Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Thu, 11 Mar 2021 19:09:20 +0000
From:   Will Deacon <will@kernel.org>
To:     Quentin Perret <qperret@google.com>
Cc:     catalin.marinas@arm.com, maz@kernel.org, james.morse@arm.com,
        julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com,
        android-kvm@google.com, linux-kernel@vger.kernel.org,
        kernel-team@android.com, kvmarm@lists.cs.columbia.edu,
        linux-arm-kernel@lists.infradead.org, tabba@google.com,
        mark.rutland@arm.com, dbrazdil@google.com, mate.toth-pal@arm.com,
        seanjc@google.com, robh+dt@kernel.org, ardb@kernel.org
Subject: Re: [PATCH v4 31/34] KVM: arm64: Wrap the host with a stage 2
Message-ID: <20210311190919.GC31586@willie-the-truck>
References: <20210310175751.3320106-1-qperret@google.com>
 <20210310175751.3320106-32-qperret@google.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20210310175751.3320106-32-qperret@google.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Precedence: bulk

On Wed, Mar 10, 2021 at 05:57:48PM +0000, Quentin Perret wrote:
> When KVM runs in protected nVHE mode, make use of a stage 2 page-table
> to give the hypervisor some control over the host memory accesses. The
> host stage 2 is created lazily using large block mappings if possible,
> and will default to page mappings in absence of a better solution.
> 
> From this point on, memory accesses from the host to protected memory
> regions (e.g. marked PROT_NONE) are fatal and lead to hyp_panic().
> 
> Signed-off-by: Quentin Perret <qperret@google.com>
> ---
>  arch/arm64/include/asm/kvm_asm.h              |   1 +
>  arch/arm64/include/asm/kvm_cpufeature.h       |   2 +
>  arch/arm64/kernel/image-vars.h                |   3 +
>  arch/arm64/kvm/arm.c                          |  10 +
>  arch/arm64/kvm/hyp/include/nvhe/mem_protect.h |  34 +++
>  arch/arm64/kvm/hyp/nvhe/Makefile              |   2 +-
>  arch/arm64/kvm/hyp/nvhe/hyp-init.S            |   1 +
>  arch/arm64/kvm/hyp/nvhe/hyp-main.c            |  11 +
>  arch/arm64/kvm/hyp/nvhe/mem_protect.c         | 246 ++++++++++++++++++
>  arch/arm64/kvm/hyp/nvhe/setup.c               |   5 +
>  arch/arm64/kvm/hyp/nvhe/switch.c              |   7 +-
>  arch/arm64/kvm/hyp/nvhe/tlb.c                 |   4 +-
>  12 files changed, 319 insertions(+), 7 deletions(-)
>  create mode 100644 arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
>  create mode 100644 arch/arm64/kvm/hyp/nvhe/mem_protect.c

I like this a lot more now, thanks:

Acked-by: Will Deacon <will@kernel.org>

Will