[PATCH v7 44/45] KVM: arm64: Allow activating realms

Steven Price
2025-02-13T16:18:07Z

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 f6879a56f087..a3eddf6917ad 100644
--- a/arch/arm64/kvm/rme.c
+++ b/arch/arm64/kvm/rme.c
@@ -1236,6 +1236,20 @@ 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;
@@ -1385,6 +1399,9 @@ 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;
@@ -1691,5 +1708,5 @@ 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);
}
--
2.43.0