[PATCH v10 23/43] KVM: arm64: Handle Realm PSCI requests

[Steven Price <steven.price@arm.com>]

The RMM needs to be informed of the target REC when a PSCI call is made
with an MPIDR argument. Expose an ioctl to the userspace in case the PSCI
is handled by it.

Co-developed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
---
Changes since v6:
 * Use vcpu_is_rec() rather than kvm_is_realm(vcpu->kvm).
 * Minor renaming/formatting fixes.
---
 arch/arm64/include/asm/kvm_rme.h |  3 +++
 arch/arm64/kvm/arm.c             | 25 +++++++++++++++++++++++++
 arch/arm64/kvm/psci.c            | 30 ++++++++++++++++++++++++++++++
 arch/arm64/kvm/rme.c             | 14 ++++++++++++++
 4 files changed, 72 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_rme.h b/arch/arm64/include/asm/kvm_rme.h
index 23dc1982dca7..7a4c82701e67 100644
--- a/arch/arm64/include/asm/kvm_rme.h
+++ b/arch/arm64/include/asm/kvm_rme.h
@@ -116,6 +116,9 @@ int realm_map_non_secure(struct realm *realm,
 			 kvm_pfn_t pfn,
 			 unsigned long size,
 			 struct kvm_mmu_memory_cache *memcache);
+int realm_psci_complete(struct kvm_vcpu *source,
+			struct kvm_vcpu *target,
+			unsigned long status);
 
 static inline bool kvm_realm_is_private_address(struct realm *realm,
 						unsigned long addr)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 9e27acd8fcec..08fd97b486e4 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1769,6 +1769,22 @@ static int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,
 	return __kvm_arm_vcpu_set_events(vcpu, events);
 }
 
+static int kvm_arm_vcpu_rmm_psci_complete(struct kvm_vcpu *vcpu,
+					  struct kvm_arm_rmm_psci_complete *arg)
+{
+	struct kvm_vcpu *target = kvm_mpidr_to_vcpu(vcpu->kvm, arg->target_mpidr);
+
+	if (!target)
+		return -EINVAL;
+
+	/*
+	 * RMM v1.0 only supports PSCI_RET_SUCCESS or PSCI_RET_DENIED
+	 * for the status. But, let us leave it to the RMM to filter
+	 * for making this future proof.
+	 */
+	return realm_psci_complete(vcpu, target, arg->psci_status);
+}
+
 long kvm_arch_vcpu_ioctl(struct file *filp,
 			 unsigned int ioctl, unsigned long arg)
 {
@@ -1891,6 +1907,15 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
 
 		return kvm_arm_vcpu_finalize(vcpu, what);
 	}
+	case KVM_ARM_VCPU_RMM_PSCI_COMPLETE: {
+		struct kvm_arm_rmm_psci_complete req;
+
+		if (!vcpu_is_rec(vcpu))
+			return -EPERM;
+		if (copy_from_user(&req, argp, sizeof(req)))
+			return -EFAULT;
+		return kvm_arm_vcpu_rmm_psci_complete(vcpu, &req);
+	}
 	default:
 		r = -EINVAL;
 	}
diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
index 3b5dbe9a0a0e..a68f3c1878a5 100644
--- a/arch/arm64/kvm/psci.c
+++ b/arch/arm64/kvm/psci.c
@@ -103,6 +103,12 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
 
 	reset_state->reset = true;
 	kvm_make_request(KVM_REQ_VCPU_RESET, vcpu);
+	/*
+	 * Make sure we issue PSCI_COMPLETE before the VCPU can be
+	 * scheduled.
+	 */
+	if (vcpu_is_rec(vcpu))
+		realm_psci_complete(source_vcpu, vcpu, PSCI_RET_SUCCESS);
 
 	/*
 	 * Make sure the reset request is observed if the RUNNABLE mp_state is
@@ -115,6 +121,11 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
 
 out_unlock:
 	spin_unlock(&vcpu->arch.mp_state_lock);
+	if (vcpu_is_rec(vcpu) && ret != PSCI_RET_SUCCESS) {
+		realm_psci_complete(source_vcpu, vcpu,
+				    ret == PSCI_RET_ALREADY_ON ?
+				    PSCI_RET_SUCCESS : PSCI_RET_DENIED);
+	}
 	return ret;
 }
 
@@ -142,6 +153,25 @@ static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
 	/* Ignore other bits of target affinity */
 	target_affinity &= target_affinity_mask;
 
+	if (vcpu_is_rec(vcpu)) {
+		struct kvm_vcpu *target_vcpu;
+
+		/* RMM supports only zero affinity level */
+		if (lowest_affinity_level != 0)
+			return PSCI_RET_INVALID_PARAMS;
+
+		target_vcpu = kvm_mpidr_to_vcpu(kvm, target_affinity);
+		if (!target_vcpu)
+			return PSCI_RET_INVALID_PARAMS;
+
+		/*
+		 * Provide the references of the source and target RECs to the
+		 * RMM so that the RMM can complete the PSCI request.
+		 */
+		realm_psci_complete(vcpu, target_vcpu, PSCI_RET_SUCCESS);
+		return PSCI_RET_SUCCESS;
+	}
+
 	/*
 	 * If one or more VCPU matching target affinity are running
 	 * then ON else OFF
diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c
index 9ce86f05a7ed..71fb1e68f88d 100644
--- a/arch/arm64/kvm/rme.c
+++ b/arch/arm64/kvm/rme.c
@@ -164,6 +164,20 @@ static void free_rtt(phys_addr_t phys)
 	kvm_account_pgtable_pages(phys_to_virt(phys), -1);
 }
 
+int realm_psci_complete(struct kvm_vcpu *source, struct kvm_vcpu *target,
+			unsigned long status)
+{
+	int ret;
+
+	ret = rmi_psci_complete(virt_to_phys(source->arch.rec.rec_page),
+				virt_to_phys(target->arch.rec.rec_page),
+				status);
+	if (ret)
+		return -EINVAL;
+
+	return 0;
+}
+
 static int realm_rtt_create(struct realm *realm,
 			    unsigned long addr,
 			    int level,
-- 
2.43.0