From mboxrd@z Thu Jan  1 00:00:00 1970
From: stefano.stabellini@eu.citrix.com (Stefano Stabellini)
Date: Fri, 27 Nov 2015 14:50:21 +0000
Subject: [PATCH v3 56/62] arm/acpi: Deny MMIO access of UART
In-Reply-To: <564B275A.6060309@huawei.com>
References: <1447753261-7552-1-git-send-email-shannon.zhao@linaro.org>
 <1447753261-7552-57-git-send-email-shannon.zhao@linaro.org>
 <564B17E2.8030205@citrix.com> <564B275A.6060309@huawei.com>
Message-ID: <alpine.DEB.2.02.1511271449260.8984@kaball.uk.xensource.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Tue, 17 Nov 2015, Shannon Zhao wrote:
> On 2015/11/17 20:04, Julien Grall wrote:
> > On 17/11/15 09:40, shannon.zhao at linaro.org wrote:
> >> From: Shannon Zhao <shannon.zhao@linaro.org>
> >>
> >> Firstly it permits full MMIO capabilities for Dom0. Then deny MMIO
> >> access of UART device.
> > 
> > I'm nearly sure we want to deny other MMIO such as the GIC regions and SMMU.
> > 
> But Dom0 will not know the real GIC hardware MMIO space, how would it
> map these regions? In case of wrong use?

It could try regions at random or by mistake.
I know that Dom0 is "trusted", but the less we trust it, the better.


> Regarding SMMU, since it doesn't support now, so I didn't add it but it
> could be added later.