Re: [PATCH] tcg/tci: Fix TCI on hppa host and update TCI test matrix

[Peter Maydell]

On Sun, 7 Jan 2024 at 07:20, Helge Deller <deller@kernel.org> wrote:
>
> Update the TCI interpreter test matrix for big-endian hosts with
> big- (hppa, hppa64) and little-endian (x86,x96-64) targets.
> I used native ppc64 and hppa hosts for those tests.
>
> Starting TCI on a hppa host crashed immediately, because hppa is
> the only archive left where the stack grows upwards.
> Write-protecting the stack guard page at the top of the stack
> fixes the crash.

We deliberately dropped support for HPPA hosts, under
commit a1eaa6281f8b and commit b1cef6d02f84bd8.
Do we really care enough about trying to run on these
ancient host CPUs to want to bring it back?

My personal rule of thumb is that if a host CPU is supported
only by TCI then we are better off saying it is entirely
unsupported -- in practice the performance will be so
terrible as to not be something anybody will want to use,
especially for older architectures which are slow to
start with.

thanks
-- PMM