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[libvirt-users] Connectivity between Guest and Host
by christopher＠padarom.io 15 May '16

15 May '16

Hello everyone, I have followed this guide to enable my Windows 10 guest to reach my Arch Linux host: https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/ht… My VM now has 2 NICs: - macvtap (VEPA) - virtual network 'isolated' I have statically assigned the IP 192.168.254.2 to my guest. The host's IP is 192.168.254.1. The interface it is using on the host is *virbr1*. I am able to ping the host from the guest and vice versa, so the network connectivity seems to be generally working. To control my VM I'd like to use Synergy which I have already set up and tested successfully once with the VM as the Server, but never since. When I try to connect the Synergy client from the host to a server running on the guest, I get the error *"failed to connect to server: address not found for: 192.168.254.2"*. This is the result of nmap: [root@thearch ~]# nmap 192.168.254.0/30 Starting Nmap 7.12 ( https://nmap.org[1] ) at 2016-05-14 17:14 CEST Nmap scan report for 192.168.254.2 Host is up (0.0010s latency). Not shown: 995 filtered ports PORT STATE SERVICE 135/tcp open msrpc 139/tcp open netbios-ssn 445/tcp open microsoft-ds 5357/tcp open wsdapi 24800/tcp open unknown MAC Address: 52:54:00:96:11:A9 (QEMU virtual NIC) Nmap scan report for 192.168.254.1 Host is up (0.0000040s latency). Not shown: 999 closed ports PORT STATE SERVICE 53/tcp open domain Nmap done: 4 IP addresses (2 hosts up) scanned in 5.16 seconds I also did nmap from a non-root user: [christopher@thearch ~]$ nmap 192.168.254.0/30 Starting Nmap 7.12 ( https://nmap.org[2] ) at 2016-05-14 17:17 CEST Nmap scan report for 192.168.254.1 Host is up (0.000073s latency). Not shown: 999 closed ports PORT STATE SERVICE 53/tcp open domain Nmap done: 4 IP addresses (1 host up) scanned in 1.26 seconds As you can see, the host 192.168.254.2 is only found when running nmap with root, not with my other user. Pinging the guest still works however. I suspect this is the core of the issue, but I don't know how to solve it. Any suggestions are appreciated. Thanks, Christopher Mühl Links: 1. https://nmap.org/ 2. https://nmap.org/

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[libvirt-users] Connectiviity between Guest and Host
by christopher＠padarom.io 15 May '16

15 May '16

Hello everyone, I have followed this guide to enable my Windows 10 guest to reach my Arch Linux host: https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/ht… My VM now has 2 NICs: - macvtap (VEPA) - virtual network 'isolated' I have statically assigned the IP 192.168.254.2 to my guest. The host's IP is 192.168.254.1. The interface it is using on the host is *virbr1*. I am able to ping the host from the guest and vice versa, so the network connectivity seems to be generally working. To control my VM I'd like to use Synergy which I have already set up and tested successfully once with the VM as the Server, but never since. When I try to connect the Synergy client from the host to a server running on the guest, I get the error *"failed to connect to server: address not found for: 192.168.254.2"*. This is the result of nmap: [root@thearch ~]# nmap 192.168.254.0/30 Starting Nmap 7.12 ( https://nmap.org ) at 2016-05-14 17:14 CEST Nmap scan report for 192.168.254.2 Host is up (0.0010s latency). Not shown: 995 filtered ports PORT STATE SERVICE 135/tcp open msrpc 139/tcp open netbios-ssn 445/tcp open microsoft-ds 5357/tcp open wsdapi 24800/tcp open unknown MAC Address: 52:54:00:96:11:A9 (QEMU virtual NIC) Nmap scan report for 192.168.254.1 Host is up (0.0000040s latency). Not shown: 999 closed ports PORT STATE SERVICE 53/tcp open domain Nmap done: 4 IP addresses (2 hosts up) scanned in 5.16 seconds I also did nmap from a non-root user: [christopher@thearch ~]$ nmap 192.168.254.0/30 Starting Nmap 7.12 ( https://nmap.org ) at 2016-05-14 17:17 CEST Nmap scan report for 192.168.254.1 Host is up (0.000073s latency). Not shown: 999 closed ports PORT STATE SERVICE 53/tcp open domain Nmap done: 4 IP addresses (1 host up) scanned in 1.26 seconds As you can see, the host 192.168.254.2 is only found when running nmap with root, not with my other user. Pinging the guest still works however. I suspect this is the core of the issue, but I don't know how to solve it. Any suggestions are appreciated. Thanks, Christopher Mühl

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[libvirt-users] libvirt + openvswitch, <parameters interfaceid='x'/> seems less-than-useful?
by Richard Harman 14 May '16

14 May '16

Hey folks, I'm working on setting up a Cuckoo sandbox malware lab at home, and can't seem to get openvswitch and libvirt to work together as-documented. I'm not subscribed to the list, so please reply-all. Thanks in advance! I've debugged this, and I think the interfaceid stuff in network XML isn't doing much besides setting a custom interfaceid in an OpenVSwitch table that really has no effect on the operation of OpenVSwitch. I think the -- set Interface vnet0 "external-ids:iface-id="{uuid here}" command run by libvirt doesn't actually set the _uuid of a new interface. :( It's just for an external system (e.g. libvirt) to track an interface *it* creates in OVS. I've got an OVS switch, "malware0" which is my malware lab network. I made a "monitor0" interface, and told OVS to make that a span/mirror of all the traffic on the malware0 switch. I attach monitor0 to my cuckoo VM, and boot the VM. Well, actually libvirt REALLY wants to create the interface itself, so I have to delete the monitor0 interface from OVS. I boot the VM, libvirt creates the monitor0 interface (with a different UUID) and it's not a span/mirror port any more. :( I had all the ports in the cuckoo VM <parameters interfaceid='{uuid here}'/>, but libvirt keeps deleting/creating ports and the OVS internal UUID changes, which means any setting applied in OVS (e.g. setting a port as a mirror) is lost during the add/delete cycle. With my cuckoo sandbox vm up: (no bfc10d05 UUID in ports, the mirror port UUID) # ovs-vsctl list bridge _uuid : 16847994-eb75-4e71-a913-50edd8a89252 mirrors : [bfc10d05-846e-4653-8417-27e1f648da93] name : "malware0" ports : [3931cb83-1f85-4fc8-880d-ffe299a85857, 6c6e3d97-d55b-4d55-8179-302412242664, 8eb4e13b-b5ea-4994-8e95-87d61db87ba6] With the cuckoo vm down: (393, 83b go away) # ovs-vsctl list bridge _uuid : 16847994-eb75-4e71-a913-50edd8a89252 mirrors : [bfc10d05-846e-4653-8417-27e1f648da93] name : "malware0" ports : [6c6e3d97-d55b-4d55-8179-302412242664] ... and lets bring up the cuckoo vm again: (only 6c6 remains) # ovs-vsctl list bridge _uuid : 16847994-eb75-4e71-a913-50edd8a89252 mirrors : [bfc10d05-846e-4653-8417-27e1f648da93] name : "malware0" ports : [1c09dd43-52d0-449b-81a2-537ddafb4966, 6c6e3d97-d55b-4d55-8179-302412242664, f90820f9-056f-47a3-bd51-c5190ad1df46]

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[libvirt-users] dhcpd (via systemd) @boottime which does not wait for the interface..
by lejeczek 14 May '16

14 May '16

hi users I have my dhcpd to serve nothing but virbr0 (libvirt), OS is Centos 7.2 Dhcpd would not start, complaining like this: No subnet declaration for virbr0 (no IPv4 addresses). ** Ignoring requests on virbr0. If this is not what you want, please write a subnet declaration in your dhcpd.conf file for the network segment to which interface virbr0 is attached. ** ##SELECTION_END## and systemctl -l shows: ... systemd[1]: start request repeated too quickly for dhcpd.service ... but suffice to restart dhcpd and all works! I'v customized systemd's service conf, I've put: After=libvirtd.service Requisite=libvirtd.service but this did not help. Would you share your thoughts? Systemd list say it's libvirt (wrong)doing. many thanks. L.

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[libvirt-users] vcpupin vs taskset performance difference
by Paraskevopoulos Georgios 13 May '16

13 May '16

Hi all, I am trying to run some performance tests using libvirt 1.2.17. For these tests it is necessary to set a specific affinity for the VCPUs of a running VM. The problem is, that I noticed a significant performance drop in my metrics when using 'vcpupin' from the virsh console instead of running 'taskset' natively. Specifically the methods I am comparing are 1. Using native shell taskset -a -cp $MY_CPUSET $MY_DOMAIN_PID 2. Using virsh console (performance ~30% down) for all $VCPUs virsh vcpupin my_domain -cpulist $MY_CPUSET -vcpu $VCPU -live virsh emulatorpin my_domain -cpulist $MY_CPUSET -live It seems that the usage of 'vcpupin' causes a performance drop even if it is run alongside 'taskset' on the same $CPU_SET Functionally everything seems to be working when I check the '/proc/' filesystem cat /proc/MY_DOMAIN_PID/*/status | grep Cpus_allowed_list My questions are: 1. Has anybody else noticed this? 2. Is this expected based on the implementation details? 3. Is this a bug that is fixed in a newer libvirt version? 4. Is there a solution to this issue? Thanks, George Paraskevopoulos Software Engineer (SDN/NFV), INTRACOM-TELECOM + 30 210 667 7689 <mailto:geopar@intracom-telecom.com> geopar(a)intracom-telecom.com 19.7 km Markopoulou Ave 19002 Peania, Athens, Greece The information in this e-mail message and any attachments are intended only for the individual or entity to whom it is addressed and may be confidential. If you have received this transmission in error, and you are not an intended recipient, be aware that any copying, disclosure, distribution or use of this transmission or its contents is prohibited. INTRACOM TELECOM and the sender accept no liability for any loss, disruption or damage to your data or computer system that may occur while using data contained in, or transmitted with, this email. Views or opinions expressed in this message may be those of the author and may not necessarily represent those of INTRACOM TELECOM.

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[libvirt-users] virt-install errors and help sought
by Narahari Lakshminarayana 13 May '16

13 May '16

Friends: I need some help and guidance from you regarding this virt-install issue I am seeing. OS : SuseEnterpriseLinuxServer (SLES) 12 Service Pack 1 virt-install version on the box virtual@SLES12-bare:~> virt-install --version 1.2.1 libvirt version : libvirt-1.3.4-565.1.x86_64 What I tried: ========= I tried to start virt-install as regular user and I am seeing errors listed below. If I start the same with sudo it works (the user virtual shown here is a sudo enabled user) I really want to start the virt-install as a regular user. Please help. Error ==== ----------------------------------------------------------------------------------------------------------------------------- virtual@SLES12-bare:~> virt-install --connect qemu:///session -n SLES12_SP1 --memory 4096 --vcpus 2 --cdrom /data/ADP_x86_64_SLES12SP1.x86_64-12.1.6.preload.iso --graphics spice --disk /data/kvm_images/SLES12_SP1.img WARNING Graphics requested but DISPLAY is not set. Not running virt-viewer. WARNING No console to launch for the guest, defaulting to --wait -1 Starting install... ERROR Failed to connect socket to '/run/user/500/libvirt/virtlogd-sock': No such file or directory Domain installation does not appear to have been successful. If it was, you can restart your domain by running: virsh --connect qemu:///session start SLES12_SP1 otherwise, please restart your installation. -------------------------------------------------------------------------------------------------------------------------------- Thank You for your time and attention. -Narahari

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[libvirt-users] Dump network traffic from each VM.
by Julio Faracco 13 May '16

13 May '16

Hi guys, Does anybody know how to dump the network trafic from each virtual machine using libvirt? Here, we usually use VPN softwares and other network tools inside Virtual Machines (Windows and Linux). Sometimes, this applications does not work properly, so we need to dump the network traffic of each Virtual Machine to compare and debug. How can I enable it using libvirt? I know that if you use a QEMU instance, you can enable the dump using "-netdev dump,...". Thanks! :-) Julio Cesar Faracco

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[libvirt-users] Need help for block committing
by Zhang Qiang 13 May '16

13 May '16

Hi all. Can snapshots of identical images being blocked committed to the base images that are not the original ones? For example, suppose I have base0 and made a snapshot of it called SN0, then I copy base0 as base0', can SN0 be block committed into base0'? I think it's possible in theory but the block commit command just takes vm, base, and top as parameters, since the snapshot file is taken from another image I don't think I can use this command to do what I want. Or can I use qemu-img to do this? Thanks.

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[libvirt-users] host freeze when starting VM
by Alexander Petrenz 12 May '16

12 May '16

Hi together, when I´m starting a VM my host freezes gradually. This seems to happen because its running out of memory and no other process is able to do anything. I have 16GB of ram in total. 8GB are reserved for hugepages. So for the daily business on the host I have 8GB left. I don´t run many or extraordinary consuming software on the host - normally just a gnome session and the chromium browser. Right now htop tells me that 10.1 of 15.4 GB are occupied, so that should be about 2GB, because I suppose 8GB are just reserved for the hugepages. I don´t have any swap space. In my latest attempt I gave a newly created VM 64MB of ram and this also brought the system down to its knees. So I would like to understand why this is happening. Is it some configuration issue I'm not aware of or maybe even some bug? Can someone give any idea on this? Thanks in advance Alex

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[libvirt-users] Questions about CMT event statistic
by Fangge Jin 11 May '16

11 May '16

Hi I'm testing cmt event of libvirt, and I have two questions. I will be very grateful if someone can give me some help. Q1:"virsh domstats --perf" and linux perf tool has different result. I have a guest with cmt event enabled, start guest and get perf statistic every 1s: # while true; do virsh domstats rhel7.2-1030 --perf; sleep 1; done In the meanwhile, I use perf tool to get the llc_occupancy of qemu-kvm process: # pidof qemu-kvm 16779 # perf stat -a -e intel_cqm/llc_occupancy/ -I 1000 -p 16779 sleep 100 And I compare the output of the above two commands, and find that they're so different: The output of "virsh domstats" The output of "perf" tool perf.cache=15753216 49152 Bytes perf.cache=14499840 11526144 Bytes perf.cache=14499840 11599872 Bytes perf.cache=14499840 11599872 Bytes perf.cache=14499840 11599872 Bytes perf.cache=14499840 11599872 Bytes perf.cache=14499840 11599872 Bytes perf.cache=14499840 11599872 Bytes perf.cache=8380416 11649024 Bytes perf.cache=8380416 11649024 Bytes perf.cache=8380416 11821056 Bytes perf.cache=8380416 11845632 Bytes perf.cache=8380416 11845632 Bytes perf.cache=8380416 11845632 Bytes perf.cache=8380416 11845632 Bytes perf.cache=8380416 11845632 Bytes perf.cache=8380416 11845632 Bytes perf.cache=8380416 11845632 Bytes perf.cache=8380416 11845632 Bytes perf.cache=8380416 11845632 Bytes perf.cache=8380416 11870208 Bytes perf.cache=8380416 11870208 Bytes perf.cache=8380416 11845632 Bytes ... ... I don't know if it's appropriate to do this comparison, but I'm still curious why they get different results. Q2:Disable&enable cmt at runtime, then "virsh domstats" will output perf.cache=0 # virsh perf rhel7.2-1030 --disable cmt # virsh perf rhel7.2-1030 --enable cmt # virsh domstats rhel7.2-1030 --perf Domain: 'rhel7.2-1030' perf.cache=0 Watch the output for more than two minutes, it's 0 all the time: # watch virsh domstats rhel7.2-1030 --perf Every 2.0s: virsh domstats rhel7.2-1030 --perf Wed Apr 27 17:36:01 2016 Domain: 'rhel7.2-1030' perf.cache=0 BR, Fangge Jin

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