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Re: [Qemu-devel] [Bug 1750229] Re: virtio-blk-pci regression: softlock i
From: |
Matwey V. Kornilov |
Subject: |
Re: [Qemu-devel] [Bug 1750229] Re: virtio-blk-pci regression: softlock in guest kernel at module loading |
Date: |
Thu, 22 Feb 2018 11:17:59 -0000 |
The same story with 4.15.4 host kernel.
2018-02-21 11:58 GMT+03:00 Matwey V. Kornilov <address@hidden>:
> Well, last_avail_idx equals to shadow_avail_idx and both of them are 1
> at the qemu side. So, only one request is transferred.
> I wonder why, probably something is badly cached, but new avail_idx
> (which is supposed to become 2) is never shown up.
>
> 2018-02-20 15:49 GMT+03:00 Matwey V. Kornilov <address@hidden>:
>> virtqueue_pop() returns NULL due to virtio_queue_empty_rcu() returns
>> true all the time.
>>
>> 2018-02-20 14:47 GMT+03:00 Matwey V. Kornilov <address@hidden>:
>>> Well, I've found that on qemu side VirtQueue for virtio_blk device
>>> infinitely calls virtio_blk_handle_vq() where virtio_blk_get_request()
>>> (virtqueue_pop() in essens) always returns NULL.
>>>
>>> 2018-02-18 15:26 GMT+03:00 Matwey V. Kornilov <address@hidden>:
>>>> ** Attachment added: ".build.kernel.kvm"
>>>>
>>>> https://bugs.launchpad.net/qemu/+bug/1750229/+attachment/5057653/+files/.build.kernel.kvm
>>>>
>>>> --
>>>> You received this bug notification because you are subscribed to the bug
>>>> report.
>>>> https://bugs.launchpad.net/bugs/1750229
>>>>
>>>> Title:
>>>> virtio-blk-pci regression: softlock in guest kernel at module loading
>>>>
>>>> Status in QEMU:
>>>> New
>>>>
>>>> Bug description:
>>>> Hello,
>>>>
>>>> I am running qemu from master git branch on x86_64 host with kernel is
>>>> 4.4.114. I've found that commit
>>>>
>>>> 9a4c0e220d8a "hw/virtio-pci: fix virtio behaviour"
>>>>
>>>> introduces an regression with the following command:
>>>>
>>>> qemu-system-x86_64 -enable-kvm -nodefaults -no-reboot -nographic
>>>> -vga none -runas qemu -kernel .build.kernel.kvm -initrd
>>>> .build.initrd.kvm -append 'panic=1 softlockup_panic=1 no-kvmclock
>>>> nmi_watchdog=0 console=ttyS0 root=/dev/disk/by-id/virtio-0' -m 2048
>>>> -drive file=./root,format=raw,if=none,id=disk,serial=0,cache=unsafe
>>>> -device virtio-blk-pci,drive=disk -serial stdio -smp 2
>>>>
>>>> Starting from this commit to master the following happens with a wide
>>>> variety of guest kernels (4.4 to 4.15):
>>>>
>>>> [ 62.428107] BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0
>>>> nice=-20 stuck for 59s!
>>>> [ 62.437426] Showing busy workqueues and worker pools:
>>>> [ 62.443117] workqueue events: flags=0x0
>>>> [ 62.447512] pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256
>>>> [ 62.448161] pending: check_corruption
>>>> [ 62.458570] workqueue kblockd: flags=0x18
>>>> [ 62.463082] pwq 1: cpus=0 node=0 flags=0x0 nice=-20 active=3/256
>>>> [ 62.463082] in-flight: 4:blk_mq_run_work_fn
>>>> [ 62.463082] pending: blk_mq_run_work_fn, blk_mq_timeout_work
>>>> [ 62.474831] pool 1: cpus=0 node=0 flags=0x0 nice=-20 hung=59s
>>>> workers=2 idle: 214
>>>> [ 62.492121] INFO: rcu_preempt detected stalls on CPUs/tasks:
>>>> [ 62.492121] Tasks blocked on level-0 rcu_node (CPUs 0-1): P4
>>>> [ 62.492121] (detected by 0, t=15002 jiffies, g=-130, c=-131, q=32)
>>>> [ 62.492121] kworker/0:0H R running task 0 4 2
>>>> 0x80000000
>>>> [ 62.492121] Workqueue: kblockd blk_mq_run_work_fn
>>>> [ 62.492121] Call Trace:
>>>> [ 62.492121] <IRQ>
>>>> [ 62.492121] sched_show_task+0xdf/0x100
>>>> [ 62.492121] rcu_print_detail_task_stall_rnp+0x48/0x69
>>>> [ 62.492121] rcu_check_callbacks+0x93d/0x9d0
>>>> [ 62.492121] ? tick_sched_do_timer+0x40/0x40
>>>> [ 62.492121] update_process_times+0x28/0x50
>>>> [ 62.492121] tick_sched_handle+0x22/0x70
>>>> [ 62.492121] tick_sched_timer+0x34/0x70
>>>> [ 62.492121] __hrtimer_run_queues+0xcc/0x250
>>>> [ 62.492121] hrtimer_interrupt+0xab/0x1f0
>>>> [ 62.492121] smp_apic_timer_interrupt+0x62/0x150
>>>> [ 62.492121] apic_timer_interrupt+0xa2/0xb0
>>>> [ 62.492121] </IRQ>
>>>> [ 62.492121] RIP: 0010:iowrite16+0x1d/0x30
>>>> [ 62.492121] RSP: 0018:ffffa477c034fcc8 EFLAGS: 00010292 ORIG_RAX:
>>>> ffffffffffffff11
>>>> [ 62.492121] RAX: ffffffffa24fbdb0 RBX: ffff92a1f8f82000 RCX:
>>>> 0000000000000001
>>>> [ 62.492121] RDX: ffffa477c0371000 RSI: ffffa477c0371000 RDI:
>>>> 0000000000000000
>>>> [ 62.492121] RBP: 0000000000000001 R08: 0000000000000000 R09:
>>>> 0000000001080020
>>>> [ 62.492121] R10: ffffdc7cc1e4fc00 R11: 0000000000000000 R12:
>>>> 0000000000000000
>>>> [ 62.492121] R13: 0000000000000000 R14: ffff92a1f93f0000 R15:
>>>> ffff92a1f8e1aa80
>>>> [ 62.492121] ? vp_synchronize_vectors+0x60/0x60
>>>> [ 62.492121] vp_notify+0x12/0x20
>>>> [ 62.492121] virtqueue_notify+0x18/0x30
>>>> [ 62.492121] virtio_queue_rq+0x2f5/0x300 [virtio_blk]
>>>> [ 62.492121] blk_mq_dispatch_rq_list+0x7e/0x4a0
>>>> [ 62.492121] blk_mq_do_dispatch_sched+0x4a/0xd0
>>>> [ 62.492121] blk_mq_sched_dispatch_requests+0x106/0x170
>>>> [ 62.492121] __blk_mq_run_hw_queue+0x80/0x90
>>>> [ 62.492121] process_one_work+0x1e3/0x420
>>>> [ 62.492121] worker_thread+0x2b/0x3d0
>>>> [ 62.492121] ? process_one_work+0x420/0x420
>>>> [ 62.492121] kthread+0x113/0x130
>>>> [ 62.492121] ? kthread_create_worker_on_cpu+0x50/0x50
>>>> [ 62.492121] ret_from_fork+0x3a/0x50
>>>> [ 62.492121] kworker/0:0H R running task 0 4 2
>>>> 0x80000000
>>>> [ 62.492121] Workqueue: kblockd blk_mq_run_work_fn
>>>> [ 62.492121] Call Trace:
>>>> [ 62.492121] <IRQ>
>>>> [ 62.492121] sched_show_task+0xdf/0x100
>>>> [ 62.492121] rcu_print_detail_task_stall_rnp+0x48/0x69
>>>> [ 62.492121] rcu_check_callbacks+0x972/0x9d0
>>>> [ 62.492121] ? tick_sched_do_timer+0x40/0x40
>>>> [ 62.492121] update_process_times+0x28/0x50
>>>> [ 62.492121] tick_sched_handle+0x22/0x70
>>>> [ 62.492121] tick_sched_timer+0x34/0x70
>>>> [ 62.492121] __hrtimer_run_queues+0xcc/0x250
>>>> [ 62.492121] hrtimer_interrupt+0xab/0x1f0
>>>> [ 62.492121] smp_apic_timer_interrupt+0x62/0x150
>>>> [ 62.492121] apic_timer_interrupt+0xa2/0xb0
>>>> [ 62.492121] </IRQ>
>>>> [ 62.492121] RIP: 0010:iowrite16+0x1d/0x30
>>>> [ 62.492121] RSP: 0018:ffffa477c034fcc8 EFLAGS: 00010292 ORIG_RAX:
>>>> ffffffffffffff11
>>>> [ 62.492121] RAX: ffffffffa24fbdb0 RBX: ffff92a1f8f82000 RCX:
>>>> 0000000000000001
>>>> [ 62.492121] RDX: ffffa477c0371000 RSI: ffffa477c0371000 RDI:
>>>> 0000000000000000
>>>> [ 62.492121] RBP: 0000000000000001 R08: 0000000000000000 R09:
>>>> 0000000001080020
>>>> [ 62.492121] R10: ffffdc7cc1e4fc00 R11: 0000000000000000 R12:
>>>> 0000000000000000
>>>> [ 62.492121] R13: 0000000000000000 R14: ffff92a1f93f0000 R15:
>>>> ffff92a1f8e1aa80
>>>> [ 62.492121] ? vp_synchronize_vectors+0x60/0x60
>>>> [ 62.492121] vp_notify+0x12/0x20
>>>> [ 62.492121] virtqueue_notify+0x18/0x30
>>>> [ 62.492121] virtio_queue_rq+0x2f5/0x300 [virtio_blk]
>>>> [ 62.492121] blk_mq_dispatch_rq_list+0x7e/0x4a0
>>>> [ 62.492121] blk_mq_do_dispatch_sched+0x4a/0xd0
>>>> [ 62.492121] blk_mq_sched_dispatch_requests+0x106/0x170
>>>> [ 62.492121] __blk_mq_run_hw_queue+0x80/0x90
>>>> [ 62.492121] process_one_work+0x1e3/0x420
>>>> [ 62.492121] worker_thread+0x2b/0x3d0
>>>> [ 62.492121] ? process_one_work+0x420/0x420
>>>> [ 62.492121] kthread+0x113/0x130
>>>> [ 62.492121] ? kthread_create_worker_on_cpu+0x50/0x50
>>>> [ 62.492121] ret_from_fork+0x3a/0x50
>>>>
>>>> Another important thing is that the commit works well on other
>>>> hardware with the same setup (same host kernel, same qemu command line
>>>> and host kernel binaries). How could I try to find the issue reason?
>>>>
>>>> To manage notifications about this bug go to:
>>>> https://bugs.launchpad.net/qemu/+bug/1750229/+subscriptions
>>>
>>>
>>>
>>> --
>>> With best regards,
>>> Matwey V. Kornilov
>>
>>
>>
>> --
>> With best regards,
>> Matwey V. Kornilov
>
>
>
> --
> With best regards,
> Matwey V. Kornilov
--
With best regards,
Matwey V. Kornilov
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1750229
Title:
virtio-blk-pci regression: softlock in guest kernel at module loading
Status in QEMU:
New
Bug description:
Hello,
I am running qemu from master git branch on x86_64 host with kernel is
4.4.114. I've found that commit
9a4c0e220d8a "hw/virtio-pci: fix virtio behaviour"
introduces an regression with the following command:
qemu-system-x86_64 -enable-kvm -nodefaults -no-reboot -nographic
-vga none -runas qemu -kernel .build.kernel.kvm -initrd
.build.initrd.kvm -append 'panic=1 softlockup_panic=1 no-kvmclock
nmi_watchdog=0 console=ttyS0 root=/dev/disk/by-id/virtio-0' -m 2048
-drive file=./root,format=raw,if=none,id=disk,serial=0,cache=unsafe
-device virtio-blk-pci,drive=disk -serial stdio -smp 2
Starting from this commit to master the following happens with a wide
variety of guest kernels (4.4 to 4.15):
[ 62.428107] BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=-20
stuck for 59s!
[ 62.437426] Showing busy workqueues and worker pools:
[ 62.443117] workqueue events: flags=0x0
[ 62.447512] pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256
[ 62.448161] pending: check_corruption
[ 62.458570] workqueue kblockd: flags=0x18
[ 62.463082] pwq 1: cpus=0 node=0 flags=0x0 nice=-20 active=3/256
[ 62.463082] in-flight: 4:blk_mq_run_work_fn
[ 62.463082] pending: blk_mq_run_work_fn, blk_mq_timeout_work
[ 62.474831] pool 1: cpus=0 node=0 flags=0x0 nice=-20 hung=59s workers=2
idle: 214
[ 62.492121] INFO: rcu_preempt detected stalls on CPUs/tasks:
[ 62.492121] Tasks blocked on level-0 rcu_node (CPUs 0-1): P4
[ 62.492121] (detected by 0, t=15002 jiffies, g=-130, c=-131, q=32)
[ 62.492121] kworker/0:0H R running task 0 4 2
0x80000000
[ 62.492121] Workqueue: kblockd blk_mq_run_work_fn
[ 62.492121] Call Trace:
[ 62.492121] <IRQ>
[ 62.492121] sched_show_task+0xdf/0x100
[ 62.492121] rcu_print_detail_task_stall_rnp+0x48/0x69
[ 62.492121] rcu_check_callbacks+0x93d/0x9d0
[ 62.492121] ? tick_sched_do_timer+0x40/0x40
[ 62.492121] update_process_times+0x28/0x50
[ 62.492121] tick_sched_handle+0x22/0x70
[ 62.492121] tick_sched_timer+0x34/0x70
[ 62.492121] __hrtimer_run_queues+0xcc/0x250
[ 62.492121] hrtimer_interrupt+0xab/0x1f0
[ 62.492121] smp_apic_timer_interrupt+0x62/0x150
[ 62.492121] apic_timer_interrupt+0xa2/0xb0
[ 62.492121] </IRQ>
[ 62.492121] RIP: 0010:iowrite16+0x1d/0x30
[ 62.492121] RSP: 0018:ffffa477c034fcc8 EFLAGS: 00010292 ORIG_RAX:
ffffffffffffff11
[ 62.492121] RAX: ffffffffa24fbdb0 RBX: ffff92a1f8f82000 RCX:
0000000000000001
[ 62.492121] RDX: ffffa477c0371000 RSI: ffffa477c0371000 RDI:
0000000000000000
[ 62.492121] RBP: 0000000000000001 R08: 0000000000000000 R09:
0000000001080020
[ 62.492121] R10: ffffdc7cc1e4fc00 R11: 0000000000000000 R12:
0000000000000000
[ 62.492121] R13: 0000000000000000 R14: ffff92a1f93f0000 R15:
ffff92a1f8e1aa80
[ 62.492121] ? vp_synchronize_vectors+0x60/0x60
[ 62.492121] vp_notify+0x12/0x20
[ 62.492121] virtqueue_notify+0x18/0x30
[ 62.492121] virtio_queue_rq+0x2f5/0x300 [virtio_blk]
[ 62.492121] blk_mq_dispatch_rq_list+0x7e/0x4a0
[ 62.492121] blk_mq_do_dispatch_sched+0x4a/0xd0
[ 62.492121] blk_mq_sched_dispatch_requests+0x106/0x170
[ 62.492121] __blk_mq_run_hw_queue+0x80/0x90
[ 62.492121] process_one_work+0x1e3/0x420
[ 62.492121] worker_thread+0x2b/0x3d0
[ 62.492121] ? process_one_work+0x420/0x420
[ 62.492121] kthread+0x113/0x130
[ 62.492121] ? kthread_create_worker_on_cpu+0x50/0x50
[ 62.492121] ret_from_fork+0x3a/0x50
[ 62.492121] kworker/0:0H R running task 0 4 2
0x80000000
[ 62.492121] Workqueue: kblockd blk_mq_run_work_fn
[ 62.492121] Call Trace:
[ 62.492121] <IRQ>
[ 62.492121] sched_show_task+0xdf/0x100
[ 62.492121] rcu_print_detail_task_stall_rnp+0x48/0x69
[ 62.492121] rcu_check_callbacks+0x972/0x9d0
[ 62.492121] ? tick_sched_do_timer+0x40/0x40
[ 62.492121] update_process_times+0x28/0x50
[ 62.492121] tick_sched_handle+0x22/0x70
[ 62.492121] tick_sched_timer+0x34/0x70
[ 62.492121] __hrtimer_run_queues+0xcc/0x250
[ 62.492121] hrtimer_interrupt+0xab/0x1f0
[ 62.492121] smp_apic_timer_interrupt+0x62/0x150
[ 62.492121] apic_timer_interrupt+0xa2/0xb0
[ 62.492121] </IRQ>
[ 62.492121] RIP: 0010:iowrite16+0x1d/0x30
[ 62.492121] RSP: 0018:ffffa477c034fcc8 EFLAGS: 00010292 ORIG_RAX:
ffffffffffffff11
[ 62.492121] RAX: ffffffffa24fbdb0 RBX: ffff92a1f8f82000 RCX:
0000000000000001
[ 62.492121] RDX: ffffa477c0371000 RSI: ffffa477c0371000 RDI:
0000000000000000
[ 62.492121] RBP: 0000000000000001 R08: 0000000000000000 R09:
0000000001080020
[ 62.492121] R10: ffffdc7cc1e4fc00 R11: 0000000000000000 R12:
0000000000000000
[ 62.492121] R13: 0000000000000000 R14: ffff92a1f93f0000 R15:
ffff92a1f8e1aa80
[ 62.492121] ? vp_synchronize_vectors+0x60/0x60
[ 62.492121] vp_notify+0x12/0x20
[ 62.492121] virtqueue_notify+0x18/0x30
[ 62.492121] virtio_queue_rq+0x2f5/0x300 [virtio_blk]
[ 62.492121] blk_mq_dispatch_rq_list+0x7e/0x4a0
[ 62.492121] blk_mq_do_dispatch_sched+0x4a/0xd0
[ 62.492121] blk_mq_sched_dispatch_requests+0x106/0x170
[ 62.492121] __blk_mq_run_hw_queue+0x80/0x90
[ 62.492121] process_one_work+0x1e3/0x420
[ 62.492121] worker_thread+0x2b/0x3d0
[ 62.492121] ? process_one_work+0x420/0x420
[ 62.492121] kthread+0x113/0x130
[ 62.492121] ? kthread_create_worker_on_cpu+0x50/0x50
[ 62.492121] ret_from_fork+0x3a/0x50
Another important thing is that the commit works well on other
hardware with the same setup (same host kernel, same qemu command line
and host kernel binaries). How could I try to find the issue reason?
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1750229/+subscriptions