gicv2-mmio-3p in ubuntu_kvm_unit_tests failed on X-hwe ARM64

Failed on Moonshot nodes.

FAIL gicv2-mmio-3p (17 tests, 3 unexpected failures)

# MAX_SMP=8
# TESTNAME=gicv2-mmio-3p TIMEOUT=90s ACCEL= ./arm/run arm/gic.flat -smp $((($MAX_SMP < 3)?$MAX_SMP:3)) -machine gic-version=2 -append 'mmio'
timeout -k 1s --foreground 90s /usr/bin/qemu-system-aarch64 -nodefaults -machine virt,gic-version=host,accel=kvm -cpu host -device virtio-serial-device -device virtconsole,chardev=ctd -chardev testdev,id=ctd -device pci-testdev -display none -serial stdio -kernel arm/gic.flat -smp 3 -machine gic-version=2 -append mmio # -initrd /tmp/tmp.3NfgqCd4oS
INFO: gicv2: mmio: number of implemented SPIs: 256
PASS: gicv2: mmio: all 3 CPUs have interrupts
INFO: gicv2: mmio: IIDR: 0x00000000
PASS: gicv2: mmio: GICD_TYPER is read-only
PASS: gicv2: mmio: GICD_IIDR is read-only
PASS: gicv2: mmio: ICPIDR2 is read-only (0x00000004)
PASS: gicv2: mmio: IPRIORITYR: consistent priority masking (0xffffffff)
PASS: gicv2: mmio: IPRIORITYR: implements at least 4 priority bits (8)
PASS: gicv2: mmio: IPRIORITYR: clearing priorities
PASS: gicv2: mmio: IPRIORITYR: accesses beyond limit RAZ/WI
PASS: gicv2: mmio: IPRIORITYR: accessing last SPIs
PASS: gicv2: mmio: IPRIORITYR: priorities are preserved
PASS: gicv2: mmio: IPRIORITYR: byte reads successful (0xff7fbf3f => 0xbf)
PASS: gicv2: mmio: IPRIORITYR: byte writes successful (0x1f => 0xff1fbf3f)
FAIL: gicv2: mmio: ITARGETSR: bits for 5 non-existent CPUs masked
PASS: gicv2: mmio: ITARGETSR: accesses beyond limit RAZ/WI
FAIL: gicv2: mmio: ITARGETSR: register content preserved (01030207 => 0103020f)
PASS: gicv2: mmio: ITARGETSR: byte reads successful (0x01030207 => 0x02)
FAIL: gicv2: mmio: ITARGETSR: byte writes successful (0x1f => 0x011f020f)
SUMMARY: 17 tests, 3 unexpected failures

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.15.0-48-generic 4.15.0-48.51~16.04.1
ProcVersionSignature: User Name 4.15.0-48.51~16.04.1-generic 4.15.18
Uname: Linux 4.15.0-48-generic aarch64
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: arm64
Date: Tue May 7 11:26:32 2019
SourcePackage: linux-hwe
UpgradeStatus: No upgrade log present (probably fresh install)