Can not checkpoint container created with nvidia-container-runtime (mounted gpu)

[gflarity]

Description

Hi,

Recently support was added for criu to checkpoint cuda applications. I've tested this on plain old processes and it seems to work as advertised.

I wanted to try this runc/containers as well. So I created a container using the nvidia-container-runtime shim which seems to just modify the config.json, adding a prestart hook that does the heavy lifting. After which I can call runc start and invoke the test cuda application I created just fine. However when I try to take a snapshot, runc checkpoint just hangs regardless of if the cuda application is even running. Taking a look at the dump.log and I can see that criu error'ed out. Here are the last few lines, full dump attached below:

(07.507264) Error (criu/mount.c:1088): mnt: Mount 251 ./proc/driver/nvidia/gpus/0000:00:04.0 (master_id: 5 shared_id: 0) has unreachable sharing. Try --enable-external-masters.
(07.507282) net: Unlock network
(07.507285) Running network-unlock scripts
(07.507287) 	RPC
(07.519624) cuda_plugin: finished cuda_plugin stage 0 err -1
(10.996267) cuda_plugin: resuming devices on pid 404642
(10.996295) cuda_plugin: Restore thread pid 404694 found for real pid 404642

I'm happy to keep digging and and see if I can find a way to try the equivalent of --enable-external-masters with criu rpc. But I wanted to file this issue incase the more experienced had any pointers. I'm specifically wondering if the external masters thing is just a rabbit hole or not? It's not so easy to just 'try' this flag with RPC than I can see. But if it solves it I'm happy to submit a PR.

Please advise, thanks!

Steps to reproduce the issue

1. sudo nvidia-container-runtime create test
2. sudo runc run test
3. sudo runc checkpoint --image-path ./dump --work-path ./workdir/ --leave-running=false test

I've attached the config.json.
config.json

Describe the results you received and expected

runc checkpoint just hangs, but if you take a look at the dump.log you can criu errored out. Dump attached.

dump.log

What version of runc are you using?

runc --version
runc version 1.2.1+dev
commit: v1.2.1-4-g2327ec22
spec: 1.2.0
go: go1.23.3
libseccomp: 2.5.5

riu --version
Version: 4.0

Host OS information

cat /etc/os-release
PRETTY_NAME="Ubuntu 24.04.1 LTS"
NAME="Ubuntu"
VERSION_ID="24.04"
VERSION="24.04.1 LTS (Noble Numbat)"
VERSION_CODENAME=noble
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=noble
LOGO=ubuntu-logo

Host kernel information

uname -a
Linux geoff-dev-testing 6.8.0-1015-gcp #17-Ubuntu SMP Mon Sep 2 17:57:02 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux