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From:   Marc Zyngier <maz@kernel.org>
To:     Zenghui Yu <yuzenghui@huawei.com>, kvmarm@lists.cs.columbia.edu
Cc:     linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KVM: arm64: vgic-v3: Drop the reporting of GICR_TYPER.Last for userspace
Date:   Tue, 17 Nov 2020 18:55:01 +0000
Message-Id: <160563920752.4179306.18040812749709622838.b4-ty@kernel.org>
In-Reply-To: <20201117151629.1738-1-yuzenghui@huawei.com>
References: <20201117151629.1738-1-yuzenghui@huawei.com>
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On Tue, 17 Nov 2020 23:16:29 +0800, Zenghui Yu wrote:
> It was recently reported that if GICR_TYPER is accessed before the RD base
> address is set, we'll suffer from the unset @rdreg dereferencing. Oops...
> 
> 	gpa_t last_rdist_typer = rdreg->base + GICR_TYPER +
> 			(rdreg->free_index - 1) * KVM_VGIC_V3_REDIST_SIZE;
> 
> It's "expected" that users will access registers in the redistributor if
> the RD has been properly configured (e.g., the RD base address is set). But
> it hasn't yet been covered by the existing documentation.
> 
> [...]

Applied to kvm-arm64/fixes-5.10, thanks!

[1/1] KVM: arm64: vgic-v3: Drop the reporting of GICR_TYPER.Last for userspace
      commit: 23bde34771f1ea92fb5e6682c0d8c04304d34b3b

I have added a Cc stable, as this definitely wants to be backported.

Cheers,

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