I just built from latest master and got the kernel trace below. ❯ qemu-system-ppc64 --version QEMU emulator version 4.2.90 (v4.2.0-2811-g83019e81d1-dirty) Copyright (c) 2003-2020 Fabrice Bellard and the QEMU Project developers
qemu-system-ppc64 \ -nographic -nodefaults -monitor pty -serial stdio \ -M pseries -cpu POWER9 -smp cores=4,threads=1 -m 4G \ -drive file=debian-ppc64el-qemu.qcow2,format=qcow2,if=virtio \ -netdev user,id=network01,hostfwd=tcp::$LocalSSHPort-:22 -device rtl8139,netdev=network01 \ [ 376.219450] watchdog: BUG: soft lockup - CPU#3 stuck for 22s! [swapper/3:0] [ 376.226712] Modules linked in: ctr(E) vmx_crypto(E) gf128mul(E) sunrpc(E) ip_tables(E) x_tables(E) autofs4(E) ext4(E) crc16(E) mbcache(E) jbd2(E) crc32c_generic(E) virtio_blk(E) 8139too(E) virtio_pci(E) virtio_ring(E) 8139cp(E) virtio(E) mii(E) [ 376.235692] CPU: 3 PID: 0 Comm: swapper/3 Tainted: G E 5.5.0-rc5-powerpc64le #1 Debian 5.5~rc5-1~exp1 [ 376.236245] NIP: c00000000000af8c LR: c000000000019664 CTR: c000000000af2c80 [ 376.236365] REGS: c0000000fffcf920 TRAP: 0901 Tainted: G E (5.5.0-rc5-powerpc64le Debian 5.5~rc5-1~exp1) [ 376.236376] MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 44002248 XER: 00000000 [ 376.236479] CFAR: c000000000af2ce0 IRQMASK: 0 GPR00: c000000000af2e38 c0000000fffcfbb0 c000000001365700 0000000000000500 GPR04: 00000000fef90000 0000002be1f69c00 0000002beaa729fa c0000000fffec880 GPR08: 0000000400000000 00000000000080ff 0000000000000001 c0080000004c6ff0 GPR12: 0000000000002000 c0000000fffec880 [ 376.238452] NIP [c00000000000af8c] replay_interrupt_return+0x0/0x4 [ 376.238488] LR [c000000000019664] arch_local_irq_restore.part.0+0x54/0x70 [ 376.238984] Call Trace: [ 376.240707] [c0000000fffcfbb0] [c0000000008ce910] napi_gro_receive+0x1e0/0x210 (unreliable) [ 376.240824] [c0000000fffcfbd0] [c000000000af2e38] _raw_spin_unlock_irqrestore+0x98/0xb0 [ 376.242114] [c0000000fffcfbf0] [c0080000004c5588] cp_rx_poll+0x580/0x610 [8139cp] [ 376.242131] [c0000000fffcfcf0] [c0000000008cf6c8] net_rx_action+0x1f8/0x550 [ 376.242139] [c0000000fffcfe10] [c000000000af3a8c] __do_softirq+0x16c/0x3d8 [ 376.242172] [c0000000fffcff30] [c0000000001329e8] irq_exit+0xd8/0x120 [ 376.242181] [c0000000fffcff60] [c000000000019fb4] __do_irq+0x84/0x1c0 [ 376.242193] [c0000000fffcff90] [c00000000002cbec] call_do_irq+0x14/0x24 [ 376.242201] [c0000000fd4b7980] [c00000000001a178] do_IRQ+0x88/0xf0 [ 376.242209] [c0000000fd4b79c0] [c000000000008d98] hardware_interrupt_common+0x158/0x160 [ 376.242243] --- interrupt: 501 at plpar_hcall_norets+0x1c/0x28 LR = check_and_cede_processor+0x48/0x60 [ 376.243892] [c0000000fd4b7cc0] [c0000000fd4b7cf0] 0xc0000000fd4b7cf0 (unreliable) [ 376.243922] [c0000000fd4b7d20] [c00000000086c710] shared_cede_loop+0x50/0x160 [ 376.243942] [c0000000fd4b7d50] [c000000000868844] cpuidle_enter_state+0xa4/0x590 [ 376.243953] [c0000000fd4b7dd0] [c000000000868dcc] cpuidle_enter+0x4c/0x70 [ 376.243983] [c0000000fd4b7e10] [c000000000177d4c] call_cpuidle+0x4c/0x90 [ 376.243991] [c0000000fd4b7e30] [c000000000178358] do_idle+0x2f8/0x400 [ 376.243998] [c0000000fd4b7ed0] [c0000000001786a8] cpu_startup_entry+0x38/0x40 [ 376.244011] [c0000000fd4b7f00] [c00000000004e910] start_secondary+0x640/0x670 [ 376.244020] [c0000000fd4b7f90] [c00000000000b354] start_secondary_prolog+0x10/0x14 [ 376.244093] Instruction dump: [ 376.244751] 7d200026 618c8000 2c030900 4182e348 2c030500 4182dcd0 2c030f00 4182f318 [ 376.244797] 2c030a00 4182ffc8 60000000 60000000 <4e800020> 7c781b78 480003d9 480003f1 -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1867786 Title: Qemu PPC64 freezes with multi-core CPU Status in QEMU: New Bug description: I installed Debian 10 on a Qemu PPC64 VM running with the following flags: qemu-system-ppc64 \ -nographic -nodefaults -monitor pty -serial stdio \ -M pseries -cpu POWER9 -smp cores=4,threads=1 -m 4G \ -drive file=debian-ppc64el-qemu.qcow2,format=qcow2,if=virtio \ -netdev user,id=network01,$ports -device rtl8139,netdev=network01 \ Within a couple minutes on any operation (could be a Go application or simply changing the hostname with hostnamectl, the VM freezes and prints this on the console: ``` root@debian:~# [ 950.428255] rcu: INFO: rcu_sched self-detected stall on CPU [ 950.428453] rcu: 3-....: (5318 ticks this GP) idle=8e2/1/0x4000000000000004 softirq=5957/5960 fqs=2544 [ 976.244481] watchdog: BUG: soft lockup - CPU#3 stuck for 23s! [zsh:462] Message from syslogd@debian at Mar 17 11:35:24 ... kernel:[ 976.244481] watchdog: BUG: soft lockup - CPU#3 stuck for 23s! [zsh:462] [ 980.110018] rcu: INFO: rcu_sched detected expedited stalls on CPUs/tasks: { 3-... } 5276 jiffies s: 93 root: 0x8/. [ 980.111177] rcu: blocking rcu_node structures: [ 1013.442268] rcu: INFO: rcu_sched self-detected stall on CPU [ 1013.442365] rcu: 3-....: (21071 ticks this GP) idle=8e2/1/0x4000000000000004 softirq=5957/5960 fqs=9342 ``` If I change to 1 core on the command line, I haven't seen these freezes. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1867786/+subscriptions