From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marc Zyngier <marc.zyngier@arm.com>
Date: Thu, 26 Sep 2013 15:07:36 +0000
Subject: Re: [PATCH resend] KVM: ARM: enable Cortex A7 hosts
Message-Id: <52444DB8.7020103@arm.com>
List-Id: <linux-sh.vger.kernel.org>
References: <1380196131-23326-1-git-send-email-ulrich.hecht@gmail.com> <20130926144041.GA1389@cbox>
In-Reply-To: <20130926144041.GA1389@cbox>
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To: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Ulrich Hecht <ulrich.hecht@gmail.com>, "kvm@vger.kernel.org" <kvm@vger.kernel.org>, "linux-sh@vger.kernel.org" <linux-sh@vger.kernel.org>, "magnus.damm@gmail.com" <magnus.damm@gmail.com>, "horms@verge.net.au" <horms@verge.net.au>, "kvmarm@lists.cs.columbia.edu" <kvmarm@lists.cs.columbia.edu>

On 26/09/13 15:41, Christoffer Dall wrote:
> On Thu, Sep 26, 2013 at 01:48:51PM +0200, Ulrich Hecht wrote:
>> KVM runs fine on Cortex A7 cores, so they should be enabled. Tested on an
>> APE6EVM board (r8a73a4 SoC).
>>
>> Signed-off-by: Ulrich Hecht <ulrich.hecht@gmail.com>
>> ---
>>  arch/arm/kvm/guest.c | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
>> index 152d036..05c62d5 100644
>> --- a/arch/arm/kvm/guest.c
>> +++ b/arch/arm/kvm/guest.c
>> @@ -192,6 +192,8 @@ int __attribute_const__ kvm_target_cpu(void)
>>  	switch (part_number) {
>>  	case ARM_CPU_PART_CORTEX_A15:
>>  		return KVM_ARM_TARGET_CORTEX_A15;
>> +	case ARM_CPU_PART_CORTEX_A7:
>> +		return KVM_ARM_TARGET_CORTEX_A15;
>>  	default:
>>  		return -EINVAL;
>>  	}
>> -- 
>> 1.8.3.1
>>
> 
> nack
> 
> we need to have support and implementation for A7 cores and not try to
> shoehorn A7 support by pretending that it's an A15.
> 
> The fact that you have tested this and it happens to work with the
> workload you ran does not mean it is the right solution.  At the very
> least, you need to document and think about the different system
> register implementation and deal with them correctly.

Not to mention that supporting Cortex-A7 requires some generic KVM/ARM
fixes to work properly.

I believe Jonny is going to post these patches shortly, along with a
more compelling set of changes to support Cortex-A7.

Cheers,

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