Re: [Qemu-devel] [PATCH v3 3/9] target-arm: Add support for S2 page-table protection bits

From: Peter Maydell <peter.maydell@linaro.org>
To: "Alex Bennée" <alex.bennee@linaro.org>
Cc: Edgar Iglesias <edgar.iglesias@xilinx.com>,
	QEMU Developers <qemu-devel@nongnu.org>,
	Alexander Graf <agraf@suse.de>,
	Sergey Fedorov <serge.fdrv@gmail.com>,
	Laurent Desnogues <laurent.desnogues@gmail.com>,
	"Edgar E. Iglesias" <edgar.iglesias@gmail.com>
Subject: Re: [Qemu-devel] [PATCH v3 3/9] target-arm: Add support for S2 page-table protection bits
Date: Wed, 14 Oct 2015 20:38:54 +0100	[thread overview]
Message-ID: <CAFEAcA_E=4jD=2Chtk-KURihhkM8r2frau3K8TL0YtauNnJQUA@mail.gmail.com> (raw)
In-Reply-To: <87a8rl7h5i.fsf@linaro.org>

On 14 October 2015 at 13:45, Alex Bennée <alex.bennee@linaro.org> wrote:
> While looking I noticed we probably extract more than we need into attrs
> considering the tableattrs is snarfed earlier. Maybe we should only do:
>
>         attrs = extract64(descriptor, 2, 10)
>             | (extract64(descriptor, 52, 7) << 10);
>
> Or even:
>
>         attrs = extract64(descriptor, 2, 10)
>             | (extract64(descriptor, 52, 3) << 10);

It seemed neater to grab all of the attribute bits, even the
reserved ones. Otherwise we'll end up needing to change the
code back later if a new attribute we care about is added.

thanks
-- PMM