[PATCH 11/11] KVM: arm64: CCA: Add Realm stage-2 MMU operations

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

From: Suzuki K Poulose <suzuki.poulose@arm.com>

Register the Realm stage-2 MMU operations now that the RMM mapping
and unmapping helpers are available. Route unmapping through the
RMM, and use the existing fault handler for Realm memory faults.

The RMM handles TLB invalidation when stage-2 mappings change, so
the host has no separate TLB flush to perform. Realm stage-2 does
not support access flags, including for shared IPAs.

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
 arch/arm64/kvm/mmu.c | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 20aedbe6ec07..bb33c07569e3 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -191,6 +191,12 @@ static int kvm_vm_flush_remote_tlbs(struct kvm *kvm)
 	return 0;
 }
 
+static int realm_flush_remote_tlbs(struct kvm *kvm)
+{
+	/* Nothing to do here, RMM does the job */
+	return 0;
+}
+
 /**
  * kvm_arch_flush_remote_tlbs() - flush all VM TLB entries for v7/8
  * @kvm:	pointer to kvm structure.
@@ -218,6 +224,13 @@ static int kvm_vm_flush_remote_tlbs_range(struct kvm *kvm,
 	return 0;
 }
 
+static int realm_flush_remote_tlbs_range(struct kvm *kvm,
+					 gfn_t gfn, u64 nr_pages)
+{
+	/* Nothing to do here, RMM does the job */
+	return 0;
+}
+
 int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm,
 				     gfn_t gfn, u64 nr_pages)
 {
@@ -353,6 +366,15 @@ static void no_stage2_unmap_range(struct kvm_s2_mmu *mmu,
 {
 }
 
+static void realm_stage2_unmap_range(struct kvm_s2_mmu *mmu,
+				     phys_addr_t start, u64 size, bool may_block,
+				     enum kvm_gfn_range_filter filter)
+{
+	struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
+
+	kvm_realm_unmap_range_filter(kvm, start, size, may_block, filter);
+}
+
 /*
  * Unmapping vs dcache management:
  *
@@ -3291,6 +3313,15 @@ static const struct kvm_vm_s2_ops kvm_default_vm_s2_ops = {
 	.vm_mem_abort			= kvm_vm_mem_abort,
 };
 
+static const struct kvm_vm_s2_ops realm_vm_s2_ops = {
+	.vm_flush_remote_tlbs		= realm_flush_remote_tlbs,
+	.vm_flush_remote_tlbs_range	= realm_flush_remote_tlbs_range,
+	.vm_age_gfn			= no_age_gfn,
+	.vm_test_age_gfn		= no_age_gfn,
+	.vm_stage2_unmap_range		= realm_stage2_unmap_range,
+	.vm_mem_abort			= kvm_vm_mem_abort,
+};
+
 #define KVM_VM_S2_OPS(flavor, ops)		\
 		[flavor] = &(ops)
 
@@ -3299,7 +3330,7 @@ static const struct kvm_vm_s2_ops *arm64_vm_s2_ops[] = {
 	KVM_VM_S2_OPS(VM_NVHE, kvm_default_vm_s2_ops),
 	KVM_VM_S2_OPS(VM_PKVM, pkvm_vm_s2_ops),
 	KVM_VM_S2_OPS(VM_PROTECTED_PKVM, protected_pkvm_vm_s2_ops),
-	[VM_REALM] = NULL,
+	KVM_VM_S2_OPS(VM_REALM, realm_vm_s2_ops),
 };
 
 static int kvm_vm_init_vm_s2_ops(struct kvm *kvm)
-- 
2.43.0