From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49944) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ctXfu-0008CI-Gl for qemu-devel@nongnu.org; Thu, 30 Mar 2017 06:51:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ctXfq-0003hH-Kw for qemu-devel@nongnu.org; Thu, 30 Mar 2017 06:51:30 -0400 Received: from foss.arm.com ([217.140.101.70]:52546) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ctXfq-0003eD-Af for qemu-devel@nongnu.org; Thu, 30 Mar 2017 06:51:26 -0400 References: <20170328201623.GD20211@cbox> <20170329185630.GA4908@cbox> From: Marc Zyngier Message-ID: <5c9b475e-d29d-f177-25b5-b9ace11b7f6f@arm.com> Date: Thu, 30 Mar 2017 11:51:21 +0100 MIME-Version: 1.0 In-Reply-To: <20170329185630.GA4908@cbox> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] host stalls when qemu-system-aarch64 with kvm and pflash List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Christoffer Dall , Radha Mohan Cc: qemu-devel@nongnu.org, "kvmarm@lists.cs.columbia.edu" On 29/03/17 19:56, Christoffer Dall wrote: > On Tue, Mar 28, 2017 at 01:24:15PM -0700, Radha Mohan wrote: >> On Tue, Mar 28, 2017 at 1:16 PM, Christoffer Dall wrote: >>> Hi Radha, >>> >>> On Tue, Mar 28, 2017 at 12:58:24PM -0700, Radha Mohan wrote: >>>> Hi, >>>> I am seeing an issue with qemu-system-aarch64 when using pflash >>>> (booting kernel via UEFI bios). >>>> >>>> Host kernel: 4.11.0-rc3-next-20170323 >>>> Qemu version: v2.9.0-rc1 >>>> >>>> Command used: >>>> ./aarch64-softmmu/qemu-system-aarch64 -cpu host -enable-kvm -M >>>> virt,gic_version=3 -nographic -smp 1 -m 2048 -drive >>>> if=none,id=hd0,file=/root/zesty-server-cloudimg-arm64.img,id=0 -device >>>> virtio-blk-device,drive=hd0 -pflash /root/flash0.img -pflash >>>> /root/flash1.img >>>> >>>> >>>> As soon as the guest kernel boots the host starts to stall and prints >>>> the below messages. And the system never recovers. I can neither >>>> poweroff the guest nor the host. So I have resort to external power >>>> reset of the host. >>>> >>>> ================== >>>> [ 116.199077] NMI watchdog: BUG: soft lockup - CPU#25 stuck for 23s! >>>> [kworker/25:1:454] >>>> [ 116.206901] Modules linked in: binfmt_misc nls_iso8859_1 aes_ce_blk >>>> shpchp crypto_simd gpio_keys cryptd aes_ce_cipher ghash_ce sha2_ce >>>> sha1_ce uio_pdrv_genirq uio autofs4 btrfs raid10 rai >>>> d456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor >>>> raid6_pq libcrc32c raid1 raid0 multipath linear ast i2c_algo_bit ttm >>>> drm_kms_helper syscopyarea sysfillrect sysimgblt fb_s >>>> ys_fops drm nicvf ahci nicpf libahci thunder_bgx thunder_xcv >>>> mdio_thunder mdio_cavium >>>> >>>> [ 116.206995] CPU: 25 PID: 454 Comm: kworker/25:1 Not tainted >>>> 4.11.0-rc3-next-20170323 #1 >>>> [ 116.206997] Hardware name: www.cavium.com crb-1s/crb-1s, BIOS 0.3 Feb 23 2017 >>>> [ 116.207010] Workqueue: events netstamp_clear >>>> [ 116.207015] task: ffff801f906b5400 task.stack: ffff801f901a4000 >>>> [ 116.207020] PC is at smp_call_function_many+0x284/0x2e8 >>>> [ 116.207023] LR is at smp_call_function_many+0x244/0x2e8 >>>> [ 116.207026] pc : [] lr : [] >>>> pstate: 80000145 >>>> [ 116.207028] sp : ffff801f901a7be0 >>>> [ 116.207030] x29: ffff801f901a7be0 x28: ffff000009139000 >>>> [ 116.207036] x27: ffff000009139434 x26: 0000000000000080 >>>> [ 116.207041] x25: 0000000000000000 x24: ffff0000081565d0 >>>> [ 116.207047] x23: 0000000000000001 x22: ffff000008e11e00 >>>> [ 116.207052] x21: ffff801f6d5cff00 x20: ffff801f6d5cff08 >>>> [ 116.207057] x19: ffff000009138e38 x18: 0000000000000a03 >>>> [ 116.207063] x17: 0000ffffb77c9028 x16: ffff0000082e81d8 >>>> [ 116.207068] x15: 00003d0d6dd44d08 x14: 0036312196549b4a >>>> [ 116.207073] x13: 0000000058dabe4c x12: 0000000000000018 >>>> [ 116.207079] x11: 00000000366e2f04 x10: 00000000000009f0 >>>> [ 116.207084] x9 : ffff801f901a7d30 x8 : 0000000000000002 >>>> [ 116.207089] x7 : 0000000000000000 x6 : 0000000000000000 >>>> [ 116.207095] x5 : ffffffff00000000 x4 : 0000000000000020 >>>> [ 116.207100] x3 : 0000000000000020 x2 : 0000000000000000 >>>> [ 116.207105] x1 : ffff801f6d682578 x0 : 0000000000000003 >>>> >>>> [ 150.443116] INFO: rcu_sched self-detected stall on CPU >>>> [ 150.448261] 25-...: (14997 ticks this GP) >>>> idle=47a/140000000000001/0 softirq=349/349 fqs=7495 >>>> [ 150.451115] INFO: rcu_sched detected stalls on CPUs/tasks: >>>> [ 150.451123] 25-...: (14997 ticks this GP) >>>> idle=47a/140000000000001/0 softirq=349/349 fqs=7495 >>>> [ 150.451124] (detected by 13, t=15002 jiffies, g=805, c=804, q=8384) >>>> [ 150.451136] Task dump for CPU 25: >>>> [ 150.451138] kworker/25:1 R running task 0 454 2 0x00000002 >>>> [ 150.451155] Workqueue: events netstamp_clear >>>> [ 150.451158] Call trace: >>>> [ 150.451164] [] __switch_to+0x90/0xa8 >>>> [ 150.451172] [] static_key_slow_inc+0x128/0x138 >>>> [ 150.451175] [] static_key_enable+0x34/0x60 >>>> [ 150.451178] [] netstamp_clear+0x68/0x80 >>>> [ 150.451181] [] process_one_work+0x158/0x478 >>>> [ 150.451183] [] worker_thread+0x50/0x4a8 >>>> [ 150.451187] [] kthread+0x108/0x138 >>>> [ 150.451190] [] ret_from_fork+0x10/0x50 >>>> [ 150.477451] (t=15008 jiffies g=805 c=804 q=8384) >>>> [ 150.482242] Task dump for CPU 25: >>>> [ 150.482245] kworker/25:1 R running task 0 454 2 0x00000002 >>>> [ 150.482259] Workqueue: events netstamp_clear >>>> [ 150.482264] Call trace: >>>> [ 150.482271] [] dump_backtrace+0x0/0x2b0 >>>> [ 150.482277] [] show_stack+0x24/0x30 >>>> [ 150.482281] [] sched_show_task+0x128/0x178 >>>> [ 150.482285] [] dump_cpu_task+0x48/0x58 >>>> [ 150.482288] [] rcu_dump_cpu_stacks+0xa0/0xe8 >>>> [ 150.482297] [] rcu_check_callbacks+0x774/0x938 >>>> [ 150.482305] [] update_process_times+0x34/0x60 >>>> [ 150.482314] [] tick_sched_handle.isra.7+0x38/0x70 >>>> [ 150.482319] [] tick_sched_timer+0x4c/0x98 >>>> [ 150.482324] [] __hrtimer_run_queues+0xd8/0x2b8 >>>> [ 150.482328] [] hrtimer_interrupt+0xa8/0x228 >>>> [ 150.482334] [] arch_timer_handler_phys+0x3c/0x50 >>>> [ 150.482341] [] handle_percpu_devid_irq+0x8c/0x230 >>>> [ 150.482344] [] generic_handle_irq+0x34/0x50 >>>> [ 150.482347] [] __handle_domain_irq+0x68/0xc0 >>>> [ 150.482351] [] gic_handle_irq+0xc4/0x170 >>>> [ 150.482356] Exception stack(0xffff801f901a7ab0 to 0xffff801f901a7be0) >>>> [ 150.482360] 7aa0: >>>> 0000000000000003 ffff801f6d682578 >>>> [ 150.482364] 7ac0: 0000000000000000 0000000000000020 >>>> 0000000000000020 ffffffff00000000 >>>> [ 150.482367] 7ae0: 0000000000000000 0000000000000000 >>>> 0000000000000002 ffff801f901a7d30 >>>> [ 150.482371] 7b00: 00000000000009f0 00000000366e2f04 >>>> 0000000000000018 0000000058dabe4c >>>> [ 150.482375] 7b20: 0036312196549b4a 00003d0d6dd44d08 >>>> ffff0000082e81d8 0000ffffb77c9028 >>>> [ 150.482378] 7b40: 0000000000000a03 ffff000009138e38 >>>> ffff801f6d5cff08 ffff801f6d5cff00 >>>> [ 150.482382] 7b60: ffff000008e11e00 0000000000000001 >>>> ffff0000081565d0 0000000000000000 >>>> [ 150.482386] 7b80: 0000000000000080 ffff000009139434 >>>> ffff000009139000 ffff801f901a7be0 >>>> [ 150.482390] 7ba0: ffff000008156e8c ffff801f901a7be0 >>>> ffff000008156ecc 0000000080000145 >>>> [ 150.482394] 7bc0: ffff801f901a7be0 ffff000008156e68 >>>> ffffffffffffffff ffff000008156e8c >>>> [ 150.482397] [] el1_irq+0xb4/0x140 >>>> [ 150.482401] [] smp_call_function_many+0x284/0x2e8 >>>> [ 150.482405] [] kick_all_cpus_sync+0x30/0x38 >>>> [ 150.482409] [] aarch64_insn_patch_text+0xec/0xf8 >>>> [ 150.482415] [] arch_jump_label_transform+0x60/0x98 >>>> [ 150.482420] [] __jump_label_update+0x8c/0xa8 >>>> [ 150.482423] [] jump_label_update+0x58/0xe8 >>>> [ 150.482429] [] static_key_slow_inc+0x128/0x138 >>>> [ 150.482434] [] static_key_enable+0x34/0x60 >>>> [ 150.482438] [] netstamp_clear+0x68/0x80 >>>> [ 150.482441] [] process_one_work+0x158/0x478 >>>> [ 150.482444] [] worker_thread+0x50/0x4a8 >>>> [ 150.482448] [] kthread+0x108/0x138 >>>> [ 150.482451] [] ret_from_fork+0x10/0x50 >>>> >>>> ==================================== >>>> >>>> I am observing that this usually happens when the guest tries to >>>> bringup or use the default virtio-net interface. >>>> And I am unable to reproduce this when directly booting the guest >>>> kernel without UEFI BIOS. >>>> So anyone observed similar issue ? >>>> >>> >>> I haven't seen this myself. >>> >>> Have you tried with other versions of QEMU and the host kernel by any >>> chance using the same setup? >> >> The earlier qemu version (atleast 2.5 which is default on ubuntu >> 16.04) have different issue. The same thing happens when I use >> vhost=on but without vhost and with virtio-net didn't see the issue. >> The Armband folks have also reported the vhost issue here >> https://bugs.launchpad.net/ubuntu/+source/edk2/+bug/1673564 > > So I just ran your setup using the flash emulation on the ThunderX in > packet.net and my host is happily continuing to run hackbench. > >> >> So I am beginning to think the issue could be related to the flash >> emulation but wanted to check on ml if anyone else is seeing it. But >> if it is flash emulation how can it hose the host like this ? > > Why do you think it's related to the flash emulation? > > From what you're telling me it sounds much more like a vhost regression. > > Can you try with v4.10 of the kernel with vhost=on ? I'm unsure about this being directly related to vhost. vhost seems to be the trigger, but the issue seems that after a smp_call_function_many() call, some of the target CPUs have either stopped responding, or missed the IPI. The IPI initiator keeps on waiting forever. I'm not seeing any of this on the HW I have access to, but this could be symptomatic of a SGI delivery problem. Any chance you could try the following patchlet on the host kernel? diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index c132f29322cc..727c7dc7592a 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -617,6 +617,15 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) */ smp_wmb(); + /* Is it a broadcast? */ + if (cpumask_weight(mask) == (num_online_cpus() - 1)) { + gic_write_sgi1r(1UL << ICC_SGI1R_IRQ_ROUTING_MODE_BIT | + irq << ICC_SGI1R_SGI_ID_SHIFT); + isb(); + return; + } + + for_each_cpu(cpu, mask) { unsigned long cluster_id = cpu_logical_map(cpu) & ~0xffUL; u16 tlist; This shouldn't make any difference (other than being slightly faster in the broadcast case, and slower in every other), but I'm prepared to try anything... Thanks, M. -- Jazz is not dead. It just smells funny...