Re: [Qemu-devel] [PATCH v4 10/21] target-arm: Add v8 mmu translation support

From: Peter Maydell <peter.maydell@linaro.org>
To: QEMU Developers <qemu-devel@nongnu.org>
Cc: Rob Herring <rob.herring@linaro.org>,
	Peter Crosthwaite <peter.crosthwaite@xilinx.com>,
	Patch Tracking <patches@linaro.org>, Michael Matz <matz@suse.de>,
	Laurent Desnogues <laurent.desnogues@gmail.com>,
	Dirk Mueller <dmueller@suse.de>,
	Will Newton <will.newton@linaro.org>,
	"kvmarm@lists.cs.columbia.edu" <kvmarm@lists.cs.columbia.edu>,
	Richard Henderson <rth@twiddle.net>
Subject: Re: [Qemu-devel] [PATCH v4 10/21] target-arm: Add v8 mmu translation support
Date: Thu, 20 Mar 2014 18:20:13 +0000	[thread overview]
Message-ID: <CAFEAcA_uobyY+38FYFYbarShnd+QwFyO1HfMapKWnuCRByadHQ@mail.gmail.com> (raw)
In-Reply-To: <1394134385-1727-11-git-send-email-peter.maydell@linaro.org>

On 6 March 2014 19:32, Peter Maydell <peter.maydell@linaro.org> wrote:
> @@ -1065,8 +1065,9 @@ static void par_write(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t value)
>   */
>  static inline bool extended_addresses_enabled(CPUARMState *env)
>  {
> -    return arm_feature(env, ARM_FEATURE_LPAE)
> -        && (env->cp15.c2_control & (1U << 31));
> +    return arm_feature(env, ARM_FEATURE_V8)
> +        || (arm_feature(env, ARM_FEATURE_LPAE)
> +        && (env->cp15.c2_control & (1U << 31)));
>  }

Just noticed a minor nit here -- rather than checking
for ARM_FEATURE_V8 we should be using arm_el_is_aa64(env, 1)
(as the translation code itself does). At the moment the
two give the same answer, but if/when we ever support
running a 32 bit kernel on an ARMv8 CPU they'll be
different, so better to get the check right to start with.

I'll fix this for the next round of these patches
(and also update the now out of date comment).

thanks
-- PMM