Re: [Qemu-devel] [PATCH v6 3/4] tcg: Add type for vCPU pointers

From: Richard Henderson <rth@twiddle.net>
To: "Lluís Vilanova" <vilanova@ac.upc.edu>, qemu-devel@nongnu.org
Cc: "Peter Maydell" <peter.maydell@linaro.org>,
	"Eduardo Habkost" <ehabkost@redhat.com>,
	"Alex Bennée" <alex.bennee@linaro.org>,
	"Stefan Hajnoczi" <stefanha@gmail.com>,
	"Anthony Green" <green@moxielogic.com>,
	"Mark Cave-Ayland" <mark.cave-ayland@ilande.co.uk>,
	"Alexander Graf" <agraf@suse.de>,
	"Bastian Koppelmann" <kbastian@mail.uni-paderborn.de>,
	"Blue Swirl" <blauwirbel@gmail.com>,
	"Max Filippov" <jcmvbkbc@gmail.com>,
	"Michael Walle" <michael@walle.cc>,
	"open list:ARM" <qemu-arm@nongnu.org>,
	"open list:PowerPC" <qemu-ppc@nongnu.org>,
	"Edgar E. Iglesias" <edgar.iglesias@gmail.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Guan Xuetao" <gxt@mprc.pku.edu.cn>,
	"Leon Alrae" <leon.alrae@imgtec.com>,
	"Aurelien Jarno" <aurelien@aurel32.net>,
	"Jia Liu" <proljc@gmail.com>
Subject: Re: [Qemu-devel] [PATCH v6 3/4] tcg: Add type for vCPU pointers
Date: Wed, 10 Feb 2016 14:24:54 +1100	[thread overview]
Message-ID: <56BAAD86.3010007@twiddle.net> (raw)
In-Reply-To: <145505248083.4785.7066950318146523490.stgit@localhost>

On 02/10/2016 08:14 AM, Lluís Vilanova wrote:
> Adds the 'TCGv_env' type for pointers to 'CPUArchState' objects. The
> tracing infrastructure later needs to differentiate between regular
> pointers and pointers to vCPUs.
>
> Also changes all targets to use the new 'TCGv_cpu' type instead of the
> generic 'TCGv_ptr'. As of now, the change is merely cosmetic ('TCGv_env'
> translates into 'TCGv_ptr'), but that could change in the future to
> enforce the difference.

I suppose.

We won't be able distinguish TCGv_env from TCGv_ptr until env can be 
auto-converted to ptr.  Which I can't imagine happening without switching to C++.

I see your motivation in 4/4, so I guess this is fine.

Acked-by: Richard Henderson <rth@twiddle.net>

r~