Performing verification for mantic. I deployed mantic onto a bare metal server, with kernel 6.5.0-26-generic from -updates.
I installed a KVM stack, synced a cloud image, and tested VM creation. $ uvt-kvm create --cpu 4 --memory 4096 --disk 10 jammy-a release=jammy arch=amd64 $ uvt-kvm ssh jammy-a Welcome to Ubuntu 22.04.4 LTS (GNU/Linux 5.15.0-101-generic x86_64) From there, I found the PID of the VM: $ ps aux | grep qemu libvirt+ 1799 107 1.5 9642380 1044752 ? Sl 03:21 0:38 /usr/bin/qemu-system-x86_64 -name guest=jammy-a,debug-threads=on -S -object {"qom-ty We run perf: $ sudo perf top -p 1799 $ virsh console jammy-a Connected to domain 'jammy-a' Escape character is ^] (Ctrl + ]) [ 161.413890] BUG: unable to handle page fault for address: fffffe18cdb1c028 [ 161.419474] #PF: supervisor read access in kernel mode [ 161.423707] #PF: error_code(0x0000) - not-present page [ 161.427949] PGD 17ffca0[ 161.429508] BUG: unable to handle page fault for address: fffffe18cdb1c028 [ 161.429513] #PF: supervisor read access in kernel mode [ 161.429516] #PF: error_code(0x0000) - n The VM suffers a page fault and crashes, and is not accessible over ssh. $ uvt-kvm ssh jammy-a (no response). I then enabled -proposed, and installed 6.5.0-27-generic: $ uname -rv 6.5.0-27-generic #28-Ubuntu SMP PREEMPT_DYNAMIC Thu Mar 7 18:21:00 UTC 2024 $ uvt-kvm create --cpu 4 --memory 4096 --disk 10 jammy-a release=jammy arch=amd64 $ uvt-kvm ssh jammy-a Welcome to Ubuntu 22.04.4 LTS (GNU/Linux 5.15.0-101-generic x86_64) We get the pid of the VM: $ ps aux | grep qemu libvirt+ 1786 42.5 1.5 7960876 1022308 ? Sl 03:37 0:40 /usr/bin/qemu-system-x86_64 -name guest=jammy-a,debug-threads=on -S -object {"qom-ty We run perf: $ sudo perf top -p 1786 This time, the VM does not crash, and stays running: $ virsh console jammy-a Connected to domain 'jammy-a' Escape character is ^] (Ctrl + ]) jammy-a login: jammy-a login: We can also ssh to the VM just fine: $ uvt-kvm ssh jammy-a Welcome to Ubuntu 22.04.4 LTS (GNU/Linux 5.15.0-101-generic x86_64) This is much better. The kernel in -proposed fixes the issue, happy to mark verified for mantic. ** Tags removed: verification-needed-mantic-linux ** Tags added: verification-done-mantic-linux -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2054218 Title: kvm: Running perf against qemu processes results in page fault inside guest To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2054218/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs