https://bugzilla.kernel.org/show_bug.cgi?id=196149 Bug ID: 196149 Summary: QEMU causes a host hang / reset on PPC64EL when used in KVM + HV mode (kvm_hv module) Product: Virtualization Version: unspecified Kernel Version: 4.9 Hardware: PPC-64 OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: kvm Assignee: virtualization_kvm@xxxxxxxxxxxxxxxxxxxx Reporter: tpearson@xxxxxxxxxxxxxxxxxxxxx Regression: No QEMU causes a host hang / reset on PPC64EL when used in KVM + HV mode (kvm_hv module) on host kernels with a page size of 4k. After a random amount of uptime, starting new QEMU virtual machines will cause the host to experience a soft CPU lockup. Depending on configuration and other random factors the host will either checkstop and reboot, or hang indefinitely. The following stacktrace was pulled from an instance where the host simply hung after starting a fourth virtual machine. Command line: qemu-system-ppc64 --enable-kvm -M pseries -cpu host -m 8G -realtime mlock=on -kernel vmlinux-4.7.0-1-powerpc64le -initrd initrd.img-4.7.0-1-powerpc64le Host kernel stack trace: [ 1067.451053] INFO: rcu_sched self-detected stall on CPU [ 1067.452646] 32-...: (5249 ticks this GP) idle=b4d/140000000000001/0 softirq=2214/2214 fqs=2576 [ 1067.454256] (t=5251 jiffies g=13030 c=13029 q=127812) [ 1067.455057] INFO: rcu_sched detected stalls on CPUs/tasks: [ 1067.455062] 32-...: (5249 ticks this GP) idle=b4d/140000000000001/0 softirq=2214/2214 fqs=2576 [ 1067.455076] (detected by 16, t=5252 jiffies, g=13030, c=13029, q=127812) [ 1067.455078] Task dump for CPU 32: [ 1067.455081] qemu-system-ppc R running task 0 4426 4324 0x00040004 [ 1067.455082] Call Trace: [ 1067.455087] [c000001f6cd13550] [0000000000000003] 0x3 (unreliable) [ 1067.466157] Task dump for CPU 32: [ 1067.466160] qemu-system-ppc R running task 0 4426 4324 0x00040004 [ 1067.466161] Call Trace: [ 1067.466168] [c000001f6cd133d0] [c00000000010d484] sched_show_task+0xe4/0x150 (unreliable) [ 1067.466172] [c000001f6cd13440] [c000000000836918] rcu_dump_cpu_stacks+0xf4/0x140 [ 1067.466175] [c000001f6cd13490] [c00000000015a064] rcu_check_callbacks+0x9f4/0xb40 [ 1067.466178] [c000001f6cd135c0] [c000000000162394] update_process_times+0x44/0x90 [ 1067.466180] [c000001f6cd135f0] [c000000000179bd8] tick_sched_handle.isra.4+0x48/0xe0 [ 1067.466183] [c000001f6cd13630] [c000000000179cd4] tick_sched_timer+0x64/0xd0 [ 1067.466185] [c000001f6cd13670] [c0000000001633d4] __hrtimer_run_queues+0x124/0x420 [ 1067.466187] [c000001f6cd13700] [c00000000016407c] hrtimer_interrupt+0xec/0x2b0 [ 1067.466191] [c000001f6cd137c0] [c000000000026bec] __timer_interrupt+0x8c/0x270 [ 1067.466197] [c000001f6cd13810] [c00000000002721c] timer_interrupt+0x9c/0xe0 [ 1067.466200] [c000001f6cd13840] [c000000000009550] decrementer_common+0x150/0x180 [ 1067.466209] --- interrupt: 901 at kvmppc_hv_get_dirty_log+0x1c8/0x510 [kvm_hv] LR = kvmppc_hv_get_dirty_log+0x1f4/0x510 [kvm_hv] [ 1067.466212] [c000001f6cd13be0] [d00000001a889620] kvm_vm_ioctl_get_dirty_log_hv+0xd8/0x180 [kvm_hv] [ 1067.466218] [c000001f6cd13c30] [d00000001a832268] kvm_vm_ioctl_get_dirty_log+0x40/0x60 [kvm] [ 1067.466223] [c000001f6cd13c60] [d00000001a826bcc] kvm_vm_ioctl+0x524/0x8f0 [kvm] [ 1067.466227] [c000001f6cd13d40] [c0000000003234f8] do_vfs_ioctl+0xd8/0x8c0 [ 1067.466230] [c000001f6cd13de0] [c000000000323db4] SyS_ioctl+0xd4/0xf0 [ 1067.466233] [c000001f6cd13e30] [c00000000000bd60] system_call+0x38/0xfc -- You are receiving this mail because: You are watching the assignee of the bug.
