Re: [PATCH v2 0/2] Drop ignore_memory_transaction_failures for xilink_zynq

[Peter Maydell <peter.maydell@linaro.org>]

On Fri, 27 Sept 2024 at 09:52, Chao Liu <chao.liu@yeah.net> wrote:
>
> Hi, thank you for your prompt reply, it's a great encouragement to me!
>
> Based on your review suggestions, I have improved the v1 patch.
>
> By using create_unimplemented_device() during the initialization phase,
> I added a "znyq.umip" device early on, which covers the 32-bit address space
> of GPA. This can better serve as a replacement for the effect of the
> ignore_memory_transaction_failures flag.
>
> Since create_unimplemented_device() sets the priority of the
> memory region (mr) to -100, normally created devices will override the address
> segments corresponding to the unimplemented devices.
>
> Even if our test set is not sufficiently comprehensive, we can create an
> unimp_device for the maximum address space allowed by the board. This prevents
> the guest system from triggering unexpected exceptions when accessing
> unimplemented devices or regions.

What would be the benefit of doing that? If we're going to
say "we'll make accesses to regions without devices not
generate faults", the simplest way to do that is to
leave the ignore_memory_transaction_failures flag set
the way it is.

thanks
-- PMM