Comment 8 for bug 1748105

3 more tests shows it will finish around 80 ~ 110 seconds on that azure instance (with Bionic 4.15 Azure)

However, it will take about 330 seconds with the same instance on Xenial 4.15 Azure (3 attempts,

And on Oracle Bionic 4.15, it will take up to 620 second to run (5 attempts, 610 ~ 620 seconds):
$ time sudo ./tests/port80
BUILD_HEAD=4671e4ba
timeout -k 1s --foreground 1800 /usr/bin/qemu-system-x86_64 -nodefaults -device pc-testdev -device isa-debug-exit,iobase=0xf4,iosize=0x4 -vnc none -serial stdio -device pci-testdev -machine accel=kvm -kernel /tmp/tmp.iqkRAFLRW3 -smp 1 # -initrd /tmp/tmp.WiUqj082JM
qemu-system-x86_64: warning: host doesn't support requested feature: CPUID.80000001H:ECX.svm [bit 2]
enabling apic
begining port 0x80 write test
done
PASS port80

real 10m17.146s
user 2m50.722s
sys 7m26.440s

So perhaps a better timeout threshold for now is 500 seconds or something.