diff mbox series

[v4,43/43] KVM: arm64: Allow activating realms

Message ID 20240821153844.60084-44-steven.price@arm.com (mailing list archive)
State New
Headers show
Series arm64: Support for Arm CCA in KVM | expand

Commit Message

Steven Price Aug. 21, 2024, 3:38 p.m. UTC
Add the ioctl to activate a realm and set the static branch to enable
access to the realm functionality if the RMM is detected.

Signed-off-by: Steven Price <steven.price@arm.com>
---
 arch/arm64/kvm/rme.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

Comments

Aneesh Kumar K.V Sept. 2, 2024, 5:13 a.m. UTC | #1
Steven Price <steven.price@arm.com> writes:

> Add the ioctl to activate a realm and set the static branch to enable
> access to the realm functionality if the RMM is detected.
>
> Signed-off-by: Steven Price <steven.price@arm.com>
> ---
>  arch/arm64/kvm/rme.c | 19 ++++++++++++++++++-
>  1 file changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c
> index 9f415411d3b5..1eeef9e15d1c 100644
> --- a/arch/arm64/kvm/rme.c
> +++ b/arch/arm64/kvm/rme.c
> @@ -1194,6 +1194,20 @@ static int kvm_init_ipa_range_realm(struct kvm *kvm,
>  	return realm_init_ipa_state(realm, addr, end);
>  }
>  
> +static int kvm_activate_realm(struct kvm *kvm)
> +{
> +	struct realm *realm = &kvm->arch.realm;
> +
> +	if (kvm_realm_state(kvm) != REALM_STATE_NEW)
> +		return -EINVAL;
> +
> +	if (rmi_realm_activate(virt_to_phys(realm->rd)))
> +		return -ENXIO;
> +
> +	WRITE_ONCE(realm->state, REALM_STATE_ACTIVE);
> +	return 0;
> +}
> +
>  /* Protects access to rme_vmid_bitmap */
>  static DEFINE_SPINLOCK(rme_vmid_lock);
>  static unsigned long *rme_vmid_bitmap;
> @@ -1343,6 +1357,9 @@ int kvm_realm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap)
>  		r = kvm_populate_realm(kvm, &args);
>  		break;
>  	}
> +	case KVM_CAP_ARM_RME_ACTIVATE_REALM:
> +		r = kvm_activate_realm(kvm);
> +		break;
>  	default:
>  		r = -EINVAL;
>  		break;
> @@ -1599,5 +1616,5 @@ void kvm_init_rme(void)
>  	if (rme_vmid_init())
>  		return;
>  
> -	/* Future patch will enable static branch kvm_rme_is_available */
> +	static_branch_enable(&kvm_rme_is_available);
>

like rsi_present, we might want to use this outside kvm, ex: for TIO.
Can we move this outside module init so that we can have a helper
like is_rme_supported()


-aneesh
Steven Price Sept. 2, 2024, 10:17 a.m. UTC | #2
On 02/09/2024 06:13, Aneesh Kumar K.V wrote:
> Steven Price <steven.price@arm.com> writes:
> 
>> Add the ioctl to activate a realm and set the static branch to enable
>> access to the realm functionality if the RMM is detected.
>>
>> Signed-off-by: Steven Price <steven.price@arm.com>
>> ---
>>  arch/arm64/kvm/rme.c | 19 ++++++++++++++++++-
>>  1 file changed, 18 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c
>> index 9f415411d3b5..1eeef9e15d1c 100644
>> --- a/arch/arm64/kvm/rme.c
>> +++ b/arch/arm64/kvm/rme.c
>> @@ -1194,6 +1194,20 @@ static int kvm_init_ipa_range_realm(struct kvm *kvm,
>>  	return realm_init_ipa_state(realm, addr, end);
>>  }
>>  
>> +static int kvm_activate_realm(struct kvm *kvm)
>> +{
>> +	struct realm *realm = &kvm->arch.realm;
>> +
>> +	if (kvm_realm_state(kvm) != REALM_STATE_NEW)
>> +		return -EINVAL;
>> +
>> +	if (rmi_realm_activate(virt_to_phys(realm->rd)))
>> +		return -ENXIO;
>> +
>> +	WRITE_ONCE(realm->state, REALM_STATE_ACTIVE);
>> +	return 0;
>> +}
>> +
>>  /* Protects access to rme_vmid_bitmap */
>>  static DEFINE_SPINLOCK(rme_vmid_lock);
>>  static unsigned long *rme_vmid_bitmap;
>> @@ -1343,6 +1357,9 @@ int kvm_realm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap)
>>  		r = kvm_populate_realm(kvm, &args);
>>  		break;
>>  	}
>> +	case KVM_CAP_ARM_RME_ACTIVATE_REALM:
>> +		r = kvm_activate_realm(kvm);
>> +		break;
>>  	default:
>>  		r = -EINVAL;
>>  		break;
>> @@ -1599,5 +1616,5 @@ void kvm_init_rme(void)
>>  	if (rme_vmid_init())
>>  		return;
>>  
>> -	/* Future patch will enable static branch kvm_rme_is_available */
>> +	static_branch_enable(&kvm_rme_is_available);
>>
> 
> like rsi_present, we might want to use this outside kvm, ex: for TIO.

I'm struggling to think why rme_is_available would be needed outside KVM
- what is "TIO"?

> Can we move this outside module init so that we can have a helper
> like is_rme_supported()

It's obviously possible, but I'm not sure where in the code it would go
- if there is an actual use case outside of KVM then presumably it would
need to move completely outside of the KVM code.

Can you elaborate on why you think it might be useful?

Steve
diff mbox series

Patch

diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c
index 9f415411d3b5..1eeef9e15d1c 100644
--- a/arch/arm64/kvm/rme.c
+++ b/arch/arm64/kvm/rme.c
@@ -1194,6 +1194,20 @@  static int kvm_init_ipa_range_realm(struct kvm *kvm,
 	return realm_init_ipa_state(realm, addr, end);
 }
 
+static int kvm_activate_realm(struct kvm *kvm)
+{
+	struct realm *realm = &kvm->arch.realm;
+
+	if (kvm_realm_state(kvm) != REALM_STATE_NEW)
+		return -EINVAL;
+
+	if (rmi_realm_activate(virt_to_phys(realm->rd)))
+		return -ENXIO;
+
+	WRITE_ONCE(realm->state, REALM_STATE_ACTIVE);
+	return 0;
+}
+
 /* Protects access to rme_vmid_bitmap */
 static DEFINE_SPINLOCK(rme_vmid_lock);
 static unsigned long *rme_vmid_bitmap;
@@ -1343,6 +1357,9 @@  int kvm_realm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap)
 		r = kvm_populate_realm(kvm, &args);
 		break;
 	}
+	case KVM_CAP_ARM_RME_ACTIVATE_REALM:
+		r = kvm_activate_realm(kvm);
+		break;
 	default:
 		r = -EINVAL;
 		break;
@@ -1599,5 +1616,5 @@  void kvm_init_rme(void)
 	if (rme_vmid_init())
 		return;
 
-	/* Future patch will enable static branch kvm_rme_is_available */
+	static_branch_enable(&kvm_rme_is_available);
 }