Hardware watchpoints on GNU/Linux AArch64

[Florian Weimer <fweimer@redhat.com>]

Running

gdb-12.1-10.fc38.aarch64
kernel-6.2.0-0.rc1.20221230gitbff687b3dad6.15.fc38.aarch64

I do not seem to be able to use hardware watchpoints.  GDB just logs
warnings:

warning: Unable to determine the number of hardware watchpoints available.
warning: Unable to determine the number of hardware breakpoints available.

I see AArch64-specific code in GDB, so this is a bit of a surprise to
me.

The machine uses virtualization:

Architecture:           aarch64
  CPU op-mode(s):       32-bit, 64-bit
  Byte Order:           Little Endian
CPU(s):                 3
  On-line CPU(s) list:  0-2
Vendor ID:              ARM
  BIOS Vendor ID:       QEMU
  Model name:           Neoverse-N1
    BIOS Model name:    virt-rhel8.6.0  CPU @ 2.0GHz
    BIOS CPU family:    1
    Model:              1
    Thread(s) per core: 1
    Core(s) per socket: 1
    Socket(s):          3
    Stepping:           r3p1
    BogoMIPS:           50.00
    Flags:              fp asimd evtstrm aes pmull sha1 sha2 crc32 atomics fphp
                         asimdhp cpuid asimdrdm lrcpc dcpop asimddp ssbs

Is this actually expected to work?  Would we have more luck on a
bare-metal system?

Thanks,
Florian