[libvirt-users] [virtual interface] detach interface during boot succeed with no changes
by Yalan Zhang
Hi guys,
when I detach an interface from vm during boot (vm boot not finished), it
always fail. I'm not sure if there is an existing bug. I have
confirmed with someone that for disk, there is similar behavior, if
this is also acceptable?
# virsh destroy rhel7.2; virsh start rhel7.2 ;sleep 2; virsh
detach-interface rhel7.2 network 52:54:00:98:c4:a0; sleep 2; virsh
dumpxml rhel7.2 |grep /interface -B9
Domain rhel7.2 destroyed
Domain rhel7.2 started
Interface detached successfully
<address type='pci' domain='0x0000' bus='0x00' slot='0x06'
function='0x0'/>
</controller>
<interface type='network'>
<mac address='52:54:00:98:c4:a0'/>
<source network='default' bridge='virbr0'/>
<target dev='vnet0'/>
<model type='rtl8139'/>
<alias name='net0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x03'
function='0x0'/>
</interface>
When I detach after the vm boot, expand the sleep time to 10, it will succeed.
# virsh destroy rhel7.2; virsh start rhel7.2 ;sleep 10; virsh
detach-interface rhel7.2 network 52:54:00:98:c4:a0; sleep 2; virsh
dumpxml rhel7.2 |grep /interface -B9
Domain rhel7.2 destroyed
Domain rhel7.2 started
Interface detached successfully
-------
Best Regards,
Yalan Zhang
IRC: yalzhang
Internal phone: 8389413
1 year, 8 months
Set hostname of guest during installation time
by john doe
Hi,
I would like to set the hostname when installing a guest, with the below
command the hostname is not set to 'try06' in the guest:
virt-install --name=try06 --graphic none --pxe --network bridge=virbr0
How can I set the hostname of the guest during installation time?
I realy appriciate the support I'm getting in here, I'm fairly new to
libvirt.
--
John Doe
3 years, 6 months
guest-fsfreeze-freeze freezes all mounted block devices
by Marc Roos
I wondered if anyone here can confirm that
virsh qemu-agent-command domain '{"execute":"guest-fsfreeze-freeze"}'
Freezes all mounted block devices filesystems. So if I use 4 block
devices they are all frozen for snapshotting. Or just the root fs?
3 years, 9 months
[libvirt-users] Question about disabling UFO on guest
by Bao Nguyen
Hello everyone,
I would like to ask a question regarding to disable UFO of virtio vNIC in
my guest. I have read the document at https://libvirt.org/formatdomain.html
*host*
The csum, gso, tso4, tso6, ecn and ufo attributes with possible
values on and off can be used to turn off host offloading options. By
default, the supported offloads are enabled by QEMU. *Since 1.2.9 (QEMU
only)* The mrg_rxbuf attribute can be used to control mergeable rx buffers
on the host side. Possible values are on (default) and off. *Since 1.2.13
(QEMU only)*
*guest*
The csum, tso4, tso6, ecn and ufo attributes with possible
values on and off can be used to turn off guest offloading options. By
default, the supported offloads are enabl
ed by QEMU.
*Since 1.2.9 (QEMU only)*
Then I disabled UFO on my vNIC on guest as the following configuration
<devices>
<interface type='network'>
<source network='default'/>
<target dev='vnet1'/>
<model type='virtio'/>
<driver name='vhost' txmode='iothread' ioeventfd='on' event_idx='off'
queues='5' rx_queue_size='256' tx_queue_size='256'>
*<host gso='off' ufo='off' />*
*<guest ufo='off'/>*
</driver>
</interface>
</devices>
Then I reboot my node to get the change effect and it works. However, can I
disable the UFO without touching the host OS? or it always has to disable
on both host and guest like that?
Thanks,
Brs,
Natsu
3 years, 9 months
Could you please help with questions about the net failover feature
by Yalan Zhang
Hi laine,
I have leave some questions on IRC, but my VPN broken time after time.
Please ignore the questions on IRC.
In my understanding, the standby and primary hostdev interface may be in
different subnet.
I'm not sure whether it is correct. Could you please help to explain? Thank
you in advance.
For example, primary hostdev is connected to vf-pool with <pf='eth0'/>,
while the standby is connected to NAT network with " forward dev='eth0'".
The standby interface will get ip as 192.168.122.x, but after NAT, it will
be in the same subnet of the vf.
So after the VF is unplugged, the packet will still broadcast in the same
subnet, and the vm will get the packet as the standby share the same mac.
Right?
Thank you!
-------
Best Regards,
Yalan Zhang
IRC: yalzhang
3 years, 10 months
qemu hook: event for source host too
by Guy Godfroy
Hello, this is my first time posting on this mailing list.
I wanted to suggest a addition to the qemu hook. I will explain it
through my own use case.
I use a shared LVM storage as a volume pool between my nodes. I use
lvmlockd in sanlock mode to protect both LVM metadata corruption and
concurrent volume mounting.
When I run a VM on a node, I activate the desired LV with exclusive lock
(lvchange -aey). When I stop the VM, I deactivate the LV, effectively
releasing the exclusive lock (lvchange -an).
When I migrate a VM (both live and offline), the LV has to be activated
on both source and target nodes, so I have to use a shared lock
(lvchange -asy). That's why I need a hook event on the source host too
(as far as I know after my tests, the migration event is only triggered
on the target host).
Is such a feature a possibility?
Thanks for your attention.
Guy Godfroy
3 years, 11 months
Re: USB-hotplugging fails with "failed to load cgroup BPF prog: Operation not permitted" on cgroups v2
by Pavel Hrdina
On Mon, Jan 20, 2020 at 09:00:15PM +0100, Pol Van Aubel wrote:
> Hi,
>
> Quoting Pavel Hrdina (2020-01-20 14:29:36)
> > On Sat, Jan 18, 2020 at 11:17:11PM +0100, Pol Van Aubel wrote:
> > > Hi all,
> > >
> > > I've disabled cgroups v1 on my system with the kernel boot option
> > > "systemd.unified_cgroup_hierarchy=1". Since doing so, USB hotplugging
> > > fails to work, seemingly due to a permissions problem with BPF. Please
> > > note that the technique I'm going to describe worked just fine for
> > > hotplugging USB devices to running domains until this change.
> > > Attaching / detaching USB devices when the domain is down still works as
> > > expected.
> > >
> > > I get the same error when attaching a device in virt-manager, as I do
> > > when running the following command:
> > >
> > > sudo virsh attach-device wenger /dev/stdin --persistent <<END
> > > <hostdev mode='subsystem' type='usb' managed='yes'>
> > > <source startupPolicy='optional'>
> > > <vendor id='0x046d' />
> > > <product id='0xc215' />
> > > </source>
> > > </hostdev>
> > > END
> > >
> > > This returns
> > > error: Failed to attach device from /dev/stdin
> > > error: failed to load cgroup BPF prog: Operation not permitted
> > >
> > >
> > > virt-manager returns basically the same error, but for completeness'
> > > sake, here it is:
> > >
> > > failed to load cgroup BPF prog: Operation not permitted
> > >
> > > Traceback (most recent call last):
> > > File "/usr/share/virt-manager/virtManager/addhardware.py", line 1327, in _add_device
> > > self.vm.attach_device(dev)
> > > File "/usr/share/virt-manager/virtManager/object/domain.py", line 920, in attach_device
> > > self._backend.attachDevice(devxml)
> > > File "/usr/lib/python3.8/site-packages/libvirt.py", line 590, in attachDevice
> > > if ret == -1: raise libvirtError ('virDomainAttachDevice() failed', dom=self)
> > > libvirt.libvirtError: failed to load cgroup BPF prog: Operation not permitted
> > >
> > >
> > > Now, libvirtd is running as root, so I don't understand why any
> > > operation on BPF programs is not permitted. I've dug into libvirt's code
> > > a bit to see what is throwing this error and it boils down to
> > > <https://github.com/libvirt/libvirt/blob/7d608469621a3fda72dff2a89308e68cc...>
> > > and
> > > <https://github.com/libvirt/libvirt/blob/02bf7cc68bfc76242f02d23e73cad3661...>
> > > but I have no clue what that syscall is doing, so that's where my
> > > debugging capability basically ends.
> > >
> > > Maybe this is something as simple as setting the right ACL somewhere. I
> > > haven't touched /etc/libvirt/qemu.conf except for setting nvram. There
> > > *is* something about cgroup_device_acl there but afaict that's for
> > > cgroups v1, when there was still a device cgroup controller. Any help
> > > would be greatly appreciated.
> > >
> > >
> > > Domain log files:
> > > Upon execution of the above commands, nothing gets added to the domain
> > > log in /var/log/qemu/wenger.log, so I've decided they're likely
> > > irrelevant to the issue. Please ask for any additional info required.
> > >
> > >
> > > System information:
> > > Arch Linux, (normal) kernel 5.4.11
> > > libvirt 5.10.0
> > > qemu 4.2.0, using KVM.
> > > Host system is x86_64 on an intel 5820k.
> > > Guest system is probably irrelevant, but is Windows 10 on the same.
> > >
> > >
> > > Possibly relevant kernel build options:
> > > $ zgrep BPF /proc/config.gz
> > > [22:55:52]: zgrep BPF /proc/config.gz
> > >
> > > CONFIG_CGROUP_BPF=y
> > > CONFIG_BPF=y
> > > CONFIG_BPF_SYSCALL=y
> > > CONFIG_BPF_JIT_ALWAYS_ON=y
> > > CONFIG_IPV6_SEG6_BPF=y
> > > CONFIG_NETFILTER_XT_MATCH_BPF=m
> > > # CONFIG_BPFILTER is not set
> > > CONFIG_NET_CLS_BPF=m
> > > CONFIG_NET_ACT_BPF=m
> > > CONFIG_BPF_JIT=y
> > > CONFIG_BPF_STREAM_PARSER=y
> > > CONFIG_LWTUNNEL_BPF=y
> > > CONFIG_HAVE_EBPF_JIT=y
> > > CONFIG_BPF_EVENTS=y
> > > # CONFIG_BPF_KPROBE_OVERRIDE is not set
> > > # CONFIG_TEST_BPF is not set
> >
> > Hi
> >
> > I've installed clean archlinux to try this out and it works as expected,
> > I'm able to attach USB device into a VM.
> >
> > My system env is mostly the same as yours except for kernel version:
> >
> > kernel 5.4.13
> > libvirt 5.10.0
> > qemu 4.2.0, using KVM.
> >
> > Please enable libvirt debug logs [1] and share the output with us.
>
> I've updated to 5.4.13 and created a barebones VM without storage to
> reproduce the behaviour. libvirtd debug logs are attached. There appear
> to be two BPF failures of the same BPF program (?). The first is on line
> 23209, which appears to be part of machine startup, and which I don't
> actually notice. The second one is where I manually add the USB device,
> on line 30599.
>
> Thanks,
Thanks for the logs, but it did not help to figure out where the issue
is. I was hoping to see some error output from the syscall but the line
that should contain it is empty:
2020-01-20 19:47:15.589+0000: 8579: debug : virBPFLoadProg:78 :
Can you please check system logs and output of dmesg?
I've managed to run into this article [1] that explains that even if you
have all permissions and no SELinux you can still be blocked by
something called kernel_lockdown and it should appear in dmesg.
Pavel
[1] <https://gehrcke.de/2019/09/running-an-ebpf-program-may-require-lifting-th...>
4 years
Ovs error when starting vm: ovs-vsctl: 'del-port' command requires at least 1 arguments
by Thomas Pircher
Hi,
my system got updated to libvirt 6.0.0 (from 5.6.0) this morning, and
now I'm having problems starting VMs that make use of openvswitch
portgroups.
When I start a VM, I get this error message on virsh:
> virsh # start testvm
> error: Failed to start domain testvm
> error: An error occurred, but the cause is unknown
The system log contains:
> Mar 30 09:45:39 tplinux ovs-vsctl[2763]: ovs|00001|db_ctl_base|ERR|'del-port' command requires at least 1 arguments
> Mar 30 09:45:39 tplinux libvirtd[735]: internal error: Child process (ovs-vsctl --timeout=5 -- --if-exists del-port) unexpected exit status 1: ovs-vsctl: 'del-port' command requires at least 1 arguments
> Mar 30 09:45:39 tplinux libvirtd[735]: internal error: Unable to delete port (null) from OVS
My network "test-net" looks like:
> <network>
> <name>test-net</name>
> <forward mode='bridge'/>
> <bridge name='test-net'/>
> <virtualport type='openvswitch'/>
> <portgroup name='fabric' default='yes'>
> <vlan trunk='yes'>
> <tag id='10' nativeMode='untagged'/>
> <tag id='20'/>
> <tag id='30'/>
> <tag id='40'/>
> <tag id='50'/>
> <tag id='60'/>
> <tag id='70'/>
> </vlan>
> </portgroup>
> </network>
And the network in the domain xml file is:
> <interface type='network'>
> <mac address='01:23:45:67:89:ab'/>
> <source network='test-net' portgroup='fabric'/>
> <model type='e1000'/>
> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
> </interface>
I didn't see any change in the changelog related to ovs or portgroups.
Is there something I need to change in my VM definition?
Thanks,
Thomas
4 years, 1 month
