Comment 0 for bug 1773184

linux-image-4.15.0.22 (20, and probably earlier, too) panics when starting a guest VM in a nested manner.

compute1 login: [ 4847.733004] general protection fault: 0000 [#1] SMP PTI
[ 4847.736595] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel ebt_arp ebt_among ip6table_raw nf_conntrack_ipv6 nf_defrag_ipv6 xt_CT xt_mac xt_comment xt_physdev xt_set ip_set_hash_net ip_set nfnetlink vhost_net vhost tap xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp kvm_intel ip6table_filter ip6_tables iptable_filter ebtable_filter ebtable_nat ebtables iptable_raw br_netfilter bridge stp llc nls_iso8859_1 kvm irqbypass joydev input_leds serio_raw sch_fq_codel ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor
[ 4847.756237] async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear hid_generic usbhid hid crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd glue_helper cryptd psmouse virtio_blk virtio_net floppy [last unloaded: kvm_intel]
[ 4847.762893] CPU: 1 PID: 13789 Comm: CPU 0/KVM Not tainted 4.15.0-22-generic #24-Ubuntu
[ 4847.765154] Hardware name: OpenStack Foundation OpenStack Nova, BIOS 1.10.2-1ubuntu1~cloud0 04/01/2014
[ 4847.767764] RIP: 0010:native_write_cr4+0x4/0x10
[ 4847.769085] RSP: 0018:ffff9daf4119bb70 EFLAGS: 00010006
[ 4847.770629] RAX: 00000000000626e0 RBX: 0000000000000046 RCX: ffff8edcbfc80000
[ 4847.772771] RDX: ffff8edcbfc94020 RSI: ffff8edcbfca5040 RDI: 00000000000606e0
[ 4847.774965] RBP: ffff9daf4119bb70 R08: fffffffffffffff8 R09: 000000000000000d
[ 4847.777175] R10: ffffc078c76e2000 R11: 0000000000000cd0 R12: 0000000000025040
[ 4847.779213] R13: 0000000000000000 R14: ffff8edc438409a0 R15: ffff8edc43855278
[ 4847.781230] FS: 00007f9a09a02700(0000) GS:ffff8edcbfc80000(0000) knlGS:0000000000000000
[ 4847.783548] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4847.785233] CR2: 00007f99fb80cd50 CR3: 0000000152e0a002 CR4: 00000000000626e0
[ 4847.787225] Call Trace:
[ 4847.788062] hardware_disable+0xaa/0xc0 [kvm_intel]
[ 4847.789460] ? vcpu_stat_get_per_vm_open+0x20/0x20 [kvm]
[ 4847.791025] kvm_arch_hardware_disable+0x19/0x40 [kvm]
[ 4847.792664] hardware_disable_nolock+0x2b/0x30 [kvm]
[ 4847.794260] on_each_cpu+0x46/0x60
[ 4847.795302] hardware_disable_all_nolock+0x35/0x40 [kvm]
[ 4847.796896] hardware_disable_all+0x1a/0x30 [kvm]
[ 4847.798267] kvm_put_kvm+0x1f8/0x260 [kvm]
[ 4847.799470] kvm_vm_release+0x21/0x30 [kvm]
[ 4847.800758] __fput+0xea/0x220
[ 4847.801681] ____fput+0xe/0x10
[ 4847.802602] task_work_run+0x9d/0xc0
[ 4847.803692] do_exit+0x2ec/0xb40
[ 4847.804676] do_group_exit+0x43/0xb0
[ 4847.805719] get_signal+0x27b/0x590
[ 4847.806742] do_signal+0x37/0x730
[ 4847.807774] ? do_futex+0x325/0x500
[ 4847.808803] ? SyS_futex+0x13b/0x180
[ 4847.809852] ? restore_altstack+0x51/0x70
[ 4847.811017] exit_to_usermode_loop+0x73/0xd0
[ 4847.812299] do_syscall_64+0x115/0x130
[ 4847.813401] entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[ 4847.814808] RIP: 0033:0x7f9a142bc10d
[ 4847.815914] RSP: 002b:00007f9a09a01798 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
[ 4847.818100] RAX: fffffffffffffe00 RBX: 00005583a8961060 RCX: 00007f9a142bc10d
[ 4847.820065] RDX: 0000000000000002 RSI: 0000000000000080 RDI: 00005583a6925e00
[ 4847.822029] RBP: 00005583a8961084 R08: 00005583a6925e00 R09: 0000000000000000
[ 4847.824002] R10: 0000000000000000 R11: 0000000000000246 R12: 00005583a896108c
[ 4847.825949] R13: 0000000000000000 R14: 00005583a6925e00 R15: 000000000000000f
[ 4847.827922] Code: 0f 1f 80 00 00 00 00 55 48 89 e5 0f 20 d8 5d c3 0f 1f 80 00 00 00 00 55 48 89 e5 0f 22 df 5d c3 0f 1f 80 00 00 00 00 55 48 89 e5 <0f> 22 e7 5d c3 0f 1f 80 00 00 00 00 55 48 89 e5 44 0f 20 c0 5d
[ 4847.832993] RIP: native_write_cr4+0x4/0x10 RSP: ffff9daf4119bb70
[ 4847.834658] ---[ end trace d54d1c7bca906f72 ]---
[ 4847.838001] Fixing recursive fault but reboot is needed!
[ 4850.411516] general protection fault: 0000 [#2] SMP PTI
[ 4850.414947] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel ebt_arp ebt_among ip6table_raw nf_conntrack_ipv6 nf_defrag_ipv6 xt_CT xt_mac xt_comment xt_physdev xt_set ip_set_hash_net ip_set nfnetlink vhost_net vhost tap xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp kvm_intel ip6table_filter ip6_tables iptable_filter ebtable_filter ebtable_nat ebtables iptable_raw br_netfilter bridge stp llc nls_iso8859_1 kvm irqbypass joydev input_leds serio_raw sch_fq_codel ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor
[ 4850.434880] async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear hid_generic usbhid hid crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd glue_helper cryptd psmouse virtio_blk virtio_net floppy [last unloaded: kvm_intel]
[ 4850.441772] CPU: 1 PID: 14003 Comm: sudo Tainted: G D 4.15.0-22-generic #24-Ubuntu
[ 4850.444372] Hardware name: OpenStack Foundation OpenStack Nova, BIOS 1.10.2-1ubuntu1~cloud0 04/01/2014
[ 4850.446997] RIP: 0010:native_flush_tlb_global+0x88/0xa0
[ 4850.448603] RSP: 0000:ffff8edcbfc83f50 EFLAGS: 00010006
[ 4850.450192] RAX: 00000000000606e0 RBX: ffff8edcbfca8880 RCX: ffff8edcbfca8880
[ 4850.452274] RDX: 0000000000060660 RSI: 0000000000000001 RDI: 0000000000000046
[ 4850.454310] RBP: ffff8edcbfc83f80 R08: 0000000000000000 R09: 0000000000000000
[ 4850.456461] R10: ffff8edcbfc83f98 R11: 0000000000000000 R12: 0000000000000000
[ 4850.458462] R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000
[ 4850.460539] FS: 00007fe811b59c80(0000) GS:ffff8edcbfc80000(0000) knlGS:0000000000000000
[ 4850.462835] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4850.464618] CR2: 00007fe810e198a0 CR3: 00000001cd334001 CR4: 00000000000626e0
[ 4850.466610] Call Trace:
[ 4850.467401] <IRQ>
[ 4850.468183] ? __do_softirq+0x128/0x2b2
[ 4850.469357] do_flush_tlb_all+0x23/0x30
[ 4850.470510] ? do_flush_tlb_all+0x23/0x30
[ 4850.471785] flush_smp_call_function_queue+0x4c/0xf0
[ 4850.473336] generic_smp_call_function_single_interrupt+0x13/0x30
[ 4850.475067] smp_call_function_interrupt+0x36/0xd0
[ 4850.476565] call_function_interrupt+0x84/0x90
[ 4850.477865] </IRQ>
[ 4850.478573] RIP: 0033:0x7fe81195f398
[ 4850.479727] RSP: 002b:00007fff968f20a8 EFLAGS: 00000287 ORIG_RAX: ffffffffffffff03
[ 4850.481969] RAX: 000000000000000b RBX: 00007fe811b5d500 RCX: 0000000000000010
[ 4850.484034] RDX: 0000000000000000 RSI: 00007fe811b5d4d0 RDI: 00007fe81171ac8b
[ 4850.486032] RBP: 00007fe81171ac8b R08: 00007fe8114f1a18 R09: 00007fe811b6b428
[ 4850.488095] R10: 000000000000000b R11: 0000000000000000 R12: 00007fe811b5c130
[ 4850.490070] R13: 00007fe811b5c350 R14: 0000000000000000 R15: 0000000000000000
[ 4850.492110] Code: 48 83 c4 28 41 5a 5d 49 8d 62 f8 c3 9c 58 66 66 90 66 90 48 89 c7 fa 66 66 90 66 66 90 65 48 8b 05 4e 72 7b 55 48 89 c2 80 f2 80 <0f> 22 e2 0f 22 e0 57 9d 66 66 90 66 90 eb b7 e8 54 00 02 00 0f
[ 4850.497339] RIP: native_flush_tlb_global+0x88/0xa0 RSP: ffff8edcbfc83f50
[ 4850.499261] ---[ end trace d54d1c7bca906f73 ]---
[ 4850.500701] Kernel panic - not syncing: Fatal exception in interrupt
[ 4850.502615] Kernel Offset: 0x29800000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[ 4850.505816] ---[ end Kernel panic - not syncing: Fatal exception in interrupt