From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marc Zyngier <marc.zyngier@arm.com>
Subject: Re: [PATCH v4 9/9] kvmtool: virtio: enable arm/arm64 support for
 bi-endianness
Date: Thu, 08 May 2014 11:15:28 +0100
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Cc: "kvmarm@lists.cs.columbia.edu" <kvmarm@lists.cs.columbia.edu>,
	kvm-devel <kvm@vger.kernel.org>,
	Pekka Enberg <penberg@kernel.org>,
	Will Deacon <Will.Deacon@arm.com>
To: Peter Maydell <peter.maydell@linaro.org>
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On 08/05/14 11:06, Peter Maydell wrote:
> On 8 May 2014 10:32, Marc Zyngier <marc.zyngier@arm.com> wrote:
>> +int kvm_cpu__get_endianness(struct kvm_cpu *vcpu)
>> +{
>> +       struct kvm_one_reg reg;
>> +       u64 psr;
>> +       u64 sctlr;
>> +
>> +       /*
>> +        * Quoting the definition given by Peter Maydell:
>> +        *
>> +        * "Endianness of the CPU which does the virtio reset at the
>> +        * point when it does that reset"
>> +        *
>> +        * We first check for an AArch32 guest: its endianness can
>> +        * change when using SETEND, which affects the CPSR.E bit.
>> +        *
>> +        * If we're AArch64, use SCTLR_EL1.E0E if access comes from
>> +        * EL0, and SCTLR_EL1.EE if access comes from EL1.
>> +        */
> 
> I note that the set of checks described here match the logic
> of the ARM ARM BigEndian() pseudocode function, which is
> a good sign.

Pure luck. Or maybe I'm now going slightly mad. Either way, consistency
is good... ;-)

Thanks,

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