On Loongnix 20.5 systems, QEMU configure with option '--enable-debug'
or '--enable-debug-tcg ', booting the Loongnix 20.5 VM in tcg mode
will get an assertion error.
"...
[ 31.484992] [drm] Initialized virtio_gpu 0.0.1 0 for virtio1 on minor 0
qemu-system-loongarch64:
/home1/gaosong/code/github/clean/qemu/tcg/loongarch64/tcg-target.c.inc:394：tcg_out_movi:
假设 ‘offset_hi == sextreg(offset_hi, 0, 20)’ 失败。
./start.sh: 行 14: 2433006 已放弃
(核心已转储)./build/qemu-system-loongarch64 --accel tcg -m 8G -cpu la464 -machine virt
-smp 8 -serial stdio -bios ./QEMU_EFI.fd -monitor
telnet:localhost:4498,server,nowait -device virtio-gpu-pci -net nic, -net user
-device nec-usb-xhci,id=xhci,addr=0x1b -device
usb-tablet,id=tablet,bus=xhci.0,port=1 -device usb-kbd,id=keyboard,bus=xhci.0,port=2
-device virtio-blk-pci,drive=test -drive
if=none,id=test,file=./Loongnix-20.5.cartoon.mini.loongarch64.cn.qcow2 "
The values of offset_hi and sextreg(offset_hi, 0, 20) are:
"[ 29.975240] virtio_gpu virtio1: fb0: virtiodrmfb frame buffer device
offset_hi is 80000
sextreg(offset_hi, 0, 20) is fffffffffff80000
offset_hi is 80000
sextreg(offset_hi, 0, 20) is fffffffffff80000
offset_hi is 80000
sextreg(offset_hi, 0, 20) is fffffffffff80000
..."
When pcalau12i + ori is not satisfied, we should use other methods instead,
instead of generating an assertion error.