[PATCH resend] KVM: ARM: enable Cortex A7 hosts

[PATCH resend] KVM: ARM: enable Cortex A7 hosts

[Ulrich Hecht]

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

Re: [PATCH resend] KVM: ARM: enable Cortex A7 hosts

[Christoffer Dall]

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.

-Christoffer

Re: [PATCH resend] KVM: ARM: enable Cortex A7 hosts

[Marc Zyngier]

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...