https://bugzilla.kernel.org/show_bug.cgi?id=194837 Bug ID: 194837 Summary: VM with virtio-scsi drive often crashes during boot with kernel 4.11rc1 Product: IO/Storage Version: 2.5 Kernel Version: 4.11rc1 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: blocking Priority: P1 Component: SCSI Assignee: linux-scsi@xxxxxxxxxxxxxxx Reporter: adamw@xxxxxxxxxxxxxxxxx Regression: No In Fedora, we use the openQA automated test system, which runs qemu VMs and does tests in them. By default, it attaches optical disc images to the test VM using a virtio-scsi drive. When Fedora 26 and Rawhide's kernels went from kernel-4.11.0-0.rc0.git9.1 to kernel-4.11.0-0.rc1.git0.1 , many openQA tests suddenly started failing because at some point in the test, the VM would fail to boot properly, with a kernel error and traceback often displayed (sometimes the screen would just be blank). I've seen three variants on this failure so far. Two have identical-looking tracebacks but a slightly different error message: https://openqa.fedoraproject.org/tests/60571#step/_console_wait_login/7 https://openqa.fedoraproject.org/tests/60572#step/_console_wait_login/6 note that one error is 'unable to handle kernel paging request' and the other is 'unable to handle kernel NULL pointer dereference', but the tracebacks look very similar. Another case shows a somewhat different traceback: https://openqa.fedoraproject.org/tests/60574#step/_console_wait_login/4 but doesn't show an error message (it may just be in the backscroll, unfortunately there's no way to recover it from that test now). The traceback is still in SCSI code, however. I can reproduce this problem manually using virt-manager, so long as I attach a SCSI optical drive to the VM (Add Hardware, Device type -> "CDROM device", Bus type -> "SCSI"). If I use an IDE optical drive (which is the default in virt-manager), the bug does not occur. So long as a SCSI optical drive is attached, about half of the attempts to boot the system with the affected kernel fail. Usually with a traceback looking like the ones from openQA, sometimes it also just apparently hangs when enumerating SCSI devices (I think that's what it's doing, the last line is 'scsi 3:0:0:0: CD-ROM QEMU QEMU CD-ROM 2.0. PQ: 0 ANSI: 5' or a bit after that). -- You are receiving this mail because: You are the assignee for the bug.
