* [PATCH] arm64: KVM: Support Cortex-A57 guest CPU on APM X-Gene host
@ 2013-07-03 8:42 Anup Patel
2013-07-03 8:46 ` Anup Patel
2013-07-03 10:54 ` Peter Maydell
0 siblings, 2 replies; 6+ messages in thread
From: Anup Patel @ 2013-07-03 8:42 UTC (permalink / raw)
To: linux-arm-kernel
Update kvm_target_cpu() to allow Cortex-A57 guest CPU on APM X-Gene.
Signed-off-by: Anup Patel <anup.patel@linaro.org>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
---
arch/arm64/kvm/guest.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 2c3ff67..765f56f 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -207,8 +207,13 @@ int __attribute_const__ kvm_target_cpu(void)
unsigned long implementor = read_cpuid_implementor();
unsigned long part_number = read_cpuid_part_number();
- if (implementor != ARM_CPU_IMP_ARM)
- return -EINVAL;
+ switch (implementor) {
+ case ARM_CPU_IMP_ARM:
+ case ARM_CPU_IMP_APM:
+ break;
+ default:
+ return -EINVAL;
+ }
switch (part_number) {
case ARM_CPU_PART_AEM_V8:
@@ -216,6 +221,7 @@ int __attribute_const__ kvm_target_cpu(void)
case ARM_CPU_PART_FOUNDATION:
return KVM_ARM_TARGET_FOUNDATION_V8;
case ARM_CPU_PART_CORTEX_A57:
+ case APM_CPU_PART_POTENZA:
/* Currently handled by the generic backend */
return KVM_ARM_TARGET_CORTEX_A57;
default:
--
1.7.9.5
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH] arm64: KVM: Support Cortex-A57 guest CPU on APM X-Gene host
2013-07-03 8:42 [PATCH] arm64: KVM: Support Cortex-A57 guest CPU on APM X-Gene host Anup Patel
@ 2013-07-03 8:46 ` Anup Patel
2013-07-03 10:54 ` Peter Maydell
1 sibling, 0 replies; 6+ messages in thread
From: Anup Patel @ 2013-07-03 8:46 UTC (permalink / raw)
To: linux-arm-kernel
On 3 July 2013 14:12, Anup Patel <anup.patel@linaro.org> wrote:
> Update kvm_target_cpu() to allow Cortex-A57 guest CPU on APM X-Gene.
>
> Signed-off-by: Anup Patel <anup.patel@linaro.org>
> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
> ---
> arch/arm64/kvm/guest.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
> index 2c3ff67..765f56f 100644
> --- a/arch/arm64/kvm/guest.c
> +++ b/arch/arm64/kvm/guest.c
> @@ -207,8 +207,13 @@ int __attribute_const__ kvm_target_cpu(void)
> unsigned long implementor = read_cpuid_implementor();
> unsigned long part_number = read_cpuid_part_number();
>
> - if (implementor != ARM_CPU_IMP_ARM)
> - return -EINVAL;
> + switch (implementor) {
> + case ARM_CPU_IMP_ARM:
> + case ARM_CPU_IMP_APM:
> + break;
> + default:
> + return -EINVAL;
> + }
>
> switch (part_number) {
> case ARM_CPU_PART_AEM_V8:
> @@ -216,6 +221,7 @@ int __attribute_const__ kvm_target_cpu(void)
> case ARM_CPU_PART_FOUNDATION:
> return KVM_ARM_TARGET_FOUNDATION_V8;
> case ARM_CPU_PART_CORTEX_A57:
> + case APM_CPU_PART_POTENZA:
> /* Currently handled by the generic backend */
> return KVM_ARM_TARGET_CORTEX_A57;
> default:
> --
> 1.7.9.5
>
Hi Catalin/Marc,
This patch depends on the patch titled "arm64: Add defines
for APM ARMv8 implementation" from Vinyak Kale.
Regards,
Anup
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] arm64: KVM: Support Cortex-A57 guest CPU on APM X-Gene host
2013-07-03 8:42 [PATCH] arm64: KVM: Support Cortex-A57 guest CPU on APM X-Gene host Anup Patel
2013-07-03 8:46 ` Anup Patel
@ 2013-07-03 10:54 ` Peter Maydell
2013-07-03 13:59 ` Marc Zyngier
2013-07-03 14:00 ` Anup Patel
1 sibling, 2 replies; 6+ messages in thread
From: Peter Maydell @ 2013-07-03 10:54 UTC (permalink / raw)
To: linux-arm-kernel
On 3 July 2013 09:42, Anup Patel <anup.patel@linaro.org> wrote:
> Update kvm_target_cpu() to allow Cortex-A57 guest CPU on APM X-Gene.
>
> Signed-off-by: Anup Patel <anup.patel@linaro.org>
> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
> ---
> arch/arm64/kvm/guest.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
> index 2c3ff67..765f56f 100644
> --- a/arch/arm64/kvm/guest.c
> +++ b/arch/arm64/kvm/guest.c
> @@ -207,8 +207,13 @@ int __attribute_const__ kvm_target_cpu(void)
> unsigned long implementor = read_cpuid_implementor();
> unsigned long part_number = read_cpuid_part_number();
>
> - if (implementor != ARM_CPU_IMP_ARM)
> - return -EINVAL;
> + switch (implementor) {
> + case ARM_CPU_IMP_ARM:
> + case ARM_CPU_IMP_APM:
> + break;
> + default:
> + return -EINVAL;
> + }
Doesn't this change mean we now accept the below part
numbers for all implementors? That doesn't look right.
> switch (part_number) {
> case ARM_CPU_PART_AEM_V8:
> @@ -216,6 +221,7 @@ int __attribute_const__ kvm_target_cpu(void)
> case ARM_CPU_PART_FOUNDATION:
> return KVM_ARM_TARGET_FOUNDATION_V8;
> case ARM_CPU_PART_CORTEX_A57:
> + case APM_CPU_PART_POTENZA:
> /* Currently handled by the generic backend */
> return KVM_ARM_TARGET_CORTEX_A57;
> default:
Do we really model all the system registers and so on correctly
sufficiently to be able to present the guest with an A57 vcpu
on an APM X-Gene host? (ie without accidentally leaking the
host ID registers/system registers/impdef registers to the
guest).
thanks
-- PMM
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] arm64: KVM: Support Cortex-A57 guest CPU on APM X-Gene host
2013-07-03 10:54 ` Peter Maydell
@ 2013-07-03 13:59 ` Marc Zyngier
2013-07-03 14:06 ` Anup Patel
2013-07-03 14:00 ` Anup Patel
1 sibling, 1 reply; 6+ messages in thread
From: Marc Zyngier @ 2013-07-03 13:59 UTC (permalink / raw)
To: linux-arm-kernel
On 03/07/13 11:54, Peter Maydell wrote:
> On 3 July 2013 09:42, Anup Patel <anup.patel@linaro.org> wrote:
>> Update kvm_target_cpu() to allow Cortex-A57 guest CPU on APM X-Gene.
>>
>> Signed-off-by: Anup Patel <anup.patel@linaro.org>
>> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
>> ---
>> arch/arm64/kvm/guest.c | 10 ++++++++--
>> 1 file changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
>> index 2c3ff67..765f56f 100644
>> --- a/arch/arm64/kvm/guest.c
>> +++ b/arch/arm64/kvm/guest.c
>> @@ -207,8 +207,13 @@ int __attribute_const__ kvm_target_cpu(void)
>> unsigned long implementor = read_cpuid_implementor();
>> unsigned long part_number = read_cpuid_part_number();
>>
>> - if (implementor != ARM_CPU_IMP_ARM)
>> - return -EINVAL;
>> + switch (implementor) {
>> + case ARM_CPU_IMP_ARM:
>> + case ARM_CPU_IMP_APM:
>> + break;
>> + default:
>> + return -EINVAL;
>> + }
>
> Doesn't this change mean we now accept the below part
> numbers for all implementors? That doesn't look right.
>
>> switch (part_number) {
>> case ARM_CPU_PART_AEM_V8:
>> @@ -216,6 +221,7 @@ int __attribute_const__ kvm_target_cpu(void)
>> case ARM_CPU_PART_FOUNDATION:
>> return KVM_ARM_TARGET_FOUNDATION_V8;
>> case ARM_CPU_PART_CORTEX_A57:
>> + case APM_CPU_PART_POTENZA:
>> /* Currently handled by the generic backend */
>> return KVM_ARM_TARGET_CORTEX_A57;
>> default:
>
> Do we really model all the system registers and so on correctly
> sufficiently to be able to present the guest with an A57 vcpu
> on an APM X-Gene host? (ie without accidentally leaking the
> host ID registers/system registers/impdef registers to the
> guest).
There is no such thing in the KVM/arm64 code. The guest sees the real
host, and I really don't lie the idea of lying to userspace by
pretending that we're going to emulate an A57.
Anup: I suggest you rework that patch to present a X-Gene vcpu. You can
implement it by declaring a new target and implementing it in terms of
the generic backend one if that's convenient. But just pretending this
is an A57 is not going to fly, sorry.
Cheers,
M.
--
Jazz is not dead. It just smells funny...
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] arm64: KVM: Support Cortex-A57 guest CPU on APM X-Gene host
2013-07-03 10:54 ` Peter Maydell
2013-07-03 13:59 ` Marc Zyngier
@ 2013-07-03 14:00 ` Anup Patel
1 sibling, 0 replies; 6+ messages in thread
From: Anup Patel @ 2013-07-03 14:00 UTC (permalink / raw)
To: linux-arm-kernel
On Wed, Jul 3, 2013 at 4:24 PM, Peter Maydell <peter.maydell@linaro.org> wrote:
> On 3 July 2013 09:42, Anup Patel <anup.patel@linaro.org> wrote:
>> Update kvm_target_cpu() to allow Cortex-A57 guest CPU on APM X-Gene.
>>
>> Signed-off-by: Anup Patel <anup.patel@linaro.org>
>> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
>> ---
>> arch/arm64/kvm/guest.c | 10 ++++++++--
>> 1 file changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
>> index 2c3ff67..765f56f 100644
>> --- a/arch/arm64/kvm/guest.c
>> +++ b/arch/arm64/kvm/guest.c
>> @@ -207,8 +207,13 @@ int __attribute_const__ kvm_target_cpu(void)
>> unsigned long implementor = read_cpuid_implementor();
>> unsigned long part_number = read_cpuid_part_number();
>>
>> - if (implementor != ARM_CPU_IMP_ARM)
>> - return -EINVAL;
>> + switch (implementor) {
>> + case ARM_CPU_IMP_ARM:
>> + case ARM_CPU_IMP_APM:
>> + break;
>> + default:
>> + return -EINVAL;
>> + }
>
> Doesn't this change mean we now accept the below part
> numbers for all implementors? That doesn't look right.
Sure, we can use nested switch case instead of two separate
switch cases.
>
>> switch (part_number) {
>> case ARM_CPU_PART_AEM_V8:
>> @@ -216,6 +221,7 @@ int __attribute_const__ kvm_target_cpu(void)
>> case ARM_CPU_PART_FOUNDATION:
>> return KVM_ARM_TARGET_FOUNDATION_V8;
>> case ARM_CPU_PART_CORTEX_A57:
>> + case APM_CPU_PART_POTENZA:
>> /* Currently handled by the generic backend */
>> return KVM_ARM_TARGET_CORTEX_A57;
>> default:
>
> Do we really model all the system registers and so on correctly
> sufficiently to be able to present the guest with an A57 vcpu
> on an APM X-Gene host? (ie without accidentally leaking the
> host ID registers/system registers/impdef registers to the
> guest).
Yes, there are very few APM impdef registers. For now A57 vcpu
is not allowed to access these impdef registers.
For rest of the registers, A57 vcpu will see:
1. MIDR and MPIDR as expected on a A57 vcpu.
2. Cache configuration related registers will be same as that
of underlying host so that cache operations work fine in guest
>
> thanks
> -- PMM
> _______________________________________________
> kvmarm mailing list
> kvmarm at lists.cs.columbia.edu
> https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
--Anup
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] arm64: KVM: Support Cortex-A57 guest CPU on APM X-Gene host
2013-07-03 13:59 ` Marc Zyngier
@ 2013-07-03 14:06 ` Anup Patel
0 siblings, 0 replies; 6+ messages in thread
From: Anup Patel @ 2013-07-03 14:06 UTC (permalink / raw)
To: linux-arm-kernel
On Wed, Jul 3, 2013 at 7:29 PM, Marc Zyngier <marc.zyngier@arm.com> wrote:
> On 03/07/13 11:54, Peter Maydell wrote:
>> On 3 July 2013 09:42, Anup Patel <anup.patel@linaro.org> wrote:
>>> Update kvm_target_cpu() to allow Cortex-A57 guest CPU on APM X-Gene.
>>>
>>> Signed-off-by: Anup Patel <anup.patel@linaro.org>
>>> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
>>> ---
>>> arch/arm64/kvm/guest.c | 10 ++++++++--
>>> 1 file changed, 8 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
>>> index 2c3ff67..765f56f 100644
>>> --- a/arch/arm64/kvm/guest.c
>>> +++ b/arch/arm64/kvm/guest.c
>>> @@ -207,8 +207,13 @@ int __attribute_const__ kvm_target_cpu(void)
>>> unsigned long implementor = read_cpuid_implementor();
>>> unsigned long part_number = read_cpuid_part_number();
>>>
>>> - if (implementor != ARM_CPU_IMP_ARM)
>>> - return -EINVAL;
>>> + switch (implementor) {
>>> + case ARM_CPU_IMP_ARM:
>>> + case ARM_CPU_IMP_APM:
>>> + break;
>>> + default:
>>> + return -EINVAL;
>>> + }
>>
>> Doesn't this change mean we now accept the below part
>> numbers for all implementors? That doesn't look right.
>>
>>> switch (part_number) {
>>> case ARM_CPU_PART_AEM_V8:
>>> @@ -216,6 +221,7 @@ int __attribute_const__ kvm_target_cpu(void)
>>> case ARM_CPU_PART_FOUNDATION:
>>> return KVM_ARM_TARGET_FOUNDATION_V8;
>>> case ARM_CPU_PART_CORTEX_A57:
>>> + case APM_CPU_PART_POTENZA:
>>> /* Currently handled by the generic backend */
>>> return KVM_ARM_TARGET_CORTEX_A57;
>>> default:
>>
>> Do we really model all the system registers and so on correctly
>> sufficiently to be able to present the guest with an A57 vcpu
>> on an APM X-Gene host? (ie without accidentally leaking the
>> host ID registers/system registers/impdef registers to the
>> guest).
>
> There is no such thing in the KVM/arm64 code. The guest sees the real
> host, and I really don't lie the idea of lying to userspace by
> pretending that we're going to emulate an A57.
>
> Anup: I suggest you rework that patch to present a X-Gene vcpu. You can
> implement it by declaring a new target and implementing it in terms of
> the generic backend one if that's convenient. But just pretending this
> is an A57 is not going to fly, sorry.
Sure, I will add separate target vcpu for X-Gene and try to re-use your
generic backend.
>
> Cheers,
>
> M.
> --
> Jazz is not dead. It just smells funny...
>
>
> _______________________________________________
> kvmarm mailing list
> kvmarm at lists.cs.columbia.edu
> https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
--Anup
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2013-07-03 14:06 UTC | newest]
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2013-07-03 8:42 [PATCH] arm64: KVM: Support Cortex-A57 guest CPU on APM X-Gene host Anup Patel
2013-07-03 8:46 ` Anup Patel
2013-07-03 10:54 ` Peter Maydell
2013-07-03 13:59 ` Marc Zyngier
2013-07-03 14:06 ` Anup Patel
2013-07-03 14:00 ` Anup Patel
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