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Date: Tue, 06 Feb 2024 12:54:48 +0000
Message-ID: <86ttml69d3.wl-maz@kernel.org>
From: Marc Zyngier <maz@kernel.org>
To: Jon Hunter <jonathanh@nvidia.com>
Cc: Sumit Gupta <sumitg@nvidia.com>,
	treding@nvidia.com,
	krzysztof.kozlowski@linaro.org,
	mark.rutland@arm.com,
	linux-kernel@vger.kernel.org,
	linux-tegra@vger.kernel.org,
	amhetre@nvidia.com,
	bbasu@nvidia.com
Subject: Re: [Patch] memory: tegra: Skip SID override from Guest VM
In-Reply-To: <c7e71e7e-ef01-4539-b481-9f4a95e6a444@nvidia.com>
References: <20240206114852.8472-1-sumitg@nvidia.com>
	<86wmrh6b2n.wl-maz@kernel.org>
	<252d6094-b2d6-496d-b28f-93507a193ede@nvidia.com>
	<c7e71e7e-ef01-4539-b481-9f4a95e6a444@nvidia.com>
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On Tue, 06 Feb 2024 12:51:35 +0000,
Jon Hunter <jonathanh@nvidia.com> wrote:
>=20
>=20
> On 06/02/2024 12:28, Jon Hunter wrote:
>=20
> ...
>=20
> >> - My own tegra186 HW doesn't have VHE, since it is ARMv8.0, and this
> >> =C2=A0=C2=A0 helper will always return 'false'. How could this result =
in
> >> =C2=A0=C2=A0 something that still works? Can I get a free CPU upgrade?
> >=20
> > I thought this API just checks to see if we are in EL2?
>=20
>=20
> Sorry to add a bit more info, I see EL2 is used for hypervisor [0],
> but on my Tegra186 with no hypervisor I see ...
>=20
>  CPU: All CPU(s) started at EL2

Yes. and yet the kernel runs at EL1 (on ARMv8.0, we can't run the
kernel at EL2 at all).

	M.

--=20
Without deviation from the norm, progress is not possible.