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From: Peter Maydell <peter.maydell@linaro.org>
Date: Thu, 20 Nov 2014 16:38:40 +0000
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Subject: Re: [Qemu-devel] [PATCH] linux-user: Use the 5KEf processor for
 64-bit emulation
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To: "Maciej W. Rozycki" <macro@codesourcery.com>
Cc: Leon Alrae <leon.alrae@imgtec.com>, QEMU Developers <qemu-devel@nongnu.org>, Aurelien Jarno <aurelien@aurel32.net>

On 20 November 2014 16:00, Maciej W. Rozycki <macro@codesourcery.com> wrote:
> Replace the 20Kc original MIPS64 ISA processor used for 64-bit user
> emulation with the 5KEf processor that implements the MIPS64r2 ISA,
> complementing the choice of the 24Kf processor for 32-bit emulation.
>
> Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
> ---
> Hi,
>
>  For user emulation mode I think we want to default to the highest ISA
> level supported, for maximum user flexibility.  Currently the MIPS64r2
> ISA is the highest 64-bit ISA we have a real processor support for so
> use it and the 5KEf which is the processor we have that implements it.
> Later, as newer processors are added, we can bump it further up.

Is it feasible to define an "any" CPU for linux-user which
basically enables all known ISA features? This is what we
do on ARM and some other target CPU families. If some CPU
features conflict with each other (so you can't validly
have a CPU with all of them) that might make it awkward, though.

-- PMM