Hello, Peter.
Thank you for you answer. 

> Hi,
> please note that user-related questions are suited for the libvirt-users 
> list.
Sorry, next time will use correct email. 
 
> The function in question which fails here is called (through a few
> callback pointers so it's opaque) from virCgroupNewDetectMachine(),
> which is called from virDomainCgroupConnectCgroup which finally gets
> called from the function attempting to reconnect to an existing qemu
> instance qemuProcessReconnect().

> The failure to reconnect results into the VM being terminated via
> qemuProcessStop().
Thank you, that make sense. 
 
On the new kernel we’re using cgroupv2. On the old installation we use libvirtd 7.6 + various kernel. But there we have cgroup v1.
It seems the problem exactly in cgroupv2
 
 
>This path is consturcted from paths which originate from detectiion of
>cgroup mounts (virCgroupDetectMounts) which uses /proc/mounts.

>But it's hard to tell because you didn't post a full debug log here or
> in the upstream issue you've reported.
/proc/mounts inside container looks like
 

milan15 : ~ [0] # docker exec -it libvirt cat /proc/mounts | grep cgroup

cgroup /sys/fs/cgroup cgroup2 rw,nosuid,nodev,noexec,relatime 0 0

cgroup2 /sys/fs/cgroup cgroup2 rw,nosuid,nodev,noexec,relatime 0 0

 
ON the host system anyway:

milan15 : ~ [0] # cat /proc/mounts | grep cgroup

cgroup2 /sys/fs/cgroup cgroup2 rw,nosuid,nodev,noexec,relatime 0 0

 
Could this be a potential problem that inside container we have two time mounted cgroup? 
 
What kind of techinical information I can provide you yet? 
 
 
>Please note that upstream libvirt doesn't really provide support for
>containered deployments as nobody really tests them upstream. Said that
>there are users who do use libvirt this way but it has many intricacies
>that can be easily messed up.
I understand this. But we have had working variant with libvirtd 7.6 and cgroupv1 for more than 3 years. 
 
--
Best Regards, 
Dmitrii Abramov
 
 
 
Четверг, 5 сентября 2024, 11:10 +03:00 от Peter Krempa <pkrempa@redhat.com>:
 
On Wed, Sep 04, 2024 at 23:47:12 +0300, Dmitrii Abramov wrote:
>
>  
> Hello, Libvirt community.
> We have one strange issue with libivrtd.

Hi,

please note that user-related questions are suited for the libvirt-users
list.

>  
> We’ve been using Libvirtd in docker for several years. This year we switched to the new generation of processes AMD 7663 and we started to use the new version(for us) of libviirtd 8.0.0. Before this we used Libvirt 6.0
>  
> Right now we have such situation: 
> if we restart the container with Libvirt or Libvirt crashes and Docker engine restarts it the new process of Libvirt send SIGTERM to all running QEMU processes. 
> This highlight from strace of qemu process:
> --- SIGTERM {si_signo=SIGTERM, si_code=SI_USER, si_pid=2045513, si_uid=0} ---
>  
> This is output from bash where you can see that PID 2045513 is a new process of Libvirt(look at the uptime of container and PID)
> milan15 : ~ [0] # ps afxj | grep 2045513
> 2044884 2045700 2045699 2044884 pts/3 2045699 S+ 0 0:00 \_ grep --color=auto 2045513
> 2045492 2045513 2045513 2045513 ? -1 Ssl 0 0:04 \_ libvirtd -l
> milan15 : ~ [0] #
> milan15 : ~ [0] # docker ps | grep "libvirt$"
> 5b9e7d81a2f3 registry.beget.ru/vps/docker-libvirt/ubuntu/jammy:20240124-1 "libvirtd -l" 6 days ago Up 2 minutes libvirt
> milan15 : ~ [0] # docker top libvirt
> UID PID PPID C STIME TTY TIME CMD
> root 2045513 2045492 2 21:20 ? 00:00:04 libvirtd -l
> milan15 : ~ [0] #
>  
> We found that in logs Libvirtd says that he is unable to access to /sys/fs/cgroups. 
> {"log":"2024-09-04 17:40:02.831+0000: 2041803: error : virCgroupV2ParseControllersFile:282 : Unable to read from '/sys/fs/cgroup/../../machine/qemu-1394-mameluk-59ad0e58-732e-4468-9d3a-9be2cbac4931.libvirt-qemu/cgroup.controllers': No such file or directory\n","stream":"stderr","time":"2024-09-04T17:40:02.831308736Z"} {"log":"2024-09-04 17:40:02.831+0000: 2041804: error : virFileReadAll:1447 : Failed to open file '/sys/fs/cgroup/../../machine/qemu-1393-pavelaw3-215f218a-48d4-4b22-b15d-90ee0665f643.libvirt-qemu/cgroup.controllers': No such file or directory\n","stream":"stderr","time":"2024-09-04T17:40:02.83143703Z"} {"log":"2024-09-04 17:40:02.831+0000: 2041804: error : virCgroupV2ParseControllersFile:282 : Unable to read from ‘/sys/fs/cgroup/../../machine/qemu-1393-pavelaw3-215f218a-48d4-4b22-b15d-90ee0665f643.libvirt-qemu/cgroup.controllers': No such file or directory\n","stream":"stderr","time":"2024-09-04T17:40:02.831453382Z"}


The function in question which fails here is called (through a few
callback pointers so it's opaque) from virCgroupNewDetectMachine(),
which is called from virDomainCgroupConnectCgroup which finally gets
called from the function attempting to reconnect to an existing qemu
instance qemuProcessReconnect().

The failure to reconnect results into the VM being terminated via
qemuProcessStop().

>  
>  
> We made several tests(added sleep and listed /sys/fs/cgroup directory before launching the new process ) — it seems that every process in container has ability to access to /sys/fs/cgroups.
> It seems that the path /sys/fs/cgroup/../../machine/ isn’t correct.

This path is consturcted from paths which originate from detectiion of
cgroup mounts (virCgroupDetectMounts) which uses /proc/mounts.

But it's hard to tell because you didn't post a full debug log here or
in the upstream issue you've reported.

> We also tried Libvirt 10.0 version and many other. The result is the same. 
> We have the same scheme on other generations of processors — and everything works excellent. 
>  
> This is an example of you docker-compose where we run Libvirt(just a part)
> version: "3.0"
> services:
>   libvirt:
>     image: mameluk_libvirtd
>     build:
>       context: .
>     privileged: true
>     volumes:
>       - /etc/docker/libvirt/etc/libvirt:/etc/libvirt:rw
>       - /lib/modules:/lib/modules:ro
>       - /dev:/dev
>       - /sys:/sys
>       - /run:/run:rw
>       - /var/lib/libvirt:/var/lib/libvirt:rslave
>       - /var/log/libvirt:/var/log/libvirt
>       - /home/docker/svc-libvirt/images:/home/svc-libvirt/images
>       - /etc/docker/libvirt/etc/lvm:/etc/lvm
>       - /home/docker/svc-libvirt/cidata:/home/svc-libvirt/cidata
>     ipc: host
>     network_mode: host
>     environment:
>       - TZ=Europe/Moscow
>     pid: host
>     restart: on-failure
>     entrypoint: ["/bin/start.sh", ""]
>       #     depends_on:
>       #- virtlogd
>     container_name: mameluk_libvirtd
>  
> System: Ubuntu 22.04 
> core:  Linux milan15 6.5.0-35-generic #35~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Tue May   7 09:00:52 UTC 2 x86_64 x86_64 x86_64 GNU/Linux
>  
>  
> Can anyone help us to solve this problem 

Please note that upstream libvirt doesn't really provide support for
containered deployments as nobody really tests them upstream. Said that
there are users who do use libvirt this way but it has many intricacies
that can be easily messed up.