firq-linear-cpu-ids-tcg and firq-nonlinear-cpu-ids-tcg in ubuntu_kvm_unit_tests failed on F-s390x

[Po-Hsu Lin]

Issue found with 5.4.0-136-generic s390x (both LPAR and zVM)

Test failed with timeout:
  Running '/home/ubuntu/autotest/client/tmp/ubuntu_kvm_unit_tests/src/kvm-unit-tests/tests/firq-linear-cpu-ids-tcg'
 [stdout] BUILD_HEAD=d6421940
 [stdout] timeout -k 1s --foreground 20 /usr/bin/qemu-system-s390x -nodefaults -nographic -machine s390-ccw-virtio,accel=tcg -chardev stdio,id=con0 -device sclpconsole,chardev=con0 -kernel /tmp/tmp.biqRhYmJvg -smp 1 -smp 1,maxcpus=3 -cpu qemu -device qemu-s390x-cpu,core-id=1 -device qemu-s390x-cpu,core-id=2 # -initrd /tmp/tmp.hITZDK2Zjx
 [stdout] SMP: Initializing, found 3 cpus
 [stderr] qemu-system-s390x: terminating on signal 15 from pid 9579 (timeout)
 [stdout] FAIL firq-linear-cpu-ids-tcg (timeout; duration=20)

 Running '/home/ubuntu/autotest/client/tmp/ubuntu_kvm_unit_tests/src/kvm-unit-tests/tests/firq-nonlinear-cpu-ids-tcg'
 BUILD_HEAD=d6421940
 timeout -k 1s --foreground 20 /usr/bin/qemu-system-s390x -nodefaults -nographic -machine s390-ccw-virtio,accel=tcg -chardev stdio,id=con0 -device sclpconsole,chardev=con0 -kernel /tmp/tmp.jeygryMuEk -smp 1 -smp 1,maxcpus=3 -cpu qemu -device qemu-s390x-cpu,core-id=2 -device qemu-s390x-cpu,core-id=1 # -initrd /tmp/tmp.6oD23fEGqG
 SMP: Initializing, found 3 cpus
 qemu-system-s390x: terminating on signal 15 from pid 10183 (timeout)
 FAIL firq-nonlinear-cpu-ids-tcg (timeout; duration=20)

This issue did not exist in the last cycle, and not with 5.4.0-133.149 this cycle before the respin. Further investigation required.