ioapic in ubuntu_kvm_unit_tests failed on Trusty

# TESTNAME=ioapic TIMEOUT=90s ACCEL= ./x86/run x86/ioapic.flat -smp 1 -cpu qemu64
timeout -k 1s --foreground 90s /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 x86/ioapic.flat -smp 1 -cpu qemu64 # -initrd /tmp/tmp.KVrgShiIao
enabling apic
paging enabled
cr0 = 80010011
cr3 = 45a000
cr4 = 20
x2apic enabled
PASS: version register read only test
PASS: id register only bits [24:27] writable
PASS: arbitration register set by id
PASS: arbtration register read only
PASS: edge triggered intr
PASS: level triggered intr
PASS: ioapic simultaneous edge interrupts
PASS: coalesce simultaneous level interrupts
PASS: sequential level interrupts
PASS: retriggered level interrupts without masking
PASS: masked level interrupt
PASS: unmasked level interrupt
PASS: masked level interrupt
PASS: unmasked level interrupt
PASS: retriggered level interrupts with mask
PASS: TMR for ioapic edge interrupts (expected false)
FAIL: TMR for ioapic level interrupts (expected false)
PASS: TMR for ioapic level interrupts (expected true)
FAIL: TMR for ioapic edge interrupts (expected true)
SUMMARY: 19 tests, 2 unexpected failures

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-169-generic 3.13.0-169.219
ProcVersionSignature: User Name 3.13.0-169.219-generic 3.13.11-ckt39
Uname: Linux 3.13.0-169-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.29
Architecture: amd64
Date: Thu Apr 11 06:20:44 2019
SourcePackage: linux-signed
UpgradeStatus: No upgrade log present (probably fresh install)