Hide Forgot
Description of problem: I have reported previously a potential link with bug 1377059 and the issue I am experiencing, but my backtraces are varied and the submitter of the previously-referenced bug seems to no longer be experiencing issues. My system, however, continues to fail regularly if guest domains making use of VT-d/IOMMU PCI passthrough are used. Below is the backtrace from the last instance of this issue (I have several more, if they are needed, and I can generate more on demand quite easily) experienced while running kernel 4.7.8-100. I had hoped that the latest kernel 4.7.10 release may include a fix for my problem, but it appears that it does not, as I recently suffered another crash (which abrt unfortunately did not capture). I am more than happy to work with whomever may address this matter with me. Thanks for all your time, coders! Additional info: reporter: libreport-2.6.4 BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffffc07266e4>] rmap_get_first+0x24/0x60 [kvm] PGD 0 Oops: 0000 [#1] SMP Modules linked in: vhost_net vhost macvtap macvlan vfio_pci vfio_iommu_type1 vfio_virqfd vfio xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 tun ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_security ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_raw ip6table_mangle iptable_security iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_raw iptable_mangle ebtable_filter ebtables ip6table_filter ip6_tables vfat fat intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel intel_cstate intel_uncore intel_rapl_perf snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device joydev snd_pcm lpc_ich snd_timer i2c_i801 snd mei_me nuvoton_cir rc_core mei soundcore ie31200_edac edac_core shpchp tpm_tis tpm nfsd auth_rpcgss nfs_acl lockd grace sunrpc xfs raid1 dm_raid raid456 async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq libcrc32c i915 mxm_wmi i2c_algo_bit drm_kms_helper crc32c_intel tg3 uas drm serio_raw usb_storage ptp pps_core r8169 mii fjes video wmi CPU: 5 PID: 2480 Comm: qemu-system-x86 Not tainted 4.7.8-100.fc23.x86_64 #1 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./Z77 Extreme4, BIOS P2.90 07/11/2013 task: ffff880623fa8000 ti: ffff880623d44000 task.ti: ffff880623d44000 RIP: 0010:[<ffffffffc07266e4>] [<ffffffffc07266e4>] rmap_get_first+0x24/0x60 [kvm] RSP: 0018:ffff880623d47a40 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000012 RDX: ffff88080ae03d58 RSI: ffff880623d47a58 RDI: ffff88080ae03d58 RBP: ffff880623d47a48 R08: ffffc9000de222e0 R09: 00000000000f4000 R10: ffffea00202a12c0 R11: 0000000000000001 R12: ffff88080ae03d58 R13: ffff8807efe5c000 R14: ffff880623d48000 R15: 0000000000000001 FS: 00007f9f5f77e700(0000) GS:ffff88082f340000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000007f83ef000 CR4: 00000000001426e0 Stack: 0000000000000000 ffff880623d47a88 ffffffffc0729237 0000000000000000 ffffffff00000000 00000000c35249f3 0000000000000000 ffff8807efe5c000 ffffffffc07291f0 ffff880623d47b10 ffffffffc0726153 01ff880623d47ae8 Call Trace: [<ffffffffc0729237>] kvm_zap_rmapp+0x47/0x70 [kvm] [<ffffffffc07291f0>] ? drop_spte+0xa0/0xa0 [kvm] [<ffffffffc0726153>] slot_handle_level_range+0x83/0xf0 [kvm] [<ffffffffc0730c45>] kvm_zap_gfn_range+0xb5/0xf0 [kvm] [<ffffffffc0745414>] kvm_mtrr_set_msr+0x1b4/0x2a0 [kvm] [<ffffffffc0714864>] ? kernel_pio+0x34/0x40 [kvm] [<ffffffffc0718e8a>] kvm_set_msr_common+0x84a/0xbf0 [kvm] [<ffffffffc07339b4>] ? em_in+0x144/0x250 [kvm] [<ffffffffc090abc1>] vmx_set_msr+0xb1/0x470 [kvm_intel] [<ffffffffc070d761>] kvm_set_msr+0x41/0x70 [kvm] [<ffffffffc0901018>] handle_wrmsr+0x58/0x160 [kvm_intel] [<ffffffffc0906fc8>] vmx_handle_exit+0x1d8/0x1470 [kvm_intel] [<ffffffffc090a64f>] ? atomic_switch_perf_msrs+0x6f/0xa0 [kvm_intel] [<ffffffffc090a948>] ? vmx_vcpu_run+0x2c8/0x490 [kvm_intel] [<ffffffffc0721caf>] kvm_arch_vcpu_ioctl_run+0x68f/0x1610 [kvm] [<ffffffffc071bae9>] ? kvm_arch_vcpu_load+0x59/0x210 [kvm] [<ffffffffc07076ed>] kvm_vcpu_ioctl+0x33d/0x620 [kvm] [<ffffffffc084f214>] ? vfio_device_fops_write+0x24/0x30 [vfio] [<ffffffffb1257fa1>] do_vfs_ioctl+0xa1/0x5b0 [<ffffffffb1258529>] SyS_ioctl+0x79/0x90 [<ffffffffb17e4f72>] entry_SYSCALL_64_fastpath+0x1a/0xa4 Code: c3 66 0f 1f 44 00 00 0f 1f 44 00 00 48 8b 07 48 85 c0 74 47 55 a8 01 48 89 e5 53 74 1c 48 83 e0 fe c7 46 08 00 00 00 00 48 89 06 <48> 8b 18 48 8b 3b 40 f6 c7 01 75 15 0f 0b 48 c7 06 00 00 00 00 RIP [<ffffffffc07266e4>] rmap_get_first+0x24/0x60 [kvm] RSP <ffff880623d47a40> CR2: 0000000000000000
Created attachment 1217121 [details] File: dmesg
To reproduce: 1) Install Fedora Server 23 on an Intel platform which supports VT-d, with all available updates. 2) Configure system for VT-d/IOMMU. 3) Install guest domain of any OS (Both Fedora 24 and Windows 10 have been tested and found to elicit the error) and configure with PCI-passthrough devices from the host. 3a) I pass through a USB hub, NVidia GeForce GTX 960, and an onboard audio controller). To the USB hub is connected a mouse and a keyboard, and sometimes Logitech game controllers (F310s), but this particular bug report demonstrates an occurrence with only mouse/keyboard attached. 4) Start and shut down the guest domain. 4a) I can usually do this only once or twice before the issue appears. I have never been able to do it three times without a crash.
This message is a reminder that Fedora 23 is nearing its end of life. Approximately 4 (four) weeks from now Fedora will stop maintaining and issuing updates for Fedora 23. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as EOL if it remains open with a Fedora 'version' of '23'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version. Thank you for reporting this issue and we are sorry that we were not able to fix it before Fedora 23 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged change the 'version' to a later Fedora version prior this bug is closed as described in the policy above. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete.
Well, it appears that the last Kernel version to be released for Fedora 23 will be 4.7 variety. The latest 4.7.10 kernel still exhibits the bug described above, and Fedora 23 is reaching EOL soon (as noted in the comment above) so it looks like the bug will be permanent with Fedora 23. That said, upgrading to Fedora 24 and Kernel 4.8 does appear to resolve the issue. So, good news! Upgrade away.
(In reply to Dylan Combs from comment #4) > Well, it appears that the last Kernel version to be released for Fedora 23 > will be 4.7 variety. Fedora 23 has 4.8.8-100.fc23 as the latest stable update. Either way, glad it's working for you.
Ah, thanks for the correction; I'll just change it to fixed in the current release.