This also apparently affects at least PV guests. Upgrading a PV domU to kernel 4.9.110-1 and rebooting yields the following output via xl's console:
Loading Linux 4.9.0-6-amd64 ... Loading Linux 4.9.0-7-amd64 ... Loading initial ramdisk ... [ vmlinuz-4.9.0-7- amd6 2.69MiB 66% 1.67MiB/s ] [ 0.128044] dmi: Firmware registration failed.a 17.29MiB 100% 9.75MiB/s ] [ 1.408778] dmi-sysfs: dmi entry is absent. [ 1.427758] general protection fault: 0000 [#1] SMP [ 1.427767] Modules linked in: [ 1.427778] CPU: 0 PID: 1 Comm: init Not tainted 4.9.0-7-amd64 #1 Debian 4.9.110-1 [ 1.427789] task: ffff88000ee36040 task.stack: ffffc90040068000 [ 1.427798] RIP: e030:[<ffffffff81614d4d>] [<ffffffff81614d4d>] ret_from_fork+0x2d/0x70 [ 1.427815] RSP: e02b:ffffc9004006bf50 EFLAGS: 00010006 [ 1.427823] RAX: 00000002175f5000 RBX: ffffffff816076d0 RCX: ffffea0000310e1f [ 1.427833] RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffffc9004006bf58 [ 1.427840] RBP: 0000000000000000 R08: 0000000000000000 R09: ffff88000a9e5000 [ 1.427847] R10: 8080808080808080 R11: fefefefefefefeff R12: 0000000000000000 [ 1.427854] R13: 179f3966a73fde7b R14: 06f99905e8f3edfb R15: cf60f5f9fd8e4751 [ 1.427866] FS: 0000000000000000(0000) GS:ffff88000fc00000(0000) knlGS:0000000000000000 [ 1.427873] CS: e033 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1.427879] CR2: 00007ffd37e72eb9 CR3: 000000000a9f4000 CR4: 0000000000042660 [ 1.427889] Stack: [ 1.427893] 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 1.427906] 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 1.427921] 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 1.427943] Call Trace: [ 1.427951] Code: c7 e8 b8 fe a8 ff 48 85 db 75 2f 48 89 e7 e8 5b ed 9e ff 50 90 0f 20 d8 65 48 0b 04 25 e0 02 01 00 78 08 65 88 04 25 e7 02 01 00 <0f> 22 d8 58 66 66 90 66 66 90 e9 c1 07 00 00 4c 89 e7 eb 11 e8 [ 1.428148] RIP [<ffffffff81614d4d>] ret_from_fork+0x2d/0x70 [ 1.428160] RSP <ffffc9004006bf50> [ 1.428168] ---[ end trace cb1a96e88a7c4794 ]--- [ 1.428298] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b [ 1.428298] [ 1.428316] Kernel Offset: disabled Note that the guest bootloader being used here is pvGRUB; not sure if that is relevant but thought I would include it. Similarly, rolling the domU back to the previous kernel/selecting the previous kernel via pvGRUB allows the VM to boot normally.
