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From:   Evgenii Stepanov <eugenis@google.com>
Date:   Tue, 9 Aug 2022 10:29:05 -0700
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Subject: Re: [PATCH] mte: Follow arm64.nomte override in MMU setup.
To:     Marc Zyngier <maz@kernel.org>
Cc:     Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Peter Collingbourne <pcc@google.com>,
        Vincenzo Frascino <vincenzo.frascino@arm.com>,
        Andrey Konovalov <andreyknvl@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Tue, Aug 9, 2022 at 9:49 AM Marc Zyngier <maz@kernel.org> wrote:
>
> In which case what is the tag memory doing in the linear map?
> Shouldn't it be marked as reserved, not mapped, and in general
> completely ignored by the NS OS?

That would be wasteful. The idea is to only reserve the parts of the
tag memory that correspond to the TZ carveout and release the rest to
the NS OS.