From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Theurer Subject: Re: kernel bug in kvm_intel Date: Thu, 26 Nov 2009 07:47:20 -0600 Message-ID: <4B0E86E8.7000705@linux.vnet.ibm.com> References: <4ACF9745.3050902@linux.vnet.ibm.com> <4AD16ACE.6040903@redhat.com> <1255372957.4883.49.camel@twinturbo.austin.ibm.com> <4AD4231F.6040608@redhat.com> <1255442640.4883.56.camel@twinturbo.austin.ibm.com> <4AD6061D.5070306@redhat.com> <1255637909.4883.129.camel@twinturbo.austin.ibm.com> <1256926052.4883.203.camel@twinturbo.austin.ibm.com> <4AEC5C24.9080506@redhat.com> <4AEC64FC.7070908@linux.vnet.ibm.com> <4AEC6699.6000202@redhat.com> <4AEC6821.7010801@redhat.com> <4AED5C3F.9050506@kernel.org> <4AED6100.6040804@redhat.com> <4AED66D0.20704@kernel.org> <4AED7178.2060906@redhat.com> <4B03BDCC.4080502@kernel.org> <4B0DDB5D.9030202@linux.vnet.ibm.com> <4B0E5901.5050203@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Tejun Heo , kvm@vger.kernel.org, Linux-kernel@vger.kernel.org To: Avi Kivity Return-path: In-Reply-To: <4B0E5901.5050203@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Avi Kivity wrote: > 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:[] [] >>> 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]> <> Pid: 5687, comm: qemu-system-x86 Not tainted >>> 2.6.32-rc7-5e8cb552cb8b48244b6d07bff984b3c4080d4bc9-autokern1 #1 >>> Call Trace: >>> [] ? show_regs+0x44/0x49 >>> [] nmi_watchdog_tick+0xc2/0x1b9 >>> [] do_nmi+0xb0/0x252 >>> [] nmi+0x20/0x30 >>> [] ? fire_user_return_notifiers+0x31/0x36 >>> <> [] do_notify_resume+0x62/0x69 >>> [] ? int_check_syscall_exit_work+0x9/0x3d >>> [] int_signal+0x12/0x17 >> > > That's a bug with the new user return notifiers. Is your host kernel > preemptible? preempt is off. > > 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. > -Andrew