Re: kvm: WARNING In kvm_apic_accept_events

[Dmitry Vyukov]

On Sat, Nov 12, 2016 at 2:56 AM, Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
> Hello,
>
> The following program triggers WARNING in kvm_apic_accept_events:
> https://gist.githubusercontent.com/dvyukov/95b845a2e637485568ea1ef181a72370/raw/d90717dd67128b21715c5e794568a1600f613d97/gistfile1.txt
>
> On commit 015ed9433be2b476ec7e2e6a9a411a56e3b5b035 (Nov 11).
>
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 23523 at arch/x86/kvm/lapic.c:2330
> kvm_apic_accept_events+0x3f6/0x460
> Modules linked in:[   55.632648] CPU: 1 PID: 2812 Comm: a.out Not
> tainted 4.9.0-rc4+ #41
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>  ffff88006be77978 ffffffff81c2f79b 0000000000000000 0000000000000000
>  ffffffff8322d6a0 ffffffff81127426 ffff88006be779c0 ffffffff8123ffef
>  ffffffff811acc46 ffffffff0000091a ffffffff8322d6a0 000000000000091a
> Call Trace:
>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>  [<ffffffff81c2f79b>] dump_stack+0xb3/0x118 lib/dump_stack.c:51
>  [<ffffffff8123ffef>] __warn+0x19f/0x1e0 kernel/panic.c:550
>  [<ffffffff812401fc>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
>  [<ffffffff81127426>] kvm_apic_accept_events+0x3f6/0x460
> arch/x86/kvm/lapic.c:2330
>  [<     inline     >] vcpu_block arch/x86/kvm/x86.c:6793
>  [<     inline     >] vcpu_run arch/x86/kvm/x86.c:6828
>  [<ffffffff810b8f20>] kvm_arch_vcpu_ioctl_run+0x1580/0x5a90
> arch/x86/kvm/x86.c:6984
>  [<ffffffff8106091e>] kvm_vcpu_ioctl+0x61e/0xdd0
> arch/x86/kvm/../../../virt/kvm/kvm_main.c:2557
>  [<     inline     >] vfs_ioctl fs/ioctl.c:43
>  [<ffffffff816b16fc>] do_vfs_ioctl+0x18c/0x1040 fs/ioctl.c:679
>  [<     inline     >] SYSC_ioctl fs/ioctl.c:694
>  [<ffffffff816b263f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
>  [<ffffffff831ebd01>] entry_SYSCALL_64_fastpath+0x1f/0xc2
> arch/x86/entry/entry_64.S:209
> ---[ end trace b2415ddd1b26dce6 ]---


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