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From: Marc Zyngier <maz@kernel.org>
To: "Ying-Chun Liu (PaulLiu)" <paul.liu@linaro.org>
Cc: u-boot@lists.denx.de, Will Deacon <willdeacon@google.com>,
	Tom Rini <trini@konsulko.com>
Subject: Re: [PATCH 1/2] arm: cpu: Add optional CMOs by VA
Date: Tue, 07 Feb 2023 16:35:25 +0000	[thread overview]
Message-ID: <0acfdc333e22249784b4abd63d8d09e6@kernel.org> (raw)
In-Reply-To: <20230207162014.58664-2-paul.liu@linaro.org>

On 2023-02-07 16:20, Ying-Chun Liu (PaulLiu) wrote:
> Exposing set/way cache maintenance to a virtual machine is unsafe, not
> least because the instructions are not permission-checked but also
> because they are not broadcast between CPUs. Consequently, KVM traps 
> and
> emulates such maintenance in the host kernel using by-VA operations and
> looping over the stage-2 page-tables. However, when running under
> protected KVM, these instructions are not able to be emulated and will
> instead result in an exception being delivered to the guest.
> 
> Introduce CONFIG_CMO_BY_VA_ONLY so that virtual platforms can select
> this option and perform by-VA cache maintenance instead of using the
> set/way instructions.
> 
> Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> Signed-off-by: Will Deacon <willdeacon@google.com>
> Cc: Tom Rini <trini@konsulko.com>

The sign-off chain looks pretty odd. Either you are the author
of this patch, and I have nothing to do on the sign-off list,
or I'm the author and the authorship is wrong. Similar things
would apply for Will.

So which one is it?

         M.
-- 
Jazz is not dead. It just smells funny...

  reply	other threads:[~2023-02-07 16:35 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-07 16:20 [PATCH 0/2] arm: cpu: Add optional CMOs by VA Ying-Chun Liu (PaulLiu)
2023-02-07 16:20 ` [PATCH 1/2] " Ying-Chun Liu (PaulLiu)
2023-02-07 16:35   ` Marc Zyngier [this message]
2023-02-07 16:40     ` Tom Rini
2023-02-07 17:06       ` Marc Zyngier
2023-02-07 17:12         ` Tom Rini
2023-02-07 17:18     ` Paul Liu
2023-02-08  8:20       ` Marc Zyngier
2023-02-07 16:20 ` [PATCH 2/2] arm64: Initialize TLB memory if CMO_BY_VA_ONLY Ying-Chun Liu (PaulLiu)

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