[PATCH] arm64: KVM: Enable minimalistic support for Thunder

[PATCH] arm64: KVM: Enable minimalistic support for Thunder

[Tirumalesh Chalamarla]

In order to allow KVM to run on Thunder implementations, add the
minimal support required.

Signed-off-by: Tirumalesh Chalamarla <tchalamarla@caviumnetworks.com>
---
 arch/arm64/include/asm/cputype.h     | 3 +++
 arch/arm64/include/uapi/asm/kvm.h    | 3 ++-
 arch/arm64/kvm/guest.c               | 6 ++++++
 arch/arm64/kvm/sys_regs_generic_v8.c | 2 ++
 4 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index a84ec60..f603dcd 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -63,6 +63,7 @@
 	((partnum)		<< MIDR_PARTNUM_SHIFT))
 
 #define ARM_CPU_IMP_ARM		0x41
+#define ARM_CPU_IMP_CAVIUM		0x43
 #define ARM_CPU_IMP_APM		0x50
 
 #define ARM_CPU_PART_AEM_V8	0xD0F
@@ -72,6 +73,8 @@
 
 #define APM_CPU_PART_POTENZA	0x000
 
+#define ARM_CPU_PART_THUNDER	0x0A1
+
 #define ID_AA64MMFR0_BIGENDEL0_SHIFT	16
 #define ID_AA64MMFR0_BIGENDEL0_MASK	(0xf << ID_AA64MMFR0_BIGENDEL0_SHIFT)
 #define ID_AA64MMFR0_BIGENDEL0(mmfr0)	\
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index d268320..6c4c556 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -59,8 +59,9 @@ struct kvm_regs {
 #define KVM_ARM_TARGET_CORTEX_A57	2
 #define KVM_ARM_TARGET_XGENE_POTENZA	3
 #define KVM_ARM_TARGET_CORTEX_A53	4
+#define KVM_ARM_TARGET_CAVIUM_THUNDER	5
 
-#define KVM_ARM_NUM_TARGETS		5
+#define KVM_ARM_NUM_TARGETS		6
 
 /* KVM_ARM_SET_DEVICE_ADDR ioctl id encoding */
 #define KVM_ARM_DEVICE_TYPE_SHIFT	0
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 9535bd5..3751f37 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -291,6 +291,12 @@ int __attribute_const__ kvm_target_cpu(void)
 			return KVM_ARM_TARGET_XGENE_POTENZA;
 		};
 		break;
+	case ARM_CPU_IMP_CAVIUM:
+		switch (part_number) {
+		case ARM_CPU_PART_THUNDER:
+			return KVM_ARM_TARGET_CAVIUM_THUNDER;
+		};
+		break;
 	};
 
 	return -EINVAL;
diff --git a/arch/arm64/kvm/sys_regs_generic_v8.c b/arch/arm64/kvm/sys_regs_generic_v8.c
index 475fd29..0e48ee8 100644
--- a/arch/arm64/kvm/sys_regs_generic_v8.c
+++ b/arch/arm64/kvm/sys_regs_generic_v8.c
@@ -94,6 +94,8 @@ static int __init sys_reg_genericv8_init(void)
 					  &genericv8_target_table);
 	kvm_register_target_sys_reg_table(KVM_ARM_TARGET_XGENE_POTENZA,
 					  &genericv8_target_table);
+	kvm_register_target_sys_reg_table(KVM_ARM_TARGET_CAVIUM_THUNDER,
+					  &genericv8_target_table);
 
 	return 0;
 }
-- 
2.1.0

Re: [PATCH] arm64: KVM: Enable minimalistic support for Thunder

[Marc Zyngier]

On 26/06/15 20:51, Tirumalesh Chalamarla wrote:
> In order to allow KVM to run on Thunder implementations, add the
> minimal support required.
> 
> Signed-off-by: Tirumalesh Chalamarla <tchalamarla@caviumnetworks.com>

CCing the KVM/ARM maintainers should be the first course of action.

Also, you may want to try Suzuki's patch instead:

http://www.spinics.net/lists/kvm/msg117703.html

Constantly adding new CPUs without providing any insight as to how they
should be emulated only brings churn, and not much benefit.

Thanks,

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

Re: [PATCH] arm64: KVM: Enable minimalistic support for Thunder

[Chalamarla, Tirumalesh]

> On Jun 29, 2015, at 1:53 AM, Marc Zyngier <marc.zyngier@arm.com> wrote:
> 
> On 26/06/15 20:51, Tirumalesh Chalamarla wrote:
>> In order to allow KVM to run on Thunder implementations, add the
>> minimal support required.
>> 
>> Signed-off-by: Tirumalesh Chalamarla <tchalamarla@caviumnetworks.com>
> 
> CCing the KVM/ARM maintainers should be the first course of action.
> 
thanks. 

> Also, you may want to try Suzuki's patch instead:
> 
> http://www.spinics.net/lists/kvm/msg117703.html
> 
will try with this.

> Constantly adding new CPUs without providing any insight as to how they
> should be emulated only brings churn, and not much benefit.
> 
we are not planning(at this point) to emulate Thunder with QEMU/others.   

> Thanks,
> 
> 	M.
> -- 
> Jazz is not dead. It just smells funny...

Re: [PATCH] arm64: KVM: Enable minimalistic support for Thunder

[Marc Zyngier]

On 29/06/15 18:06, Chalamarla, Tirumalesh wrote:
> 
>> On Jun 29, 2015, at 1:53 AM, Marc Zyngier <marc.zyngier@arm.com> wrote:
>>
>> On 26/06/15 20:51, Tirumalesh Chalamarla wrote:
>>> In order to allow KVM to run on Thunder implementations, add the
>>> minimal support required.
>>>
>>> Signed-off-by: Tirumalesh Chalamarla <tchalamarla@caviumnetworks.com>
>>
>> CCing the KVM/ARM maintainers should be the first course of action.
>>
> thanks. 
> 
>> Also, you may want to try Suzuki's patch instead:
>>
>> http://www.spinics.net/lists/kvm/msg117703.html
>>
> will try with this.
> 
>> Constantly adding new CPUs without providing any insight as to how they
>> should be emulated only brings churn, and not much benefit.
>>
> we are not planning(at this point) to emulate Thunder with QEMU/others.   

Fair enough. If cross-cpu VM migration is none of your concern, then
Suzuki's patch should be enough.

Thanks,

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

Re: [PATCH] arm64: KVM: Enable minimalistic support for Thunder

[Peter Maydell]

On 29 June 2015 at 18:11, Marc Zyngier <marc.zyngier@arm.com> wrote:
> On 29/06/15 18:06, Chalamarla, Tirumalesh wrote:
>>
>>> On Jun 29, 2015, at 1:53 AM, Marc Zyngier <marc.zyngier@arm.com> wrote:
>>> Constantly adding new CPUs without providing any insight as to how they
>>> should be emulated only brings churn, and not much benefit.
>>>
>> we are not planning(at this point) to emulate Thunder with QEMU/others.
>
> Fair enough. If cross-cpu VM migration is none of your concern, then
> Suzuki's patch should be enough.

"Emulate with QEMU" is a completely different thing from
"support cross-cpu VM migration" !

-- PMM

Re: [PATCH] arm64: KVM: Enable minimalistic support for Thunder

[Chalamarla, Tirumalesh]

the discussion on the generic cpu seems to be stuck, is there a possibility to take this patch. so that Thunder has a chance to run some KVM.

Thanks,
Tirumalesh.  
> On Jun 29, 2015, at 10:11 AM, Marc Zyngier <marc.zyngier@arm.com> wrote:
> 
> On 29/06/15 18:06, Chalamarla, Tirumalesh wrote:
>> 
>>> On Jun 29, 2015, at 1:53 AM, Marc Zyngier <marc.zyngier@arm.com> wrote:
>>> 
>>> On 26/06/15 20:51, Tirumalesh Chalamarla wrote:
>>>> In order to allow KVM to run on Thunder implementations, add the
>>>> minimal support required.
>>>> 
>>>> Signed-off-by: Tirumalesh Chalamarla <tchalamarla@caviumnetworks.com>
>>> 
>>> CCing the KVM/ARM maintainers should be the first course of action.
>>> 
>> thanks. 
>> 
>>> Also, you may want to try Suzuki's patch instead:
>>> 
>>> http://www.spinics.net/lists/kvm/msg117703.html
>>> 
>> will try with this.
>> 
>>> Constantly adding new CPUs without providing any insight as to how they
>>> should be emulated only brings churn, and not much benefit.
>>> 
>> we are not planning(at this point) to emulate Thunder with QEMU/others.   
> 
> Fair enough. If cross-cpu VM migration is none of your concern, then
> Suzuki's patch should be enough.
> 
> Thanks,
> 
> 	M.
> -- 
> Jazz is not dead. It just smells funny...