riscv invalid PTE (reversed bit set) can be more clear when "info mem"

[Dark Paper]

Hello,

According to https://github.com/riscv/riscv-isa-manual/pull/759, it is considered invalid for a non-leaf PTE to have its U bit set. Since QEMU version 7.0.0, an exception is correctly raised when this occurs during execution. However, when using the "info mem" command, the memory mapping is still displayed as if the virtual memory system is functioning correctly.

I believe it would be beneficial for debugging if "info mem" could also show an error message when an invalid PTE is detected in such cases. This would provide clearer insights into potential issues in the memory mapping process.

As I’m new to mailing lists, any feedback or advice on this suggestion would be greatly appreciated.

Thank you for your time!

Best regards,
Dark Paper