Just spotted that earlier in the boot we get:

[    8.808508] virtio_blk virtio3: [vda] 209715200 512-byte logical blocks (107 GB/100 GiB)
[    8.808649] ------------[ cut here ]------------
[    8.815777] vda: detected capacity change from 0 to 107374182400
[    8.816623] WARNING: CPU: 3 PID: 212 at mm/page_alloc.c:4813 __alloc_pages_nodemask+0x540/0x694
[    8.816630] Modules linked in: net_failover virtio_blk(+) xhci_pci_renesas virtio_scsi(+) failover fjes(-) aes_neon_bs aes_neon_blk aes_ce_blk crypto_s
imd cryptd aes_ce_cipher
[    8.837701] CPU: 3 PID: 212 Comm: systemd-udevd Not tainted 5.8.0-8-generic #9
[    8.842236] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
[    8.846585] pstate: 20400005 (nzCv daif +PAN -UAO BTYPE=--)
[    8.850112] pc : __alloc_pages_nodemask+0x540/0x694
[    8.853106] lr : alloc_pages_current+0xe0/0x17c
[    8.856024] sp : ffff8000106138c0
[    8.858175] x29: ffff8000106138c0 x28: ffff000170252dc0 
[    8.861565] x27: 0000000000000000 x26: 0000000000000015 
[    8.865006] x25: 00000001abcfef80 x24: 0000000000000015 
[    8.868466] x23: ffff000170252dc0 x22: 0000000000000000 
[    8.871794] x21: ffffdb2796703050 x20: 0000000000040dc0 
[    8.875143] x19: ffffdb2796703250 x18: 0000000000000000 
[    8.878529] x17: 0000000000000000 x16: 0000000000000000 
[    8.881917] x15: 0000000000000000 x14: 73656a662f74656e 
[    8.885218] x13: 2f73726576697264 x12: 2f636972656e6567 
[    8.888554] x11: 2d646c6975622f64 x10: 6c6975622f6e6169 
[    8.892032] x9 : ffffdb2792b6dfa4 x8 : 63672e7366677562 
[    8.895415] x7 : 65645f73656a662f x6 : ffff0001558ef353 
[    8.898814] x5 : 0000000000000018 x4 : 0000000000000dd5 
[    8.902124] x3 : ffffdb27966ea138 x2 : 0000000000000001 
[    8.905418] x1 : ffffdb27966ea030 x0 : 0000000000000001 
[    8.908698] Call trace:
[    8.910278]  __alloc_pages_nodemask+0x540/0x694
[    8.913278]  alloc_pages_current+0xe0/0x17c
[    8.915967]  kmalloc_order+0x48/0xec
[    8.918325]  kmalloc_order_trace+0x54/0x21c
[    8.921165]  __kmalloc+0x454/0x5c0
[    8.923368]  kmalloc_array.constprop.0+0x30/0x50
[    8.926301]  gcov_info_dup+0x98/0x2c0
[    8.928557]  remove_info+0x1e0/0x244
[    8.930876]  gcov_event+0xfc/0x170
[    8.933097]  gcov_module_notifier+0x164/0x174
[    8.935848]  notifier_call_chain+0xa0/0x110
[    8.938435]  blocking_notifier_call_chain+0x80/0xe0
[    8.941579]  do_init_module+0x360/0x43c
[    8.944198]  load_module+0x8fc/0xa50
[    8.946591]  __do_sys_finit_module+0x190/0x1c0
[    8.949485]  __arm64_sys_finit_module+0x48/0x64
[    8.952376]  invoke_syscall+0x74/0x150
[    8.954901]  el0_svc_common.constprop.0+0x94/0x264
[    8.956405] sr 0:0:0:0: Power-on or device reset occurred
[    8.957610]  do_el0_svc+0x5c/0x7c
[    8.960983] sr 0:0:0:0: [sr0] scsi3-mmc drive: 16x/50x cd/rw xa/form2 cdda tray
[    8.962169]  el0_svc+0x70/0x114
[    8.965694] cdrom: Uniform CD-ROM driver Revision: 3.20
[    8.967253]  el0_sync_handler+0x140/0x39c
[    8.971738]  el0_sync+0x17c/0x180
[    8.973450] ---[ end trace 267579295e47a82a ]---
[    8.976042] gcov: could not save data for '/home/cking/unstable/debian/build/build-generic/drivers/net/fjes/fjes_debugfs.gcda' (out of memory)
[    8.986263] gcov: could not save data for '/home/cking/unstable/debian/build/build-generic/drivers/net/fjes/fjes_trace.gcda' (out of memory)
[    8.996162] gcov: could not save data for '/home/cking/unstable/debian/build/build-generic/drivers/net/fjes/fjes_ethtool.gcda' (out of memory)
[    9.006231] gcov: could not save data for '/home/cking/unstable/debian/build/build-generic/drivers/net/fjes/fjes_hw.gcda' (out of memory)
[    9.010491] sr 0:0:0:0: Attached scsi CD-ROM sr0
[    9.013246] sr 0:0:0:0: Attached scsi generic sg0 type 5
[    9.014959] gcov: could not save data for '/home/cking/unstable/debian/build/build-generic/drivers/net/fjes/fjes_main.gcda' (out of memory)