June 2017 - Users - libvirt List Archives

[libvirt-users] why increasing vCPUs increasing the CPU sockets for QEMU+KVM
by girish kumar 06 Jun '17

06 Jun '17

Hi All, I am new here, please warn me If I am not following proper etiquette of this mailing list. I am breaking my head, regarding why libvirt is defining multiple CPU sockets when I increase the vCPU count. As and when I increase the vCPU count in libvirt guest XML, it is increasing the CPU sockets in qemu instance. " -smp 4,sockets=4,cores=1,threads=1 " instead " -smp 4,sockets=1,cores=4,threads=1" Does not this lower the performance of the guest as the host and guest architectures gets different in that case. Also please suggest a guest configuration which will take advantage of the host CPU architecture. Your help will be highly appreciated. -- Regards, Girish

2 3

[libvirt-users] vm live migration memory copy
by Hui Jing 04 Jun '17

04 Jun '17

Hi All, I am wondering when we do live migration, how much memory is transferred? I guess it must be one of the three below, but not sure which one: 1. The amount of memory allocated to VM 2. The memory currently used by VM (actual Mem usage in guest) 3. The memory used by the qemu process (RSS). Best Regards, Hui

2 1

[libvirt-users] Debugging Windows 10 Guest Flakiness
by David Morrison 02 Jun '17

02 Jun '17

Hello, I'm not sure if I'm asking this question in the right place, so please redirect me if there's a better list. I recently set up a Windows 10 guest on an Arch Linux host with libvirt and KVM/Qemu, using IOMMU to enable GPU passthrough. I followed this guide to set up the VM: https://wiki.archlinux.org/index.php/PCI_passthrough_via_OVMF The problem that I'm having is that the guest is very flaky: sometimes the guest will just hang indefinitely, and sometimes the guest loses network connectivity. Usually when either of these behaviors happens, restarting the libvirtd daemon on the host resolves the issue, but that's not always true, and sometimes when I restart libvirtd it causes my entire (host) machine to lock up! I have enabled log_output level 1 in /etc/libvirt/libvirtd.conf and have monitored the log file during one of these hangs, but I don't see any obvious errors or problems in the log file itself (and there's a lot of information to sort through, so I may have missed something). Some specifics about my setup: Motherboard: ASUS Sabertooth X79 CPU: Intel i7 4930K Host GPU: GeForce GT 730 Guest GPU: GeForce GTX 780 Virtual network interface: NAT with the virtio driver I'm *reasonably* confident that the problem is not with the GPU passthrough setup, as I'm able to run FurMark (a GPU burn-in tool) on the guest with no problems. However, I haven't yet been able to reliably reproduce the error at all, so I'm pretty much at a loss as to where to go from here. Can anyone on this list point me in a good direction to look, or have you seen anything like this before? I'm happy to provide debug logs or any other information that is helpful, as well. Thanks for your time, David

1 0

[libvirt-users] No way to stop virStream error after guest stop
by JosÉ Luis Valencia Gutierrez 02 Jun '17

02 Jun '17

Hello everyone, I am opening a virChannel(unix) to a domain and receiving data with a non-blocking virStream using events, when the connected domain gets stopped(which deletes the channel unix socket) by calling destroy, shutdown, pause or migrate on that domain, with the stream open the read event is triggered repeatedly, and virStreamRecv returns 0 bytes indicating EOF but neither virStreamFinish nor virStreamFinish is working to stop the stream to trigger the event . Each time the event is called I got this errors. libvirt: I/O Stream Utils error : this function is not supported by the connection driver: virStreamRecv libvirt: I/O Stream Utils error : this function is not supported by the connection driver: virStreamFinish libvirt: I/O Stream Utils error : this function is not supported by the connection driver: virStreamEventRemoveCallback Is there other way to stop getting this errors? or perhaps this is a bug. Thanks in advance. Jose Valencia

2 8

[libvirt-users] libvirtd not accepting connections
by Michael C. Cambria 01 Jun '17

01 Jun '17

Hi, Ever since I recently upgraded to Fedora 25, I can't get kvm working. It's worked on this system since initial fedora 20 install. All upgrades were done via yum, then once available, dnf. I do have libvirt-sock in LISTENING state: STREAM LISTENING /var/run/libvirt/libvirt-sock I noticed I also have multiple connections in CONNECTING state: STREAM CONNECTING 0 /var/run/libvirt/libvirt-sock STREAM CONNECTING 0 /var/run/libvirt/libvirt-sock STREAM CONNECTING 0 /var/run/libvirt/libvirt-sock I rebooted and tried again. Each e.g. 'virsh -c" or virt-manager command I issue, I end up with another socket in CONNECTING state. restarting libvirtd.service close them leaving just one LISTENING strace for virsh -c shows: 4301 socket(AF_UNIX, SOCK_STREAM, 0) = 5 4301 connect(5, {sa_family=AF_UNIX, sun_path="/var/run/libvirt/libvirt-sock"}, 110) = 0 4301 getsockname(5, {sa_family=AF_UNIX}, [128->2]) = 0 4301 futex(0x7f3c0a2e4fc8, FUTEX_WAKE_PRIVATE, 2147483647) = 0 4301 fcntl(5, F_GETFD) = 0 4301 fcntl(5, F_SETFD, FD_CLOEXEC) = 0 4301 fcntl(5, F_GETFL) = 0x2 (flags O_RDWR) 4301 fcntl(5, F_SETFL, O_RDWR|O_NONBLOCK) = 0 systemctl status libvirtd.service and journalctl -f -u libvirtd.service do not show any log entries for libvird after it has been started. e.g. it doesn't log anything about the connection attempts. Anyone have an idea where to look next? Thanks, MikeC

2 1

[libvirt-users] VM memory monitor
by zhunxun＠gmail.com 01 Jun '17

01 Jun '17

Hello，I want to know what the "virsh dommemstat " really stand for?the rss in result really indicatre the physical memory that the VM has used? thanks! zhunxun(a)gmail.com

1 0