From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38652) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cu5mV-00065m-GH for qemu-devel@nongnu.org; Fri, 31 Mar 2017 19:16:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cu5mT-00034F-EO for qemu-devel@nongnu.org; Fri, 31 Mar 2017 19:16:35 -0400 Received: from mail-pg0-x243.google.com ([2607:f8b0:400e:c05::243]:35477) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cu5mT-00033s-61 for qemu-devel@nongnu.org; Fri, 31 Mar 2017 19:16:33 -0400 Received: by mail-pg0-x243.google.com with SMTP id g2so20249654pge.2 for ; Fri, 31 Mar 2017 16:16:32 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <62b3784e-4c10-cf42-f2d2-285d314b23cd@redhat.com> References: <20170328201623.GD20211@cbox> <20170329185630.GA4908@cbox> <62b3784e-4c10-cf42-f2d2-285d314b23cd@redhat.com> From: Radha Mohan Date: Fri, 31 Mar 2017 16:16:31 -0700 Message-ID: Content-Type: text/plain; charset=UTF-8 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: Laszlo Ersek Cc: Christoffer Dall , qemu-devel@nongnu.org, "kvmarm@lists.cs.columbia.edu" , Wei Huang , Drew Jones , "Michael S. Tsirkin" , Jason Wang On Thu, Mar 30, 2017 at 9:47 AM, Laszlo Ersek wrote: > On 03/29/17 20:56, 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 ? > > Does this QEMU pull req help by any chance? I will try all the suggestions above and get back. It would take few days as I have few priority things to clear off my plate. > > [Qemu-devel] [PULL 0/2] vhost, pc: fixes > http://lists.nongnu.org/archive/html/qemu-devel/2017-03/msg06103.html > > It says "Region caching is still causing issues around reset". (Region > caching was a recent, very intrusive, virtio change in QEMU that sort of > blew up everything and developers have been dealing with the fallout > ever since. <-- my personal account anyway) > > In another (separate, downstream) discussion, I explained that the > VirtioNetDxe driver in OVMF and ArmVirtQemu does a virtio reset on the > virtio network device in an ExitBootServices() callback; that is, when > the kernel's UEFI stub takes control of the system. Resetting the virtio > device is supposed to cause the host to de-configure the device and to > forget all about it. If that doesn't occur correctly, the guest kernel > can definitely end up in a crappy state (the host might still consider > memory areas belong to the virtio device that were originally allocated > by the firmware, but are now overwritten by the guest kernel). > > In addition, I found some relevant-looking, recent vhost commits in the > kernel: > > 275bf960ac69 vhost: better detection of available buffers > 0ed005ce02fa vhost_net: tx batching > 635b8c8ecdd2 tap: Renaming tap related APIs, data structures, macros > 9a393b5d5988 tap: tap as an independent module > e3b56cdd4351 vhost: try avoiding avail index access when getting > descriptor > f88949138058 vhost: introduce O(1) vq metadata cache > > I think the symptoms could be a strange interplay between recent QEMU > and kernel changes that are tickled by the firmware's virtio-net driver > the wrong way. > > Thanks > Laszlo > >> >> Thanks, >> -Christoffer >> _______________________________________________ >> kvmarm mailing list >> kvmarm@lists.cs.columbia.edu >> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm >> > From mboxrd@z Thu Jan 1 00:00:00 1970 From: Radha Mohan Subject: Re: host stalls when qemu-system-aarch64 with kvm and pflash Date: Fri, 31 Mar 2017 16:16:31 -0700 Message-ID: References: <20170328201623.GD20211@cbox> <20170329185630.GA4908@cbox> <62b3784e-4c10-cf42-f2d2-285d314b23cd@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 3E55F40948 for ; Fri, 31 Mar 2017 19:14:29 -0400 (EDT) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id fmK29sukKkZc for ; Fri, 31 Mar 2017 19:14:27 -0400 (EDT) Received: from mail-pg0-f67.google.com (mail-pg0-f67.google.com [74.125.83.67]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 8CD3C40190 for ; Fri, 31 Mar 2017 19:14:27 -0400 (EDT) Received: by mail-pg0-f67.google.com with SMTP id 79so20358545pgf.0 for ; Fri, 31 Mar 2017 16:16:33 -0700 (PDT) In-Reply-To: <62b3784e-4c10-cf42-f2d2-285d314b23cd@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: Laszlo Ersek Cc: Christoffer Dall , "Michael S. Tsirkin" , Jason Wang , qemu-devel@nongnu.org, "kvmarm@lists.cs.columbia.edu" List-Id: kvmarm@lists.cs.columbia.edu On Thu, Mar 30, 2017 at 9:47 AM, Laszlo Ersek wrote: > On 03/29/17 20:56, 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 ? > > Does this QEMU pull req help by any chance? I will try all the suggestions above and get back. It would take few days as I have few priority things to clear off my plate. > > [Qemu-devel] [PULL 0/2] vhost, pc: fixes > http://lists.nongnu.org/archive/html/qemu-devel/2017-03/msg06103.html > > It says "Region caching is still causing issues around reset". (Region > caching was a recent, very intrusive, virtio change in QEMU that sort of > blew up everything and developers have been dealing with the fallout > ever since. <-- my personal account anyway) > > In another (separate, downstream) discussion, I explained that the > VirtioNetDxe driver in OVMF and ArmVirtQemu does a virtio reset on the > virtio network device in an ExitBootServices() callback; that is, when > the kernel's UEFI stub takes control of the system. Resetting the virtio > device is supposed to cause the host to de-configure the device and to > forget all about it. If that doesn't occur correctly, the guest kernel > can definitely end up in a crappy state (the host might still consider > memory areas belong to the virtio device that were originally allocated > by the firmware, but are now overwritten by the guest kernel). > > In addition, I found some relevant-looking, recent vhost commits in the > kernel: > > 275bf960ac69 vhost: better detection of available buffers > 0ed005ce02fa vhost_net: tx batching > 635b8c8ecdd2 tap: Renaming tap related APIs, data structures, macros > 9a393b5d5988 tap: tap as an independent module > e3b56cdd4351 vhost: try avoiding avail index access when getting > descriptor > f88949138058 vhost: introduce O(1) vq metadata cache > > I think the symptoms could be a strange interplay between recent QEMU > and kernel changes that are tickled by the firmware's virtio-net driver > the wrong way. > > Thanks > Laszlo > >> >> Thanks, >> -Christoffer >> _______________________________________________ >> kvmarm mailing list >> kvmarm@lists.cs.columbia.edu >> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm >> >