Booting ACRN on Apollo Lake UP2 causes platform reboot

[gvancuts]

Describe the bug Booting ACRN (v2.3 or master) on UP2 leads to a reboot of the platform.

Platform Apollo Lake UP2

Codebase v2.3 and master

Scenario Tried with both sdc and industry, using RELEASE=0

To Reproduce

• Build ACRN v2.3 or master using make BOARD=apl-up2 SCENARIO=sdc
• Install all build artefacts, configure Grub
• Reboot the UP2 board

Expected behavior Service VM (Ubuntu) coming up

Additional context It was observed that turning off the serial output "fixes" the issue and the Service VM comes up as expected (and ACRN is running correctly).

So either building with RELEASE=1 or using uart=disabled makes the Service VM come up correctly.

[fuzhongl]

@gvancuts please share dmesg |grep ttyS for native and Service VM boot.

[gvancuts]

Native (Ubuntu 20.04) environment:

$ dmesg | grep ttyS
[    3.225468] dw-apb-uart.8: ttyS4 at MMIO 0x91526000 (irq = 4, base_baud = 115200) is a 16550A
[    3.245452] dw-apb-uart.9: ttyS5 at MMIO 0x91524000 (irq = 5, base_baud = 115200) is a 16550A

In the Service VM (using uart=disabled):

$ dmesg | grep ttyS
[    0.000000] Command line: root=/dev/mmcblk0p3 console=ttyS0 idle=halt rw rootwait console=tty0 consoleblank=0 no_timer_check quiet loglevel=3 i915.nuclear_pageflip=1 i915.enable_gvt=1 hvlog=2M@0xe00000 memmap=0x600000$0xa00000 ramoops.mem_address=0xa00000 ramoops.mem_size=0x400000 ramoops.console_size=0x200000 reboot_panic=p,w module_blacklist=dwc3_pci i915.enable_guc=0x02 cma=64M@0- maxcpus=4 uart=disabled root=PARTUUID=3ceead4a-f25a-4526-87aa-6950a9670537
[    0.059669] Kernel command line: root=/dev/mmcblk0p3 console=ttyS0 idle=halt rw rootwait console=tty0 consoleblank=0 no_timer_check quiet loglevel=3 i915.nuclear_pageflip=1 i915.enable_gvt=1 hvlog=2M@0xe00000 memmap=0x600000$0xa00000 ramoops.mem_address=0xa00000 ramoops.mem_size=0x400000 ramoops.console_size=0x200000 reboot_panic=p,w module_blacklist=dwc3_pci i915.enable_guc=0x02 cma=64M@0- maxcpus=4 uart=disabled root=PARTUUID=3ceead4a-f25a-4526-87aa-6950a9670537
[    0.170939] printk: console [ttyS0] enabled
[    0.989115] serial8250: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
[    4.444943] dw-apb-uart.8: ttyS1 at MMIO 0x91526000 (irq = 4, base_baud = 115200) is a 16550A
[    4.446632] dw-apb-uart.9: ttyS2 at MMIO 0x91524000 (irq = 5, base_baud = 115200) is a 16550A