Re: kernel bug in kvm_intel

[Avi Kivity]

On 11/26/2009 03:35 AM, Andrew Theurer wrote:
> > NMI backtrace for cpu 9
> > CPU 9:
> > Modules linked in: tun sunrpc af_packet bridge stp ipv6 binfmt_misc 
> > dm_mirror dm_region_hash dm_log dm_multipath scsi_dh dm_mod kvm_intel 
> > kvm uinput sr_mod cdrom ata_generic pata_acpi ata_piix joydev libata 
> > ide_pci_generic usbhid ide_core hid serio_raw cdc_ether usbnet mii 
> > matroxfb_base matroxfb_DAC1064 matroxfb_accel matroxfb_Ti3026 
> > matroxfb_g450 g450_pll matroxfb_misc iTCO_wdt i2c_i801 i2c_core 
> > pcspkr iTCO_vendor_support ioatdma thermal rtc_cmos rtc_core bnx2 
> > rtc_lib dca thermal_sys hwmon sg button shpchp pci_hotplug qla2xxx 
> > scsi_transport_fc scsi_tgt sd_mod scsi_mod crc_t10dif ext3 jbd 
> > mbcache uhci_hcd ohci_hcd ehci_hcd usbcore [last unloaded: processor]
> > Pid: 5687, comm: qemu-system-x86 Not tainted 
> > 2.6.32-rc7-5e8cb552cb8b48244b6d07bff984b3c4080d4bc9-autokern1 #1  
> > -[7947AC1]-
> > RIP: 0010:[<ffffffff810b802b>]  [<ffffffff810b802b>] 
> > fire_user_return_notifiers+0x31/0x36
> > RSP: 0018:ffff88095024df08  EFLAGS: 00000246
> > RAX: 0000000000000000 RBX: 0000000000000800 RCX: ffff88095024c000
> > RDX: ffff880028340000 RSI: 0000000000000000 RDI: ffff88095024df58
> > RBP: ffff88095024df18 R08: 0000000000000000 R09: 0000000000000001
> > R10: 000000caf1fff62d R11: ffff8805b584de40 R12: 00007fffae48e0f0
> > R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
> > FS:  00007f45c69d57c0(0000) GS:ffff880028340000(0000) 
> > knlGS:0000000000000000
> > CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> > CR2: fffff9800121056e CR3: 0000000953d36000 CR4: 00000000000026e0
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> > Call Trace:
> > <#DB[1]> <<EOE>> Pid: 5687, comm: qemu-system-x86 Not tainted 
> > 2.6.32-rc7-5e8cb552cb8b48244b6d07bff984b3c4080d4bc9-autokern1 #1
> > Call Trace:
> > <NMI>  [<ffffffff8100af53>] ? show_regs+0x44/0x49
> >  [<ffffffff812e57b2>] nmi_watchdog_tick+0xc2/0x1b9
> >  [<ffffffff812e4e73>] do_nmi+0xb0/0x252
> >  [<ffffffff812e48a0>] nmi+0x20/0x30
> >  [<ffffffff810b802b>] ? fire_user_return_notifiers+0x31/0x36
> > <<EOE>>  [<ffffffff8100b844>] do_notify_resume+0x62/0x69
> >  [<ffffffff8100bf48>] ? int_check_syscall_exit_work+0x9/0x3d
> >  [<ffffffff8100bf8e>] int_signal+0x12/0x17

That's a bug with the new user return notifiers.  Is your host kernel 
preemptible?

I think I saw this once but I'm not sure.  I can't reproduce with a host 
kernel build, some silly guest workload, and 'perf top' to generate an 
nmi load.

--
error compiling committee.c: too many arguments to function

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