| Summary: | Using emulatorpin sets machine.slice/cpuset.cpus incorrectly | ||
|---|---|---|---|
| Product: | [Community] Virtualization Tools | Reporter: | rokupstys |
| Component: | libvirt | Assignee: | Libvirt Maintainers <libvirt-maint> |
| Status: | NEW --- | QA Contact: | |
| Severity: | high | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | unspecified | CC: | libvirt-maint |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | x86_64 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | Bug | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
Description of problem: /sys/fs/cgroup/cpuset/machine.slice/cpuset.cpus on machine.slice creation is always set to cores that emulator is pinned to via <emulatorpin>. This results in following error on VM startup: Unable to write to '/sys/fs/cgroup/cpuset/machine.slice/machine-qemu\x2d2\x2dwin.scope/vcpu0/cpuset.cpus': Permission denied Compiled against library: libvirt 2.3.0 Using library: libvirt 2.3.0 Using API: QEMU 2.3.0 Running hypervisor: QEMU 2.7.0 Always reproducible. Steps to Reproduce: 1. Create VM with cpu setup: <vcpu placement='static'>4</vcpu> <cputune> <vcpupin vcpu='0' cpuset='2'/> <vcpupin vcpu='1' cpuset='3'/> <vcpupin vcpu='2' cpuset='4'/> <vcpupin vcpu='3' cpuset='5'/> <emulatorpin cpuset='0-1'/> </cputune> <cpu mode='host-passthrough'> <topology sockets='1' cores='4' threads='1'/> </cpu> 2. Start VM via virsh or virt-manager. Actual results: Error: Unable to write to '/sys/fs/cgroup/cpuset/machine.slice/machine-qemu\x2d2\x2dwin.scope/vcpu0/cpuset.cpus': Permission denied ~ % cat /sys/fs/cgroup/cpuset/machine.slice/cpuset.cpus 0-1 Expected results: No error, VM should start. ~ % cat /sys/fs/cgroup/cpuset/machine.slice/cpuset.cpus 0-5 Additional info: As a workaround i added following line to /etc/libvirt/hooks/qemu script: echo 0-5 > /sys/fs/cgroup/cpuset/machine.slice/cpuset.cpus With this workaround VM always fails starting the first time but starts properly the second time.