architecture: 0.878
register: 0.877
device: 0.861
graphic: 0.796
assembly: 0.730
mistranslation: 0.687
performance: 0.645
vnc: 0.616
PID: 0.563
semantic: 0.563
permissions: 0.511
debug: 0.507
peripherals: 0.505
arm: 0.500
hypervisor: 0.477
risc-v: 0.477
user-level: 0.466
VMM: 0.430
TCG: 0.415
network: 0.409
kernel: 0.381
x86: 0.378
ppc: 0.350
i386: 0.348
socket: 0.340
boot: 0.284
KVM: 0.231
virtual: 0.210
files: 0.153
--------------------
register: 0.938
virtual: 0.937
assembly: 0.721
debug: 0.653
architecture: 0.613
hypervisor: 0.606
boot: 0.421
kernel: 0.284
user-level: 0.100
TCG: 0.070
permissions: 0.047
device: 0.018
files: 0.014
VMM: 0.010
KVM: 0.006
peripherals: 0.006
arm: 0.005
semantic: 0.005
performance: 0.005
risc-v: 0.004
PID: 0.002
network: 0.001
vnc: 0.001
socket: 0.001
graphic: 0.001
ppc: 0.001
x86: 0.001
mistranslation: 0.000
i386: 0.000

AArch64 virt can't write to memory related to gicv3
Description of problem:
According to the info in generated dtb, the memory-mapped registers of gicv3-distributor have a base addr, which is `0x0800_0000`.
And I have checked the validity by reading `gicd_typer`, which means the base addr is right.

But when I want to configure the gicv3-distributor (like changing `gicd_ctlr`), the value is not changed, keeping the default value. The same thing happens on any register of GICD in my machine.

**Even I write to this memory by gdb `set` command, the value is also unchangeable.**

The addr of `gicd_ctlr` should be `0x0800_0000`(offset=0), which should be readable and writable, isn't it?

I try to modify the value of this addr in assembly as soon as the **machine starts, without enabling MMU**. 
This problem should be easier to reproduce.