From: Oliver Upton <oliver.upton@linux.dev>
To: Marc Zyngier <maz@kernel.org>
Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
kvm@vger.kernel.org, James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>
Subject: Re: [PATCH 0/3] KVM: arm64: Get rid of REG_HIDDEN_USER
Date: Wed, 11 Sep 2024 11:00:05 -0700 [thread overview]
Message-ID: <ZuHapdH3F8ZnSuIC@linux.dev> (raw)
In-Reply-To: <20240904082419.1982402-1-maz@kernel.org>
On Wed, Sep 04, 2024 at 09:24:16AM +0100, Marc Zyngier wrote:
> REG_HIDDEN_USER was introduced as a way to deal with the ARMv8.3 flavour of
> FEAT_NV, where most EL12 sysreg accesses would trap and yet be mapped to a
> EL1 register (KVM doing in SW what FEAT_NV2 does in HW). This handling
> imposed that the EL12 register shouldn't be visible to userspace, hence the
> special REG_HIDDEN_USER visibility.
>
> Since 4d4f52052ba8 ("KVM: arm64: nv: Drop EL12 register traps that are
> redirected to VNCR") and the admission that KVM would never be supporting
> the original FEAT_NV, REG_HIDDEN_USER only had a few users, all of which
> could either be replaced by a more ad-hoc mechanism, or removed altogether.
>
> This series goes ahead and cleans it up for good, removing a tiny bit of
> unnecessary complexity.
Yeah, let's toss it.
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
--
Thanks,
Oliver
next prev parent reply other threads:[~2024-09-11 18:02 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-04 8:24 [PATCH 0/3] KVM: arm64: Get rid of REG_HIDDEN_USER Marc Zyngier
2024-09-04 8:24 ` [PATCH 1/3] KVM: arm64: Simplify handling of CNTKCTL_EL12 Marc Zyngier
2024-09-04 8:24 ` [PATCH 2/3] KVM: arm64: Simplify visibility handling of AArch32 SPSR_* Marc Zyngier
2024-09-04 8:24 ` [PATCH 3/3] KVM: arm64: Get rid of REG_HIDDEN_USER visibility qualifier Marc Zyngier
2024-09-11 18:00 ` Oliver Upton [this message]
2024-09-11 19:32 ` [PATCH 0/3] KVM: arm64: Get rid of REG_HIDDEN_USER Marc Zyngier
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