'/> <feature policy='require' name='arat'/> <feature policy='disable' name='spec-ctrl'/> <feature policy='require' name='xsaveopt'/> <feature policy='require' name='abm'/> </cpu> <clock offset='localtime'> <timer name='rtc' tickpolicy='catchup'/> <timer name='pit' tickpolicy='delay'/> <timer name='hpet' present='yes'/> <timer name='hypervclock' present='yes'/> </clock> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>destroy</on_crash> <devices> <emulator>/usr/bin/qemu-system-x86_64</emulator> <disk type='block' device='disk'> <driver name='qemu' type='raw' cache='none' io='native' ioeventfd='on' iothread='1'/> <source dev='/dev/zvol/datastore/vm/testvm-vda'/> <backingStore/> <target dev='vda' bus='virtio'/> <alias name='virtio-disk0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> </disk> <disk type='file' device='cdrom'> <driver name='qemu'/> <target dev='hdc' bus='ide'/> <readonly/> <alias name='ide0-1-0'/> <address type='drive' controller='0' bus='1' target='0' unit='0'/> </disk> <controller type='ide' index='0'> <alias name='ide'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/> </controller> <controller type='usb' index='0' model='piix3-uhci'> <alias name='usb'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/> </controller> <controller type='pci' index='0' model='pci-root'> <alias name='pci.0'/> </controller> <controller type='virtio-serial' index='0'> <alias name='virtio-serial0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> </controller> <interface type='bridge'> <source bridge='lan'/> <target dev='vnet0'/> <model type='virtio'/> <alias name='net0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> <channel type='unix'> <source mode='bind' path='/var/lib/libvirt/qemu/channel/target/domain-12-testvm/org.qemu.guest_agent.0'/> <target type='virtio' name='org.qemu.guest_agent.0' state='connected'/> <alias name='channel0'/> <address type='virtio-serial' controller='0' bus='0' port='1'/> </channel> <input type='tablet' bus='usb'> <alias name='input0'/> <address type='usb' bus='0' port='1'/> </input> <input type='mouse' bus='ps2'> <alias name='input1'/> </input> <input type='keyboard' bus='ps2'> <alias name='input2'/> </input> <graphics type='vnc' port='5901' autoport='no' listen='0.0.0.0'> <listen type='address' address='0.0.0.0'/> </graphics> <video> <model type='cirrus' vram='16384' heads='1' primary='yes'/> <alias name='video0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </video> <memballoon model='none'/> </devices> <seclabel type='dynamic' model='dac' relabel='yes'> <label>+0:+100</label> <imagelabel>+0:+100</imagelabel> </seclabel> </domain>

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[libvirt-users] Copy volume from one storage to another
by Shashwat shagun 08 Aug '18

08 Aug '18

Hi, I want to copy a volume from one to pool to another pool through libvirt golang api but I’m unaware of any such functions. Can anybody guide me a little bit here? Best Regards, Shashwat Shagun me(a)shashwat.tech

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[libvirt-users] LIBVIRT-4.6.0 can't work with QEMU 3.0.0
by Holger Schranz 08 Aug '18

08 Aug '18

Hello, if I try to use Llibvirt-4.6.0 together with qemu-3.0.0-rc4. I run into an issue. Please see the following Memo. Best regards Holger ================================================================================ Procduce QEMU-3.0.0-RC4 and LIBVIRT-4.6.0: QEMU-3-0-0-RC4: make clean ./configure --enable-libiscsi --enable-libusb --enable-bzip2 --enable-libnfs --enable-spice --enable-user --enable-virtfs --enable-opengl --enable-sdl --enable-gtk --enable-virglrenderer --disable-seccomp --prefix=/usr;make -j$(grep -c ^processor /proc/cpuinfo) su make install LIBVIRT-4.6.0 make clean ./configure -q --with-lxc --with-storage-iscsi --with-storage-scsi --with-interface --with-storage-lvm --with-storage-fs --with-udev --with-vmware --with-storage-mpath --prefix=/usr;make -j$(grep -c ^processor /proc/cpuinfo) su systemctl stop libvirtd.service cd libvirt-4.5.0 make uninstall cd .. cd libvirt-4.6.0 make install systemctl status libvirtd.service -l systemctl daemon-reload systemctl start libvirtd.service systemctl status libvirtd.service -l ? libvirtd.service - Virtualization daemon Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled; vendor preset: disabled) Active: active (running) since Wed 2018-08-08 09:05:26 CEST; 3s ago Docs: man:libvirtd(8) https://libvirt.org Main PID: 137948 (libvirtd) Tasks: 19 (limit: 32768) CGroup: /system.slice/libvirtd.service ?? 4725 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/lib/libvirt_leaseshelper ?? 4726 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/lib/libvirt_leaseshelper ??137948 /usr/sbin/libvirtd Aug 08 09:05:26 etcsvms5 systemd[1]: Starting Virtualization daemon... Aug 08 09:05:26 etcsvms5 systemd[1]: Started Virtualization daemon. Aug 08 09:05:26 etcsvms5 libvirtd[137948]: 2018-08-08 07:05:26.876+0000: 137964: info : libvirt version: 4.6.0 Aug 08 09:05:26 etcsvms5 libvirtd[137948]: 2018-08-08 07:05:26.876+0000: 137964: info : hostname: etcsvms5 Aug 08 09:05:26 etcsvms5 libvirtd[137948]: 2018-08-08 07:05:26.876+0000: 137964: error : virNetworkObjAssignDefLocked:589 : operation failed: network 'default' already exists with uuid 52abe250-4f23-40fe-875e-0808d57ce72d Aug 08 09:05:27 etcsvms5 dnsmasq[4725]: read /etc/hosts - 8 addresses Aug 08 09:05:27 etcsvms5 dnsmasq[4725]: read /var/lib/libvirt/dnsmasq/default.addnhosts - 0 addresses Aug 08 09:05:27 etcsvms5 dnsmasq-dhcp[4725]: read /var/lib/libvirt/dnsmasq/default.hostsfile Aug 08 09:05:27 etcsvms5 libvirtd[137948]: 2018-08-08 07:05:27.711+0000: 137964: warning : virLXCDriverCapsInit:82 : Failed to get host CPU cache info Aug 08 09:05:27 etcsvms5 libvirtd[137948]: 2018-08-08 07:05:27.719+0000: 137964: warning : umlCapsInit:73 : Failed to get host CPU cache info etcsvms5:/home/shl/Install/libvirt-4.6.0 # ---> test1: Start virt-manager etcsvms5:/home/shl/Install/libvirt-4.6.0 # virsh version Compiled against library: libvirt 4.6.0 Using library: libvirt 4.6.0 Using API: LXC 4.6.0 Running hypervisor: LXC 4.4.140 etcsvms5:/home/shl/Install/libvirt-4.6.0 # Information on virt-manager window: Unable to connect to libvirt qemu:///system. no connection driver available for qemu:///system Libvirt URI is: qemu:///system Traceback (most recent call last): File "/usr/share/virt-manager/virtManager/connection.py", line 1036, in _do_open self._backend.open(self._do_creds_password) File "/usr/share/virt-manager/virtinst/connection.py", line 144, in open open_flags) File "/usr/lib64/python2.7/site-packages/libvirt.py", line 104, in openAuth if ret is None:raise libvirtError('virConnectOpenAuth() failed') libvirtError: no connection driver available for qemu:///system ---> TEst2: Call VM via virsh create etcsvms5:/home/shl/Install/libvirt-4.6.0 # cd /kvm/CS8400/M4 etcsvms5:/kvm/CS8400/M4 # cd VLP0 etcsvms5:/kvm/CS8400/M4/VLP0 # virsh create M4-VLP0.xml error: Failed to create domain from M4-VLP0.xml error: invalid argument: could not find capabilities for arch=x86_64 domaintype=kvm etcsvms5:/kvm/CS8400/M4/VLP0 # ----- switch back to LIBVIRT.4-5-0 and all runs o.k. --- Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft. https://www.avast.com/antivirus

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[libvirt-users] Qemu guest display black after reboot
by Allence 06 Aug '18

06 Aug '18

Hey, every friend. I have a question. My guests are not working, unbelievable. I can use it the first time I use it. But after I close my guest and start over, my guests will not appear. My screen is black. My environment: Guest: windows 10 vm-bios: ovmf host: ubuntu 1604 qemu: 2.12 libvirt: 4.2 kernel: 4.17.2 xml config: gpu: <qemu:commandline> <qemu:arg value='-device'/> <qemu:arg value='vfio-pci,host=0000:01:00.0,romfile=/root/rom.file,multifunction=on,x-vga=on'/> </qemu:commandline> features: <kvm> <hidden state='on'/> </kvm>

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[libvirt-users] Trouble passing PCI device in isolated IOMMU group
by Quincy Wofford 06 Aug '18

06 Aug '18

I'm attempting PCI-passthrough from host to guest on an HP ProLiant 380P, which has an outdated BIOS (2014), but it does support VT-d. I'm running CentOS 7, kernel 3.10.0-862.9.1.el7.x86_64. I have an Intel 82580 NIC installed with 4 ports. Each of these ports is in its own IOMMU group (I enabled SR-IOV at the BIOS, which might be the reason they show up separately) After detaching and adding a 'hostdev' device with the appropriate pci address, I attempt to start my VM. I get " failed to set iommu for container: Operation not permitted". As recommended here ( http://vfio.blogspot.com/2014/08/vfiovga-faq.html) I parsed dmesg in an attempt to find: ------------------- No interrupt remapping support. Use the module param "allow_unsafe_interrupts" to enable VFIO IOMMU support on this platform ------------------- ...but nothing similar exists in my logs. Since this device is showing up in its own IOMMU group, I assume ACS override won't get me any further. In any case, it is not an option for me to leave ACS override on. I can turn it on for testing, the server is not currently in production. Any idea why this could be failing?

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