emulator in ubuntu_kvm_unit_test timeout with "jump to non-canonical address" test with J-realtime on openstack AMD64

[Po-Hsu Lin]

emulator test in ubuntu_kvm_unit_test will timeout with J-realtime on openstack amd64 instance. This issue can be seen after we start testing on openstack with 5.15.0-1036.39 in sru-20230320.

Test log:
 Running '/home/ubuntu/autotest/client/tmp/ubuntu_kvm_unit_tests/src/kvm-unit-tests/tests/emulator'
 BUILD_HEAD=d8edb59a
 timeout -k 1s --foreground 90s /usr/bin/qemu-system-x86_64 --no-reboot -nodefaults -device pc-testdev -device isa-debug-exit,iobase=0xf4,iosize=0x4 -vnc none -serial stdio -device pci-testdev -machine accel=tcg -kernel /tmp/tmp.ZwF6eq54JA -smp 1 # -initrd /tmp/tmp.zaTVj0FnC8
 enabling apic
 smp: waiting for 0 APs
 SKIP: Skipping tests the require forced emulation, use kvm.force_emulation_prefix=1 to enable
 paging enabled
 cr0 = 80010011
 cr3 = 1007000
 cr4 = 20
 PASS: mov reg, r/m (1)
 PASS: or
 PASS: add
 PASS: xor
 PASS: sub
 PASS: adc(0)
 PASS: adc(0)
 PASS: sbb(0)
 PASS: sbb(1)
 PASS: and
 PASS: test
 PASS: repe/cmpsb (1)
 PASS: repe cmpsb (1.zf)
 PASS: repe cmpsw (1)
 PASS: repe cmpll (1)
 PASS: repe cmpsq (1)
 PASS: repe cmpsb (2)
 PASS: repe cmpsw (2)
 PASS: repe cmpll (2)
 PASS: repe cmpsq (2)
 PASS: repe/cmpsb (1)
 PASS: repe cmpsb (1.zf)
 PASS: repe cmpsw (1)
 PASS: repe cmpll (1)
 PASS: repe cmpsq (1)
 PASS: repe cmpsb (2)
 PASS: repe cmpsw (2)
 PASS: repe cmpll (2)
 PASS: repe cmpsq (2)
 PASS: scasb match
 PASS: scasb mismatch
 PASS: scasw match
 PASS: scasw mismatch
 PASS: scasd match
 PASS: scasd mismatch
 PASS: scasq match
 PASS: scasq mismatch
 PASS: smsw (1)
 PASS: smsw (2)
 PASS: smsw (3)
 before 80010011 after 80010019
 PASS: lmsw (1)
 before 80010011 after 80010011
 PASS: lmsw (2)
 PASS: lmsw (3)
 PASS: outsb up
 PASS: outsb down
 PASS: incl
 PASS: decl
 PASS: incb
 PASS: decb
 PASS: lock incl
 PASS: lock decl
 PASS: lock incb
 PASS: lock decb
 PASS: lock negl
 PASS: lock notl
 PASS: lock negb
 PASS: lock notb
 PASS: btcl imm8, r/m
 PASS: btcl reg, r/m
 PASS: btcq reg, r/m
 PASS: bsfw r/m, reg
 PASS: bsfl r/m, reg
 PASS: bsfq r/m, reg
 PASS: bsfq r/m, reg
 PASS: bsrw r/m, reg
 PASS: bsrl r/m, reg
 PASS: bsrq r/m, reg
 PASS: bsrq r/m, reg
 PASS: imul ax, mem
 PASS: imul eax, mem
 PASS: imul ax, mem, imm8
 PASS: imul eax, mem, imm8
 PASS: imul ax, mem, imm
 PASS: imul eax, mem, imm
 PASS: imul rax, mem
 PASS: imul rax, mem, imm8
 PASS: imul rax, mem, imm
 PASS: movdqu (read)
 PASS: movdqu (write)
 PASS: movaps (read)
 PASS: movaps (write)
 PASS: movapd (read)
 PASS: movapd (write)
 PASS: movups (read)
 PASS: movups (write)
 PASS: movupd (read)
 PASS: movupd (write)
 PASS: movups unaligned
 PASS: movupd unaligned
 FAIL: unaligned movaps exception
 PASS: movups unaligned crosspage
 PASS: movups crosspage exception
 PASS: shld (cl)
 PASS: shrd (cl)
 PASS: ltr
 PASS: cross-page mmio read
 PASS: cross-page mmio write
 PASS: string_io_mmio
 SKIP: MOVBE unsupported by CPU
 PASS: no fep: #DB occurred after MOV SS
 PASS: push $imm8
 PASS: push %reg
 PASS: push mem
 PASS: push $imm
 PASS: pop mem
 PASS: pop mem (2)
 PASS: pop reg
 PASS: ret
 PASS: leave
 PASS: enter
 PASS: xchg reg, r/m (1)
 PASS: xchg reg, r/m (2)
 PASS: xchg reg, r/m (3)
 PASS: xchg reg, r/m (4)
 PASS: xadd reg, r/m (1)
 PASS: xadd reg, r/m (2)
 PASS: xadd reg, r/m (3)
 PASS: xadd reg, r/m (4)
 PASS: mov %cr8
 PASS: ljmp
 PASS: divq (fault)
 PASS: divq (1)
 PASS: mulb mem
 PASS: mulw mem
 PASS: mull mem
 PASS: mulq mem
 PASS: movq (mmx, read)
 PASS: movq (mmx, write)
 PASS: movb $imm, 0(%rip)
 PASS: Test ret/iret with a nullified segment
 PASS: mov null, %ss
 FAIL: mov null, %ss (with ss.rpl != cpl)
 PASS: cmovnel
 PASS: push16
 qemu-system-x86_64: terminating on signal 15 from pid 9798 (timeout)
 FAIL emulator (timeout; duration=90s)

Bump the timeout to 180 seconds does not help. This issue still exist with the latest upstream kvm-unit-tests code (02d8befe99f8)

It's the test_jmp_noncanonical() test in test_emulator_64() that cause this hang. Comment it out can make this test finish properly.

It's worthy to note that this test has passed with j/ibm on openstack amd64.