[PATCH v14 28/44] arm64: RMI: Create the realm descriptor

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

Creating a realm involves first creating a realm descriptor (RD). This
involves passing the configuration information to the RMM. Do this as
part of realm_ensure_created() so that the realm is created when it is
first needed.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v13:
 * The RMM no longer uses AUX granules, so no need to ask it how many it
   needs.
 * Adapted to other changes.
Changes since v12:
 * Since RMM page size is now equal to the host's page size various
   calculations are simplified.
 * Switch to using range based APIs to delegate/undelegate.
 * VMID handling is now handled entirely by the RMM.
---
 arch/arm64/kvm/rmi.c | 88 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 86 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index fb96bcaa73ed..cae29fd3353c 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -418,6 +418,77 @@ static void realm_unmap_shared_range(struct kvm *kvm,
 			     start, end);
 }
 
+static int realm_create_rd(struct kvm *kvm)
+{
+	struct realm *realm = &kvm->arch.realm;
+	struct realm_params *params = realm->params;
+	void *rd = NULL;
+	phys_addr_t rd_phys, params_phys;
+	size_t pgd_size = kvm_pgtable_stage2_pgd_size(kvm->arch.mmu.vtcr);
+	int r;
+
+	realm->ia_bits = VTCR_EL2_IPA(kvm->arch.mmu.vtcr);
+
+	if (WARN_ON(realm->rd || !realm->params))
+		return -EEXIST;
+
+	rd = (void *)__get_free_page(GFP_KERNEL_ACCOUNT);
+	if (!rd)
+		return -ENOMEM;
+
+	rd_phys = virt_to_phys(rd);
+	if (rmi_delegate_page(rd_phys)) {
+		r = -ENXIO;
+		goto free_rd;
+	}
+
+	if (rmi_delegate_range(kvm->arch.mmu.pgd_phys, pgd_size)) {
+		r = -ENXIO;
+		goto out_undelegate_tables;
+	}
+
+	params->s2sz = VTCR_EL2_IPA(kvm->arch.mmu.vtcr);
+	params->rtt_level_start = get_start_level(realm);
+	params->rtt_num_start = pgd_size / PAGE_SIZE;
+	params->rtt_base = kvm->arch.mmu.pgd_phys;
+
+	if (kvm->arch.arm_pmu) {
+		params->pmu_num_ctrs = kvm->arch.nr_pmu_counters;
+		params->flags |= RMI_REALM_PARAM_FLAG_PMU;
+	}
+
+	if (kvm_lpa2_is_enabled())
+		params->flags |= RMI_REALM_PARAM_FLAG_LPA2;
+
+	params_phys = virt_to_phys(params);
+
+	if (rmi_realm_create(rd_phys, params_phys)) {
+		r = -ENXIO;
+		goto out_undelegate_tables;
+	}
+
+	realm->rd = rd;
+	kvm_set_realm_state(kvm, REALM_STATE_NEW);
+	/* The realm is up, free the parameters.  */
+	free_page((unsigned long)realm->params);
+	realm->params = NULL;
+
+	return 0;
+
+out_undelegate_tables:
+	if (WARN_ON(rmi_undelegate_range(kvm->arch.mmu.pgd_phys, pgd_size))) {
+		/* Leak the pages if they cannot be returned */
+		kvm->arch.mmu.pgt = NULL;
+	}
+	if (WARN_ON(rmi_undelegate_page(rd_phys))) {
+		/* Leak the page if it isn't returned */
+		return r;
+	}
+free_rd:
+	free_page((unsigned long)rd);
+	return r;
+}
+
 static void realm_unmap_private_range(struct kvm *kvm,
 				      unsigned long start,
 				      unsigned long end,
@@ -647,8 +718,21 @@ static int realm_init_ipa_state(struct kvm *kvm,
 
 static int realm_ensure_created(struct kvm *kvm)
 {
-	/* Provided in later patch */
-	return -ENXIO;
+	int ret;
+
+	switch (kvm_realm_state(kvm)) {
+	case REALM_STATE_NONE:
+		break;
+	case REALM_STATE_NEW:
+		return 0;
+	case REALM_STATE_DEAD:
+		return -ENXIO;
+	default:
+		return -EBUSY;
+	}
+
+	ret = realm_create_rd(kvm);
+	return ret;
 }
 
 static int set_ripas_of_protected_regions(struct kvm *kvm)
-- 
2.43.0